Let’s start with a fundamental question – do you need to drink to get drunk? The surprising answer is no. Our body can make ethanol, thus making us walking beer factories. This phenomenon of endogenous ethanol production is called Auto-Brewery.
Auto-brewery is fascinating and very few doctors would think about this when encountering a patient who they think is drunk. Imagine the plight of a teetotaler trying to persuade the doctor that he is drunk,but not because he drank 🙂
How does this happen?
While very little is known about the auto-brewery syndrome, the following are considered necessary for its development
- High carbohydrate intake
- Prolonged stay of the food in the gut due to
- Gut dysmotility
- Surgical alteration , creating a ‘vat’
- Colonization by organizations which cause fermentation of carbohydrates
- Candida spp
- Sacharomyces cerevisiae – both due to prolonged antibiotic therapy
- Chronic -The above 3 conditions tend to coexist in one of the commonest patient groups- obese diabetics. They may have autonomic dysfunction leading to intestinal dysmotility. Many of these patients also have Non Alcoholic Fatty liver disease -NAFLD. If a subgroup of these patients have endogenous ethanol production, their liver disease may well be ‘alcoholic’. There is very little data to support or refute this claim. In a study of blood alcohol levels, the diabetic patients were found to have 5 times as much BAC (blood alcohol concentration) as non diabetics (1). While the authors conclude that this is not enough to be picked up in routine breath analyser tests, the implications of such long standing increased BAC on liver are intriguing, to say the least.
- Acute- Acute alcohol intoxication has been reported in a patient who hasn’t touched alcohol in 30 years (2) ! Some cases of metabolic encephalopathy in which no apparent cause is forthcoming may be due to ethanol intoxication from endogenous production. However we must be careful to rule out the usual suspects and should only entertain this diagnosis if BAC is high in a teetotaler or abstinent patient.
- Medico legal
- It is unlikely that endogenous ethanol production is severe enough to cause positive breath analyser test in cases of drunken drive (3). This line of argument also doesn’t hold much water in the courts if the published medico legal literature is anything to go by.
To conclude auto-brewery is an interesting medical oddity. As the mechanistic insights are still not very clear, we must be cautious in making this diagnosis. Whether auto-brewery is the culprit in a subset of diabetic patients with neuropathy with NAFLD is not known.
Hafez EM, Hamad MA, Fouad M, Abdel-Lateff A. Auto-brewery syndrome: Ethanol pseudo-toxicity in diabetic and hepatic patients. Hum Exp Toxicol. 2017 May;36(5):445–50.
Welch BT, Coelho Prabhu N, Walkoff L, Trenkner SW. Auto-brewery Syndrome in the Setting of Long-standing Crohn’s Disease: A Case Report and Review of the Literature. J Crohns Colitis. 2016 Dec;10(12):1448–50.
Logan BK, Jones AW. Endogenous ethanol “auto-brewery syndrome” as a drunk-driving defence challenge. Med Sci Law. 2000 Jul;40(3):206–15.