The authors found that the presence of pasteurized A. muciniphila (6 × 108 TFU of pasteurized A. muciniphila for 10 days) was associated with a significant (i) reduction in colonic hypersensitivity in both the NMS and PI-IBS models; (ii) improvement in the gut barrier function, as evidenced by lower FITC-dextran levels; and (iii) increase in expression of tight junction protein ZO-1 in the NMS and restored Claudin-2 levels in the PI-IBS models. This evidence concerns the gene TJP1 and irritable bowel syndrome.