The Role of Maternal Gut Firmicutes/Bacteroidetes Ratio in Shaping Fetal Development and Neonatal Microbial Communities

According to research, intrauterine exposure to non-pathogenic maternal microorganisms during pregnancy is influenced by the mother's nutritional, metabolic, and immunological status. This study investigates the association between maternal gut microbiota composition, fetal development, and neonatal microbiota, with the aim of exploring their interconnected health dynamics. A cohort-based correlational study was conducted involving 114 women (≥18 years old, ≤12 weeks of gestation) attending prenatal consultations at the ISSSTE General Hospital in Pachuca de Soto, Hidalgo, México. Data were collected at four stages: before 11 weeks, at 11-14 weeks, at 20-24 weeks, and at 31 weeks of pregnancy. Assessments included anthropometric measurements, biochemical markers, and intestinal microbiota analysis. The Firmicutes/Bacteroidetes (F/B) ratio positively correlated with venous duct flow and expected weight for gestational week (r = 0.02272, <i>p</i> = 0.0323; r = 0.2344, <i>p</i> = 0.0271). Bacteroidetes showed a positive correlation with birth weight (r = 0.2876, <i>p</i> = 0.0063), birth height (r = 0.5889, <i>p</i> < 0.001), and head circumference (r = 0.2163, <i>p</i> = 0.0418). Correlation analysis revealed significant relationships between maternal and neonatal microbiota, particularly for Bacteroidetes and Firmicutes. The findings suggest that maternal gut microbiota significantly influences fetal growth and neonatal microbiota composition. These insights underscore the importance of maternal health during pregnancy.