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Ask the Expert: Professor Glenn Gibson on the Gut Microbiome and COVID-19

Expert answers, Gut microbiome health

Ask the Expert: Professor Glenn Gibson

In our new Ask the Expert series, we're sitting down with renowned science and medical professionals to get their insights into how to stay healthy.

In our second edition of Ask the Expert, Pendulum Chief Operating Officer Mohan Iyer chatted with Professor Glenn Gibson. Glenn is Professor of Food Microbiology at University of Reading in the UK and he is the Head of Food Microbial Sciences. He is the co-author of the first paper on prebiotics in 1995 (most highly cited paper on functional foods) and has published almost 500 papers on probiotics and prebiotics. 

Watch their full conversation or read key quotes from their discussion below.

What exactly is food microbiology, and how does your work intersect with gut microbiome research?

My official title is a food microbiologist, but my training is in anaerobic microbiology. Traditional food microbiology is usually foodborne pathogens, like salmonella, all these bad guys that we've heard about. My work is a little bit different because I work on food after it's been digested by humans. My research, for over 30 years now, has been on the human gut so, how diet influences the gut microbiome and what we can do to improve human health as a result of that.


Can you tell me more about the All-Party Parliamentary Group (APPG) on the Human Microbiome? What was the research that convinced you and the other scientists in the group to write a letter about exploring the connection between COVID-19 and the gut microbiome to the UK Health Secretary?

In the UK, APPGs do not have any legislative power but what they do is inform key opinion leaders, like members of parliament, members of the House of Lords, people in the National Health Services, etc. about particular areas of interest. An APPG is sort of a focus group for Parliamentarians. 

It’s quite rare that there is a science APPG, but in 2019, myself and a campaigner called Alan Barnard set up this one with the help of Julie Elliott, MP who is the chair. What we hope to do is to help inform people about the gut microbiome, where the research lies, what can be done to improve health and ultimately improve the health of the nation if that's possible and save money for National Health Services. 

As a result, we have various activities, but one of the actions that we felt was important was to raise awareness of how probiotics and prebiotics may potentially help with the current pandemic which has really changed the face of the world in terms of biology, social gathering and healthcare. The answers are ultimately going to be viral treatments for COVID-19 and vaccines, but those could be a long time away and we felt that looking at probiotic and prebiotic research, may be one channel into what could be done now. 


I just read your very timely paper, Using Probiotics to Flatten the Curve of Coronavirus Disease COVID-2019 Pandemic. What exactly is the connection between the gut microbiome and COVID-19? 

The history behind that paper was when around the start of March, I wrote a blog for an organization, which is very dear to my heart, called ISAPP, the International Scientific Association for Probiotics and Prebiotics. My friend and colleague who really is the leading probiotics researcher in the world Gregor Reid (Distinguished Professor of Microbiology and Immunology and Surgery at Western University in Canada, and the Endowed Chair in Human Microbiome and Probiotics at the Lawson Health Research Institute) did one around the same time. One of the things that always struck me about probiotics and one of the most convincing trials I've seen was a study from the University of Kiel years ago where they took 500 people during the cold and flu season and gave them a probiotic or a placebo. The people who got the probiotics (a three strain product) had 20% fewer symptoms and their recovery was improved by two days. 

So I began to think, is there really anything in this? Meanwhile, Gregor, unbeknownst to me, was also thinking along the same lines. So we put our blogs out saying that probiotics and prebiotics can improve gastrointestinal health, they are safe, easy to use and straightforward, there are mechanisms of effect for this and there are thousands and thousands of research papers on what they can do for the gut. It also looks like they may have systemic effects which are mediated by immune regulation through dampening inflammation as well as direct inhibition of pathogens. 

So together with that key University of Kiel study and some other lines of evidence on combating respiratory effects through probiotics and prebiotics, we wrote our blogs and then we were approached by some scientists in Switzerland and they asked if we would be interested in writing a research publication with them by pulling the evidence together. That's what we did, and that is the article you saw which then led to the letter that went to the secretary for health here in the UK.


In your paper, you mention repairing or strengthening the gut barrier, which is often an important mechanism for probiotics. Can you share more about this? 

I think what struck me was that the virus [COVID-19] has been detected in the gut as well as in the respiratory area. There are some lines of evidence, mainly from China, suggesting that it actually lasts longer in the gut and there is a common receptor site apparently, which is the ACE2 receptor site, which is both present in the lung and the GI tract. 

Some of the things probiotics can do is interfere with potential colonization sites in the gut, increase immune enhancing properties and dampen down inflammation. We do know that this virus mediates a very heavy and awful inflammatory cascade, so given the anti-inflammatory effects of probiotics and prebiotics, we wondered whether there might be an argument for some kind of counterbalance. It also seems that probiotics may potentially be able to directly inhibit viruses through maybe acidification. They make very powerful acids. There is also a school of thought that would suggest that probiotics and prebiotics can improve barrier function so if indeed it is in the gut, maybe their use helps to stop leaking out of the gut. Butyric acid is a fuel for gut cells, it helps them to function properly. 

The problem is up until a few months ago, not many of people, including me, had heard of COVID-19 so there is no research on probiotics and prebiotics for COVID-19 at the moment. However, I do know there are a lot of trials going on. What we try to say in the paper is that there are potential mechanisms and it is with looking at - same with  our APPG letter. Very similar viruses to COVID-19 like other coronavirus have been successfully managed with probiotics. They have an excellent track record of safety. There is pretty much negligible, if any, risk. These products are available. We are very anxious to see the results of trials that are ongoing because then we will have some definitive proof. But while we're waiting for that, I see nothing wrong in really exploring this and our letter to the health secretary was just saying take a look at this. We're not suggesting any more than just have a look and ask your experts. I think it would have been remissive of us not to raise that. 


We are in the thick of COVID-19. We don’t have treatments. We don’t have vaccines. What advice do you have for people right now? 

I take probiotics and prebiotics every day. I would encourage people to speak to their healthcare workers about the possibility of using this or investigate it themselves. As I said, I take them, my family takes them, and I've been telling everyone I know since this pandemic started to take them. 


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