Kombucha

Kombucha is a beverage made by fermenting sweetened black tea (green and oolong tea are also used) with a symbiotic culture of bacteria and yeasts (SCOBY). Believed to have originated in China, kombucha has gained worldwide popularity as a functional food. The SCOBY consists of several acetic acid and lactic acid bacteria. Following fermentation, kombucha's chemical makeup includes sugars, tea polyphenols, fiber, ethanol, amino acids and water-soluble vitamins ⁽¹⁾. Health benefits attributed to kombucha include reduction of blood pressure and cholesterol along with anticancer and immunostimulatory effects.

Preclinical studies have shown anti-inflammatory, antioxidant, immunostimulatory ⁽⁵⁾, hypolipidemic ⁽²⁰⁾, and hepatoprotective ^{(6) (18) (19) (21) (23)} effects with limited toxicity ⁽⁷⁾. In a small study involving 24 subjects with non-insulin dependent diabetes mellitus, daily intake of kombucha was associated with normalized blood sugar values ⁽²⁴⁾. Randomized studies have yet to be conducted ^{(8) (1)}.

Kombucha is used as an immunostimulant, and to treat diabetes, cancer and AIDS ⁽³⁾. The high caffeine and sugar content of the tea may account for increase in energy levels following its consumption ⁽⁴⁾. However, kombucha can be easily contaminated during fermentation. Allergic reactions, jaundice, serious illness, and death have been associated following consumption of home-grown kombucha ^{(9) (10) (11)}. It may also reduce the absorption of drugs that are sensitive to gastric pH level ⁽¹²⁾.

• Atherosclerosis
• Cancer treatment
• Diabetes
• AIDS
• High blood pressure
• Immunostimulation

Kombucha demonstrated antimicrobial activity against a large number of pathogenic microorganisms at neutral pH and following denaturation, which suggests that it contains antimicrobial compounds other than acetic acid and large proteins ⁽¹³⁾.

Fermentation increases the potential for contamination with other microorganisms. Contamination with anthrax ⁽¹⁰⁾; and Aspergillus ⁽¹⁴⁾, a fungus that is dangerous to people with lowered immune systems, have been reported.

• Growing kombucha in unsanitary conditions has resulted in contaminated product ⁽¹⁰⁾
• Lead poisoning has been associated with kombucha tea brewed in a glazed ceramic pot ⁽¹⁵⁾

Patients with suppressed immune systems should not consume kombucha beverages produced in an uncontrolled environment ⁽²⁸⁾.

Case Reports

Cutaneous anthrax: In 20 people following topical use of kombucha grown in unhygienic conditions ⁽¹⁰⁾.

Consumption of oral kombucha has been reported to cause:

• Severe illness and death ^{(9) (17)}
• Lead poisoning from kombucha brewed in a lead-glazed ceramic pot ⁽¹⁵⁾
• Hepato- and gastrointestinal toxicities including allergic reactions, jaundice and nausea, vomiting, head and neck pain ^{(2) (11) (25)}
• Yeast infections ⁽¹²⁾
• Myositis associated with pleural effusions, pericardial effusion with tamponade, and 'mechanic's hands' ⁽²²⁾
• Severe metabolic lactic acidosis in a 54-year-old asthmatic woman after she drank kombucha tea ⁽²⁶⁾
• Clostridium septicum sepsis due to bacteremia and hematogenous spread, resulting in encephalitis and pneumocephalus in a patient following consumption of kombucha tea and performing coffee enemas ⁽²⁷⁾

Kombucha tea is acidic. This may affect the bioavailability of drugs that depend on stomach pH levels for dissolution and absorption ⁽¹²⁾.