|Other names||Gut fermentation syndrome|
Auto-brewery syndrome is a rare medical condition in which intoxicating quantities of ethanol are produced through endogenous fermentation within the digestive system. Saccharomyces cerevisiae, a type of yeast best known for its uses in producing bread and alcoholic beverages, has been identified as a pathogen for this condition. Recent research has also shown that Klebsiella bacteria can similarly ferment carbohydrates to alcohol in the gut, which can accelerate non-alcoholic fatty liver disease.
Claims of endogenous fermentation of this type have been used as a defense against drunk driving charges. But since some judges reject this defense and have issued prison terms, doctors caution that "these patients have to be very careful about driving a motor vehicle" since in those jurisdictions, these patients would be arrested for being over the legally defined blood alcohol content limit (which varies vastly by state and local jurisdiction) even if the patients were not actually impaired at the time of arrest.
One case went undetected for 20 years.
A variant occurs in persons with liver abnormalities that prevent them from excreting or breaking down alcohol normally. Patients with this condition can develop symptoms of auto-brewery syndrome even when the gut yeast produces a quantity of alcohol that is too small to intoxicate a healthy individual.
Another variant, urinary auto-brewery syndrome, is when the fermentation occurs in the urinary bladder rather than the gut. This single reported case is associated with diabetes due to the presence of sugar in the urine for the yeast to ferment. The person did not develop symptoms of intoxication, but did test positive in the urine for alcohol. Fermentation may continue after the urine is expressed, resulting in it developing an odor resembling wine. 
This disease can have profound effects on everyday life. As well as the recurring side effects of excessive belching, dizziness, dry mouth, hangovers, disorientation, irritable bowel syndrome, and chronic fatigue syndrome, it can lead to other health problems such as depression, anxiety and poor productivity in employment. The random state of intoxication can lead to personal difficulties, and the relative obscurity of the condition can also make it hard to seek treatment. [unreliable medical source?]
A case of urinary fermentation of carbohydrates by endogenous microorganisms leading to urinary ethanol has been reported.
Alcohol can be detected by testing blood or the breath. This may have to be repeated at multiple times of the day to account for naturally occurring fluctuations.
There are different treatments that can be used by themselves or in combination. Dietary carbohydrate control, antifungal or antibiotic therapy, general antibiotic avoidance, and probiotics have all shown positive effects as treatments.
- Doucleff, Michaeleen (September 17, 2013). "Auto-Brewery Syndrome: Apparently, You Can Make Beer In Your Gut". The Salt. NPR.
- "A one-woman brewery: Patient's bladder causes her to urinate alcohol".
- Kaji, H.; Asanuma, Y.; Yahara, O.; Shibue, H.; Hisamura, M.; Saito, N.; Kawakami, Y.; Murao, M. (1984). "Intragastrointestinal Alcohol Fermentation Syndrome: Report of Two Cases and Review of the Literature". Journal of the Forensic Science Society. 24 (5): 461–71. doi:10.1016/S0015-7368(84)72325-5. PMID 6520589.
- Yuan, J.; et al. (2019-09-19). "Fatty Liver Disease Caused by High-Alcohol-Producing Klebsiella pneumoniae". Cell Metabolism. 30 (4): 675–688.e7. doi:10.1016/j.cmet.2019.08.018. PMID 31543403.
- Painter, Kelly; Cordell, Barbara; Sticco, Kristin L. (2019). "Auto-brewery Syndrome (Gut Fermentation)". StatPearls. PMID 30020718.
- Logan, BK; Jones, AW (July 2000). "Endogenous ethanol 'auto-brewery syndrome' as a drunk-driving defence challenge". Medicine, Science and the Law. 40 (3): 206–15. doi:10.1177/002580240004000304. PMID 10976182.
- "New York drink driver says her body is a brewery". BBC News. 2015-12-31. Retrieved 3 January 2016.
- Castrodale, Jelisa (April 26, 2019). "Man Imprisoned for Drunk Driving Says His Body Actually Turns Food into Alcohol: Surprisingly, there's legitimate science to back it up". Vice.
- "Auto-brewery syndrome occurs when a disturbance to the gut microbiome results in the fermentation of sugars". Quirks & Quarks. October 25, 2019. CBC Radio One.
- "Auto-brewery syndrome: Teetotal Teesville man can't stay sober as everything he eats turns to alcohol". Teesside Gazette. Teesside, England. October 7, 2013. Retrieved April 22, 2014.
- Geertinger, P.; Bodenhoff, J.; Helweg-Larsen, K.; Lund, A. (1982-09-01). "Endogenous alcohol production by intestinal fermentation in sudden infant death". Zeitschrift für Rechtsmedizin. 89 (3): 167–172. doi:10.1007/BF01873798. PMID 6760604.
- Thomson, Helen (March 5, 2015). "The Man Who Gets Drunk on Chips". BBC News.
- "Auto-Brewery Syndrome: Woman Failed Urine Tests As Her Bladder Was Brewing Alcohol".
- Chester, Nick (February 11, 2014). "The Man Who Is Drunk All the Time Because His Body Produces Its Own Alcohol". VICE. Retrieved 19 November 2014.
- Boyter, Scott (April 10, 2017). "Auto Brewery Syndrome – What It Is, and How to Deal With It". GundryMD.com. Retrieved 13 April 2017.
- Kruckenberg, Katherine M.; DiMartini, Andrea F.; Rymer, Jacqueline A.; Pasculle, A. William; Tamama, Kenichi (25 February 2020). "Urinary Auto-brewery Syndrome: A Case Report". Annals of Internal Medicine. doi:10.7326/L19-0661.
- Painter, Kelly; Cordell, Barbara; Sticco, Kristin L. (October 9, 2019). "Auto-brewery Syndrome (Gut Fermentation)". NCBI - National Center for Biotechnology Information. Retrieved 5 November 2019.