Kombucha, is produced by the fermentation of tea and sugar by a symbiotic association of bacteria and yeasts forming a ``tea fungus''. It originated in China where the ``Divine Che'' was prized in 220 BC during the Tsin Dynasty for its detoxifying and energizing properties (Roche, 1998). In 414, Doctor Kombu brought the tea fungus to Japan from Korea to cure the digestive troubles of the Emperor. ``Tea Kvass'' was introduced into Russia by oriental merchants and then into Eastern Europe and Europe around the turn of this century. This refreshing beverage tasting like sparkling apple cider is often produced in the home by fermentation using a tea fungus passed from home to home.
Benefits of a Kombucha Drink
First reports coming from Russia at the beginning of this century and during World War I stated that the ``Russian secret home remedy'' also called ``Wonderdrink'' helped for headaches, gastric illnesses, and especially regulates intestinal activities often disturbed by the lifestyle in the army (Allen, 1998). Between 1925 and 1950, several medical studies conducted by doctors and physicians confirmed the traditional claims about Kombucha and reported beneficial effects such as antibiotic properties, regulation of gastric, intestinal and glandular activities, relief of joint rheumatism, gout and haemorrhoids, positive influence on the cholesterol level, arteriosclerosis, toxin excretion and blood cleansing, diabetes, nervousness, and aging problems (Allen, 1998).
In 1951, an important population study conducted in Russia by the ``Central Oncological Research Unit'' and the ``Russian Academy of Sciences in Moscow'' found that the daily consumption of Kombucha was correlated with an extremely high resistance to cancer. The 1960's, researches reaffirmed the cancer healing properties of Kombucha, its detoxifying effects and proposed that a long term consumption increased the immune system performance and boosted interferon production. The Russian findings about Kombucha properties were further supported in Switzerland, Germany and Netherlands (Allen, 1998). A recent study reported the antibiotic activity of Kombucha against Helicobacter pylori, Esherichia coli, Staphylococcus aureus and Agrobacterium tumefaciens mainly related to the acetic acid produced during the fermentation (Steinkraus, Shapiro, Hotchkiss & Mortlock, 1996). Tea extracts used at the same concentration did not exhibit any effect. A study on the antimicrobial activity of some organic acids indicated that acetic acid can inhibit fungal growth and presents a mild activity at low pH against lactic acid bacteria (Matsuda, Yano, Maruyama & Kumagai, 1994). In the same conditions and over a range of pH values, d and l- lactic acid inhibit lactic acid bacteria but present no activity against fungi while gluconic acid exhibits only weak activities against both types of microorganisms.
Most properties of Kombucha are attributed to the acidic composition of the beverage. Its detoxifying property is presumably due to the capacity of glucuronic acid to bind to toxin molecules and to increase their excretion from the organism by the kidneys or the intestines. Gout, rheumatism, arthritis or kidney stones likely produced by the accumulation of toxins in the body may be relieved this way. Heavy metals or environmental pollutants can also be excreted through the kidneys after glucuronidation.
The action of Kombucha Drink intake on the nervous system could be associated with its content of the B com- plex of vitamins (Roche, 1998). It has been observed that patients suffering from cancer do not have l-lactic acid in their connective tissues and have a blood pH higher than 7.56. Kombucha can re-equilibrate the blood pH and the lactic acid concentration (Roche, 1998). The laxative activity of Kombucha is also attributed to its lactic acid content (Reiss, 1994). There are some indications that lactic acid bacteria can also exert immunostimulatory effects in the host (Marteau & Rambaud, 1993) but at this time, it is not known if micro-organisms present in Kombucha can colonize the human gastrointestinal system.
The tea fungus is also used for medical purposes in skin therapy. The cellulosic pellicle formed mainly by Acetobacter xylinum during the fermentation of tea has been used as a temporary skin substitute on burns and in other skin injuries (Fontana, Franco, De Souza, Lyra & De Souza, 1991).