Two-hit perinatal injuries cause gut microbial dysbiosis in offspring

Perinatal exposure to infection and the subsequent inflammatory response have been linked to the development of autism spectrum disorder (ASD). In this study, we systematically investigated the impact of two-hit perinatal injuries, combining lipopolysaccharide-induced fetal inflammation and postnatal hypoxia, on the brain-gut axis in offspring. We evaluated key parameters such as social behavior (n = 12), motor function (n = 10), anxiety-like behavior (n = 8), myelination (n = 3), fecal microbiome composition (n = 14), and short-chain fatty acid (SCFA) concentrations (n = 5) in Wistar rats with perinatal injury. Our findings revealed that offspring with perinatal injury exhibited significant impairments in social behavior and motor function, alongside heightened anxiety-like behaviors. Additionally, hypomyelination was observed in the anterior cingulate cortex, motor cortex, and somatosensory cortex. Microbiome analysis demonstrated a trend toward decreased in alpha diversity, a significantly altered microbiota composition relative to controls, as indicated by beta diversity analysis, and significantly reduced levels of Faecalibacterium, a lower Firmicutes-to-Bacteroidota ratio, and an increase in Prevotellaceae and Candidatus stoquefichus. These changes were accompanied by a marked reduction in fecal SCFAs, particularly acetic acid. This study is the first to establish a direct link between two-hit perinatal injuries and disruptions in the brain-gut axis, resulting in gut microbial dysbiosis and altered SCFA levels. Our findings underscore the critical role of gut microbiota and SCFAs in neurodevelopment and offer new insights for developing interventions that target the gut-brain axis to mitigate the effects of perinatal inflammation.