Probiotics can treat diseases and keep food and water clean
‘Good’ bacteria to the rescue
Probiotics can treat diseases and keep food and water clean
A nasty sinus infection sent Andrea Edmunds, then a 19-year-old student at St. Francis Xavier University in Antigonish, N.S., to see her doctor three years ago. The cure—a powerful antibiotic—turned out to be worse than the disease. Not only did it target the bacteria in her sinuses, as intended, but it also went on a killing spree of the microbes in her gut. Suffering from diarrhea and painful stomach cramps, she was unable to eat or keep water down until she was finally hospitalized and given a different antibiotic.
Doctors determined that by killing off neighbouring microbes, the first antibiotic had allowed a bacterium called Clostridium difficile, a normal inhabitant of the intestinal tract, to overgrow and cause Andreas problems. Even after she returned home, her symptoms continued. Desperate for a treatment, her sister Lindsey, then 15, and their mother, Gail, turned to the Internet. There they discovered probiotics, nutritional supplements that are showing promising results not only in treating a range of human ailments but also in combatting potentially lethal contaminations of food and water.
Unlike antibiotics, which are drugs designed to kill bacteria, probiotics are the socalled good bacteria that exert beneficial effects by altering the balance of the microbes that naturally live in the intestinal, genital and urinary tracts. Intrigued by what they were reading, the Edmunds family bought probiotics from a local health food store and, within a week, saw Andreas condition improve dramatically. That got the wheels turning in her young sisters head.
Armed with a phone book, Lindsey embarked on a project that would win her fame in the medical community—and $60,000 in scholarships as she starts classes as a freshman this month at the University of Western Ontario. First, she mailed a survey to 100 physicians in Nova Scotia to determine if they had heard of probiotics and whether they would prescribe them to their patients. Of the 68 who responded, many had never heard of probiotics, but most said they would like to see more information and research. Written up as a project for her high school
in Antigonish, Lindsey’s study earned her a bronze medal in the 1998 National Science Fair in Edmonton. Then last May, she published her findings in the Canadian Medical Association Journal, becoming, at 17, one of the youngest authors ever to appear in its pages.
Her subject, probiotics, is attracting considerable research attention. Recent studies have found that certain strains of bacteria can help control inflammatory bowel disease, eradicate vaginal infections, control symptoms of lactose intolerance, food allergies and autoimmune diseases, and significantly reduce the severity and duration of diarrhea experienced by travellers and individuals taking antibiotics. Other research shows that probiotics can greatly reduce the impact of viral diarrhea among young children.
On another front, a clinical study in several long-term care facilities in Toronto and neighbouring regions is under way to determine if probiotics can help curb an outbreak of antibiotic-resistant E. coli. “There is very little you can do to get rid of this organism,” says Dr. Allison McGeer, an infectious diseases specialist at Mount Sinai Hospital in Toronto who is piloting the study. “That’s why we’ve turned to probiotics.”
In the animal industry, researchers are exploring probiotics as an alternative to antibiotics in preventing disease and promoting growth. That research stems from increasing concerns about antibiotic resistance and antibiotic residues in meat products, says Ming Fan, a nutritional ecologist at the University of Guelph, in Ontario. Magdalena Kostrzynska, a scientist with Agriculture and Agri-Food Canada in the Food Research Program in Guelph, has found that probiotics can inhibit the ability of the toxin-producing E. coli Ol57:H7 to attach itself to cells that line the gut. That is the strain blamed for seven deaths last year from contaminated water in Walkerton, Ont.
Impeding the deadly E. coli strain from taking up residence in the intestines of catde would reduce the risk of human exposure through undercooked beef or tainted water. Also, other studies have found that probiotics can significantly reduce the amount of salmonella, a common agent in food poisoning in broiler chickens.
Probiotic bacteria do the job by releasing products of their metabolism that give them a competitive edge over neighbouring microbes, including the harmful varieties. Varying from strain to strain, those byproducts can include lactic acid, hydrogen peroxide and substances that prevent certain bad bugs from attaching to cells and infecting them. Some strains even enhance the immune response against disease-causing organisms.
In Japan, 24 million people drink to their intestinal health every day with a probiotic beverage called Yakult. A Finnish company called Valió sells one of the best-studied strains, Lactobacillus rhamnosus GG, in 29 countries—not including Canada. Probiotics appear as beverages, cultures for fermenting dairy or soy milk, and in capsule and tablet forms.
Their low North American profile may be about to grow. Gregor Reid, a microbiologist at the University of Western Ontario, is working with colleagues to establish the Canadian Research and Development Centre for Probiotics. A $6-million endeavour, it will be the first in North America to study the bacteria and the microbiology of the gut and urogenital tracts. “We have two to three pounds of bacteria in our bodies and scientists have paid zero attention to that,” says Reid. “We would not be alive today if it wasn’t for these bugs. It’s a delicate balance that we don’t understand.” Reid’s group has so far identified two highly potent strains of lactobacilli, one that can prevent recurrent vaginal infections, and another that can prevent Staphylococcus aureus, known as staph, from infecting wounds.
A Montreal firm, Institut Rosell-Lallemand, already makes 60 probiotic strains that have been studied extensively by its own scientists as well as university and government researchers. Many health-food and supplement manufacturers use Institut Rosell-Lallemand probiotics, says biochemist Thomas Tompkins, the company’s director of research. One of its products, Fermalac Vaginal, has Health Canada’s approval as an over-the-counter drug for the treatment of vaginal infections. That product can be taken along with antimicrobial therapy prescribed by a doctor, or as a preventive measure for women who experience recurrent vaginal problems, says Tompkins.
For Lindsey Edmunds, probiotics not only put her sister on the road to recovery, they also led to a flood of telephone calls, awards, job offers and media appearances. As she embarks on her university years, she’s sure of one thing. “I’ll definitely take a career in science,” says Lindsey. “I love doing research, finding out how things work—why they do what they do.” E3
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