Fig. 1From: Alterations in the intestinal microbiome and mental health status of workers in an underground tunnel environmenta Microbial alpha diversity in ES and BS. Boxplot showed greater gut microbial diversity in BS than ES according to Shannon (t = 3.375, P = 0.001) and Simpson (t = 2.757, P = 0.008) indices with paired samples t-test. b Microbial beta diversity. Principal coordinate analysis (PCoA) of ES compared to BS based on Bray-Curtis dissimilarities in the relative abundance of ASVs (PERMANOVA, R2 = 0.028, P = 0.002)Back to article page