If you believe the commercials, eating yogurt loaded with probiotics (beneficial bacteria) will reduce abdominal bloating and regulate your digestive system.
But no one can predict whether consuming Lactobacillus or Bifidus regularis in yogurt or other beneficial bacteria in food or capsule form will make you healthier.
“Either you will improve, or you won’t. The majority of people who take these probiotics notice a change in their bowel habits — for better or for worse,” says Thomas Morledge, MD, of Cleveland Clinic’s Center for Integrative Medicine.
Adds Cleveland Clinic gastroenterologist Bret Lashner, MD: “There is no harm done with probiotics, but don’t expect miracles. Only some people will benefit.”
The mystery of beneficial bacteria
The intestines contain hundreds of different types of bacteria, which form a complex ecosystem. Specific probiotics appear to nourish certain cells. For example, Lactobacillus produces short-chain fatty acids that colon cells use as fuel.
Our immune system is largely centered in our gut, and any problem with the immune system surrounding the intestines can have far-reaching consequences. For example, inflammatory bowel disease causes inflammation in the joints, eyes and skin.
No one knows how probiotics work, but in theory, they correct intestinal dysregulation, modulate the immune system and relieve any symptoms.
A theory that’s hard to prove
Unfortunately, “there are few credible studies showing that probiotics work — mostly anecdotal information is available,” says Dr. Lashner.
Most studies have shown mixed results. In clinical trials for irritable bowel syndrome, some patients experienced improvement in symptoms, and some didn’t. In a study on upper respiratory infection, probiotics reduced the duration of the illness, but the results were not duplicated when a different probiotic was used.
An exception appears to be using probiotics for infant colic. “The trial was a home run. But once again, it’s hard to figure out why it worked,” says Dr. Morledge, adding that the long-term effects of giving babies probiotics is unknown.
Not all probiotics are created equal
Because probiotics are not standardized, it’s hard to say how much you get in a cup of yogurt. According to Dr. Morledge, capsules are likely to be more potent. But probiotic capsules, which are not regulated by the FDA, may contain additional undesirable products, such as stimulant laxatives, which can be addictive, or digestive enzymes, which can cause ulcers.
So should you or shouldn’t you?
Wondering whether or not to take probiotics? The answer is, it’s up to you.
“No research on probiotics for general wellness has been done, but that’s not to say no clinical benefit may be had. I see no harm in trying Lactobacillus or Bifidus. They are very safe,” says Dr. Morledge.
Probiotics are often effective in preventing loose stools or diarrhea from antibiotic use. “They should be taken two hours before or after the antibiotic,” says Dr. Morledge.
A note of caution: If your immune system is seriously compromised, a yeast-based probiotic such as Saccharomyces boulardii can be dangerous and has resulted in fatal blood infections, he notes.