Probiotic yogurts ‘likely to be useless’

PROBIOTIC yogurts and food supplements with “good bacteria” are “useless” in many cases, scientists have said.

The so-called good bacteria is said to help restore the natural balance of bacteria in the stomach and intestines after they are disrupted by illness or treatment.

The live bacteria and yeasts are promoted as having health benefits and are added to yogurts or taken as food supplements.

However, a series of experiments published in the journal Cell showed that many people’s digestive tracts prevented standard probiotics successfully colonising them. They are only effective for some people, and may be a waste of time and money for others.

Previous studies have used patients’ excrement as a proxy for microbe activity in the gastrointestinal tract, but the latest research measured gut colonisation directly. In the study, a healthy group of volunteers was fed probiotic strains. In half of cases the good bacteria went in the mouth and straight out of the other end.

In the rest, they lingered briefly before being crowded out by existing microbes.

Professor Eran Elinav, an immunologist at the Weizmann Institute of Science in Israel and the study’s senior author, said: “Surprisingly, we saw that many healthy volunteers were actually resistant, in that the probiotics couldn’t colonise their gastrointestinal tracts.

“This suggests that probiotics should not be universally given as a ‘one size fits all’ supplement.

“Instead, they could be tailored to the needs of each individual.”

Professor Eran Segal, a computational biologist, said: “This opens the door to diagnostics that would take us from an empiric universal consumption of probiotics, which appears useless in many cases, to one that is tailored to the individual.”