Effect of mother's weight on infant's microbiota acquisition, composition, and activity during early infancy: a prospective follow-up study initiated in early pregnancy.

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. We analyzed the fecal microbiota composition of infants of overweight and normal-weight mothers and assessed the relations of weight and excessive weight gain of mothers during pregnancy on the microbiota of infants. Mothers (n = 16) whose prepregnancy body mass index (BMI; in kg/m²) was ≥25 were selected with their infants from a prospective follow-up study of 256 women. Women with a BMI <25 (n = 26) and their infants served as control subjects. At the ages of 1 and 6 mo, infant stool samples were available for the analysis of microbiota composition by fluorescence in situ hybridization combined with flow cytometry and quantitative real-time polymerase chain reaction. Infants' fecal microbial composition was related to the weight and weight gain of their mothers during pregnancy. Fecal Bacteroides and Staphylococcus concentrations were significantly higher in infants of overweight mothers during the first 6 mo. Higher weights and BMIs of mothers were related to higher concentrations of Bacteroides, Clostridium, and Staphylococcus and lower concentrations of the Bifidobacterium group. Prevalences of Akkermansia muciniphila, Staphylococcus, and Clostridium difficile groups were lower in infants of normal-weight mothers and of mothers with normal weight gains during pregnancy. The composition and development of infant gut microbiota are influenced by BMI, weight, and weight gain of mothers during pregnancy.