Microbiome of the first stool and overweight at age 3 years: A prospective cohort study.

BACKGROUND:Several reports have revealed that the first-pass meconium hosts a diverse microbiome, but its clinical significance is not known. OBJECTIVE:We designed a prospective population-based cohort study to evaluate whether the meconium microbiome predicts subsequent growth in children. METHODS:The study comprised 212 consecutive newborns with a meconium sample and a follow-up sample at 1 year of age. Trained nurses measured the children for weight and length using standardized techniques. We used next-generation sequencing of bacterial 16S rRNA gene and machine-learning approach for the analysis. RESULTS:The children with overweight at 3 years of age differed in their meconium microbiome from those with normal weight, having a higher proportion of Bacteroidetes phylum (29% vs 15%, P = .013). Using the machine-learning approach, the gut microbiome at birth predicted subsequent overweight with area under the curve 0.70 (SD 0.04). A lower proportion of Staphylococcus at birth was associated with greater length/height at 1 year (ß = -.68, P = .029) and 2 years of age (β = -.74, P = .030). CONCLUSIONS:The microbiome of the first-pass meconium predicted subsequent overweight at the age of 3 years. The association between the gut microbiome and overweight appears to start already during pregnancy and at birth.