Researchers speculate the underlying causes of ABS are related to prolonged antibiotic use,[5] poor nutrition and/or diets high in carbohydrates,[6] and to pre-existing conditions such as diabetes and genetic variations that result in improper liver enzyme activity.[7] In the last case, decreased activity of aldehyde dehydrogenase can result in accumulation of ethanol in the gut.[7] Any of these conditions, alone or in combination, could cause ABS, and result in dysbiosis of the microbiome.[5]
Another variant, urinary auto-brewery syndrome, is when the fermentation occurs in the urinary bladder rather than the gut.[citation needed]
Claims of endogenous fermentation have been attempted as a defense against drunk driving charges, some of which have been successful,[8] but the condition is so rare and under-researched they are currently not substantiated by available studies.[7]
This disease can have profound effects on everyday life. Symptoms that usually accompany ABS include elevated blood alcohol levels as well as symptoms consistent with alcohol intoxication—such as slurred speech, stumbling, loss of motor functions, dizziness, and belching.[9] Mood changes and other neurological problems have also been reported.[1] Several cases in the United States and one inBelgium have argued endogenous fermentation as a defense against drunk driving.[7][10]
Certain clinical conditions such astype 2 diabetes mellitus andliver cirrhosis have been identified as producing higher levels of endogenous ethanol.[4] Research has also shown thatKlebsiella bacteria can similarly ferment carbohydrates to alcohol in the gut, which can acceleratenon-alcoholic fatty liver disease.[11] Gut fermentation can occur in patients withshort bowel syndrome after surgical resection because of fermentation of malabsorbed carbohydrates.[1]
Kaji et al. noticed a correlation between this syndrome and previous abdominal surgeries and disturbances, such as a dilation of theduodenum. Stagnation of the contents ensues, which favors proliferation of the causative organisms.[9]
Fermentation is a biochemical process during which yeast and certain bacteria convert sugars to ethanol, carbon dioxide, as well as other metabolic byproducts.[13][14] The fermentation pathway involves pyruvate formed from yeast in the EMP pathway, while some bacteria obtain pyruvate through the ED pathway.[13]Pyruvate is then decarboxylated toacetaldehyde in a reaction involving the enzymepyruvate decarboxylase.[13] Reduction of acetaldehyde to ethanol producesNAD+, which is catalyzed byalcohol dehydrogenase (ADH).[13] ADH rids the body of alcohol through a process calledfirst pass metabolism.[7] However, if the rate of ethanol breakdown is less than the rate of production, intoxication ensues.[citation needed]
Alcohol levels within the body are usually detected throughblood orbreath. The best way to identify endogenous ethanol in the bloodstream is through gas chromatography. Ingas chromatography the breath or blood is heated so that the different components of the vapor or blood separate. The volatile compounds then pass through a chromatograph that isolates ethanol from the other volatiles so that it can be quantified.[15]
More convenient methods include serum measurements and breathalyzers, especially during an acute attack at home.[11] Different countries have different baselines forblood alcohol levels when identifying intoxication through breathalyzers. In the United States it is 0.08 g/dL.[citation needed]
In diagnosing ABS through serum measurement methods, patients must fast in order that baseline blood alcohol and blood glucose levels can be established. They are then administered a dose of IG glucose to see if there is an increase in blood alcohol as well as blood sugar.[16] Blood glucose level can be measured with enzyme-amperometric biosensors, as well as withurine test strips.[17] Many of these tests are performed in combination to rule out lab mistakes and alcohol ingestion so that the syndrome is not misdiagnosed.[11]
First, patients diagnosed with ABS are treated for the immediate symptoms ofalcohol intoxication.[1] Next, patients can take medications if they test positive for the types of fungi or bacteria that cause gutfermentation. For example,antifungals such asfluconazole ormicafungin can be prescribed by a physician.[9][6][18] Often,probiotics are given concurrently to ensure that the proper bacteria recolonize the gut, and to prevent recolonization by the microorganisms that caused the syndrome.[18] Patients also typically undergo a diet therapy where they are placed on a high protein, low carbohydrate diet to avoid the symptoms of ABS.[1] The treatments listed above can be used individually or in combination to reduce the effects of the syndrome.[1]
In 2019, a 25-year-old man presented with symptoms consistent with alcohol intoxication, including dizziness, slurred speech and nausea. He had no prior alcoholic drinks but had a blood alcohol level of 0.3 g/dL. The patient was given 100 mg of the antifungalfluconazole daily for 3 weeks, and his symptoms were resolved.[9]
In 2004, a 44-year-old male was treated with the antibioticsclavulanic acid andamoxicillin for an unrelated condition. Eight days after being discharged, he returned to the emergency room with abdominal pain and belching and was in a state of confusion. An esophagogastroscopy showed the presence ofS. cerevisiae andC. albicans in his gastric fluid, causing endogenous ethanol production.[19]
Reported in 2001, a 13-year-old girl withshort gut syndrome suddenly developed symptoms of intoxication after eating "excess carbohydrates and juices". She had no access to alcohol any time the symptoms were present. Her small intestine was colonized by two organisms:C. glabrata andS. cerevisiae. She was treated with fluconazole and her symptoms resolved.[20]
A case of urinary fermentation of carbohydrates by endogenous microorganisms leading to urinary ethanol has been reported. 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.[21][22]
^Kaji H, Asanuma Y, Yahara O, Shibue H, Hisamura M, Saito N, et al. (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.PMID6520589.
^Geertinger P, Bodenhoff J, Helweg-Larsen K, Lund A (September 1982). "Endogenous alcohol production by intestinal fermentation in sudden infant death".Zeitschrift für Rechtsmedizin. Journal of Legal Medicine.89 (3):167–72.doi:10.1007/BF01873798.PMID6760604.S2CID29917601.
^abcdFath BD, Jørgensen SE (23 August 2018).Encyclopedia of ecology. Fath, Brian D. (Second ed.). Amsterdam, Netherlands.ISBN978-0-444-64130-4.OCLC1054599976.{{cite book}}: CS1 maint: location missing publisher (link)
^Jones AW, Mårdh G, Anggård E (1983). "Determination of endogenous ethanol in blood and breath by gas chromatography-mass spectrometry".Pharmacology, Biochemistry, and Behavior.18 (Suppl 1):267–72.doi:10.1016/0091-3057(83)90184-3.PMID6634839.S2CID36120089.
^Simic M, Ajdukovic N, Veselinovic I, Mitrovic M, Djurendic-Brenesel M (March 2012). "Endogenous ethanol production in patients with diabetes mellitus as a medicolegal problem".Forensic Science International.216 (1–3):97–100.doi:10.1016/j.forsciint.2011.09.003.PMID21945304.
^Spinucci G, Guidetti M, Lanzoni E, Pironi L (July 2006). "Endogenous ethanol production in a patient with chronic intestinal pseudo-obstruction and small intestinal bacterial overgrowth".European Journal of Gastroenterology & Hepatology.18 (7):799–802.doi:10.1097/01.meg.0000223906.55245.61.PMID16772842.
^Dashan A, Donovan K (August 2001). "Auto-brewery syndrome in a child with short gut syndrome: case report and review of the literature".J Pediatr Gastroenterol Nutr.33 (2):214–215.doi:10.1097/00005176-200108000-00024.PMID11568528.
^Kruckenberg KM, DiMartini AF, Rymer JA, Pasculle AW, Tamama K (February 2020). "Urinary Auto-brewery Syndrome: A Case Report".Annals of Internal Medicine.172 (10):702–704.doi:10.7326/L19-0661.PMID32092761.S2CID211475605.
