Zhong W, et al. - in this study, authors examined 20 diarrhea-predominant irritable bowel syndrome (IBS-D) cases, 28 patients with ulcerative colitis (UC) (16 active, 12 inactive) and 16 healthy subjects to delineate the bacterial colonization in the intestinal mucosa along with mucosa-associated microbiota in the subjects with IBS-D, UC, and the healthy control, and also to investigate the association of the mucosa-associated microbiota with clinical manifestations. They noted the mucosa-associated bacteria colonizing in the surface of mucosa and the adjacent mucin layer in the IBS-D cases. They found Escherichia coli, as well as Bacteroides in the lamina propria, in addition to bacterial colonization in the above-mentioned areas in active UC. They suggested a correlation between the changes of mucosa-associated microbiota to some clinical manifestations in IBS-D and UC.