Gut fermentation syndrome: A systematic review of case reports

United European Gastroenterol J. 2021 Apr;9(3):332-342. doi: 10.1002/ueg2.12062. Epub 2021 Apr 22.


Background: The gut fermentation syndrome (GFS), also known as the endogenous alcohol fermentation syndrome or auto brewery syndrome, is a rare and underdiagnosed medical condition where consumed carbohydrates are converted to alcohol by the microbiota in the gastrointestinal or urinary tract. The symptoms of GFS can have severe impact on patients' wellbeing and can have social and legal consequences. Unfortunately, not much is reported about GFS. The aim of this systematic review was to assess the evidence for GFS, causal micro-organisms, diagnostics, and possible treatments.

Methods: A protocol was developed prior to initiation of the systematic review (PROSPERO 207182). We performed a literature search for clinical studies on 1 September 2020 using PubMed and Embase. We included all clinical studies, including case reports that described the GFS.

Results: In total, 17 case reports were included, consisting of 20 patients diagnosed with GFS. The species that caused the GFS included Klebsiella pneumoniae, Candida albicans, C. glabrata, Saccharomyces cerevisiae, C. intermedia, C. parapsilosis, and C. kefyr.

Conclusions: GFS is a rare but underdiagnosed disease in daily practice. The disease is mostly reported by Saccharomyces and Candida genera, and some cases were previously treated with antibiotics. Studies in Nonalcoholic Fatty Liver disease suggest a bacterial origin of endogenous alcohol-production, which might also be causal micro-organisms in GFS. Current treatments for GFS include antibiotics, antifungal medication, low carbohydrate diet, and probiotics. There might be a potential role of fecal microbiota transplant in the treatment of GFS.

Keywords: Candida albicans; Saccharomyces cerevisiae; auto-brewery syndrome; drunkenness disease; endogenous alochol fermentation syndrome; gut fermentation syndrome; microbiota; nonalcoholic fatty liver disease; nonalcoholic steatohepatitis.

Publication types

  • Systematic Review

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Antifungal Agents / therapeutic use
  • Bias
  • Candida / metabolism
  • Diet, Carbohydrate-Restricted
  • Dietary Carbohydrates / metabolism*
  • Ethanol / metabolism*
  • Fecal Microbiota Transplantation
  • Fermentation*
  • Gastrointestinal Microbiome / physiology*
  • Humans
  • Klebsiella pneumoniae / metabolism
  • Medical Records / statistics & numerical data
  • Non-alcoholic Fatty Liver Disease / microbiology
  • Probiotics / therapeutic use
  • Saccharomyces cerevisiae / metabolism
  • Syndrome


  • Anti-Bacterial Agents
  • Antifungal Agents
  • Dietary Carbohydrates
  • Ethanol