Figure 2.

Relative abundance of the taxa related to irritable bowel syndrome (IBS). The boxplots represent the relative abundance of (A) Proteobacteria, (B) Bacteroides, (C) Enterobacteriaceae, and (D) Faecalibacterium in the pre- and post-treatment samples. The abundances in the probiotic and placebo groups are shown on the left and right plots of each panel, respectively. Asterisks (*) indicate significant differences between the pre- and post-treatment samples. The phylum Proteobacteria (A) and genus Bacteroides (B) which are known to be abundant in patients with IBS, significantly decreased in abundance in the probiotic group (P = 0.022 and P = 0.003, respectively).