UCLA

BACKGROUND: Pain, a common debilitating symptom among kidney transplant recipients (KTRs), is among the most common and undertreated symptoms after kidney transplantation. AIMS: Characterize associations between gut microbiome features and pain interference before and after kidney transplantation. DESIGN: Longitudinal, repeated measures study, collecting fecal specimens and pain interference data pretransplant and 3 months posttransplant. SETTING: Participants were recruited at the kidney transplant clinic at the University of Illinois Hospital & Health Sciences System. PARTICIPANTS/SUBJECTS: 19 living donor kidney transplant recipients. METHODS: We assessed fecal microbial community structure with shotgun metagenomic sequencing; we used pain interference scores derived from the Patient-Reported Outcomes Measurement Information System-57. RESULTS: We measured a reduction in the Shannon diversity index in both groups after transplantation but observed no significant differences between groups at either time point. We did observe significant differences in fecal microbial Bray-Curtis similarity index among those reporting pain interference pre- transplant versus no pain interference at 3-months posttransplant (R = .306, p = .022), and between pain interference groups at posttransplant (R = .249, p = .041). Pairwise models showed significant differences between groups posttransplant in relative abundances of several taxa, including a 5-fold reduction.ßin Akkermansia among those with pain interference and a higher relative abundance of taxa associated with chronic inflammation in those with pain interference posttransplant. Functional gene analysis identified two features that were significantly enriched in those with pain interference, including a peptide transport system gene. CONCLUSIONS: Gut microbiota community structure differs between groups with and without pain interference at 3 months after kidney transplantation. Several taxa involved in intestinal barrier integrity and chronic inflammation were associated with posttransplant pain.