Maria Marco, PhD – Understanding the Journey of Microbes Through the Microbiome Scientific Advisor to the Kerry Health and Nutrition Institute & Professor of Food Science and Technology at the University of California - Davis, USA

Maria Marco, PhD

Published on: Feb 19 2020

Meet Dr. Maria Marco, in conversation with Nathan Pratt from the Kerry Health and Nutrition Institute

Nathan: What is your focus within microbiome research?

Maria: My goal is to take our understanding of probiotics, fermented foods, and the microbiome to the next level. This means not just understanding health benefits certain probiotics may have, but how they actually interact with the environment of our gastrointestinal tract.

Probiotics are living organisms that we introduce to our bodies’ living, dynamic environments. The more we understand about how they interact with this environment, the microbes that already live there, and the food we eat, the better solutions we can find for human health and food safety.

What sparked your interest in science?

The first thing that comes to my mind is my love of astronomy in elementary school. I remember being so excited by the space shuttle launches and learnings in the 1980s, and even kept a notebook of facts and newspaper clippings about the galaxy. I didn’t want to be an astronaut. I was just fascinated by the galaxy, and that people could study something so nebulous and far away.

I think this attraction to the mystery and complexity of the natural world has been the driver of my lifelong interest in science. In high school biology, I learned that animals and cells can hold the same complexity as outer space, despite being on a much smaller scale. That is when I really began my path on the career I have today.

Why did you choose to study microbiology?

When I began learning about microbiology, I realized it allowed me to apply science to something practical, something beyond the theoretical parts of science. It’s fascinating to me to learn about microbiology at a cellular level, but the fact that it links directly to disease and medicine, environmental science, food safety, and more was the reason it drew me in.

As I began learning about fermented foods, I connected with the link this area of science has to ancient food preservation practices, processes humans were using long before modern times. I love to think about the role of women in developing these processes so long ago, and how women are now involved in all aspects of science with a much greater scope.

What are the most exciting discoveries you’ve contributed to?

The most exciting discovery I’ve been a part of is investigating the way probiotics respond to being in the digestive tract.

Think about going to a new place, like a new city or country. There’s a lot to take in and adjust to, like changes in temperature or weather, different landscapes like mountains, different languages or cultures, and so on.

In much the same way, probiotics have a journey through our digestive tract. A microbe has its own way of sensing what’s going on around it. Are there other microbes around that it needs to defend itself against? Is there food around?

By using certain scientific techniques, we’re able to sense how a microbe changes its gene expression and protein synthesis in real time to adjust to its environment.

For example, a probiotic might sense other bacteria in our small intestine, and create antimicrobial peptides, which are tools it might create to defend itself. But these peptides can also signal our small intestine to improve its barrier integrity, meaning it’s better able to defend against pathogens from invading our bodies. By understanding how microbes react in our GI tract, we’re better able to understand their role in health.

Close up of petri dishes in lab

How does the popularity of the microbiome trend in the food and beverage industry impact your work?

I love seeing the boom in interest around fermented foods and probiotics. It creates great feedback and interest between the public and scientific community. There’s enthusiasm for scientists working in this field, students are excited to become a part of it to learn more, and so on.

This really drives a sense of applied learning and science.

What’s the most exciting thing right now in microbiome research?

The most exciting thing in my field right now is the fact that we are learning more and more about the link between our resident microbiota (the microbes we have living in our GI tract) and probiotics. The more we learn about one, the more we can learn about the other.

What will we know about microbiome research in 5 years that we don’t know now?

I think we will be much closer to understanding what a healthy gut microbiome looks like. Right now, we know that certain probiotics, fibers, foods, etc can impact the microbiome in a certain way, but we are still trying to learn what a healthy microbiome looks like, which is extremely challenging.

Once we know this, we will be able to identify which people will benefit from which probiotics, specifically, to a much deeper level.

What advice would you give to newcomers in your field?

  1. Diversify your skills. You need skills outside of your immediate discipline to make significant advances in science. 20 years ago, you would see research grants with a single investigator, but now these grants consist of a multidisciplinary team of investigators.For example, if you only study microbiology, how can you study their impact on humans in a way that goes beyond understanding the microbes themselves? You need human nutrition, immunology, informatics, physiology, etc to understand the whole picture.
  2. Be prepared to collaborate. This links closely with #1. You can’t be an expert in everything, but diversifying your skills helps you speak the language you need to with different collaborators, and also allows you to ask deeper questions of them.

What are good resources to learn more about the microbiome, fermented foods, and health?

Are Fermented Foods the Same as Probiotics? is an expert-written piece on the nuances between a fermented food and a probiotic, and their links to health.

The Value of Fermented Foods for Health is a great at-a-glance reference for why fermented foods are gaining popularity.

For anybody wanting to understand fermented foods – Robert Hutkins, “Microbiology and Technology of Fermented Foods” 2nd Ed. is a great resource. It tackles the right questions on the topic and looks at the ancient practice of fermented foods with a modern perspective.”

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