So, while it may sound obvious, a varied and balanced diet that provides adequate nutrients is the foundation of a healthy immune system.  However, some nutrients receive particular attention for their role in immune health, including vitamins A, C and D, as well as the minerals such as zinc and selenium¹.

There is also evidence for the immune benefits of other nutrients and ingredients, such as long-chain omega-3 fatty acids, probiotics and beta-glucans².

Immunonutrition

Read how each of the nutrients listed below support the immune system.  It is important to bear in mind that micronutrients have additional health benefits to immune health.  Click on each nutrient/non-nutrient below to learn more:

• Vitamin A
• Vitamin C
• Vitamin D
• Selenium
• Zinc
• Probiotics
• Beta Glucans

How the Immune System Works?

The immune system is the body’s way of protecting itself from infection by foreign invaders like bacteria and viruses.  It helps the body stay healthy and recover when illness does occur and is made up of the innate (general) and adaptive (specialised) immune system³.

The innate immune system is the body’s first line of defence.  When pathogens like infectious bacteria or viruses get into the respiratory tract or gastrointestinal system, the innate immune system responds by sending cells like neutrophils or macrophages to remove the threat.  These cells try to engulf the invading pathogen or create enzymes to destroy it.

The adaptive immune system specifically targets the pathogen and takes over from the innate immune system.  It is often described as the ‘memory’ of the immune system.  Once exposed to a pathogen, the immune system can remember the identity of that pathogen for the future and quickly mount a defence specific to that pathogen.

Impact of Age and Physical Activity on Immune Health

Immune health becomes especially important in vulnerable age groups like infants and the elderly. Both physical and psychological stress can also compromise the immune system.  Examples include over-exercising, emotional stress and surgery.

This article was published in March 2022 and updated on June 15, 2026.

Some selenoproteins, called glutathione peroxidases, are important for the body’s antioxidant system, which protects DNA and cells from oxidative damage.  This includes protecting the body’s immune cells from damage^{1, 2}.

Selenium also plays a role in activating immune cells ¹ and helping them function, such as assisting macrophages to more effectively destroy or engulf pathogens.  The role of selenium in the response to vaccines continues to be investigated³.

Figure 1. A summary of selenium and immune responses¹.   © 2018 by the authors ¹. Licensee MDPI, Basel, Switzerland.  Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Recommended Intakes

The recommended daily intake of selenium varies around the world².  The Chinese Nutrition Society⁴ set a Reference Nutrient Intake (RNI) of 60mg per day for adults.  Similarly, in the US the Institute of Medicine has set a Recommended Dily Allowance of 55mg per day⁵.  In addition, the European Food Safety Authority set an adequate intake (AI) of 70mg per day for adults⁶.

Dietary Sources

Meats, eggs, nuts, seeds, seafood and whole grains are good sources of selenium.  The selenium content of foods is linked to the selenium content of the soil (see ‘Deficiency’ section below).

Table 1. Selenium content of common foods in the diet⁷

Deficiency

Selenium deficiency is expected to affect up to 1 billion people worldwide.  This deficiency primarily affects people in areas where the soil is low in selenium⁷ and, as a result, the foods that grow in that soil are low in selenium.

The distribution of selenium in the soil is extremely uneven, with significant differences even within countries.  Regions with lower selenium intakes⁸ include certain areas of New Zealand, China and Italy, among many others.

In areas where the soil is rich in the soil, selenium deficiency is rare.  For example, the average daily intake of selenium in the US is almost twice the daily recommendation.  Certain regions of China, where selenium is plentiful in the soil, also have high intakes of selenium⁹.

Excess Intakes

Selenium has a narrow window between adequate and toxic levels.  Getting too much selenium can lead to symptoms like gastrointestinal or neurological symptoms, hair loss, nausea and fatigue, among others⁷.

For this reason, in the US a tolerable upper limit of selenium has been set at 400mg per day for adults³ .  The EFSA recently revised their upper limit to 255mg per day for adults including pregnant and lactating women¹⁰.  Lower limits are recommended for younger groups.

Selenium Supplementation

People who are deficient in selenium are shown to have impaired immune responses² and studies show that reinstating selenium status through supplementation can improve the body’s ability to fight infection.

Those with adequate selenium intake through their diet are unlikely to see additional benefits.  A recent meta-analysis of selenium¹¹ supplementation trials showed a very mixed picture of effects but no conclusive evidence of an beneficial effect on the immune system beyond the recommended dietary intake.

This article was publishing in March 2020 and updated on April 07, 2026.

Dietary Sources

Beta glucans are naturally occurring polysaccharides that serve as energy stores and structural components of plant walls found in a variety of foods including oats, barley and seaweed, as well as many types of microorganisms (bacteria, yeast and fungi).

While they all share a “common” beta chemical bond between the individual glucose units, there are many subtle, but important, differences in structure within the beta glucan family that lead to large differences in function and potential health benefits.

When choosing a beta glucan, it is key to focus on what clinical research is available to support the specific ingredient’s mechanism of action, demonstrate effectiveness for the desired benefit and show the safety of the ingredient.

Mushroom Beta-Glucans

As the chemical composition of each type of mushroom varies, so does the biological activities of their beta glucans.

Although are associated with immune health benefits, their molecular structure is varied and inconsistent, making it difficult to characterise their efficacy².

The most studied strain of mushroom beta glucan is lentinan, a substance derived from Lentinus edodes (Shiitake) with a beta-1,3-D-glucan backbone comprising very short beta-1,6 side chains.

Further clinical research is needed to fully understand how each type of mushroom beta glucan works².

Yeast Beta-Glucans

Yeast beta-glucan are  one of the most extensively studies of the beta-glucans.

A recent review recommends that future research should define the origin, molecular weight and structure of yeast beta-glucans by using standardised tools (e.g. structural analysis, chemical degradation and/or nuclear magnetic resonance) to accurately characterise and clarify structure–function relationships³.

For this reason, choosing a generic yeast beta-glucan may not deliver the targeted health benefit which should be demonstrated using a well characterised ingredient in clinical trials.

Yeast-derived beta glucans usually originate from either baker’s yeast or brewer’s yeast.

Even though both are structured as beta 1,3/1,6 glucan from Saccharomyces cerevisiae, differences in the source (or strain) of yeast and the method used to isolate and purify the yeast beta-glucan are important factors affecting the final structure of the yeast beta-glucan⁴ and may ultimately influence biological activity⁴.

Yeast Beta-Glucans Impact on Immune Health

The immune system has the ability to recognise and eliminate pathogens by first activating the innate (general) immune response, which acts in a fast and un-targeted manner to phagocytose and eliminate the invader.  Innate immune cells can also adapt to challenge and alter subsequent responses, which is referred to as trained immunity.

The current paradigm for the immunomodulating action of yeast beta-glucans is through improving the innate immune system by making key white blood cells better able to find and kill potential pathogens^{1, 5}.

Studies into the cellular and molecular mechanisms of action show that beta-1,3/1,6-glucans are engulfed and processed by macrophages and dendritic cells that later travel to the different immune organs releasing fragmented soluble beta-1,3-glucan particles.

This results in the priming of leukocytes via certain receptors including Dectin-1 and leads to enhanced immuno-surveillance and improved antimicrobial and inflammatory responses¹.  In theory this should translate into enhanced resistance to infection.

Upper respiratory tract infections (URTIs) are the leading cause of acute disease in humans and poses a substantial burden to the healthcare system⁶.   A specific baker’s yeast beta-glucan containing a highly purified natural beta-1,3/1,6-glucan has been shown to reduce either the incidence and/or duration or severity of URTIs in clinical trials with children⁷, athletes⁸ and those engaging in intense exercise^9,10.

A meta-analysis of 13 randomised controlled trials has also demonstrated that yeast beta-glucans could significantly reduce the incidence and duration of URTIs.  However, due to the high heterogeneity and small number of included studies, more high-quality research and clinical trials are warranted¹¹.

Yeast beta-glucans area also being explored for their potential to improve vaccine effectiveness¹².

This article was published in April 2020 and updated on April 14, 2026.

Zinc is a popular nutrient in winter supplements.  It is an essential nutrient and the second most abundant trace element in the body, after iron¹.

It is found in every cell in the body and involved in many bodily processes.  It is required by cells from both the innate (general) and adaptive (specialised) immune system².

The innate immune system is the body’s first line of defence.  When pathogens like infectious bacteria or viruses get into the respiratory tract or gastrointestinal system, the innate immune system responds by sending cells like neutrophils or macrophages to remove the threat.  These cells try to engulf the invading pathogen or create enzymes to destroy it.

The adaptive immune system specifically targets the pathogen and takes over from the innate immune system.  It is often described as the ‘memory’ of our immune system.  Once exposed to a pathogen, the immune system can remember the identity of that pathogen for the future and quickly mount a defence specific to that pathogen.

The role of Zinc in the immune system includes:

• • helping to maintain the integrity of the skin and muscular membranes, preventing pathogen entry into the body.
  • supporting the growth and differentiation of immune cells.
  • supporting the phagocytic activity of monocytes and help regulate cytokine release.
  • antibody production, particularly IgG and helping the immune system distinguish between “self” and “non-self”³.

This role has been recognised in an approved European Union health claim for zinc stating that it “contributes to the normal function of the immune system” and is available to foods that meet defined criteria within the EU⁴.

Are there Recommended Intakes for Zinc?

Zinc recommendations range from 5 to 11mg per day for adults, varying by each global region⁵.  In the US, the Institute of Medicine (IOM) recommendations are 11mg per day for men and 8mg per day for women⁶.

Similarly, the Chinese Nutrition Society Reference intake (RNI) is 12mg per day for adult men and 8.5 mg per day for women⁸.  In Europe, the European Food Safety Authority has established a Population Reference Intake of 9.4 to 16.3mg per day for men with low to higher intakes of dietary phytate and 7.5 to 12.7mg per day for adults women with low to higher intakes of phytate⁷.

Most people in developed countries get enough zinc through their diet, meaning their immune system isn’t missing the zinc it needs.  For example, in the US around 18% of people do not meet the Estimated Average Requirement (EAR) of zinc per day.

This means most people are not zinc deficient, but  certain people may still benefit from eating more zinc in their diet.

Where can Zinc be Sourced in Dietary Sources

Zinc is mostly found in seafood, beef, poultry, beans, nuts or fortified cereal.  Phytic acid, found in cereals, legumes and nuts, is known to decrease zinc bioavailability¹.  Evidence shows that the biofortification of varieties of staple crops may be useful in improving the zinc status of an individual⁵.

Table 1. Zinc content of common foods in the diet⁹

What Happens with a Zinc Deficiency?

Zinc deficiency is a widespread global health issue, particularly prevalent in low- and middle-income countries.  About 17.3% of the world’s population¹⁰ is at risk of inadequate zinc intake.  When the body doesn’t have enough zinc, it does not develop a strong immune response.

Zinc deficiency affects many different organs and tissues in the body with signs and symptoms varying by age⁹.  For example, zinc deficiency can delay growth and cause diarrhoea and alopecia in children and it can alter cognitive and psychological function in older adults.

Most people in developed countries get enough zinc through their diet but it can affect more vulnerable groups.  For example, the percentage of people in the US that do not meet the  Estimated Average Requirement (EAR) of zinc varies from 16% in households with full food security to 27% in those with very low food security¹¹.

In Europe, the average intake of zinc is above the recommended amount.  However, certain vulnerable populations may benefit from including more zinc rich foods or supplements in their diet e.g. those on plant-based diets with little animal foods and the elderly⁵.

Are there Health Risk of Excess Intakes?

Excessive amounts of zinc can cause nausea, dizziness, headaches, gastric distress, vomiting and loss of appetite and chronic large doses of 50mg of zinc or more can inhibit copper absorption and reduce immune function⁹.

Excessive intakes from food sources are unlikely but may occur with excessive supplementation.  The IOM Tolerable Upper Intake Level for zinc is 40mg per day for adults.  EFSA has set the Tolerable Upper Intake Level (UL) for total daily zinc intake from all sources (diet and supplements) at 25mg per day for adults.

This level is based on the reduction of copper status¹².  Lower limits are recommended for younger groups.

Is Zinc Supplementation Effective?

A 2024 Cochrane review ¹³ based on 34 randomised controlled trials in children and adults (15 prevention, 19 treatment) showed that compared with placebo, taking zinc preventatively may make little to no difference to whether a person catches a cold or to the duration or severity of the cold.

Taking zinc for treatment of an existing cold may reduce the duration but the authors were not confident of the quality of the result which they describe as low to very low.

The most common negative sides effects were irregularities in taste and stomach upset.  A recent review however supports a preventive role of zinc supplementation in reducing the incidence and burden of respiratory infections, particularly in children with recurrent disease and in zinc-deficient populations¹⁴.

This article was published in March 2020 and updated on March 31, 2026.

Vitamin C is one of the most common nutrients that comes to mind when thinking about immune health.  It is a water-soluble vitamin that serves as a cellular antioxidant, which means it protects cells from reactive oxygen species and cellular damage¹.

By protecting both skin barriers and immune cells from damage, vitamin C enables them to function properly.  It is required by cells from both the innate (general) and adaptive (specialised) immune system².

The innate immune system is the body’s first line of defence.  When pathogens like infectious bacteria or viruses get into the respiratory tract or gastrointestinal system, the innate immune system responds by sending cells like neutrophils or macrophages to remove the threat.  These cells try to engulf the invading pathogen or create enzymes to destroy it.

The adaptive immune system specifically targets the pathogen and takes over from the innate immune system.  It is often described as the ‘memory’ of the immune system.  Once exposed to a pathogen, the immune system can remember the identity of that pathogen for the future and quickly mount a defence specific to that pathogen.

Vitamin C promotes barrier function, supports the function of neutrophils, monocytes and macrophages and the activity of NK cells.  It also has a role in the differentiation and function of T cells, especially cytotoxic T cells and in antibody production¹.

This role has been recognised in an approved European Union health claim for vitamin C, stating that it “contributes to the normal function of the immune system” and is available to foods subject to condition within the EU³.

Are there Recommended Intakes for Vitamin C?

Global daily vitamin C intake recommendations range from 40 to 110mg per day, depending on region⁴.  In the US, the Institute of Medicine’s (IoM) recommendations are 90mg per day for men and 75mg per day for women⁵.

In the EU, the European Food Safety Authority has established a Population Reference Intake of 110mg per day for adult men and 95mg per day for adult women⁶.  Similarly, the Chinese Nutrition Society Reference Nutrient intake is 100mg per day for adult men and women⁷.

What are the Dietary Sources of Vitamin C?

Vitamin C can be found in many fruits and vegetables, such as kiwis, oranges, peppers and broccoli.  The table below shows amounts of vitamin C found in commonly consumed foods.

Source: National Institutes of Health Vitamin C Fact Sheet for Health Professionals ⁸

What Happens with Vitamin C Deficiency?

About 53% of the global population have an inadequate intake of vitamin C ⁹, but the exact number varies depending on global region.  Inadequate intakes were more prevalent in men than women and in areas like South Asia.

Scurvy is a nutritional disorder caused by low vitamin C levels which manifests with varied symptoms affecting multiple organ system due to its role in connective tissue synthesis.  Although it is rarely seen, sporadic cases still occur.

In developed countries, it is mainly diagnosed in the elderly and malnourished individuals and is associated with alcoholism and poor dietary habits¹⁰.

People who smoke or are exposed to second-hand smoke need more vitamin C in their diets because smoke increases the amount of vitamin C that the body needs to repair damage caused by free radicals⁵.

Are there and Risks with Excess Intakes of Vitamin C?

In general, vitamin C has low toxicity and high intakes of vitamin C do not cause serious adverse effects.  However, high doses of vitamin C can lead to diarrhoea, nausea, abdominal cramps and other gastrointestinal disturbances⁵.

There are some concerns surrounding high vitamin C intakes, such as the formation of kidney stones and excess iron absorption, but these are not generally considered a risk in healthy individuals.

While EFSA did not establish an upper limit, the IoM Tolerable Upper Intake Level for vitamin C ranges from 400 to 2,000mg per day, depending on age⁵.

What about Vitamin C Supplementation?

There is some evidence that vitamin C doses exceeding recommended daily values could have potential benefit.

A Cochrane review¹¹ of clinical trials testing vitamin C’s effect on immune health found that regular supplementation (>200mg per day) did not influence how often participants got common colds but reduced the duration of cold symptoms.

A recent meta-analysis¹² of trials which used doses of Vitamin C above 1g per day found a greater benefit on more severe measures of the common cold.

Severe Acute Respiratory Syndrome Coronavirus, which is a respiratory condition, is marked by significant oxidative stress and an excessive inflammatory response that results in tissue damage of the respiratory system.

For this reason, there has been interest in combining antioxidants like vitamin C with antiviral and anti-inflammatory treatments to improve patient outcomes.  However, a recent review¹³ suggests that further trials are necessary to determine optimal doses and conditions of use.

This article was first published in May 2022 and updated on March 24, 2026.

The ‘gut microbiota’ refers to the microorganisms (which may include bacteria, fungi and viruses) living in our intestines and they play a vital role in gut health and the management of several gastrointestinal disorders.

The term ‘microbiome’ refers to both microorganisms along with their collective genomes and metabolites (the molecules they produce)¹.

The composition of gut microbiota can be affected by a wide variety of dietary components including carbohydrates, dietary fibres, fat, polyphenols, plant extracts and by ingredients such as fermented foods, prebiotics and probiotics².

What are Probiotics?

Probiotics are defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”³.  Usually, this benefit is exerted in the gastrointestinal tract.

Probiotics influence health through non-specific, species-specific and strain-specific mechanisms.  Non-specific effects—varying across strains and species—include inhibiting pathogenic microbes in the gut, producing bioactive compounds like short-chain fatty acids and lowering colonic pH.

Species-specific actions may involve vitamin synthesis, strengthening the gut barrier, bile salt metabolism, enzymatic functions and toxin neutralisation. Together, these mechanisms can broadly affect human health and disease⁴.

It is key to remember that the health benefits of probiotics are considered to be strain specific.

For more information on how probiotics work see this section.

How do Probiotics Impact the Immune System?

Immune health is one of the more commonly studied health outcomes of probiotics and the following mechanisms have been proposed^{4, 5}:

1. Probiotics have been shown to help protect against infection by improving the strength of the intestinal barrier.  This reduces the ability of infectious microbes to enter the body via the gastrointestinal tract.
2. Enhancing phagocytic activity (the process of engulfing and ingesting solid particles, such as bacteria by the cell membrane).
3. Some probiotics, or the products they produce, can interact with immune cells of the human body to influence their effectiveness.  For example, some probiotics can increase the production of cytokines (e.g. Interleukin-1 (IL-1), IL-2, IL-10, IL-12, tumour necrosis factor alpha (TNF-α)) in the intestine.  These cytokines act as chemical messengers to regulate immune responses.

When it comes to researching aspects of immunity, studies often measure the frequency of the common cold or upper respiratory tract infections (URTIs) and the duration and severity of symptoms among study participants.

A 2022 Cochrane Review⁵ titled “Probiotics for Preventing Acute Upper Respiratory Tract Infections”, which included 23 randomised controlled trials, found that probiotics were significantly better than placebo or no treatment  for reducing the number and duration of URTIs.

They also reduced the number of participants who used antibiotics for URTIs.  This means that probiotics are likely working with the immune system to have a protective effect against the pathogens that cause URTIs.

Because studies have shown that probiotics may have an impact on upper respiratory tract infections (URTIs), there was significant interest in their potential role during the COVID-19 pandemic.

However, the International Scientific Association for Probiotics and Prebiotics (ISAPP)  stated that no probiotics or prebiotics have been shown to prevent or treat COVID-19 or to inhibit the growth of SARS-CoV-2⁶.

In the post-pandemic period, probiotics continue to be studied for their possible role in areas such as vaccine effectiveness and support for individuals experiencing post-COVID-19 syndrome⁷.

Antibiotics can disturb gastrointestinal microbiota and lead to reduced resistance to pathogens such as Clostridioides difficile and associated diarrhoea (CDAD).  The use of probiotics for the prevention of Clostridioides difficile infection has been researched for many years.

A recent Cochrane meta-analysis concluded that probiotics may be effective for preventing CDAD in those receiving an antibiotic for any reason, suggesting that for every 65 people taking probiotics, one case of CDAD may be prevented⁸.

Large trials comparing probiotics with placebo in people with a low risk of CDAD are needed.  This will be an interesting area to keep an eye on as the science progresses.

How to Choose a Probiotic

Resources from the International Scientific Association for Probiotics and Prebiotics (ISAPP)

The probiotic marketplace can be confusing for consumers.  See  for some basic information on how to choose a probiotic for healthy people.  There is also useful information about how to read a US and hypothetical European probiotic label.

Here are some basic principles to guide your search:

• • There is no one strain or one dose that is best.  Sometimes lower dose products or products with fewer strains have the best evidence.
  • Any health benefit claim made should be substantiated with a human trial.  The types of claims allowed in the US on foods and dietary supplements are restricted by law.  Contact the manufacturer to get information on what studies have been conducted, or consult Clinical Guide for Probiotic Products Available in the United States⁹ or the  Guide to Probiotic Products Available in the United Kingdom¹⁰.
  • One of the biggest challenges in the probiotic market is keeping the probiotic strain alive.  Responsible manufactures go to great lengths to be sure their probiotics retain viability and deliver an efficacious dose through the end of the product’s shelf-life.  Unfortunately, not all products on the market are responsibly formulated so consumers should buy products from companies they trust.

Resources for Healthcare Professionals
In addition to resources from ISAPP, in 2023, the  World Gastroenterology Organisation published a resource for professionals working specifically in gastroenterology “WGO Practice Guideline. Probiotics and Prebiotics”¹¹.

Resources for Researchers
Health benefits of probiotics can be strain-specific and meta-analysis may not represent the ‘gold standard’ for evidence in this area.  This paper identifies common mistakes and offers expert panel recommendations for conducting meta-analysis for probiotic studies¹².

This perspective literature review describes state-of-the-art tools for harnessing the microbiome for precision health and a corresponding future vision of healthcare¹³.

This article was first published in April 2020 and updated on March 11, 2026.

This long history as a folk remedy laid the groundwork for elderberry’s dramatic resurgence in the recent wellbeing market.

In the past number of years, consumer demand for natural, plant-based ingredients to support health has surged, a trend amplified by public health events such as the global COVID-19 pandemic.

During these periods, elderberry became a leading ingredient in the immune-support supplement category, with consumers seeking natural alternatives to support respiratory health³.

This success in the supplement sector has since resulted in its expansion into the broader functional food and beverage industry⁴.

Elderberry extracts are now increasingly incorporated into products such as flavoured beverages, snack bars, yogurts, and wines^5-7, valued not only for their potential health benefits but also for their unique flavour profile and natural colouring capabilities.

What are the Key Varietals?

For the food and nutraceutical industries, three subspecies of Sambucus nigra L. are of primary interest:

• • • Sambucus nigra ssp. nigra (European Elderberry): Native to Europe, North Africa, and parts of Asia, this is the most extensively studied and commercially cultivated subspecies.
    • Sambucus nigra ssp. canadensis (American Elderberry): Native to a large portion of North America, this subspecies is gaining significant commercial attention because it may confer greater stability during processing compared with its European counterpart.
    • Sambucus nigra ssp. cerulea (Blue Elderberry): Native to western North America, this subspecies is distinguished by its ecological resilience, including notable drought and fire resistance, making it a sustainable crop option in challenging climates.

The foundational nutritional value of elderberry provides a complex matrix of proteins, lipids, and fibre².

A thorough understanding of the nutritional and phytochemical composition of elderberry is essential for its effective application as a functional ingredient.  The distribution of these compounds varies significantly across different parts of the plant.

The Phytochemical Matrix

Not only are elderberries good sources of vitamins and minerals, but they also have an extensive and complex phytochemical composition^4,8.

Phytochemicals form the cornerstone of elderberry bioactivities, responsible for its antioxidant properties, vibrant colour, and many of its health benefits.

The concentration and profile of these compounds vary dramatically depending on the elderberry subspecies, plant part, and growing conditions^2,4.  The types of phytochemicals found in elderberries include flavonoids, anthocyanins, and carotenoids among others.

Anthocyanins, Flavonols and Other Flavonoids

Anthocyanins are responsible for the characteristic deep purple-black colour of elderberries and are central to their market identity as an immune-supporting ingredient^1,2.

Quantitative analysis reveals significant variation among subspecies where the European Elderberry contains the highest levels of anthocyanins, followed by the American Elderberry, whereas Blue Elderberry has the lowest anthocyanin content.

A noteworthy distinction of the American Elderberry is its high concentration of acylated anthocyanins, which can enhance pigment stability against degradation from heat and light, a highly desirable trait for food and beverage applications.

Beyond anthocyanins, elderberry is a rich source of other flavonoids, particularly flavonols, which contribute significantly to its overall antioxidant and anti-inflammatory capacity.  The flowers and leaves are often more concentrated sources of these compounds than the berries.

Carotenoids and Tocopherols

Elderberries are also rich in carotenoids and tocopherols, with a distribution that is highly specific to the plant part.

Berries are an exceptionally potent source of the carotenoids Lutein and Zeaxanthin, which are recognised for their role in eye health.

In contrast, the leaves are the exclusive source of other powerful antioxidant carotenoids, Astaxanthin and Canthaxanthin.

Furthermore, leaves are the primary reservoir of α-tocopherol, the most biologically active form of vitamin E.  Regional variations are also pronounced, with studies showing that samples from southern climates may accumulate higher levels of tocopherols.

Bioactivity and Health Benefits 

The rich and diverse phytochemical profile of the elderberry translates into a broad spectrum of potential bioactivities^1-5.

Figure 1 outlines the potential benefits of Elderberries and the way in which these are mediated through bioactive compounds have been proposed⁹.

Figure 1. Proposed Potential Health Benefits of Elderberry⁹.

Potential Antioxidant Activity

A foundational mechanism underpinning many of the elderberry health benefits is its potent antioxidant capacity^1,10.

The antioxidant effects are multifaceted including mechanisms such as direct free-radical scavenging and metal chelation, which position elderberry as a potential effective natural antioxidant ingredient.

Extracts from the flowers, berries, and leaves all demonstrate significant ability to neutralise harmful free radicals and mitigate oxidative stress, which is a key driver of ageing and chronic disease.

Anti-Inflammatory and Immunomodulatory Effects

The most well-known and commercially significant application of elderberry is for immune support, particularly in the context of respiratory health³.  Its efficacy is rooted in anti-inflammatory and immunomodulatory activities.

Elderberry extracts have been shown to modulate the immune response by inhibiting the production of pro-inflammatory mediators.  This action helps to balance the immune response, preventing excessive inflammation that can cause tissue damage during an infection^10,11.

Neuroprotective Properties

An emerging area of research is the neuroprotective potential of elderberry.  The bioactive compounds in elderberry can cross the blood-brain barrier and exert protective effects directly within the central nervous system⁵.

In vitro and in vivo studies have shown that elderberry extracts and their constituent polyphenols can protect neuronal cells from oxidative damage, reduce neuroinflammation, and improve cognitive and motor function in animal models.

Application in Functional Foods and Beverages

The application of elderberry is twofold: as a natural additive for colour and preservation, and as a core functional ingredient to deliver potential health benefits².

Elderberry as a Natural Additive: Colour and Preservation

In response to strong consumer demand for “clean-label” products, elderberry serves as an excellent natural alternative to synthetic additives.

The final colour is pH-dependent, exhibiting red shades in acidic environments (e.g., yogurts, fruit beverages) and shifting towards blue and purple in more neutral or alkaline conditions ^5,12.

Beyond colour, elderberry’s potential antioxidant properties make it a valuable natural preservative.

By inhibiting lipid and protein oxidation, elderberry extracts may extend the shelf-life and maintain the quality of perishable foods.  This has been demonstrated effectively in meat products, where encapsulated elderberry extract was shown to significantly delay the oxidative processes that lead to rancidity and discolouration in beef burgers¹³.

Formulation with Elderberry as a Functional Ingredient

The primary driver for incorporating elderberry into food products is its status as a functional ingredient, capable of imparting health benefits beyond basic nutrition¹⁴.  Its versatility allows for its use in a wide range of food matrices.

In the dairy sector, elderberry has been successfully incorporated into products such as yogurt and kefir^15,16.  Studies have shown that the addition of elderberry juice, puree, or pomace powder increases the product’s total phenolic and anthocyanin content, thereby boosting its antioxidant capacity.

However, formulation requires careful consideration of texture; direct addition of juice can decrease viscosity, while using restructured or encapsulated forms can maintain or even improve consistency and has been shown to lead to higher consumer acceptance.

The stability of the bioactive compounds is also a key factor, with evidence showing that elderberry anthocyanins can remain stable during the shelf-life of yogurt¹⁵, particularly when protected within a restructured matrix.

In bakery applications, elderberry adds both functional and nutritional value¹⁷.  The incorporation of elderberry powder into gluten-free wafers has been shown to increase the final product’s flavonoid and mineral content while also improving batter properties by reducing delamination¹⁸.

Similarly, adding elderberry juice to croissants or fermented elderberry to bread enhances their antioxidant capacity and bioactive compound content without negatively impacting nutritional quality.

Fermentation has been shown to enhance the bioactivity of the elderberry before its incorporation, leading to a final product with a higher phenolic content and an extended shelf-life.

The meat industry represents a significant opportunity for elderberry application.  Due to the high susceptibility of meat to oxidative degradation, the antioxidant properties of elderberry are particularly valuable.

A study on beef burgers demonstrated that an encapsulated elderberry extract acted as a highly effective “meat extender,” significantly delaying both lipid and protein oxidation more effectively than synthetic antioxidants during refrigerated storage¹³.  This not only extends shelf-life but also adds a health-promoting, clean-label ingredient to the product.

Another novel application is the use of elderberry vinegar as a marinade or spray for grilled meats, which has been shown to inhibit the formation of harmful polycyclic aromatic hydrocarbons by over 80%¹⁹.

A central challenge in utilising elderberry is the need for thermal treatment to ensure safety conflicts with the desire to preserve heat-sensitive bioactive compounds.

Raw elderberries should not be consumed because certain parts contain cyanogenic glycosides (CNGs)², which must be degraded through heating to render the product safe for consumption.

Therefore, it is critical that elderberry products intended for consumption must undergo a heating step.

Considerations

As consumer interest in more natural, proactive health products continues to grow, science-backed, botanical ingredients, such as elderberry, have an opportunity to take a further foothold in the health and wellbeing market.

While future studies are needed to further confirm the efficacy of elderberries and how they mediate immune benefits, the research has shown that, at a minimum, elderberry is a safe option with the botanical showing no evidence of over stimulating the immune system.

The functional potential of an elderberry ingredient is not uniform. Factors such as climate, soil type, and genotype directly influence the concentration of key bioactive compounds.

Therefore, sourcing elderberry cannot be a simple commodity-based decision. It requires a strategic approach that aligns the specific phytochemical profile of a given source with the desired health benefit and final product application, moving beyond a generic “elderberry extract” to a precisely characterised, high-performance functional ingredient.

HMPs are the live beneficial bacteria that are naturally present in breast milk.

Over the past number of years, HMPs have seen a surge in scientific interest, driven by growing awareness of the microbiome’s role in maternal and early-life health and immunity.

Recently, the science on HMPs was presented by KHNI experts at two industry conferences, ChinaGut in Zhejiang, China, and Growth Asia Summit in Singapore.

ChinaGut 2025

The ChinaGut 2025 conference with the theme of “GUTSY Young, Bright Future “, was held from June 6 – 8, 2025 at the Ningbo International Conference Centre, Zhejiang, China.  This year’s event featured over 30 academic sessions, more than 10 industry-focused sessions, and fourteen key scientific areas including the microbiome, nutrition, digestive system diseases, and immunity.

Dr. Jaume Núñez, Product Manager for Vegetative Probiotics at Kerry, presented the latest scientific research on HMPs as well as providing market trends and consumer insights.  Breast milk is the gold standard of infant nutrition, containing all nutrients required to support a baby’s healthy growth.

However, many mothers lack support or experience difficulties in breastfeeding leading to infants not reaping the benefits of consuming breast milk.

One of the top reasons why women stop breastfeeding is due to mastitis which occurs in approximately 10-20% of mothers who are breastfeeding.  Dr. Núñez highlighted that mastitis is associated with a dysbiosis in the microbiota in breast ducts.

Research findings presented showed the benefits of HMPs supplementation (specifically Lactobacillus) for the prevention and treatment of mastitis, as well as improving infant health.  HMPs are believed to play a role in antimicrobial defence by inhibiting bacterial growth.

Other potential mechanisms of action include increasing the abundance of microbes which produce favourable metabolites, reducing intestinal dysbiosis, and activating the host’s immune response.

A comment from Dr. Núñez:

“Over half of Asian female supplement consumers are seeking alternative solutions to support their pregnancy and breastfeeding journey.  When a mother’s microbiota is transmitted to her baby, this plays a key role in immune system development, allergy and asthma prevention, and nutrient absorption.  Therefore, the addition of HMPs may play an important role for bottle-fed babies.  We need to keep deepening into HMPs mechanisms of action and how they adapt to the different metabolic and immune characteristics of a woman or a child.”

Growth Asia Summit 2025

At the recent Growth Asia Summit 2025 in Singapore in July, two main research topics stood out namely Healthy Ageing, particularly the role of cellular interventions in extending people’s health span versus lifespan, and Women’s Health, with strong focus on nutrition across life stages.

A presentation on HMPs and their positive impact on maternal and infant health was given by Dr Mónica Maria Olivares, RDA Director of Women’s and Infant Health at Kerry.  The audience heard about the fast-growing probiotics market in the Asia Pacific region.

Dr. Olivares followed on by emphasizing the importance of an infant’s first 1,000 days of life, i.e. from conception to two years, for lifelong health.

Similar with what Dr. Núñez discussed in China, one of Dr. Olivares key messages was that breast milk provides essential nutrients and probiotics that nurture an infant’s gut and immunity.

Research documenting the benefits of HMPs such as enhanced infant gut microbiome development and improved resistance to gastrointestinal and respiratory infections was presented.

Different mechanisms, such as the competition with pathogenic bacteria, production of antimicrobial compounds, maturation of the immune system, and improvement of the immune response, have been attributed to the anti-infectious activity of HMPs.

In summary, our understanding on the health benefits of HMPs for mothers and infants continues to evolve.  Further research will give further insights into their health promoting effects and may elucidate the distinct mechanisms of action for specific strains.

Subsequently, this will increase the availability of targeted products to support mothers and infants through breastfeeding.

While the exact cause of PMD remains multifactored and complex, emerging research highlights the influential role of diet and the gut microbiome in modulating hormonal balance and mood regulation.

Understanding the intricate relationship between the gut, diet, and PMD is crucial.

PMD, as its name suggests, occurs 2 to 7 days (and sometimes more) before period and stops when it begins or on the following days. PMD affects millions of women of all backgrounds.

Recent studies establish that approximately 90% of women of childbearing age experience at least one mild symptom and that between 20-40%, the symptoms interfere with their daily activities¹.

The most common symptoms of PMD include many manifestations, both physical and emotional.  These symptoms are sore or tender breasts, headache, fatigue, skin changes, acne, irritability, mood swings, food cravings, and depression.

There are also gastrointestinal (GI) symptoms such as intestinal pain and bloating, diarrhoea or constipation².  PMD is not associated with age, educational level, or revenue³.

The pathophysiology of PMD is not clear, but experts link PMD with hormonal changes, serotonergic dysfunction, impaired gamma-aminobutyric acid (GABA) function, stress, and poor lifestyle habits such as longer durations of internet use and shorter sleep durations.

Treatment of PMD includes prescribed drugs, such as oral contraceptives or serotonin reuptake inhibitors (with some adverse effects), lifestyle modifications (meditation, exercise, diet, etc). Dietary changes include consuming soy isoflavones and soy products, although not every woman is responsive to these natural compounds.

A recent review concluded that diet is an essential modulating factor to manage PMD symptoms although clear and specific recommendations are difficult to conclude.  It is suggested that calcium, magnesium, vitamins B & D, and some herbal supplements can be useful and effective to support quality of life and help to control some PMD symptoms³.

Role of Gut Microbiome in Premenstrual Disorder

The gut microbiome comprises trillions of microorganisms residing in the gastrointestinal tract, including bacteria, viruses, fungi, eukaryotic parasites, and archaea⁴.  These microbes play a crucial role in host physiology, influencing nutrient metabolism, immune function, and neurological signalling.

The composition and diversity of the gut microbiome are influenced by various factors, including diet, lifestyle, medications, and hormonal fluctuations.  An increasing number of studies are now linking PMD with imbalance of the gut microbiome.

Dysbiosis, characterised by an imbalance in microbial composition and function, has been associated with increased inflammatory markers, hormonal imbalances, and neurotransmitter disturbances—all of which are implicated in PMD symptomatology.  Moreover, dysbiosis can disrupt intestinal barrier integrity, leading to the translocation of microbial products and triggering systemic inflammation, further exacerbating PMD symptoms.

Takeda et al.⁵ compared the structure of the faecal microbiome of women experiencing PMD that negatively affect their daily activities to women with no serious PMD (controls). Slight differences in microbiome were observed and the authors concluded that Parabacteroides and Megasphaera negatively predicted the more severe symptoms of PMD⁵.

In another study comparing Japanese women experiencing PMD, it was observed that alpha diversity was increased, and beta diversity was different in the PMD group than the control group.  The composition of the faecal microbiome differed between women with PMD vs controls.  After controlling for confounders, Collinsella spp. had the highest effect size in participants of 30-40 years of age⁶.  But it is not just about who is there, i.e. what type of microorganism are part of the gut microbiome.

The gut microbiome plays a pivotal role in the production of various metabolites, including S-(-)equol, short-chain fatty acids (SCFAs), neurotransmitters, and hormones.  Interestingly, it has been shown that only about 30-60% of people have a gut microbiome able to produce S-(-)equol, a metabolite biotransformed from isoflavones by certain gut microbes. S-(-)equol has agonist-antagonist oestrogen action, which contributes to improvement of PMD symptoms⁷.

SCFAs (butyrate, acetate, and propionate), have anti-inflammatory properties and exert regulatory effects on immune function and synthesis of neurotransmitter.

Furthermore, certain gut bacteria can produce neurotransmitters like serotonin, dopamine, and gamma-aminobutyric acid (GABA), which modulate mood, cognition, and behaviour⁸. Dysregulation of these microbial metabolites may contribute to the mood disturbances and cognitive changes observed in PMD.

There are many influences on PMD. From lack of sleep and extensive use screens to added stress and sedentary lifestyles.  These lifestyles result in dysfunction in serotonergic and GABA transmitters and hormonal imbalance.

By modifying one’s lifestyle to include exercise, mindfulness, and a healthy diet (including dietary diversity, high fibre, probiotics, etc.), this improves the gut microbiome, which supports neurotransmitter production and hormone balance.

Premenstrual Disorder and Probiotics

Some probiotics have been shown to synthesise metabolites such as SCFAs, neurotransmitters, and hormones.  Probiotics have also been evaluated to alleviates symptoms of PMD.

In 1996, a study on sixteen women administered three capsules daily of a probiotic containing one billion of L. acidophilus NCDO 1748 and one billion of Bifidobacterium bifidum NCDO 2203 strains in combination with antidepressant drug (S-adenosyl-L-methionine) revealed modulation of their gut microbiome, normalization of enzymatic activities of faecal enzymes and relief of PMD symptoms, as observed in most participants⁹.

More recently, in a study on 80 women experiencing PMD, women receiving 10 billion L. paragasseri OLL2809 daily had less irritability and greater change in premenstrual arousal score compared to placebo after three menstrual cycles¹⁰.

Tablets of L. gasseri CP2305 were administered daily to 56 women over the course of 6 cycles. Overall, the probiotic group reported less PMD symptoms than placebo, including depressed mood and anxiety.  Also, in this group, an increase in salivary oestradiol and progesterone in the luteal phase was observed¹¹.

Unfortunately, the exact mechanisms of action (MoAs) of probiotics to alleviates symptoms of PMD is not clearly known.

Action on the mucosal barriers and immune system to modulate gut inflammation, antimicrobial activity against pathogenic microbes, secretion of gut hormones, and neurotransmitters are some MoAs that have been associated with probiotics in this context.

Lactobacilli and Bifidobacteria have been shown to biotransform dietary isoflovanes into S-(-)equol or dietary fibres in to SCFA, two types of metabolites that have been associated with better outcomes in PMD.

Conclusion

The gut microbiome exerts profound effects on various aspects of women’s health, including the pathophysiology of PMD.

Dysbiosis-driven inflammation, hormonal dysregulation, and alterations in neurotransmitter signalling contribute to the complex symptomatology of PMD.  More research in this field is needed to fully explain these complicated interactions so optimal treatments are available to relieve the symptoms of PMD.

However, these initial research developments suggest that women who suffer from PMD may be able to manage their symptoms through dietary approaches to support their gut microbiome such as incorporating micronutrients, prebiotics, probiotics or probiotic-rich foods.

By focusing on gut health, women can have a holistic and accessible approach to mitigate the symptoms of PMD, ultimately enhancing their quality of life.

Decades later, this observation was noticed again, where vaccinated children in high-mortality areas of West Africa had a significantly lower mortality rate¹.

In 2012, the mystery behind these observations was finally solved and a new type of immune protection was identified, which is now called trained immunity².

The understanding of immune memory has been centred around the idea of targeted disease-specific approaches.  The aim of a vaccine is to induce a disease specific memory in the adaptive immune system (memory T and B cells), which then can spring into action if an individual is exposed to that disease.

However, trained immunity research has been ground-breaking within the field of immunology due to its differences in immune memory.

It revealed that cells of the innate immune system also have a kind of memory, although this memory works in a very different way and results in defence against a broad range of threats.

With the discovery of trained immunity, we now know that it is possible to also increase protection against multiple, unrelated diseases.

This important discovery has therefore presented new opportunities to bolster immune defences against a myriad of threats in a non-targeted manner; a new method to protect ourselves from future disease.

Moreover, research has recently shown that it is possible to induce trained immunity through food³.

How Does Innate Training Occur?

A growing body of research over the past decade has helped identify key mechanisms which explain how innate training occurs.

Innate training agents, such as the BCG vaccine^2,4 and the adenoviral ChAdOx1 nCoV-19 vaccine⁵ are able to induce trained immunity via metabolic reprogramming and epigenetic modifications⁶.

Epigenetic Changes – Placing a Bookmark

DNA contains instructions for making proteins, including proteins crucial for launching immune responses.  However, DNA is a very tightly coiled structure where gaining access to the instructions required can take precious time.

Training stimuli, such as the BCG vaccine, in essence creates bookmarks in this instruction manual to be placed on crucial pages for launching immune responses.

This act of “placing the bookmark” is done via epigenetic changes; reversible chemical modifications to the DNA structure that loosen the DNA at certain sites, making the genes/instructions at those sites more easily accessible.

These epigenetic changes are made possible due to altered metabolism within the cell, which provides the materials for these chemical modifications to occur.

Consequently, when a subsequent danger is detected in future, the relevant pages/genes are more easily read, allowing an immune response that is more rapid and potent, compared with non-trained immune cells.

This more potent response is also possible due to metabolic reprogramming.

Metabolic Reprogramming – Meeting Energy Requirements

When an immune cell is activated as part of launching an immune response, processes engage which require a lot of energy and the production of numerous compounds, such as immune messenger signals.

These energy and production demands are met by metabolic machinery.

Innate training stimuli initiate metabolic reprogramming, which not only provides the necessary building blocks for epigenetic changes to occur to the DNA (“placing the bookmark”), but also increases the metabolic machinery available to the cell, to meet future energy and production requirements.

This could be seen as the trained cell building up its energy infrastructure to be better prepared for future challenges.

When a subsequent danger is detected, the innate immune cells can immediately spring into action, as this enhanced metabolic machinery is ready to meet the required energy and production needs, facilitating a rapid and robust immune response ⁷.

Is Trained Immunity Long Lasting?

A hallmark of the adaptive immune response is the induction of long-lived memory cells, which mobilise should a “memorised” danger appear again.

This is the type of memory targeted with a vaccine, to induce long-lived protection.  Trained immunity has also been shown to last for several months, despite innate immune cells not living for very long.

Innate immune cells are replaced regularly, both by cell division and by influx of new cells, coming from hematopoietic stem cells in bone marrow.

These stem cells divide and mature into different types of immune cells, replenishing the body’s immune cells as needed.

The explanation of innate training above has focused on individual innate immune cells coming across training stimuli and thus having a more efficient responses against subsequent dangers.

This type of trained immunity is known as peripheral trained immunity and is thought to be maintained, at least to a degree, by cell division – where epigenetic modifications (bookmarks) can be passed on to daughter cells⁸.

Although this is believed to contribute to the longevity of trained immunity, the core component is due to training of hematopoietic stem cells in the bone marrow, as identified by epigenetic changes therein.  This is known as central trained immunity⁹.

How this training occurs is not fully understood, although certain immune messenger signals have been identified to contribute to this phenomenon.

It has also been postulated that stem cells may be able to detect danger signals, in a similar manner as innate immune cells, possibly leading to similar metabolic and epigenetic outcomes.

Because stem cells divide and become lots of different immune cells, their training can result in altered amounts of certain immune cells, as well as affect their responses.

For instance, central trained immunity induced by BCG vaccination, has been shown to result in a higher number of innate immune cells that are more effective at fighting off infections up to five months post vaccination, due to altered gene expression¹⁰.

Although studies have shown that innate training can be long lasting, there is an important aspect of this phenomenon that needs to be highlighted: it is reversible.

Epigenetic changes, placing bookmarks at relevant pages, are a core component of trained immunity, which are caused by chemical modification to the DNA.

However, these modifications can be reversed and the bookmarks consequently removed^11,12.  This is a highly dynamic feedback system, where the innate immune response is adapting to new information all the time.

Can The Immune Response Be Trained?

There are numerous substances and challenges that have been shown to cause trained immunity, such as the earlier mentioned BCG and adenovirus COVID-19 vaccines and more are being discovered all the time.

However, most identified innate trainers need to be either administered by medical staff or occur as the result of an infection/being sick, neither of which is ideal for day-to-day protection.

To both induce and maintain trained immunity, the most desirable approach is something an individual can eat or drink.

Fortunately, research suggests that certain functional/bioactive ingredients found in everyday food, beverages and dietary supplements may be able to induce and maintain this process of trained immunity.

For instance,  food-safe whole beta glucan particles (WGPs) not only induce trained immunity in isolated innate immune cells (peripheral trained immunity) but also resulted in central trained immunity when ingested by mice³.

This discovery has opened new dietary possibilities to bolster defences against immune challenges.

Summary

There is growing enthusiasm in understanding the influence of diet and supplementation on the immune system.

These approaches include the use of probiotics to support balanced gut flora and the inclusion of essential nutrients, such as vitamin C, to maintain regular immune function.

What is exciting about the discovery of trained immunity and the possibility to induce it through diet, is that it enables next level immune protection.

As discussed herein, it is a recently discovered, natural enhancement of the innate immune defence, enabling the immune system to be at the ready for future challenges.