title: The impact of intestinal microflora on serum bilirubin levels.
abstract: OBJECTIVE
  Intestinal microflora plays an important role in the pathogenesis of neonatal jaundice by inhibiting enterosystemic circulation of bilirubin. The present study aimed to investigate the influence of intestinal microflora on serum bilirubin levels in hyperbilirubinemic Gunn rats.
  
  
  METHODS
  After a baseline phase Gunn rats received oral antibiotics (either clindamycin/neomycine or co-trimethoxazole for four days, phase II). Intestinal colonization was carried out either with a bilirubin-reducing strain of C. perfringens or C. pasteurianum incapable of reducing bilirubin (phase III). Serum bilirubin and fecal bile pigments were determined at the end of each phase.
  
  
  RESULTS
  Oral administration of clindamycin/neomycine resulted in the disappearance of fecal urobilinoids. Simultaneously, serum bilirubin increased dramatically (186+/-31 vs. 289+/-35 micromol/l, P=0.004). Intestinal colonization with C. perfringens led to reappearance of fecal urobilinoid production accompanied with a partial decrease of serum bilirubin (289+/-35 vs. 239+/-17 micromol/l, P=0.013), whereas the effect of C. pasteurianum on bile pigment metabolism was negligible. Co-trimethoxazole therapy had no effect on serum and intestinal metabolism of bilirubin.
  
  
  CONCLUSIONS
  Intestinal microflora greatly affects intravascular metabolism of bilirubin. Prolonged use of certain antibiotics in man may lead to an increase in serum bilirubin levels, while the enhancement of intestinal catabolism may have an opposite effect.
authors.affiliation: Institute of Clinical Biochemistry and Laboratory Diagnostics, 1st Medical Faculty, Charles University of Prague, U Nemocnice 2, Praha 2, 128-08 Prague, Czech Republic. vitek@cesnet.cz
authors.forename: Libor
authors.initials: L
authors.lastname: Vítek
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Zelenka
authors.forename: Marie
authors.initials: M
authors.lastname: Zadinová
authors.forename: Jirí
authors.initials: J
authors.lastname: Malina
mesh_terms: D000818:Animals; D001663:Bilirubin / Q000032:analysis / Q000097:blood*; D003016:Clostridium perfringens / Q000502:physiology*; D005243:Feces / Q000737:chemistry; D014453:Glucuronosyltransferase / Q000172:deficiency; D006801:Humans; D007231:Infant, Newborn; D007422:Intestines / Q000382:microbiology*; D007567:Jaundice, Neonatal / Q000382:microbiology / Q000503:physiopathology; D008297:Male; D051381:Rats; D011911:Rats, Gunn
chemical_list: D014453:Glucuronosyltransferase; D001663:Bilirubin