Impact of maternal obesogenic diet on maternal and offspring microbiome development

Pregnancy can alter gut microbiota composition, but how an obesogenic diet impacts maternal gut microbiota, and the extent to which this influences offspring microbiome can be obscured by confounding factors. This study examined changes in gut microbiota composition across pre-pregnancy, gestation and lactation in rat dams fed either a high-fat, high-sugar Cafeteria (Caf) diet or Chow. Microbiome development was assessed in their offspring weaned onto chow. Caf diet consumption during pregnancy increased weight gain and adiposity, and compromised subsequent maternal nursing behaviour. α- and β diversity measures in Caf-fed dams showed a different trajectory across the progression of pregnancy, with no change in Bacteroidetes and Firmicutes abundance compared with Chow dams. Offspring born to Caf dams exhibited greater adiposity and plasma leptin at weaning and 14 weeks of age than those born to Chow dams. Maternal Caf diet induced clear differences in β diversity in weanlings but not α diversity. SourceTracker analysis revealed similarities in the gut microbiota of Chow weanlings and maternal gut microbiota in lactation, whereas the microbiota of Caf weanlings was similar to the maternal gut microbiota during gestation. Maternal Caf diet exerted only marginal effects on gut microbiota composition in 14-week-old offspring.