Bridging the gap between gut microbiota and social life: beyond autism, the case of alcohol use disorder

Background and Objective Gut microbiota and social functioning are both substantially altered in individuals with severe alcohol use disorder (sAUD). Based on previous investigations of their relationship in autism spectrum disorder (ASD) and other psychiatric disorders, we investigated the interactions between gut-related measures and social functioning among sAUD patients. The social dimension has a crucial association with the risk of relapse after detoxification. Design Forty-six sAUD patients undergoing detoxification were categorized as dysbiotic or non-dysbiotic based on their gut microbiota composition, and compared with healthy controls in a cross-sectional study. Metabolomic profiles, inflammatory markers levels, dietary habits, psychological symptoms, and social functioning were compared. We applied a comprehensive assessment of social functioning combining sociodemographic data, an emotional intelligence questionnaire, a social cognition task and personal social networks (evaluated through mapping techniques). Results One third of the sAUD patients exhibited microbial alterations. The dysbiotic patients were younger, leaner, and reported higher alcohol craving compared to the non-dysbiotic patients. The dysbiotic subgroup also displayed altered metabolomic and nutritional profiles and a higher plasma IL-8 level. Interestingly, we observed a coherent profile of severe impairments across social functioning indexes in the dysbiotic group: they had lower sociability scores, displayed impairment in social cognition (with greater difficulty in spontaneously considering another’s perspective), were more often divorced/separated and unemployed, and had a smaller, less cohesive, and less diverse personal social network compared to the non-dysbiotic group. Conclusion As previously shown in ASD, we found a significant relationship between gut dysbiosis and various aspects of social functioning in sAUD. Targeting the gut microbiota could offer a novel approach to address social impairments that mediate the risk of relapse in psychiatric disorders.