Bifidobacterium Alleviated Experimentally Induced Colitis by Upregulating In ‐doleamine 2, 3‐Dioxygenase Expression

ABSTRACT The goal of this study was explore the role of indoleamine 2, 3‐dioxygenase (IDO) in the therapeutic effect of probiotics on inflammatory bowel disease (IBD). Trinitro‐benzene sulfonic acid (TNBS) was used to induce colitis in mice, and 1‐methyltryptophan (1‐MT) was used to block the expression of IDO. Clinical manifes‐tations, macroscopic and microscopic colonic alterations were assessed using the dis‐ease activity index (DAI), Wallace‐Keenan, and Curtner scoring systems, respectively. The expression of colonic IDO was detected by western blot. An immunohistochemis‐try analysis was used to evaluate the level of CD11c+ cells and the expression of IL‐17 and Foxp3. The results showed that the DAI, Wallace‐Keenan, and Curtner scores were lower in the Bifidobacterium treatment group than the control group, and the therapeutic effect of Bifidobacterium was blocked by 1‐MT (P<0.05). Additionally, Bifidobacterium was observed to increase the expression of IDO and the number of CD11c+ cells, CD11c+ and IDO double positive cells, and Foxp3+ Treg cells, while decrease the number of IL‐17+cells (P<0.05). The generation of Foxp3+ Treg cells induced by Bifidobacterium was abrogated by 1‐MT (P<0.05). The results of our study suggest that Bifidobacterium may attenuate TNBS‐induced colitis by inducing the expression of IDO, which can further increase the generation of Foxp3+ Treg cells.
Source: Microbiology and Immunology - Category: Microbiology Authors: Tags: Original Article Source Type: research