Quebec, Canada—Women may experience weight-loss benefits from taking a daily probiotic, according to a new data published in the British Journal of Nutrition.

The study, headed by Angelo Tremblay, professor at Université Laval, located here, was based upon previous research that showed the intestinal flora of obese individuals to be different than those of a healthy weight. The researchers set out to test the hypothesis that resetting obese individuals’ flora balance with probiotics could promote healthy bacteria that could lead to weight-loss.

In a double-blind trial, 125 overweight men and women were given either two capsules of Lactobacillus rhamnosus or a placebo daily. For 12 weeks, all participants followed a restricted calorie diet; they then followed a diet designed to maintain their current weight for an additional 12 weeks.

After the initial 12-week period, women taking the placebo had lost an average of 5.7 pounds, while the women given probiotics had an average weight loss of 9.7 pounds. Of note, there was no difference in average weight loss for the men in this study. Tremblay offers the explanation that “it may be a question of dosage, or the study period may have been too short.”

During the maintenance period, women in the placebo group did not lose any more weight. Those taking probiotics, however, lost additional weight for a total 24-week average weight-loss per person of 11.4 pounds, double that of those taking placebo.  In addition, the group experienced a drop in the appetite-regulating hormone leptin, as well as a reduction in the intestinal bacteria associated with obesity.

Tremblay and his team theorize that probiotics alter the permeability of the intestinal wall, thereby preventing proinflammatory molecules, which may lead to obesity and glucose intolerance, from entering the bloodstream.

Published in WholeFoods Magazine, March 2014 (online 2/7/14)