Fig. 5

FMT from healthy volunteers ameliorated the neurotransmitter perturbation by the Trp-Kyn pathway by affecting the rate-limiting enzymes in both the brain and colon. A Levels of Trp-Kyn metabolic pathway-derived neurotransmitters in the mice PFCs. B Levels of Trp-Kyn metabolic pathway-derived neurotransmitters in the mice colons. C Protein expression of the rate-limiting enzymes of the Trp-Kyn Pathway in the mice PFCs and colons. D Statistical plots of the mice PFCs. E Statistical plots of the mice colons. Data were displayed as mean ± SEM. Significant differences were determined via one-way ANOVA and Tukey’s multiple comparison procedure. ^*p < 0.05, ^**p < 0.01 vs. the CTR group; ^#p < 0.05, ^##p < 0.01, ^###p < 0.001 vs. the CRS group; ^&p < 0.05, ^&&p < 0.01, ^&&&p < 0.001 vs. the CRS + HC-tr group