Association Between Gut Microbiota Dysbiosis and Bilirubin Metabolism Dysregulation in Children with Heart Failure.

Patients with heart failure (HF) demonstrate dysregulation in bilirubin metabolism. The specific characteristics of intestinal bilirubin metabolism in HF remain unclear. This study involved metagenomic sequencing and metabolomic profiling of fecal samples from 45 children with HF and 32 healthy children. Serum total bilirubin levels were 11.3umol/L, 19.4umol/L and 5.0umol/L in HF New York Heart Association (NYHA) I-II, NYHA III-IV and control group (p < 0.001 ), and the median gut microbiome health index (GMHI) were - 0.78, -1.53 and 0.09 in each (p < 0.001). The abundance of 2 bacteria species containing bilirubin reductase, Ruminococcus gnavus (p = 0.028) and Clostridium sp.M62/1 (p = 0.002) significantly decreased in NYHA III-IV group. The gut downstream bilirubin products, urobilinogen and stercobilin were decreased in the HF group; while the upstream bilirubin products, unconjugated and conjugated bilirubin increased. Dysbiosis of the gut microbiome and the decrease of bilirubin reductase containing bacteria in pediatric HF patients related to a reduction in gut bilirubin metabolism.