Although there were no significant differences in the numbers of Iba-1-positive cells in the lumbar spinal cord and other selected CNS regions among the three groups (Fig. 4a, b, Supplementary Table 4), microglia from IBS-FMT rats showed significant changes in cell morphology, including decreases in dendritic area, dendritic length, the number of branch points, the number of segments, the number of terminal points, and interactions. The gene discussed is AIF1; the disease is irritable bowel syndrome.