Kombucha tea health benefit and side effects
March 22 2017 by Ray Sahelian, M.D. see a list of hundreds of health and nutrition topics

Kombucha, popularly called kombucha mushroom, a combination of yeast species and acid forming bacteria, that was quite popular in the US in the mid to late 1990s, but has since not been in the limelight. Some people call it kombucha mushroom but technically it is a symbiosis of several yeast species and bacteria.

Benefit
There have not been any reliable human studies with kombucha tea published in recent years in the Western medical literature, therefore, at this point, it is difficult to report definitive proof of kombucha benefit. Rodents studies indicate it has antioxidant and immune influencing properties, ulcer-healing, along with liver protecting and anti-stress potential. It may have anti-bacterial activity. Other studies in rodents indicate that, compared to black tea, kombucha tea is a better inhibitor of alpha-amylase and lipase activities in the plasma and pancreas and a better suppressor of increased blood glucose levels, which could be of benefit to those with high blood sugar issues or who have diabetes. However, some human case studies as listed below raise some concern about possible risks and dangers.

J Med Food. 2014. Current evidence on physiological activity and expected health effects of kombucha fermented beverage. The aim of this review is to give an overview of the recent studies in search of experimental confirmation of the numerous KT health-promoting aspects cited previously. Analysis of the literature data is carried out in correspondence to the recent concepts of health protection's requirements. Attention is given to the active compounds in kombucha tea, responsible for the particular effect, and to the mechanisms of their actions. It is shown that KT can efficiently act in health prophylaxis and recovery due to four main properties: detoxification, antioxidation, energizing potencies, and promotion of depressed immunity. The recent experimental studies on the consumption of KT suggest that it is suitable for prevention against broad-spectrum metabolic and infective disorders. This makes KT attractive as a fermented functional beverage for health prophylaxis.

Pharm Biol. 2015. Protective effect of kombucha on rats fed a hypercholesterolemic diet is mediated by its antioxidant activity. Kombucha is claimed to have various beneficial effects on human health, but there is very little scientific evidence available in the literature. The present study investigates the effects of Camellia sinensis (GT) and KT, two natural drinks, on cholesterol and antioxidant status using a high cholesterol rat model. The findings revealed that kombucha administration induced attractive curative effects on hypercholesterolemic, particularly in terms of liver-kidney functions in rats. Its effect on humans needs to be studied further.

Kombucha side effects, caution, toxicity, risks, harm, danger
Kombucha side effects have been reported. A rare case of myositis has been mentioned with drinking. Other possible problems include harm to liver and lactic acidosis. These harmful effects are rare compared to the number of people who drink this tea.

A case of kombucha tea toxicity.
J Intensive Care Med. 2009. Division of Pulmonary/Critical Care Medicine, Cedars-Sinai Medical Center.
Kombucha mushroom tea is touted to have medicinal properties. Here, we present a case of hyperthermia, lactic acidosis, and acute renal failure within 15 hours of Kombucha tea ingestion. A 22 year old male, newly diagnosed with HIV, became short of breath and febrile to 103 F within twelve hours of Kombucha tea ingestion. He subsequently became combative and confused, requiring sedation and intubation for airway control. Laboratories revealed a lactate of 12 mmol/L, and serum creatinine of 2 mg/dL. Kombucha tea is black tea fermented in a yeast-bacteria medium. Several case reports exist of serious, and sometimes fatal, hepatic dysfunction and lactic acidosis within close proximity to ingestion. While Kombucha tea is considered a healthy elixir, the limited evidence currently available raises considerable concern that it may pose serious health risks.

A case of anti-Jo1 myositis with pleural effusions and pericardial tamponade developing after exposure to a fermented Kombucha beverage.
Clin Rheumatol. 2004. Division of Rheumatology, Thomas Jefferson University Hospital, Philadelphia, PA
The pathogenesis of the idiopathic inflammatory myopathies has been postulated to be an environmental trigger causing the expression of the disease in a genetically predisposed patient. We report a case of anti-Jo1 antibody-positive myositis which was associated with pleural effusions, pericardial effusion with tamponade, and 'mechanic's hands', probably related to the consumption of a fermented Kombucha beverage. Kombucha 'mushroom', a symbiosis of yeast and bacteria, is postulated to be the trigger for our patient's disease owing to the proximity of his symptoms to the consumption of the beverage.

Can a person experience an onset of psychosis from ingesting kombucha tea? A friend began drinking this tea and within 2 weeks began having psychosis like behavior.
   Perhaps it is possible in rare cases that this can occur, but one has to rule out other supplements, medications, drugs, etc., that the person may have been ingesting.

Review and opinion
At this point I think kombucha tea is a healthy drink when it is prepared hygienically. Until more studies are done, I prefer people not drink it on a daily basis but perhaps 2 to 3 times a week.

Kombucha Tea Research
Hepatoprotective and curative properties of kombucha tea against carbon tetrachloride-induced toxicity.
J Microbiol Biotechnol. 2009; Murugesan GS, Sathishkumar M, Swaminathan K. Microbial Biotechnology Division, Department of Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, India.
Kombucha tea (KT) is sugared black tea fermented with a symbiotic culture of acetic acid bacteria and yeasts, which is said to be tea fungus. KT is claimed to have various beneficial effects on human health, but there is very little scientific evidence available in the literature. In the present study, KT along with black tea (BT) and black tea manufactured with tea fungus enzymes (enzyme-processed tea, ET) was evaluated for liver protective and curative properties against CCl4-induced toxicity, using male albino rats as an experimental model by analyzing aspartate transaminase, alanine transaminase, and alkaline phosphatase in plasma and malondialdehyde content in plasma and liver tissues. Results showed that BT, ET, and KT have the potential to revert the CCl4-induced hepatotoxicity.

Kombucha: a systematic review of the clinical evidence.
Forsch Komplementarmed Klass Naturheilkd. 2003.
Complementary Medicine, Peninsula Medical School, Universities of Exeter and Plymouth, UK.
Kombucha tea has become a popular complementary remedy. The aim of this systematic review was to critically evaluate the evidence related to its efficacy and safety of kombucha mushroom. Computerised literature searches were carried out to locate all human medical investigations of kombucha mushroom regardless of study design. No kombucha mushroom clinical studies were found relating to the efficacy of this remedy. Several case reports and case series raise doubts about the safety of kombucha mushroom. They include suspected liver damage, metabolic acidosis and cutaneous anthrax infections. One fatality is on record. On the basis of these data it was concluded that the largely undetermined kombucha benefit do not outweigh the side effects of kombucha. It can therefore not be recommended for therapeutic use.

Lead induced oxidative stress: beneficial effects of Kombucha tea.
Biomed Environ Sci. 2003.
To evaluate the effect of oral administration of Kombucha tea on lead induced oxidative stress. Sprague Dawley rats were administered 1 mL of 3.8% lead acetate solution daily alone or in combination with Kombucha tea orally for 45 d, and the antioxidant status and lipid peroxidation were evaluated. Oral administration of lead acetate to rats enhanced lipid peroxidation and release of creatine phosphokinase and decreased levels of reduced glutathione (GSH) and antioxidant enzymes (superoxide dismutase, SOD and glutathione peroxidase, GPx). Lead treatment did not alter humoral immunity, but inhibited DTH response when compared to the control. Lead administration also increased DNA fragmentation in liver. Oral administration of Kombucha tea to rats exposed to lead decreased lipid peroxidation and DNA damage with a concomitant increase in the reduced glutathione level and GPx activity. Kombucha tea supplementation relieved the lead induced immunosuppression to appreciable levels. The results suggest that Kombucha tea has potent antioxidant and immunomodulating properties.

Studies on toxicity, anti-stress and hepato-protective properties of Kombucha tea.
Biomed Environ Sciences. 2001.
The objective of the study was to evaluate toxicity, anti-stress activity and hepato-protective properties of Kombucha tea. Kombucha tea was fed orally for 15 days using three different doses i.e. normal dose, five and ten times the dose. Rats were then sacrificed and various biochemical, and histological parameters were estimated. The effect of oral administration of different doses of kombucha tea to albino rats was examined and the results indicate that kombucha tea has no significant toxicity as revealed by various biochemical and histopathological parameters. Kombucha tea has been found to prevent lipid peroxidation and fall in reduced glutathione level when rats were exposed to cold and hypoxia in simulated chamber. Further, kombucha tea has also been found to decrease the Wrap-restraint faecal pellet output in rats. K-tea has also been found to decrease paracetamol induced hepatotoxicity significantly. The study shows that kombucha tea has anti-stress and hepato-protective activities.

Yeast ecology of Kombucha fermentation.
Int J Food Microbiology. 2004.
Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and physiological tests. During the fermentation of each of the four products, yeasts were enumerated from both the cellulosic pellicle and liquor of the Kombucha. The number and diversity of species varied between products, but included Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii and Zygosaccharomyces bailii. While these yeast species are known to occur in Kombucha, the enumeration of each species present throughout fermentation of each of the four Kombucha cultures demonstrated for the first time the dynamic nature of the yeast ecology. Kombucha fermentation is, in general, initiated by osmotolerant species, succeeded and ultimately dominated by acid-tolerant species.
 

Questions
I am confused as to whether kombucha tea is a healthy drink or can cause harm.
   At this point my understanding is thait has the health benefit of being an antioxidant, but until long term studies are done, it would be best to limit its use to once or twice a week.

Q. I heard about a gluconic acid in kombucha tea, have you heard about this?
   A. Gluconic acid is found naturally in fruit, honey, kombucha tea and wine and is used as a food additive, an acidity regulator. See gluconate for more info.

Q.  I am from Chennai, India, doing my masters in microbiology. I was fascinated by kombucha tea and planned to do my project on it but unfortunately my guide and other professors whom i can look up to have not heard about kombucha and are unable to direct me. I would like to know if there are any tests available to prove any of health benefits. If there are health benefits but how can we prove them?
   A. As of 2013, we have not come across any human clinical trials with kombucha tea, so we can't say kombucha tea has health benefit s with any confidence.

I have seen drinks containing raw kombucha at health food stores, and also decaf green tea kombucha. Just wondering about benefits, side effects, etc.

I am a 46 yr old female with no chronic ailments other than a bad back—on no prescription meds. For health reasons – general fatigue- detox- rosacea – I am about to begin kombucha intake once the batch is brewed. I would be willing to have blood work prior to beginning consumption etc. and thus become a human test subject. I have kept careful notes on my kombucha preparation and if need be, can forward other information if interest is serious.
   I would be interested to see the results of the blood work before and after.

After taking it, I found it was the only thing that helped my chronic fatigue. I do not think kombucha tea is dangerous. It is the ONLY thing that has ever really helped me.

I have recently stopped drinking (and I was a heavy daily drinker) and am now looking at good beverages. I thought this product wonderful until someone in my group indicated that kombucha contains alcohol? Is there an amount of alcohol that could count as drinking an alcoholic beverage? or is it so negligible that it need not be considered?
     Due to the acidic fermentation process used in its brewing, this drink contains ethyl alcohol in amounts that range from 0.5% to 1.5, a very small percentage.