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Just like friends can pass along sourdough starter, a small, round, flat, gray, gelatinous object has become a popular gift among those interested in natural medicine. You insert this object in sweetened black tea and let it ferment for 7 days. By the end of the week, you have a strong-tasting drink and a big, flat, gray, gelatinous object you can cut up and pass on to your friends.
Described variously as Manchurian mushroom, Kombucha tea, or just Kombucha, this tea is said to have been used for centuries to cure a wide variety of illnesses. The earliest known scientific analysis of Kombucha occurred in Germany in the 1930s, and subsequent studies have provided accurate information about this dubious product.1
The word kombucha literally means "tea made from kombu seaweed." However, what is called Kombucha tea today has no seaweed in it. Furthermore, despite the name Manchurian mushroom, Kombucha is not a mushroom either. The gelatinous mass is a colony of numerous species of fungi and bacteria living together, and the same microorganisms permeate the tea. The precise composition of any sample of Kombucha depends to a great extent on what was floating around in your kitchen when you grew it.
The most common microorganisms found in Kombucha tea include species of Brettanomyces, Zygosaccharomyces, Saccharomyces, Candida, Torula, Acetobacter, and Pichia. However, some analyzed specimens have been found to contain completely different organisms, and there is no guarantee that they will be harmless.2,3
Kombucha tea is widely supposed to have miraculous medicinal properties, ranging from curing cancer to restoring gray hair to its original color. Other reputed effects include normalizing weight, improving blood pressure, increasing energy, decreasing arthritis pain, restoring normal bowel movements, removing wrinkles, curing acne, strengthening bones, improving memory, and generally solving every health problem that exists.
However, there is no evidence that Kombucha tea is effective for these or any other uses.
This database does not recommend the use of homemade Kombucha tea. Commercially produced Kombucha should be safer, but it has no known medicinal effects.
In a set of animal studies, researchers prepared a batch of Kombucha and found that it was essentially nontoxic when taken at appropriate doses.9 However, because Kombucha is a complex and variable mixture of microorganisms, it isn't clear that any other batch of the tea would be equally safe. In fact, there are case reports, which suggest that Kombucha preparations can cause such problems as nausea, jaundice, shortness of breath, throat tightness, headache, dizziness, liver inflammation, and even unconsciousness.4,5,6 It isn't clear whether the cause of these symptoms is an unusual reaction to a generally nontoxic substance, or a response to unusual toxins that developed in a particular batch of Kombucha.
In addition, there is one case report of severe lead poisoning caused by regular use of Kombucha brewed in a ceramic pot.7 When brewed or stored in some ceramics, the risk of lead poisoning results because Kombucha tea is acidic. Many ceramic glazes contain a low level of lead that would not make the pottery dangerous for ordinary use; but if an acidic solution like Kombucha is steeped in them for a long time, a dangerous amount of lead may leech into the solution.
There is also one report of Kombucha becoming infected with anthrax and passing along the infection to an individual who rubbed it on his skin to alleviate pain.8 Apparently, anthrax from nearby cows got into the Kombucha mixture and grew.
1. Mayser P, Fromme S, Leitzmann C, et al. The yeast spectrum of the 'tea fungus Kombucha'. Mycoses. 1995;38:289-295.
2. Mayser P, Fromme S, Leitzmann C, et al. The yeast spectrum of the 'tea fungus Kombucha'. Mycoses. 1995;38:289-295.
4. Srinivasan R, Smolinske S, Greenbaum D. Probable gastrointestinal toxicity of Kombucha tea: is this beverage healthy or harmful? J Gen Intern Med. 1997;12:643-644.
5. [No authors listed]. Unexplained severe illness possibly associated with consumption of Kombucha tea—Iowa, 1995. From the Centers for Disease Control and Prevention. JAMA. 1996;275:96-98.
6. Perron AD, Patterson JA, Yanofsky NN. Kombucha "mushroom" hepatotoxicity. Ann Emerg Med. 1995;26:660-661.
7. Phan TG, Estell J, Duggin G, et al. Lead poisoning from drinking Kombucha tea brewed in a ceramic pot. Med J Aust. 1998;169:644-646.
8. Sadjadi J. Cutaneous anthrax associated with the Kombucha "mushroom" in Iran [letter]. JAMA. 1998;280:1567-1568.
9. Vijayaraghavan R, Singh M, Rao PV, et al. Subacute (90 days) oral toxicity studies of Kombucha tea. Biomed Environ Sci. 2000;13:293-299.
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 12/15/2015