Gut-brain cholinergic signaling mediates the antiseizure effects of Bacteroides fragilis.

Gut dysbiosis has been implicated in epilepsy, yet probiotic efficacy and mechanisms remain unclear. Here, we identify that Bacteroides fragilis (B. fragilis) is markedly reduced in children with epilepsy and show that oral B. fragilis administration suppresses seizures in both pentylenetetrazole- and kainic-acid-induced mouse models. Mechanistically, B. fragilis activates colonic choline acetyltransferase-positive (ChAT