Prenatal physical activity and the gut microbiota of pregnant women: results from a preliminary investigation.

Purpose: To determine whether physical activity (PA), specifically meeting the recommended 150 minutes of moderate-intensity PA per week, is associated with gut microbiota composition in pregnant women.

Methods: In an ongoing birth cohort study, questions from the Behavioral Risk Factor Surveillance System, which provides data on PA variables, were used to determine whether pregnant women met or exceeded the PA recommendations. To profile the composition of gut bacterial microbiota, 16S rRNA sequencing was performed on stool samples obtained from pregnant women. Differences in alpha diversity metrics (richness, Pielou's evenness, and Shannon's diversity) according to PA were determined using linear regression, whereas beta diversity relationships (Canberra and Bray-Curtis) were assessed using Permutational multivariate analysis of variance (PERMANOVA). Differences in relative taxon abundance were determined using DESeq2.

Results: The complete analytical sample included 23 women that were evaluated for both PA and 16S rRNA sequencing data (median age [Q1; Q3] = 30.5 [26.6; 34.0] years; 17.4% Black), and 11 (47.8%) met or exceeded the PA recommendations. Meeting or exceeding the PA recommendations during pregnancy was not associated with gut microbiota richness, evenness, or diversity, but it was related to distinct bacterial composition using both Canberra (p = 0.005) and Bray-Curtis (p = 0.022) distances. Significantly lower abundances of Bacteroidales, Bifidobacteriaceae, Lactobacillaceae, and Streptococcaceae were observed in women who met or exceeded the PA recommendations (all false discovery rates adjusted, p < 0.02).

Conclusion: Pregnant women who met or exceeded the PA recommendations showed altered gut microbiota composition. This study forms the basis for future studies on the impact of PA on gut microbiota during pregnancy.