Maternal gut microbiota mediate intergenerational effects of high-fat diet on descendant social behavior.

Dysbiosis of the maternal gut microbiome during pregnancy is associated with adverse neurodevelopmental outcomes. We previously showed that maternal high-fat diet (MHFD) in mice induces gut dysbiosis, social dysfunction, and underlying synaptic plasticity deficits in male offspring (F(1)). Here, we reason that, if HFD-mediated changes in maternal gut microbiota drive offspring social deficits, then MHFD-induced dysbiosis in F(1) female MHFD offspring would likewise impair F(2) social behavior. Metataxonomic sequencing reveals reduced microbial richness among female F(1) MHFD offspring. Despite recovery of microbial richness among MHFD-descendant F(2) mice, they display social dysfunction. Post-weaning Limosilactobacillus reuteri treatment increases the abundance of short-chain fatty acid-producing taxa and rescues MHFD-descendant F(2) social deficits. L. reuteri exerts a sexually dimorphic impact on gut microbiota configuration, increasing discriminant taxa between female cohorts. Collectively, these results show multigenerational impacts of HFD-induced dysbiosis in the maternal lineage and highlight the potential of maternal microbiome-targeted interventions for neurodevelopmental disorders.