Understanding how host genetics and the gut microbiota shape brain function has become a central issue in modern neuroscience and psychiatry. The question addressed in this thesis is therefore how serotonergic genetic variation, microbiota disruption, and ASD-related genetic background contribute to emotional and neurodevelopmental phenotypes. To address this question, this thesis examines three complementary experimental routes: a serotonergic genetic route using the 5-HTT model, a microbial perturbation route using antibiotic-induced microbiota disruption, and a developmental/genetic microbiota route using ASD-related mouse models. By connecting molecular, behavioral, and microbial levels across these models, this thesis aims to clarify how genotype, microbiota composition, and developmental context together inform gut–brain mechanisms relevant to neuropsychiatric vulnerability.
Menghan received her Master’s degree in Pathogenic Biology from Jinan University in Guangzhou, China. In 2021, she joined the Donders Institute as a PhD candidate under the supervision of Prof. Dr. Judith Homberg and Assoc. Prof. Dr. Alejandro Arias Vasquez. Her doctoral research focused on the roles of serotonergic signaling and the gut microbiota in modulating behavior. She aims to continue working in the field of gut–brain axis research.