Supplementation with a Limosilactobacillus fermentum K73 synbiotic modulates gut microbiota function and behavior in gnotobiotic mice transplanted with microbiota from children diagnosed with autism spectrum disorder

Gut dysbiosis has been implicated in numerous pathological conditions, including neurodevelopmental and neurodegenerative disorders. Recently, dietary interventions targeted at restoring microbial balance have therefore gained attention as potential therapeutic strategies. We recently demonstrated that an encapsulated synbiotic containing high-oleic palm oil and Limosilactobacillus fermentum K73 can modulate the metabolic activity and composition of human-derived gut microbiota in an in vitro batch bioreactor. Here, we extended this work through an in vivo supplementation pilot study using gnotobiotic mice colonized with gut microbiota from Colombian pediatric patients diagnosed with autism spectrum disorder (ASD) or age-matched neurotypical (NT) donors. Behavioral assessments and analyses of gut microbiota composition and function were performed before and after synbiotic supplementation. First, we found that the gut microbiota from Colombian ASD patients exhibited significantly reduced richness relative to NT donors, consistent with reports from other geographical regions, and displayed distinct compositional features unique to this population. Humanization of the gnotobiotic mice with this donor microbiota was successful, with murine gut communities reflecting features of their corresponding donor microbiota. Notably, synbiotic supplementation induced significant increases in the abundance of beneficial taxa and the production of short chain fatty acids that were more pronounced in mice colonized with ASD-derived microbiota, with concurrent behavioral changes associated with beneficial modulation of gut microbiota. Overall, we provide evidence that supports synbiotic supplementation as a viable strategy to positively modulate gut microbiome in conditions of dysbiosis. Our study also expands the body of knowledge of gut microbiome to understudied populations such as Latin America.