Maternal diet during pregnancy and intestinal markers are associated with early gut microbiota.

BACKGROUND: Diet has an important role in host-microbiome interplay, which may result in intestinal permeability changes and physiopathological effects at a systemic level. Despite the importance of maternal microbiota as the main contributor to the initial microbial seeding, little is known about the effects of maternal diet during pregnancy on maternal-neonatal microbiota. OBJECTIVES: This study aimed at ascertaining the possible associations between maternal dietary intake during pregnancy and neonatal microbiota at birth and to evaluate the relationship with maternal intestinal markers. METHODS: In a nested cross-sectional study in the longitudinal MAMI cohort, maternal-neonatal microbiota profiling at birth (n = 73) was assessed by 16S rRNA gene sequencing. Maternal intestinal markers as zonulin, intestinal alkaline phosphatase (IAP) activity and faecal calprotectin were measured in faeces. Furthermore, maternal-neonatal clinical and anthropometric data, as well as maternal nutrient intake during pregnancy obtained by FFQ questionnaires, were collected. RESULTS: Maternal diet is associated with both maternal and neonatal microbiota at the time of birth, in a delivery mode-dependent manner. The existing link between maternal diet, intestinal makers and neonatal gut microbiota would be mainly influenced by the intake of saturated (SFA) and monounsaturated fatty acids (MUFA). Members of Firmicutes in the neonatal microbiota were positively associated with maternal fat intake, especially SFA and MUFA, and negatively correlated to fibre, proteins from vegetable sources and vitamins. CONCLUSIONS: Maternal diet during pregnancy, mainly fat intake (SFA and MUFA), was related to intestinal markers, thus likely shifting the microbial transmission to the neonate and priming the neonatal microbial profile with potential health outcomes. CLINICAL TRIAL REGISTRY: NCT03552939.

Perinatal environment shapes microbiota colonization and infant growth: impact on host response and intestinal function.

BACKGROUND: Early microbial colonization triggers processes that result in intestinal maturation and immune priming. Perinatal factors, especially those associated with birth, including both mode and place of delivery are critical to shaping the infant gut microbiota with potential health consequences. METHODS: Gut microbiota profile of 180 healthy infants (n = 23 born at home and n = 157 born in hospital, 41.7% via cesarean section [CS]) was analyzed by 16S rRNA gene sequencing at birth, 7 days, and 1 month of life. Breastfeeding habits and infant clinical data, including length, weight, and antibiotic exposure, were collected up to 18 months of life. Long-term personalized in vitro models of the intestinal epithelium and innate immune system were used to assess the link between gut microbiota composition, intestinal function, and immune response. RESULTS: Microbiota profiles were shaped by the place and mode of delivery, and they had a distinct biological impact on the immune response and intestinal function in epithelial/immune cell models. Bacteroidetes and Bifidobacterium genus were decreased in C-section infants, who showed higher z-scores BMI and W/L during the first 18 months of life. Intestinal simulated epithelium had a stronger epithelial barrier function and intestinal maturation, alongside a higher immunological response (TLR4 route activation and pro-inflammatory cytokine release), when exposed to home-birth fecal supernatants, compared with CS. Distinct host response could be associated with different microbiota profiles. CONCLUSIONS: Mode and place of birth influence the neonatal gut microbiota, likely shaping its interplay with the host through the maturation of the intestinal epithelium, regulation of the intestinal epithelial barrier, and control of the innate immune system during early life, which can affect the phenotypic responses linked to metabolic processes in infants. TRIAL REGISTRATION: NCT03552939 . Video Abstract.