Skip Navigation LinksSkip Navigation Links
Centers for Disease Control and Prevention
Safer Healthier People
Blue White
Blue White
bottom curve
CDC Home Search Health Topics A-Z spacer spacer
Blue curve MMWR spacer

Unexplained Severe Illness Possibly Associated with Consumption of Kombucha Tea -- Iowa, 1995

Kombucha tea is a popular health beverage made by incubating the Kombucha mushroom in sweet black tea. Although advocates of Kombucha tea have attributed many therapeutic effects to the drink (1-3), its beneficial and/or adverse effects have not been determined scientifically. During April 1995, cases of unexplained severe illness (including one death) occurred in two persons in a rural town in northwestern Iowa who had been drinking Kombucha tea daily for approximately 2 months. Based on the findings of a preliminary investigation by the Iowa Department of Public Health (IDPH), on April 10 IDPH issued a news release recommending that persons refrain from drinking Kombucha tea until the role of the tea in the two cases of illness had been evaluated fully. This report summarizes the investigation of these cases by the IDPH, CDC, and the Food and Drug Administration (FDA). Patient 1

On April 1, a 59-year-old woman was found unconscious in her home by a neighbor and was transported to a local hospital. On arrival in the emergency department, respiratory therapy was initiated with oxygen. Her family members reported that, 1 hour earlier, she appeared fatigued but had no specific medical complaints. Analysis of arterial blood samples indicated severe metabolic acidosis; her pH level was 6.9 (normal: 7.37-7.43); pO2, 474.9 mm Hg (normal: 75-80 mm Hg); and pCO2, 39.2 mm Hg (normal: 35-45 mm Hg). She also had elevated levels of lactic acid (9.85 mM {normal: 0.67 mM-2.47 mM}) and a base excess of -19.5 (normal: -2- +2). Her daughter and her primary physician reported that she took medications for hypertension, anemia, and mild renal insufficiency. Soon after admission, symptoms of disseminated intravascular coagulopathy began; she suffered cardiac arrest and was resuscitated, but her condition continued to deteriorate. She died on April 3.

The cause of the woman's acute metabolic disorder was not established. An autopsy detected evidence of peritonitis with fecal contamination of the peritoneal cavity, although the location of perforation could not be determined. Neither the woman's clinical history nor autopsy findings supported a cardiogenic cause. Toxicologic analyses for a series of prescription and nonprescription drugs and carbon monoxide and cyanide poisoning were negative. Her daughter reported that, during the previous 2 months, the patient had drank approximately 4 oz of Kombucha tea daily. Patient 2

On April 10, a previously healthy 48-year-old woman had onset of shortness of breath and was transported by ambulance to the same hospital as patient 1. On admission, she was in respiratory distress. Chest radiographs revealed extensive acute pulmonary edema. Analysis of arterial blood samples indicated severe metabolic acidosis with uncompensated respiratory acidosis; her pH level was 6.7; pO2, 86 mm Hg; and pCO2, 67 mm Hg. She had elevated levels of lactic acid (12.4 mM) and a base excess of -28. The woman suffered cardiac arrest but was resuscitated and stabilized. She improved and was discharged on April 13.

Toxicologic analyses for a series of prescription and nonprescription drugs were negative, and there was no evidence of a septic or cardiogenic cause. The patient reported drinking Kombucha tea during the previous 2 months and had obtained her original mushroom from the same person as patient 1. On April 10, immediately before the onset of illness, she had increased the amount of tea she consumed from 4 oz daily to 12 oz, and she had increased the period of incubation for that batch of tea from 7 days to 14 days. Investigation

The mushrooms used by both women were derived from the same parent mushroom. At least 115 additional persons in the town had used or were using mushrooms from the same source as for the two ill women, but no other cases of unexplained acute illness were reported among these persons. A review of hospital emergency department records for March 1-April 10 did not detect other cases of unexplained lactic acidosis or other likely cases of tea-associated acute illness.

Samples of the mushrooms and samples of the tea consumed by both case-patients were sent to FDA for analysis. Microbiologic analysis of the tea and mushrooms identified several species of yeast and bacteria, including Saccharomyces cerevisiae and Candida valida. No known human pathogens or toxin-producing organisms were identified. The alcohol content of the tea ranged from 0.7% to 1.3%; no methanol was detected.

To characterize the methods used for preparing the tea, IDPH and CDC surveyed a nonrandom sample of 24 persons in the town who regularly drank Kombucha tea. The average age of survey participants was 57.1 years. Of the 21 participants for whom information was available, 20 had obtained their mushrooms from friends or relatives, and 15 (71%) of these had given mushrooms to their friends. One person had purchased a mushroom from a commercial producer. Of the 20 participants who had prepared the tea themselves, most (12 {60%}) reported incubating the Kombucha mushroom at room temperature for 7-10 days in 3 quarts of sweetened tea and drinking 4 oz of it per day. Patient 1 followed this regimen; patient 2 had incubated the mushroom longer (14 days) and consumed more tea (12 oz per day). Five (25%) other persons who had prepared their own tea reported incubating the mushroom for 13-14 days, and two (8%) of the 24 total participants reported consuming up to 8 oz of tea per day. Of the 21 persons for whom information was available, five (23%) discarded batches of tea because of their concerns about the appearance or taste of the tea or because of visible mold growth. Prevalence of Kombucha Tea Drinking

To assess the prevalence of Kombucha tea drinking in the town, a 1% sample of households (n=129) was contacted by telephone using random-digit dialing. The mean age of the respondents was 51.2 years (standard deviation= plus or minus 19.5 years), and 91 (70%) were women. Five persons (3.8%; 95% confidence interval {CI}=1.4%- 8.4%) reported that at least one household member had tried Kombucha tea. Of these, two (1.6% of total sample; 95% CI=0.3%- 5.0%) were persons who had regularly consumed the tea. Both had stopped drinking the tea after less than 2 weeks -- one because of the tea's taste and one because of symptoms unrelated to those of the two patients.

Reported by: RW Currier, DVM, J Goddard, K Buechler, MP Quinlisk, MD, State Epidemiologist, Iowa Dept of Public Health; SL Wolfe, MD, Spencer; TJ Carroll, MD, T Bennett, MD, Office of the Medical Examiner, Sioux City; J Stokes, MD, Univ of Iowa, Iowa City. Center for Food Safety, Food and Drug Administration. Health Studies Br, Div of Environmental Hazards and Health Effects, National Center for Environmental Health, CDC.

Editorial Note

Editorial Note: The Kombucha "mushroom" is a symbiotic colony of several species of yeast and bacteria that are bound together by a surrounding thin membrane. Although the composition of the Kombucha colony varies, some of the species reportedly found in the mushroom include S. ludwigii, S. pombe, Bacterium xylinum, B. gluconicum, B. xylinoides, B. katogenum, Pichia fermentans, and Torula sp. (1). Kombucha tea can contain up to 1.5% alcohol and a variety of other metabolites (e.g., ethyl acetate, acetic acid, and lactate). During incubation, the thin, gelatinous mushroom floats in the tea and duplicates itself by producing a "baby" on top of the original mushroom. These offspring are then given to other persons for starting their own cultures. Although there are at least two commercial producers of Kombucha mushrooms in the United States, the sharing of the mushrooms is believed to have helped to promote its popularity in the United States.

Beneficial effects attributed to consumption of Kombucha tea have included prevention of cancer, relief of arthritis, treatment of insomnia, and stimulation of regrowth of hair (1-3). Because the tea is believed to stimulate the immune system, it has become popular among persons with human immunodeficiency virus infection (3). In addition, the investigation in Iowa suggests that the tea has become popular among the elderly (who are less likely to try alternative therapies) (4).

FDA has evaluated the practices of the commercial producers of the Kombucha mushroom and has found no pathogenic organisms or hygiene violations (5). However, because the tea is produced under varying conditions in individual homes, contamination with pathogenic organisms such as Aspergillus is possible. When prepared as directed, the pH of the tea decreases to 1.8 in 24 hours. Although this level of acidity should prevent the survival of most potentially contaminating organisms, tea drinkers have reported molds growing on the Kombucha (CDC, unpublished data).

Because folk medicines and herbal remedies, including Kombucha tea, are considered neither a food nor a drug (6-8), they are not routinely evaluated by FDA or the U.S. Department of Agriculture. Although the investigation described in this report did not establish a causal link between the illness of the two women and their consumption of Kombucha tea, reasons for the occurrence and severity of the lactic acidosis in both cases have not been determined. Drinking this tea in quantities typically consumed (approximately 4 oz daily) may not cause adverse effects in healthy persons; however, the potential health risks are unknown for those with preexisting health problems or those who drink excessive quantities of the tea.

Because of the acidity of Kombucha tea, it should not be prepared or stored in containers made from materials such as ceramic or lead crystal, which both contain toxic elements than can leach into the tea. Because of the increasing use of this tea (even in groups that usually do not use alternative therapies), health-care professionals should consider consumption of Kombucha tea in the differential diagnosis of persons with unexplained lactic acidosis. Physicians and the public should report adverse health effects associated with consumption of Kombucha tea to FDA's MedWatch program, telephone (800) 332-1088 or (301) 738-7553.


  1. Stamets P. My adventures with the blob. Mushroom -- the Journal (Winter) 1994:5-9.

  2. O'Neill M. A magic mushroom or a toxic food? New York Times 1994, December 28:B1, B8.

  3. Timmons S. Fungus among us. New Age Journal (November/December) 1994.

  4. Eisenberg DM, Kessler RC, Foster C, et al. Unconventional medicine in the United States: prevalence, cost, and patterns of use. N Engl J Med 1993;328:246-52.

  5. Food and Drug Administration. FDA cautions consumers on "Kombucha Mushroom Tea" {News release}. Washington, DC: US Department of Health and Human Services, Public Health Service, Food and Drug Administration, March 23, 1995.

  6. CDC. Chaparral-induced toxic hepatitis -- California and Texas, 1992. MMWR 1992;41:812-4.

  7. CDC. Jin Bu Huan toxicity in children -- Colorado, 1993. MMWR 1993;42:633-6.

  8. CDC. Anticholinergic poisoning associated with an herbal tea -- New York City, 1994. MMWR 1995;44:193-5.

Disclaimer   All MMWR HTML versions of articles are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the electronic PDF version and/or the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

**Questions or messages regarding errors in formatting should be addressed to

Page converted: 09/19/98


Safer, Healthier People

Morbidity and Mortality Weekly Report
Centers for Disease Control and Prevention
1600 Clifton Rd, MailStop E-90, Atlanta, GA 30333, U.S.A


Department of Health
and Human Services

This page last reviewed 5/2/01