FIG 5.

C. difficile infection in mice increases cecal and serum p-cresol levels and reduces serum DBH enzyme activity. (A) p-cresol producing ability of C. difficile UK1: C. difficile UK1 converted the substrate p-HPA to p-cresol in 24 h (n = 3). (B) Cecal p-cresol concentration: C. difficile infection significantly increased cecal p-cresol levels in mice (n = 4). (C) Serum p-cresol concentration: C. difficile infection significantly increased serum p-cresol levels (n = 4). (D) Relative serum DBH activity: C. difficile infection significantly decreased serum DBH activity as indicated by a reduced peak area representing the tyramine octopamine transformation per hour (n = 4). All data in (A–D) are presented as the mean, and error bars indicate SEM. One-way ANOVA with adjusted P-value was used to test for statistical significance **P < 0.01, *P < 0.05.