For years, probiotics have been touted as a fast track to a healthy gut, but new research suggests that might not be true.

A group of researches from Israel recently published two studies evaluating the effectiveness of over the counter probiotics on the human stomach's microbiome - the community of microbes living in our gut. The results show that in many cases, probiotics just don't do anything at all.

The first study analyzed the microbiomes of 25 health volunteers before and after they consumed probiotics. Researches found that the bacteria they ingested was often passed directly though the body instead of staying in the gut. When it did stay, it was overwhelmed by the stomach's preexisting bacteria. This suggests that, for the most part, taking probiotic products does nothing for you.

The second study had even worse results. Researchers measured probiotic effectiveness after volunteers consumed antibiotics, which kill or inhibit a variety of bacterial growth in the gut. Consuming the probiotics actually slowed the regrowth of the individual's regular gut bacteria. However, when given a pill containing their own, regular stomach bacteria, subjects recovered from the antibiotics much more quickly.

"We've identified for the first time a very major potential adverse effect of probiotics that was not considered before," Eran Elinav - the study's senior author - told CTV News.

However, some members of the scientific community are challenging the significance of these findings. Marie Claire Arrieta - co-author of the book 'Let Them Eat Dirt' and assistant professor in physiology and pharmacology at the University of Calgary - argues that the findings are irrelevant since neither study looked at people with stomach and intestinal conditions.

"This is as if someone was to study the effects of insulin in a group of healthy non-diabetic people and presented their findings as if they were given to diabetic people."

Either way, you might want to lay off the yogurt the next time you get prescribed an antibiotic.