In a recent study, 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 (control group) or antibiotics (antibiotic group). After 25‐days of infusion, ileal and fecal microbiota, serum amino acids and neurotransmitters, and hypothalamic transcriptomics were analyzed. Whilst 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 <0.05), suggesting the infusion specifically targeted large intestinal microbes. Concentrations of AAAs were likewise decreased in the blood and hypothalamus (P <0.05) by antibiotic infusion. Antibiotic infusion further decreased concentrations of hypothalamic 5‐HT and dopamine, in line with AAAs being their precursors. Furthermore, RNA sequencing identified an upregulation in gene expressions of neurotransmitter transporters and synthetases (q <0.001).
The items with an up arrow indicate the increased concentration in the antibiotic group compared with the control group, whereas those with a down arrow indicate the decreased items in the antibiotic group