Bile acid malabsorption (BAM) or bile acid diarrhea (BAD) complicates more than 30% of Crohn's disease (CD), yet no non-invasive biomarker reliably identifies patients who will benefit from fecal microbiota transplantation (FMT). We investigated whether serum 7α-hydroxy-4-cholesten-3-one (C4), a hepatic bile-acid synthesis precursor, can predict BAM and FMT response in inflammatory bowel disease (IBD). We included 106 pairs of IBD patients treated with FMT from two longitudinal cohorts of prospective trials and 24 matched healthy individuals to identify a multi-omics analysis of microbiota-metabolism and evaluate real-world effectiveness of FMT. Fecal and serum samples before and after FMT along with medical information were collected and detected through 16S rRNA amplicon sequencing and untargeted liquid chromatography mass spectrometry. Mice models were used to preliminarily verify the exacerbation of colitis through administration of primary BAs and treated by FMT. Patients in BAM group tended to achieve sustained higher and stable clinical response (66.67% vs. 49.41%) and remission (52.38% vs. 40.00%) than non-BAM group at 3 months after FMT, along with a significantly decrease of C4 (P < 0.001), improvement of obvious abdominal pain and diarrhea, which was especially obvious in CD patients with ileal resection and ileal /ileocolonic type. Random forest classifiers predicted BAM in IBD patients with 18 or top 4 differential OTUs, showing an area under the curve of 0.92 and 0.83, respectively. Furthermore, results from primary bile acid-induced colitis mice models reinforced these findings. Serum C4 and a minimal gut microbiota may identify IBD patients with BAM who are most likely to achieve durable remission after FMT. These translatable biomarkers can guide precision use of microbiota-directed therapy. ClinicalTrials.gov: NCT01790061 and NCT01793831.
Lu et al. (Mon,) studied this question.