TRPV1 and irritable bowel syndrome: In another study, colonic miR-199a/b correlated with pain and TRPV1 expression in patients with IBS-D.155 In the future, it is possible that integrated studies examining genetic variants, epigenetic markers, gene expression and gene-environment interactions through complementary analyses of the microbiome and metabolome will offer refined genetic biomarkers targeting diagnosis and drug development for visceral hypersensitivity in IBS.