Our interview with Dr Mary Ellen Sanders

Dr Mary Ellen Sanders was Co-Founder and Founding President, and is the current Executive Science Officer, of the International Scientific Association for Probiotics and Prebiotics (ISAPP). Dr Sanders was recently on the ISAPP consensus panel to develop the definition and scope for “fermented foods, and we caught up with her to find out more about her career and the role fermented foods play in human health. 


1. Can you tell us about your career pathand what led to your interest in food science and microbiology, and in particular your interest in probiotics? 

I was aimless when I got to college. My brother was getting his degree in viticulture and oenology  the science and study of wine and winemaking. He said, “Mary Ellen, how about I’ll make the wine and you make the cheese.” So I changed my major to food science. 

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It turned out I really enjoyed food microbiology, which focused on the ‘good’ microbes used for making food, rather than food-poisoning microbes. Then I had a once-in-a-lifetime opportunity to be a grad student working for the incredible Todd Klaenhammer at North Carolina State. There, some people in the lab were working on probiotics. I thought it was a sham at first, but when I started consulting in 1990 I realised that there was a lot of interest in probiotics and if I wanted anyone to hire me, I needed to learn about them. So I started reading about probiotics and, encouraged by Dr Joe O’Donnell at the California Dairy Research Foundation, published a review article in 1993 on “Effect of Consumption of Lactic Cultures on Human Health”. That article opened my eyes to the really interesting field of probiotics. And it got me noticed when few people provided this service in the United States.  


2. Can you share what ISAPP is and where the idea for setting up ISAPP came from? 

Professor Glenn Gibson, Dr Irene Lenoir-Wijnkoop (then at Danone Research) and I were working on a scientific program committee for a 1999 Danone symposium to be held in New York City. We discussed how there was no scientific ‘home’ for the multidisciplinary scientists involved in probiotic and prebiotic research. We thought a probiotic and prebiotic association of scientists would really be welcomed. At the meeting, we invited all who were present to weigh in on the idea. Overall, people thought it was a great idea. So we moved ahead. A couple years later, in 2002, ISAPP was incorporated. Professor Gregor Reid hosted ISAPP’s inaugural meeting in London Ontario, Canada. ISAPP’s mission is to advance the science of probiotics and prebiotics, although its scope has expanded to include synbiotics, postbiotics and fermented foods – basically substances that connect microbes and health. ISAPP’s all-academic board of directors and its focus on science distinguishes it from other organisations, which serves an advocacy role for the industry.  


3. What does your role as Executive Science Officer at ISAPP entail 

The ISAPP board of directors is, and always has been, the brains and the ingenuity behind ISAPP. Any success I’ve cobbled together as the Executive Director/ESO is fully due to taking the lead from them. The board comprises volunteers who believe that ISAPP can make a difference for the probiotic and prebiotic fields. They establish our many activities (see here for a 2020 summary).  

I see my role as making their jobs as easy as possible, to “grease the wheels” so to speak, to make their ideas come to life. I also bring expertise in probiotics that allows me to raise key questions, identify opportunities, critically review happenings in the field, provide follow-up, manage daily association activities and in general, help move the ISAPP train down the track. 


4. Over recent years, the terms ‘probiotics’, ‘prebiotics’, ‘synbiotics’ and ‘fermented foods’ have albeen defined – do you think having these official definitions has helpedor will help, to correct for the misuse of these terms by the food industry, media and the general public? 

Yes. We rely on words to communicate, and words that are precisely defined bring clarity to communications. It’s important for all involved with these substances to agree upon definitions for these terms and use them appropriately. ISAPP’s approach has been to bring top experts together to come to agreements and this format I believe has helped create solid outcomes and justifiable rationales. The ISAPP consensus statements are top cited articles for Nature Review Gastroenterology and Hepatology (NRGH), so they clearly resonate with the field. Of course, we can’t control continued misuse of these words, but when a strong scientific consensus exists for how these terms should be used, misuse should be far simpler to identify, and subsequently not condonedBy the way,  we have recently added ‘postbiotics’ to our consensus panel topics, In Press at Nature Reviews Gastroenterology and Hepatology (NRGH). 


5. ISAPP recently published the ISAPP consensus statement on fermented foods in Nature Reviews Gastroenterology & Hepatology. Can you share with us what the updated definition is of fermented foods and how they differ from probiotics?  

The updated definition of fermented foods is: “foods made through desired microbial growth and enzymatic conversions of food components.” Fermented foods are part of the cuisine of most regions of the world, with unique types in each region. Life is definitely better with fermented foods – cheeses, wine, beer, bread, fermented vegetables and many more! But there’s a lot we don’t know about them 

Many are made with microbes that are not defined, so the exact microbiological make up of fermented foods may not be known. Further, the role of many fermented foods in health has not been studied. These are two ways in which fermented foods and probiotics differ. Another important way is that some fermented foods do not retain the live microbes used in their making. Probiotics, of course, must contain live microorganisms when consumed. So there are several key differences between probiotics and fermented foods. Anytime you see a headline or a blog post by a so-called expert that equates fermented foods and probiotics, you are permitted – nay, encouraged – to cringe. See here for a convenient infographic that lays out the specific differences between probiotics and fermented foods. 


6. Is there evidence to suggest fermented foods are good for our health? 

There are some large associative studies that suggest some fermented foods may have cardiometabolic health benefits. But causality can’t be concluded from those studies. There are randomised controlled trials on probiotic fermented milks and yoghurts, and these studies provide causal links between to digestive and immune benefits, among others. We need more controlled trials with traditional fermented foods, but of course, these are challenging. To do a good study, your food and its microbial makeup must be well-defined, and often, traditional fermented foods are not. 


7. ‘Fermented foods’ seem to be one of the latest food trends and we see a surge in their availability in food retailers as well as people encouraging you to make your own at home – is there any advice you would give people either when choosing or making their own fermented foods? 

I greatly encourage people to make their own fermented foods. In my case I make my own yogurt and bread, but there are so many other fermented foods that are great to make at home. There are a lot of informative resources out there that provide guidance. See here for some useful information and this ISAPP blog for some useful suggestions and links for safely making fermented foods at home 


8. What does a typical working day look like for youHow have you had to adapt during the COVID-19 pandemic? 

I spend way too much time in front of a computer screen. But I try to get to the barn to ride my 22-year old Morgan gelding, Noah, or to the gym to break up the screen time. Since I’ve been working from a home office for 30 years, the pandemic didn’t change my daily work life much. The biggest change is no travel. It was heart-breaking for me to have to cancel our 2020 ISAPP meeting, which was planned for the beautiful Banff area in Canada. Although I’ve never relished preparing to leave on a business trip, I always enjoyed myself once I arrived. I am so fortunate to work with people I really enjoy. And I miss seeing them. 


9. If you could go back to when you were a student and give yourself one piece of advice, what would it be?  

Pick your research advisor carefully. Find a great scientist who will teach you to love what you do and guide you to success.