a decreasing trendP > 0.05
thetaiotaomicron exhibited a decreasing trend ( P > 0.05, Supplementary Fig. 9B ), negatively correlated with depression severity ( r = − 0.7199, P < 0.01, Supplementary Fig. 9D ) and Th17 cell percentages ( r = − 0.6800, P < 0.05, Supplementary Fig. 9E ).