Aggression: A gut reaction? The effects of gut microbiome on aggression

Recent research has unveiled conflicting evidence regarding the link between aggression and the gut microbiome. In our investigation, we meticulously examined the behavioral patterns of four groups of mice - wild-type, germ-free (GF), mice treated with antibiotics, and recolonized GF mice - to gain mechanistic insights into the impact of the gut microbiome on aggression. We discovered a significant correlation between diminished microbiome and increased aggression. Importantly, this behavioral shift could be restored when a WT microbiota was reinstated. Microbiota manipulation also significantly altered brain function, particularly in aggression-associated genes, and urine metabolite profiles. Notably, our study extends beyond the murine model, shedding light on clinical implications of early-life antibiotic exposure. We found that fecal microbiome transplants from 1mo old infants prescribed antibiotics during their first days of life led to a marked increase in aggression in recipient mice. This research demonstrates that the microbiota modulates aggression and underscores its importance in the realm of behavioral science. One-Sentence SummaryThe antibiotic-altered gut microbiome is implicated in increased aggression. It also leads to altered brain function, particularly in genes linked to aggression, and urine metabolite profiles showing a multi-system response to microbiota disruption.