Drunk without drinking: a case of autobrewery syndrome (2024)

ABSTRACT

Information about autobrewery syndrome is limited in the medical literature. This rare syndrome occurs when yeast overgrowth leads to ethanol fermentation in the intestines. We present a patient with symptoms of alcohol intoxication with objective laboratory evidence of elevated blood ethanol levels without a history of alcohol consumption. We reviewed the literature and discussed current diagnostic and therapeutic options.

INTRODUCTION

There is limited information in the medical literature about autobrewery syndrome, also known as enteric fermentation syndrome.¹This rare syndrome occurs due to yeast overgrowth in the intestines, leading to the fermentation of ethanol, causing symptoms similar to alcohol poisoning without consuming alcohol.¹We present a patient with autobrewery syndrome and review the available literature, including published case reports on the syndrome.

CASE REPORT

A 25-year-old white man, with no medical history or previous surgeries, presented with the chief complaint of being intoxicated without drinking. Two months ago, the patient noticed that he felt very drunk after drinking his usual one or two 12-ounce beers in the evening. This progressed to a drunken feeling, even when completely abstaining from alcohol. He continued to feel this way 1-2 times a week until his wife decided to take him to the emergency room during one of his "seizures." His wife described his symptoms as slurred speech, fatigue, stumbling, dizziness and nausea. He would eventually "pass out" and wake up in the morning with no further symptoms. His symptoms were somewhat acute and often occurred in the evening, but without any recognizable trigger. Upon further investigation, he had recently started a ketosis diet to lose weight. He was not taking any over-the-counter or prescription medications. His physical examination was unremarkable and vital signs were normal. Although symptomatic on a previous emergency department visit, he underwent a complete workup, including a urinalysis, a basic metabolic panel, liver function tests, a complete blood count, and thyroid studies, all of which were unremarkable. However, he had an elevated lactic acid level of 20 mg/dl and a blood alcohol concentration of 0.3 g/dl (also elevated on a subsequent emergency department visit) in the absence of alcohol consumption. His symptoms improved and he was sent home without further treatment.

At the outpatient clinic he saw a gastroenterologist and an endocrinologist who performed a celiac disease test, a basic stool test with culture, a thyroid test and a hypoglycemia test, all of which turned up nothing. His wife chose to purchase a breathalyzer and discovered that in the absence of alcohol consumption, and although asymptomatic, he would achieve a score of 0.04% to 0.07%. His wife served as a control and scored 0% on these occasions. When the patient had symptoms, he tested with an elevated alcohol concentration, often around 0.2%. Based on the above investigation, other etiologies were excluded and a working diagnosis of autobrewery syndrome was made. The patient was then placed on empirical trial with oral fluconazole 100 mg daily for three weeks to treat this suspected syndrome, in addition to continuing her normal diet. Upon completion of his therapy, the patient reported complete resolution of his symptoms, with no further episodes at follow-up four weeks later.

DISCUSSION

There is limited data on autobrewery syndrome, also known as enteric fermentation syndrome.¹Xiaodi et al. refer to approx. 58 cases have been described, many of which come from Japan.¹There are no clearly identifiable risk factors; However, Kaji et al noted an association with previous abdominal surgery and structural or functional disorders, such as a dilated duodenum, which can cause stagnant contents, potentially providing a favorable site for abnormal spread of the causative organism.²In one case, a possible risk factor for antibiotic use was reported, as well as a reported co-infectionHelicobacter pylori.^3,4Probiotics can also alter normal intestinal flora, and although its role in this syndrome is unclear, it has been reported to predispose toSaccharomycesmoldy insects.^5,6There was no ethanol fermentation in these patients; however, it is possible that probiotics could predispose patients to themSaccharomycesscatter. Many case reports were able to identify a causative pathogen, often by gastric aspirates, duodenal fluid, or fecal cultures.¹Kaji et al. determined that the most common organisms involved in the "autobrewery syndrome" areCandida spp. InSachharomyces.²

Candidaspecies, as well as other fungi, are part of the normal intestinal flora.⁷Bivin and Heinen examined five infant formulas containing four common types of yeast, includingCandidaInSachharomyces. Their research showed that all species produced ethanol in vitro, with the highest ethanolSachharomycesorganisms.⁷Additionally, a study conducted in the United Arab Emirates looked at 1,563 random subjects of different nationalities, ages and genders. They found that in this population the average endogenous ethanol level was 0.113 mg/dl.⁸Although this was considered clinically unimportant, it suggested that at some basal level these individuals may be fungal colonizers producing small amounts of ethanol.⁸Currently, gas chromatography is the gold standard for identifying the presence of alcohol in the bloodstream, but serum measurements can serve as a reliable and more convenient measure of blood levels during an acute episode.²Breathalyzers have also been shown to be reliable in estimating blood alcohol levels.⁹In addition, the above-mentioned patient also had increased lactic acid levels, which may be related to ethanol metabolism.¹⁰

Although we cannot completely rule out abuse or occult binge drinking in this patient, we believe that the therapeutic study demonstrating relief of symptoms after fluconazole provides the strongest supporting evidence for the correct diagnosis of this syndrome. Several diagnostic modalities have been proposed. Kaji et al. reported 2 patients with suspected autobrewery syndrome in whom gastric juices, duodenal fluids, and fecal samples were cultured on Sabouroud glucose agar and foundCandida albicansInCandida krusei.²The main benefit of culture is identifying the sensitivity of the organism to fungicides. The topical antifungal agent is not known, especiallySachharomyces.¹¹Some of these cases also resolved with surgical interventions, such as gastrectomy.²Another suspected case responded without recurrence to a course of fluconazole.³The dosage and duration of treatment in the above case studies vary; For example, Cordell and McCarthy reported resolution after a three-week course of oral fluconazole 100 mg daily, followed by a 45-day course of nystatin taken four times daily.⁴

An increased alcohol concentration in the blood associated with symptoms consistent with intoxication and no alcohol intake gives rise to the suspicion of autobrewery syndrome. It is necessary to rule out covert alcohol use and laboratory errors, and therefore a good social history and repeated laboratory measurements during acute episodes are warranted. Approved breathalyzers used by this patient may also assist in home detection during acute attacks and diagnosis. Interestingly, this difficult-to-diagnose syndrome has been used as a defense mechanism against drunk driving.¹²Fungal stool cultures can provide a useful diagnostic test for growth and tenderness, especially if the patient does not respond to initial therapy.

No clear risk factors were identified in this patient. Previous cases suggested a high-carb diet, while this patient had recently switched to a ketosis diet.^2,3One speculation might be that sugar substitutes were used that could provide a means of fermentation. This, in combination with an undiagnosed alcohol hydrogenase deficiency, could be predisposing in this patient. Ultimately, this patient's symptoms resolved completely after a three-week course of oral fluconazole 100 mg per day and a normal diet. Further studies and case reports are needed to fully characterize this interesting syndrome.

INFORMATION

Author Contributions: All authors contributed equally to the preparation of this manuscript. BJ Akhavan guarantees the article.

Financial Disclosure: Nothing to report.

Informed consent was obtained for this case report.

REFERENCES