Antibiotics‐induced modulation of large intestinal microbiota altered aromatic amino acid profile and expression of neurotransmitters in the hypothalamus of piglets

The evidence of gut microbiota‐mediated modulation of brain function has been widely recognized from studies using germ‐free rodents or animals with oral antibiotic‐induced microbiota depletion. Since the large intestine harbors greater numbers and more diverse of microbes than in the small intestine, large intestinal microbiota may play a crucial role in the modulation of brain function. In this study, a large intestinal microbiota‐targeted strategy was used to investigate the impact of large intestinal microbiota on brain function. Twelve piglets (12.08 ± 0.28 kg) fitted with a T‐cannula at the distal ileum were fed a standard diet and randomly assigned to two groups (n = 6) for ileal infusion of either saline or antibiotics. After 25 days of infusion, ileal and fecal microbiota, serum amino acids and neurotransmitters, and hypothalamic transcriptomics were analyzed. While the antibiotic infusion did not change the proximal ileal microbial composition, it markedly altered the fecal microbial composition and increased aromatic amino acid (AAAs) metabolism (p