*3.2. Impact of FMT on Gut Microbial Composition at 4 Weeks after the Initiation of Intervention*

There were no significant baseline clinical differences between FMT and placebo groups [10]. We focused on the fecal sample collected at baseline vs. 4 weeks after the initiation of FMT as this was the time point at which the changes in bile acid levels were most significant [10]. No significant differences in the relative abundance of bacteria were noted at the phyla level (Figures 1 and 2A). At the genus level, FMT-enriched *Paraprevotella* and *Longibaculum* (Figure 2B,C, *p* < 0.05) compared to placebo. On the species level, FMT tended to increase the relative abundance of *Clostridium hylemonae*, a bacterial species known to convert primary to secondary bile acids (Figure 2D) [17,18]. Finally, FMT increased *Desulfovibrio fairfieldensis* compared with placebo (Figure 2E, *p* < 0.05). Of note, *Paraprevotella*, *Longibaculum, Clostridium hylemonae,* and *Desulfovibrio fairfieldensis* did not differ between groups at the baseline.
