Fig. 6

Correlation between gut archaeal species and host blood parameters. a Correlations between archaeal species abundance and blood parameters. Correlations between species abundance and blood biochemical measurements were calculated through spearman correlation test with FDR correction. Correlation coefficient was calculated, whilst statistical significance was determined for all pairwise comparisons. Only statistically significant correlations were shown where the correlation dot was color-intensified according to correlation direction (positive or negative) and coefficient size. b, c Correlations between the fecal abundance of M. smithii and the blood level of cholinesterase, viewed via regression plot, in urban (b) and rural (c) residents respectively. Correlation coefficient Rho and statistical significance were calculated by spearman correlation analysis, **p < 0.01