MICROBIOTA PROMOTES 5-HT BIOSYNTHESIS BY ELEVATING TPHI EXPRESSION IN COLONIC ECS oTph→> substrate; tryptophan(色氨酸)↑ product:5-HITP(5-羟基色氨酸)」 o Oral supplementation of 5-HTP=> 5-HTTMICROBIOTA PROMOTES 5-HT BIOSYNTHESIS BY ELEVATING TPH1 EXPRESSION IN COLONIC ECS  Tph↓=> substrate: tryptophan（色氨酸）↑ => product: 5-HTP（5-羟基色氨酸） ↓  Oral supplementation of 5-HTP => 5-HT↑