Background: Obesity is among the leading causes of disease and death. Bariatric surgery is the most effective treatment of obesity. There is increasing evidence that after gastric bypass surgery, patients and animal models show a decreased preference for sweet and fatty foods. The underlying mechanism may include alterations in taste function.

Background: Results of experimental studies suggest that deviations in gut microbiota composition predispose to excessive energy storage and obesity. The mother influences the original inoculum and the development of infant microbiota, which in turn is associated with later weight gain. Objective: We characterized the gut microbiota in women according to their body mass index (BMI) and the effect of weight gain over pregnancy on the composition of microbiota before delivery. Design: Overweight women (n = 18) were selected according to their prepregnancy BMI from a prospective follow-up study. Normal-weight women (n = 36) were selected as controls in consecutive order of recruitment. Excessive weight gain during pregnancy was defined as >16.0 kg for normal-weight and >11.5 kg for overweight states according to Institute of Medicine recommendations. The composition of gut microbiota was analyzed by fluorescent in situ hybridization coupled with flow cytometry (FCM-FISH) and by quantitative real-time polymerase chain reaction (qPCR). Results:Bacteroides and Staphylococcus were significantly higher in the overweight state than in normal-weight women as assessed by FCM-FISH and qPCR. Mother's weight and BMI before pregnancy correlated with higher concentrations of Bacteroides, Clostridium, and Staphylococcus. Microbial counts increased from the first to third trimester of pregnancy. High Bacteroides concentrations were associated with excessive weight gain over pregnancy (P = 0.014). Conclusions: Gut microbiota composition and weight are linked, and mother's weight gain is affected by microbiota. Microbiota modification before and during pregnancy may offer new directions for preventive and therapeutic applications in reducing the risk of overweight and obesity.

Background: It has been reported that deviations in gut microbiota composition may predispose toward obesity, and specific groups of commensal gut bacteria may harvest energy from food more efficiently than others. Alterations in microbiota compositions of mothers may be transferred to infants and lead to an increased risk of overweight.

The perinatal nutritional environment impacts upon the health and well-being of mother and child also in the long term. The aim of the present study was to determine the safety and efficacy of perinatal probiotic-supplemented dietary counselling by evaluating pregnancy outcome and fetal and infant growth during the 24 months' follow-up. Altogether, 256 women were randomised at their first trimester of pregnancy into a control and a dietary intervention group. The intervention group received intensive dietary counselling provided by a nutritionist and were further randomised, double-blind to receive probiotics (Lactobacillus rhamnosusGG andBifidobacterium lactisBb12; diet/probiotics) or placebo (diet/placebo). Firstly, probiotic intervention reduced the frequency of gestational diabetes mellitus (GDM); 13 % (diet/probiotics)v.36 % (diet/placebo) and 34 % (control);P = 0·003. Secondly, the safety of this approach was attested by normal duration of pregnancies with no adverse events in mothers or children. No significant differences in prenatal or postnatal growth rates among the study groups were detected. Thirdly, distinctive effects of the two interventions were detected; probiotic intervention reduced the risk of GDM and dietary intervention diminished the risk of larger birth size in affected cases;P = 0·035 for birth weight andP = 0·028 for birth length. The results of the present study show that probiotic-supplemented perinatal dietary counselling could be a safe and cost-effective tool in addressing the metabolic epidemic. In view of the fact that birth size is a risk marker for later obesity, the present results are of significance for public health in demonstrating that this risk is modifiable.