Bilirubin {90000214}

Shared Reference Notes

• [1.1] 
  - Bilirubin > versatile functions > cell signaling (behaving almost like a “real” hormonal substance), modulation of metabolism, to immune regulation >affecting biological activities with apparent clinical and even therapeutic consequences. - Chronic mild unconjugated hyperbilirubinemia, a typical sign of #Gilbert’s syndrome > lower incidence of diseases of civilisation (cardiovascular diseases, arterial hypertension, diabetes, obesity, metabolic syndrome, certain cancers, autoimmune, and neurodegenerative diseases).
• [1.2] 
  - Nine species in the genus #Bifidobacterium were predicted to be bilirubin reducers.
• - Gut Microbiota bilirubin reductase > a single enzyme performs the reduction of bilirubin to urobilinogen > is a core feature of a healthy #Adult human microbiome - Bilirubin reduction is a strain-specific feature.
• [#Urobilin ] - The majority of bilR genes were identified in #Firmicutes species, including common human gut species such as #Roseburia intestinalis, #Roseburia inulinivorans and #Faecalibacterium prausnitzii.
• - BilR is predominantly encoded by #Firmicutes species > bilirubin-reducing capacity of the human gut microbiota is largely influenced by the abundance of #Firmicutes-associated bilirubin reducers.
• [#Inflamatory bowel disease] - The prevalence of bilirubin reductase is decreased in patients with IBD > disruption of bilirubin metabolism combined with increase in unconjugated primary bile acids in patients with IBD could contribute to the increased incidence of calcium bilirubinate gallstones that has been observed in these patients.
• [#Infants] - neonates are often missing Bilirubin reductase > #Neonatal jaundice is exacerbated by the absence or low abundance of bilirubin-reducing microorganisms in the gut.
• [#Obesity] - bilirubin reduction by gut microorganisms is important to overall health because serum bilirubin concentrations have been observed to be correlated inversely with adiposity and cardiovascular disease

References Notes