How and when to take probiotics

Scientists are just beginning to understand how intestinal bacteria affect many areas of health.

DEAR DR. ROACH » With the current focus on gut health, I have been hearing a lot about probiotic supplements. Who should take them? Does the number of bacteria matter more than the types listed on the container? Does one take them daily, for a brief time period, or for extended time periods? — K.V.S. DEAR READER » Probiotics are healthy bacteria in the large intestines that aid in digestion and possibly other functions in the body. Scientists are just beginning to understand how the intestinal bacteria (called the microbiome) affect many areas of health.

There are a few indications for probiotics that are well-accepted. The most important are in people with gastrointestinal conditions, especially in people with inflammation from inflammatory bowel disease. Some infections, including Clostridium difficile, may be prevented and treated with probiotics. This is not the primary treatment (which usually is antibiotics against C-diff), but it may be a useful adjunctive treatment or in recurrent cases. Gastroenterologists prescribe several different types of probiotics for these conditions. The particular type of probiotic may depend on the underlying condition and symptoms.

There is very preliminary data that suggest probiotics may be helpful in young children to prevent allergies, but it’s not solid enough to recommend yet.

Probiotics are generally safe, but there have been a few cases of the probiotics entering the bloodstream in people with diseased immune systems. They are fairly expensive, however.

Having healthy gut bacteria may be of benefit in people with no specific problems. However, it is not necessary to take in bacteria to have a shift to healthier gut flora. A diet more based in plants, whole grains and nuts, with less dairy, meat and sweets (such as the Mediterranean diet) showed clear changes in the microbiome in a few days, compared with a typical Western diet. There are so many benefits to this type of diet, including reduction in heart disease risk, diabetes risk and obesity, that I recommend this diet or a similar one rather than taking probiotics for people who are interested in improving gut health.