185825534A range of studies have shown that the microbiota of obese individuals is quite different to that of people with no weight problems. Now, a study led by researchers from the Université Laval in Canada and Nestlé, has taken things further by showing that, with the help of probiotics, the balance of the gut microbiota may be changed in order to increase the number of digestive bacteria that encourage healthy weight.

Professor Angelo Tremblay and his colleagues worked with 125 overweight men and women on a weight-loss diet. In addition to this diet, half the sample was given two daily pills containing probiotics from the Lactobacillus rhamnosus family, while the others consumed a placebo. The results showed that over 12 weeks, the women in the group that had taken the probiotics had lost 4.4kg with the diet, while the group that only followed the weight-loss plan lost 2.6kg. Furthermore, in the following months, the women who had consumed the probiotics continued to lose some weight while those who had taken the placebo either stabilised or gained weight. In short, women consuming probiotics lost twice as much weight over the 24-week period of the study. Researchers also noted a drop in the appetite-regulating hormone leptin in this group, as well as a lower overall concentration of the intestinal bacteria related to obesity.

And what about the male participants?  “We don’t know why the probiotics didn’t have any effect on men. It may be a question of dosage, or the study period may have been too short,” says Professor Tremblay. The results of this study were published in the British Journal of Nutrition.