Display options
Share it on

Clin Transl Gastroenterol. 2016 Aug 25;7(8):e187. doi: 10.1038/ctg.2016.44.

Rifaximin Exerts Beneficial Effects Independent of its Ability to Alter Microbiota Composition.

Clinical and translational gastroenterology

Dae J Kang, Genta Kakiyama, Naga S Betrapally, Jeremy Herzog, Hiroshi Nittono, Phillip B Hylemon, Huiping Zhou, Ian Carroll, Jing Yang, Patrick M Gillevet, Chunhua Jiao, Hajime Takei, William M Pandak, Takashi Iida, Douglas M Heuman, Sili Fan, Oliver Fiehn, Takao Kurosawa, Masoumeh Sikaroodi, R B Sartor, Jasmohan S Bajaj

Affiliations

  1. Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, Virginia, USA.
  2. Microbiome Analysis Center, George Mason University, Manassas, Virginia, USA.
  3. Department of Medicine, University of North Carolina, Division of Gastroenterology and Hepatology, Chapel Hill, North Carolina, USA.
  4. Junshin Clinic Bile Acid Institute, Tokyo, Japan.
  5. Department of Microbiology and Immunology, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, Virginia, USA.
  6. Department of Chemistry, College of Humanities and Sciences, Nihon University, Tokyo, Japan.
  7. West Coast Metabolomics Center, University of California, Davis, California, USA.
  8. School of Pharmaceutical Science, Health Sciences University of Hokkaido, Tobetsu, Japan.

PMID: 27560928 PMCID: PMC5543406 DOI: 10.1038/ctg.2016.44

Abstract

OBJECTIVES: Rifaximin has clinical benefits in minimal hepatic encephalopathy (MHE) but the mechanism of action is unclear. The antibiotic-dependent and -independent effects of rifaximin need to be elucidated in the setting of MHE-associated microbiota. To assess the action of rifaximin on intestinal barrier, inflammatory milieu and ammonia generation independent of microbiota using rifaximin.

METHODS: Four germ-free (GF) mice groups were used (1) GF, (2) GF+rifaximin, (3) Humanized with stools from an MHE patient, and (4) Humanized+rifaximin. Mice were followed for 30 days while rifaximin was administered in chow at 100 mg/kg from days 16-30. We tested for ammonia generation (small-intestinal glutaminase, serum ammonia, and cecal glutamine/amino-acid moieties), systemic inflammation (serum IL-1β, IL-6), intestinal barrier (FITC-dextran, large-/small-intestinal expression of IL-1β, IL-6, MCP-1, e-cadherin and zonulin) along with microbiota composition (colonic and fecal multi-tagged sequencing) and function (endotoxemia, fecal bile acid deconjugation and de-hydroxylation).

RESULTS: All mice survived until day 30. In the GF setting, rifaximin decreased intestinal ammonia generation (lower serum ammonia, increased small-intestinal glutaminase, and cecal glutamine content) without changing inflammation or intestinal barrier function. Humanized microbiota increased systemic/intestinal inflammation and endotoxemia without hyperammonemia. Rifaximin therapy significantly ameliorated these inflammatory cytokines. Rifaximin also favorably impacted microbiota function (reduced endotoxin and decreased deconjugation and formation of potentially toxic secondary bile acids), but not microbial composition in humanized mice.

CONCLUSIONS: Rifaximin beneficially alters intestinal ammonia generation by regulating intestinal glutaminase expression independent of gut microbiota. MHE-associated fecal colonization results in intestinal and systemic inflammation in GF mice, which is also ameliorated with rifaximin.

References

  1. Genome Biol. 2011 Jun 24;12(6):R60 - PubMed
  2. Gastroenterology. 2011 Nov;141(5):1773-81 - PubMed
  3. PLoS One. 2013;8(4):e60042 - PubMed
  4. World J Gastroenterol. 2014 Jul 21;20(27):9106-15 - PubMed
  5. Clin Exp Gastroenterol. 2015 Dec 04;8:309-25 - PubMed
  6. Gut. 2016 May;65(5):830-9 - PubMed
  7. J Hepatol. 2014 May;60(5):940-7 - PubMed
  8. Metab Brain Dis. 2005 Dec;20(4):319-25 - PubMed
  9. J Pharmacol Exp Ther. 2007 Jul;322(1):391-8 - PubMed
  10. Gastroenterology. 2005 Apr;128(4):891-906 - PubMed
  11. J Lipid Res. 2006 Feb;47(2):241-59 - PubMed
  12. Expert Rev Gastroenterol Hepatol. 2015 May;9(5):539-42 - PubMed
  13. Pain Res Treat. 2012;2012:414697 - PubMed
  14. Hepatology. 2014 Aug;60(2):715-35 - PubMed
  15. Eur J Pharmacol. 2011 Oct 1;668(1-2):317-24 - PubMed
  16. Hepatology. 2010 Oct;52(4):1484-8 - PubMed
  17. J Hepatol. 2004 Feb;40(2):247-54 - PubMed
  18. Metab Brain Dis. 2009 Mar;24(1):147-57 - PubMed
  19. Liver Int. 2009 Jul;29(6):783-8 - PubMed
  20. Inflamm Bowel Dis. 2015 Aug;21(8):1883-93 - PubMed
  21. N Engl J Med. 2010 Mar 25;362(12):1071-81 - PubMed
  22. Gastroenterology. 2014 Feb;146(2):484-96.e4 - PubMed
  23. Chem Biodivers. 2010 May;7(5):1065-75 - PubMed
  24. J Lipid Res. 2014 May;55(5):978-90 - PubMed
  25. Gut Microbes. 2014 Jul 1;5(4):571-5 - PubMed
  26. J Hepatol. 2012 Apr;56(4):893-9 - PubMed
  27. Am J Physiol Gastrointest Liver Physiol. 2013 Feb 1;304(3):G227-34 - PubMed
  28. Am J Gastroenterol. 2014 Nov;109(11):1757-63 - PubMed
  29. J Biol Chem. 2011 Jul 8;286(27):23637-43 - PubMed
  30. N Engl J Med. 2011 Jan 6;364(1):22-32 - PubMed
  31. Am J Physiol Gastrointest Liver Physiol. 2012 Jan 1;302(1):G168-75 - PubMed
  32. Mayo Clin Proc. 2015 Aug;90(8):1116-24 - PubMed

Publication Types

Grant support