By Ruth Winter, MS
We have all heard about the evil bacteria that contaminate our meat and spinach and other edibles we may ingest but can there be good bacteria deliberately added to our food? The answer is “yes” and I’ve been giving some to myself and my family for years. The beneficial ones are called probiotics--- a word compounded from Latin and a Greek meaning "favorable to life.”
The World Health Organization defines probiotics as "live microorganisms that when administered in adequate amounts confer a health benefit on the on the host." The idea that friendly bacteria in yogurt, for example, can crowd out pathogenic organisms was originally purported by Russian-French bacteriologist Ilya Metchnikoff in The Prolongation of Life published in 1907.
Today, most products contain bacteria isolated from milk products and typically contain species of Lactobacillus or Bifidobacterium, both of which I have used in powdered or pill form. Now, more and more live micro-organisms are being added to food or added to animal feed. They are considered "friendly germs," due to their ability to help restore microbial balance in the intestine and in the immune system. In addition to lactobacilli, bifidobacteria, streptococci, and some yeasts and molds--alone or as mixtures-- are now direct food additives.
In marketing probiotics, companies either make health claims based on their own research or refer to the wide range of studies conducted with various probiotic strains. Many studies have shown that probiotics may, indeed, boost the immune system. A recent investigation reported by Dr. Mark Besselink of Utrecht University Medical Center in the Netherlands in the journal Surgery described 14 randomized-controlled trials on the use of probiotics. The friendly bacteria were given to patients undergoing abdominal surgery, liver transplantation or severe trauma. Nine showed a significant decrease in infectious complications causing Dr. Besselink to say he was “enthusiastic about preoperative probiotics." In another study published in 2008 in the British Journal of Sports Medicine, probiotic supplements were found to reduce the number and length of infections suffered by long-distance runners. Strenuous training can affect the immune system and make athletes vulnerable to coughs and colds. The study conducted in Australia found taking probiotics more than halved the days the athletes had symptoms. In another clinical study published in The British Medical Journal, 113 patients had been hospitalized and given antibiotics. A follow-up after discharge showed the group taking probiotic drinks fared much better. Only 12% of those people developed antibiotic-associated diarrhea compared to 34% of the ex-patients not taking probiotics.
The belief is that when administered orally, Lactobacillus rhamnosus GG adheres to the mucous membrane of the intestines and helps restore the balance of the gastrointestinal (GI) microflora; promote gut-barrier functions; diminish the production of cancer-causing compounds by other intestinal bacteria; and activate the innate immune response and enhance adaptive immunity, especially during infections.
Scientific understanding of probiotics and their potential for preventing and treating health conditions is still in an early stage, despite the fact that probiotic have been used in folk medicine for many years. Traditional medicine practioners are now paying attention to the “friendly bacteria”. A conference co-funded by the US National Center for Complementary and Alternative Medicine (NCCAM) and convened by the American Society for Microbiology explored this topic. According to the conference report, there is encouraging evidence shown by scientific studies for some uses of probiotics. They are as follows:
• To treat diarrhea (this is the strongest area of evidence, especially for diarrhea from rotavirus)
• To prevent and treat infections of the urinary tract or female genital tract
• To treat irritable bowel syndrome
• To reduce recurrence of bladder cancer
• To shorten how long an intestinal infection lasts that is caused by a bacterium called Clostridium difficile
• To prevent and treat pouchitis (a condition that can follow surgery to remove the colon)
• To prevent and manage atopic dermatitis (eczema) in children
Some preliminary studies cited by researcher at the NCCAM Conference also report that certain probiotics can play a role in reducing the development of allergy in children. They also reported the apparent ability of probiotics to decrease Helicobacter pylori colonization in the stomach (which produces ulcers); help patients cope with side effects of antibiotic therapy; manage relapse of some inflammatory bowel conditions; lower the risk of certain cancers; decrease dental-caries-causing microbes in the mouth, and keep healthy people healthy.
The conference panel, in addition noted that in studies of probiotics as cures or any beneficial effect was usually low; a strong placebo effect often occurs; and more research (especially in the form of large, carefully designed clinical trials) is needed in order to draw firmer conclusions. Such research has started. For example:
• At the Mayo Clinic College of Medicine, researchers have been examining probiotics for possibly decreasing the levels of certain substances in the urine that can cause problems such as kidney stones.
• A team at Tufts-New England Medical Center is studying probiotics for treating an antibiotic-resistant type of bacteria that causes severe infections in people who are hospitalized, live in nursing homes, or have weakened immune systems.
• Researchers at Tufts University are conducting a preliminary study on whether yogurt has the potential to reduce growth problems related to diarrhea and malnutrition in weaning infants.
• An Ohio State University team is studying whether Lactobacillus could potentially boost infants' immune systems and help ward off diarrhea-causing infections.
• Researchers at the Johns Hopkins University are investigating whether probiotics could have a role in treating fatty liver disease (a chronic condition in which fat accumulates in the liver).
Among the many questions yet to be answered are:
• Exactly how do probiotics interact with the body (such as the gut and its bacteria) to prevent and treat diseases and will new technology in medicine find the answers?
• How really viable and effective are probiotic bacteria after being added to food?
• What are the most effective ways to administer probiotics for therapeutic purposes, as well as the best doses and schedules?
• What is the potential of probiotics to help with the problem of antibiotic-resistant bacteria in the gut?
• Can probiotics prevent unfriendly bacteria from getting through the skin or mucous membranes and traveling through the body such in cases of patients suffering burns, shock, trauma, or suppressed immunity?
What about side-effects? Some live microorganisms have a long history of use as probiotics without causing illness in people. Probiotics' safety has not been thoroughly studied scientifically, however. More information is especially needed on how safe they are for young children, elderly people, and people with compromised immune systems. Probiotics' side effects, if they occur, reportedly tend to be mild and digestive such as gas or bloating. More serious effects have been seen in some people. Probiotics, for example, might theoretically cause infections that need to be treated with antibiotics, especially in people with underlying health conditions. They could also cause unhealthy metabolic activities, too much stimulation of the immune system, or gene transfer (insertion of genetic material into a cell).
Probiotic products taken by mouth as a dietary supplement are manufactured and monitored as foods, not drugs. Their quality (e.g., their identity, potency, purity, and shelf life) can vary--even from lot to lot or bottle to bottle. The National Center for Complementary and Alternative Medicine (NCCAM) and the National Institutes of Health are funding research. For more information you can check the US government’s http://nccam.nih.gov/health/probiotics/ and usprobiotic.org (commercially sponsored).