Fig. 8.

Fecalase-mediated metabolism. (a) Antibiotic-induced depletion of β-glucuronidase activity translates to altered deconjugation of 5-HT-GLU. Antibiotics downregulate β-glucuronidase enzymatic activity in fecalase (vs vehicle; p < 0.0001). The conversion of 5-HT-GLU to the parent compound, 5-HT, is significantly decreased in fecalase prepared from antibiotic-treated vs vehicle-treated rats (One-way ANOVA, p < 0.05). Probiotics do not alter the β-glucuronidase activity or the rate of deconjugation of 5-HT-GLU. Data are expressed as mean + SEM *p < 0.05 ***p < 0.001 (n =  9–10 for enzymatic readout; n = 7 for 5-HT-HPLC data). (b)Ex vivo incubation of OLZ and RISP with fecalase. The amount of remaining OLZ and RISP is not altered after 48 h incubation with fecalase from antibiotic- and probiotic-treated rats compared to vehicle-treated rats. Data are expressed as mean + SEM, relative to the drug-only incubation controls (n = 6–7/group).