The human gastrointestinal tract requires “good bacteria” to help the body to absorb and utilize nutrients from food properly. Previous studies demonstrate that the intestinal flora of obese individuals differs from that of people of normal weight. Some scientists speculate that this difference may be due to the fact that a diet high in fat and low in fiber promotes certain bacteria at the expense of others. Angelo Tremblay, from Laval University (Canada), and colleagues enrolled 125 overweight men and women to undergo a 12-week weight-loss diet, followed by a 12-week period aimed at maintaining body weight. Throughout the entire study, half the participants swallowed 2 pills daily containing probiotics from the Lactobacillus rhamnosus family, while the other half received a placebo. After the 12-week diet period, researchers observed an average weight loss of 4.4 kg in women in the probiotic group, as compared to 2.6 kg in the placebo group. After the 12-week maintenance period, the weight of the women in the placebo group had remained stable but the probiotic group had continued to lose weight, for a total of 5.2 kg per person. In other words, the women consuming probiotics seemed to have 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. Speculating that probiotics may act by altering the permeability of the intestinal wall and keep certain proinflammatory molecules from entering the bloodstream, which may help to prevent the chain reaction that leads to glucose intolerance, type 2 diabetes, and obesity.
Marina Sanchez, Christian Darimont, Vicky Drapeau, Shahram Emady-Azar, Melissa Lepage, Angelo Tremblay, et al. “Effect of Lactobacillus rhamnosus CGMCC1.3724 supplementation on weight loss and maintenance in obese men and women.” British J Nutr., 2 Dec. 2013.