GIP and irritable bowel syndrome: After FMT, a correlation was found between NEUROG3 cells and Actinobacteria (r = 0.79, P = 0.025) also Bifidobacterium (r = 0.79, P = 0.025) in the total group of IBS patients and between GIP cells and Actinobacteria (r = −1, P = 0.017) also Bifidobacterium (r = −1, P = 0.017) in the idiopathic-IBS subgroup.