Gregor Reid Talks about the Benefits of Probiotics
Special Topics Interview: June 2010
In our Special Topics analysis of probiotics research, the work of Dr. Gregor Reid ranks at #7 by total papers and #16 by total cites, based on 54 papers cited a total of 1,239 times. His current record in in the Web of Science® for the past decade includes 97 papers cited a total of 1,597 times between January 1, 2000 and May 6, 2010. In Essential Science IndicatorsSM from Thomson Reuters, his papers can be found in the field of Microbiology.
Dr. Reid is Professor of Microbiology and Immunology and Surgery at the Schulich School of Medicine & Dentistry of the University of Western Ontario, as well as the Director of the Canadian Research and Development Centre for Probiotics and Assistant Director of the Lawson Health Research Institute, both in London, Ontario.
Would you tell us a bit about your educational background and research experiences?
I earned my B.Sc. (Honours) degree in microbiology from the University of Glasgow in 1978, and my Ph.D. from Massey University, New Zealand, in 1982. I earned an Executive MBA degree from Monash University, Melbourne, Australia, in 1998.
I came to Canada in 1982 as a Postdoctoral Research Fellow at the University of Calgary in Alberta, but shortly thereafter was based at Toronto General Hospital. I moved to London as Director of Research Services at the University of Western Ontario in 1990 and to Lawson Health Research Institute in 1996. In 2001, I was appointed the Chair of the United Nations/World Health Organization Expert Panel and Working Group on Probiotics.
I have received numerous awards over the years, most recently, the 2007 Elie Metchnikoff Prize for Nutrition and Health (with Dr. Andrew Bruce), an Honorary Doctorate in biology from the University of Orebro, Sweden, in 2008, an Endowed Research Chair in Human Microbiology and Probiotics in 2009, membership in the Canadian Academy of Health Sciences in 2009, and the Hellmuth Prize for most outstanding research at the University of Western Ontario in 2010.
Also, the Fem-Dophilus product Dr. Bruce and I created was voted one of the Top 10 Medical Breakthroughs in 2007 by the US's Prevention magazine, as well as the Best of Supplements by Better Nutrition magazine in 2008.
What first drew your interest to probiotics?
I was really inspired by Dr. Andrew Bruce, who was head of Urology in Toronto when I joined in 1982. Back then, we didn't really call it "probiotics," but Dr. Bruce was very interested in the role of host microbiota and beneficial microbes in retaining and restoring health.
He felt that these microbes had a role to play, and so we started researching it, and it became exciting and almost addictive because we believed that there was truly something of value about these organisms.
"We're dead without our organisms; it's as simple as that."
Around 1986-87, we picked out one or two lactobacilli strains that we felt, if we administered them to the vaginas of women who had lost their natural lactobacilli, it might reduce their recurrences of infection. Our first clinical study was published in 1988 (Bruce AW, Reid G, "Intravaginal installation of lactobacilli for prevention of recurrent urinary-tract infections," Canadian Journal of Microbiology 34: 339-43, March 1988).
The term "probiotics" had been loosely used and had different definitions over the years, but the concept hadn't really been taken seriously until the last 10 years or so.
Several of your highly cited papers deal with the use of probiotic lactobacilli to restore and maintain urogenital flora. Would you talk a bit about this aspect of your work? How did you come to select Lactobacillus in particular?
In 1973, Dr. Bruce did a study in which he looked at the vaginal microbes from a group of women who suffered from recurrent bladder infections with E. coli (these bacteria come from the rectum, go into the vagina, then infect the bladder) and he found that the vagina was indeed heavily colonized by these pathogens.
On the contrary, the vaginas of women who had never suffered from UTI were colonized by lactobacilli, and he felt this was significant.
When I joined him in 1982 after he'd moved from McGill, we decided to look at lactobacilli. We had isolated a few strains and screened them for properties that we felt would be useful in colonizing the vagina and competing against pathogenic organisms.
What is it about lactobacilli that make them protective?
Back in 1987, the method we used was whether lactobacilli could inhibit or kill pathogens in the lab, and adhere to the surface of the vagina. If they did that and competitively excluded pathogens from attaching, we selected them, but we still didn't know their mechanism in humans.
Of course, since then, science has advanced and it's safe to say we know an awful lot more now, albeit not the precise mechanisms. And so, in a sense, we were lucky in the organisms that we chose. If we had to start from scratch again, I don't know that we'd do the same in vitro experiments—they might be helpful in picking the organisms, but it doesn't mean they will work for sure in humans.
I think now we realize there are other factors; for example, creating an environment that the pathogen doesn't particularly like—reducing the pH, displacing the pathogen from binding to the surface, inhibiting or killing it, or in some cases downregulating the virulence properties of the pathogens without having to kill them.
The other mechanism is probably modulating the immune system, so that the host is fighting against the pathogen. We did one study where we looked at gene expression and it showed that some host defense genes were upregulated by Lactobacillus GR-1. So it's a combination of a number of things.
I don't believe that one Lactobacillus strain is a magic bullet. We found that we needed two strains because one is essentially very good against gram-negative organisms and a second strain competes against gram-positive pathogens.
I think you need to understand the place in which you're putting these organisms, what they do for host, and how they influence the micro-environment they're going into. Too many companies just seem to pick strains out of a hat, throw them all in, and hope something might work. That was never our approach—and I think it's the wrong approach.
Four years ago, you talked about the importance of establishing guidelines for probiotics to aid their acceptance by the medical community in a paper for Current Pharmaceutical Design. What sort of progress would you say has been made towards this acceptance?
Regulatory agencies are now allowing companies to use the word "probiotics" on labels of food products, and they shouldn't be because that word has a definition that should be strictly adhered to. Essentially you have to prove that adding "probiotics" to products results in a properly documented benefit, usually by comparing it with placebo. Too few companies do this..
It's taken a long time, but I think we're turning a corner. Health Canada, for example, has come out with actually pretty strict guidelines that companies will have to adhere to, and I'm hoping it works—it's one thing to come out with policies and guidelines, it's another thing to have the people within the government to chase down the companies and say, "Sorry we're not letting you call this product a probiotic."
That's going to be very difficult, because I think in 2008 there were over 300 so-called probiotic products launched, and I'm betting you that less than 10 were really probiotic.
In Europe, EFSA (European Food Safety Authority) has not been as clear about what they want. I would much prefer if they'd say, "You provide us with A B C and D, and we'll let you have the following claims."
"I think you need to understand the place in which you're putting these organisms, what they do for host, and how they influence the micro-environment they're going into."
A lot of products have been rejected and it makes it sound like probiotics aren't reliable and haven't been proved to do anything if the European authorities aren't even allowing them to make claims, when in fact many of the ones that EFSA have rejected were quite rightly rejected—the strains or products don't do what is claimed.
Still, there are good products out there that I think should have approved claims, and hopefully they will very soon as consumers need to know what they are buying.
How much do ordinary/healthy people need probiotics in their food, like yogurt, on a daily basis?
There's no evidence that you can take too many probiotics. I would say once or twice a day is fine, with, say, a food probiotic with breakfast and a capsule later in the day, depending on what you want the products to do for you.
So for lunch today I had Activia, because I quite like yogurt, and this product has been shown to improve gut function. If my wife was to take one, then she would take RepHresh Pro-B with the two strains that we developed because they're good for vaginal health. In fact, I could also take them because I know they have gut benefits, it's just they're not promoted for that purpose.
If I travel, which I do often, to countries where the food and water supplies are a bit dubious, then I'll take my strains and Saccharomyces boulardii, as they are in capsules that can be easily transported, with the aim of preventing diarrhea.
It's said that half of what we poop is bacteria and two to three pounds of our weight is bacteria in the gut, so how are we replenishing them? We presume that food does that and helps the beneficial bacteria multiply in your gut, but that's not necessarily the case. While many foods need to be eaten fresh, even 50 years ago, a lot are now sterilized or processed, so that's one reason I take probiotics daily to compensate.