PROBIOTICS
Probiotics (which means “for life”) are beneficial bacteria found in the intestinal tract. The two most important species of bacteria are Lactobacillus acidophilus and Bifidobacterium bifidum. When these bacteria are low in number, it can allow overgrowth of harmful bacteria or Candida (yeast) organisms. The traditional diet of many native cultures included fermented foods high in these beneficial bacteria. Sauerkraut, yogurt, miso, tempeh, and cheese are examples of fermented foods. Use of probiotics to keep the intestinal lining healthy has good scientific evidence to back up such an approach.
Probiotics can be useful in a variety of clinical conditions.
When antibiotics are taken, they will usually kill many
on the beneficial bacteria in the colon. This can lead to
overgrowth of toxic bacteria. The classic example is overgrowth
of Clostridium difficile and production of a toxin by the
bacteria that causes severe diarrhea. The normal gut flora
(typical healthy bacteria) can be reintroduced by taking
oral probiotics. This reestablishes a healthy bowel and
function returns to normal. Studies show that using high
doses of probiotics (15-20 billion organisms daily) while
on antibiotics can help prevent diarrhea and harmful bacterial
overgrowth.
Studies of prophylactic probiotic use to prevent traveler’s
diarrhea show some effectiveness. The probiotic must be
taken consistently while traveling and may not be effective
in some countries. I recommend a backup antibiotic to have
on hand in case the traveler’s diarrhea is severe.
Acute infectious diarrhea in children has been shown to respond to probiotics, especially Lactobacillus. Duration of illness was lessened compared to use of placebo (an inactive or inert substance). The effect was greatest on the most common kind of childhood diarrhea caused by the rotavirus.
Inflammatory bowel disease (colitis or Crohn’s disease) has been treated with probiotics. Preliminary studies have shown a reduction in symptoms and remission of illness in some treated patients. This type of treatment should be done under supervision of an experienced clinician.
Vaginal yeast infections are very common after courses of antibiotics. Using a vaginal douche of Lactobacillus acidophilus has been shown to keep the pH(acidity level) of vaginal secretions low and to prevent yeast and other types of vaginal infections from occurring. Species of acidophilus that generate hydrogen peroxide (H2O2) seem to work best at this. Even eating yogurt with live acidophilus shows some benefit to vaginal resistance to infection.
Recurrent urinary tract infections (UTI’s) are common in some women. A study using once a week insertion of acidophilus suppositories reduced UTI’s in one group of women by 75%. The source of the infection is commonly the vaginal opening, which is colonized by harmful bacteria.
People with cancer who receive radiation to the intestinal area may benefit by using probiotics to prevent diarrhea that is commonly associated with the radiation. Chemotherapy for cancer kills the most rapidly growing cells in the body. Since the cells lining the intestines are completely renewed every 3 days, most people on chemotherapy experience diarrhea and other distressing gastrointestinal symptoms. These may be lessened by use of probiotics.
Other clinical conditions that have been studied using probiotics include childhood eczema, recurrent otitis media (middle ear infection), high cholesterol and control of H. pylori (bacteria causing ulcers). The typical dose in most studies was 3 to 5 billion live organisms daily. A high quality brand must be used since only live bacteria can grow and colonize the bowel. Many brands are refrigerated to insure the bacteria stays alive.
One way to improve the effect of taking a probiotic is to take FOS (fructo-oligosaccarides). These short-chain polysaccarides (polymer chains of sugars) are not metabolized by humans. However, they promote growth of probiotic bacteria and inhibit growth of harmful bacteria. Usual doses are 2-3 grams daily. Properly prepared probiotics have been shown to be safe.
Daniel Blodgett MD