Researchers have launched the first scientific society and established the first institute in North America dedicated to studying probiotics—live microorganisms consumed or applied to specific anatomic sites for their purported health benefits. The International Scientific Association for Probiotics and Prebiotics (ISAPP) held its inaugural conference 3-5 May in London, Ontario, Canada, attended by 70 researchers from five continents. A day earlier, researchers at the Lawson Health Research Institute and the University of Western Ontario (UWO) in London, Ontario, inaugurated the Canadian Research and Development Centre for Probiotics (CRCDP).

More than two dozen strains of bacteria, mostly in the genera Lactobacillus and Bifidobacterium, are used as dietary supplements, according to a recent report from the Swiss market-research firm Giract. Moreover, probiotic-containing foods and supplements, including yogurts, fermented milk, capsules, and powders, now make up a worldwide product sector that is worth hundreds of millions of dollars in sales per year. And prebiotics—otherwise indigestible food ingredients that, when consumed, fuel the growth of beneficial gut microbes—represent a similar product sector.

For researchers in these fields, however, respect has been elusive, in part because some companies make unsupported health claims about these products. What’s more, mainstream medical researchers have been slow to recognize the potential health value of these microbe-containing products, according to Gregor Reid, director of CRCDP and UWO professor of immunology and microbiology. "This field has not been trendy and has had next to no funding, but it has major implications for the health of people," he says.

Hence, a group of microbiologists, dairy scientists, geneticists, immunologists, and gastroenterologists formed the multidisciplinary ISAPP. "We wanted to provide an opportunity for everybody to get together without relying on [a single company] to do it," says Mary Ellen Sanders, the first president of the new association, who is an adjunct research professor at California Polytechnic State University in San Luis Obispo, Calif., and runs a consulting business in Centennial, Colo., that advises food, dairy, and dietary supplement companies. ISAPP’s main financial support so far has come from dairy and food industry groups, with some help from the government of the United Kingdom. CRCDP was funded initially by $1.7 million from the Ontario provincial government and $4.2 million from industry groups, UWO, and the University of Guelph.

Despite skepticism in some circles, available evidence indicates that probiotics can treat or prevent diarrhea, urinary tract infections, and food allergies, and could one day help hold off gut diseases, surgical wounds, and other ailments, Reid says. For example, when administered as a supplement or in fermented milk, a purified form of Lactobacillus GG (LGG) appeared effective in double-blinded, placebo-controlled clinical trials against different types of diarrhea, including rotavirus-induced diarrhea in children, antibiotic-associated diarrhea, and traveler’s diarrhea.

This strain also helps to prevent a recurrent food-associated allergic condition called atopic eczema in infants, according to a double-blind, placebo-controlled clinical trial reported last year in The Lancet by Erika Isolauri of Turku University in Turku, Finland [357:1076-1079, 2001)]. In addition, earlier this year Reid and several colleagues reported that probiotics appear effective for treating vaginal infections in humans. In a separate study, Lactobacillus RC-14 prevented surgical wound infections in rats. The bacterium or the biosurfactant that it produces kept Staphylococcus aureus, a potentially life-threatening pathogen, from sticking to cells and causing subcutaneous abscesses, according to Jeffrey Howard of UWO, Reid, and their colleagues.

Such studies are just the beginning, says Todd Klaenhammer of North Carolina State University in Raleigh. The genomes of five probiotic Lactobacillus and Bifidobacterium strains are already sequenced, and genome sequences of 12 additional probiotic strains are on the way. With such extensive genomic data becoming available, researchers plan to design chips with which to pinpoint genes critical for colonizing, interacting with, and functioning in human tissues, such as the gut and vagina, and to knock out specific bacterial genes to evaluate their roles in these host-related interactions. "The field is now positioned to do the right microbiology and the right clinical trials," he says.

Meanwhile, regulators are searching to define some standards for the many products that are marketed as probiotics. The influential Codex Alimentarius, an advisory commission of the U.N. Food and Agriculture Organization and World Health Organization that recommends food-safety standards to individual countries, accepted new guidelines for probiotic products in June. Tighter standards and better science are needed to improve the credibility of the probiotics field, which could have a big impact on human health, according to Reid. "Science should be driving this, not quackery or industry," he says.

Dan Ferber
Dan Ferber writes from Urbana, Ill.

Copyright © 2002 Dan Ferber. Reproduction or distribution is prohibited without permission from the author.

Reprinted with permission from the American Society for Microbiology (ASM News, August 2002).