Adolescence, the Microbiota-Gut-Brain Axis, and the Emergence of Psychiatric Disorders

Predispose, precipitate, perpetuate, and protect: how diet and the gut influence mental health in emerging adulthood

“…Several mechanisms are implicated in regulating the GBM axis, including the hypothalamic–pituitary–adrenal axis (HPA), microbial metabolites, hippocampal neurogenesis, neuronal pathways (via the vagus nerve), neuroactive pathways (serotonin and neuroactive metabolites), the kynurenine pathway, and immune pathways ( 9 ). Importantly, recent findings suggest a unique vulnerability in the gut microbiota (GM) during the period of emerging adulthood ( 10 – 12 ). The GM regulates the integrity of the intestinal membrane and inflammation along the gastrointestinal tract ( 13 ).…”

“…There is strong theoretical rationale linking food intake and mental health as being mediated through the GBM ( 12 ). The prevalence of a less nutrient-rich and more processed diet with numerous additives may well be predisposing whole segments of the human population to poor mental health, starting at a young age.…”

“…Food intake and the GBM may also play an important role as a precipitating factor for mental illnesses in EAs, made vulnerable by the instability of the GBM in adolescence and young adulthood, a period during which most mental illnesses have their onset ( 10 , 11 ). Several studies and reviews over the past decade have explored the GBM axis and the complex bidirectional relationship between diet and mental health ( 14 , 45 – 47 ), including among adolescents ( 12 ). In the context of EAs, this relationship is particularly complex, since eating behaviors, experimentation with substances and hormonal states are often irregular during this developmental stage.…”