Review on the current evidence on physiological activity and health effects of kombucha

Review on the current evidence on physiological activity and health effects of kombucha

Introduction

Kombucha beverage is fermented probiotic drink made from tea, which has been used as a traditional remedy to boost detoxification and overall health in the Far East for centuries. It is produced in a process of fermentation of sweetened green or black tea that is added to Kombucha scoby (a symbiotic culture of bacteria and yeast) which creates a very distinctive beverage with sweet, sour and tart flavor, rich in probiotic cultures and various other nutrients. The Kombucha drink is used as base for production of Kombucha extract in a specific technologic process of short, low temperature pasteurization and concentration. The Kombucha beverage has a distinctive nutritional content of minerals, vitamins, certain enzymes, organic acids and probiotic bacteria and fungy. The Kombucha extract contains traces amount of specific minerals (Mg, Ca, K, Zn, Fe, Cu, Mn, Ni and Co) and vitamins (B1, B2, B3, B5, B6 and C) and a unique combination of organic acids such as acetic, lactic, gluconic and predominately glucuronic acid that provide wide range of beneficial metabolic effects in the body. Although the process of production of the extract destroys all probiotic cultures, the end product in form of Kombucha extract reaches over 100 times greater concentration of the specific acids and other beneficial compounds compared with their presence in the Kombucha beverage (1 Tbs of around 10ml of Kombucha extract has nutritional potency that equals around 600 ml of the fermented Kombucha beverage). The research and analyses conducted by the USFDA,other authorized national food agencies, health institutes and scientists and medical researchers worldwide have confirmed the safety for using Kombucha and its products as novel and functional food/ food supplement and large number of beneficial health properties that are clearly presented in the text bellow.

Current view on Kombucha health benefits

During the last 15 years there has been a constant rise of the interest for Kombucha and its products which correlate to an increasing number of studies and research that continue to prove the various health benefits of Kombucha. In general, the beneficial properties of Kombucha have been attributed primarily to the specific acidic composition (high concentration of glucuronic acid (GlcUA), lactic, usnic acid, etc.) and their participation and impact on various metabolic processes in the body.

The present day lifestyle with continual stress and lack of time has put negative impact on the quality of nutrition and eating habits. The overly processed and refined food rich in additives and preservatives, the intake of fast foods filled with oxidized fats and excess of sugar, agricultural produce contaminated with pesticides, heavy metals and other industrial chemicals, alcohol consumption and overuse of medication overburdens the organism with toxins that continually damage our cells and block various metabolic functions, while restricting the body from obtaining all nutrients necessary to maintain a healthy metabolism. Optimal regulation of the liver detoxification pathways is an essential element of the human metabolism, critical to maintaining good health and wellbeing. In addition to ensuring normal liver function the detoxification capacity of the body directly impacts immune function, weight loss, lipid and sugar metabolism as well as the work of the endocrine (hormonal) system. Impaired detoxification pathways and weakened liver function affect all organ systems and lead to development of various chronic diseases. It is recognized that insufficient and imbalanced nutrition can have a detrimental effect on detoxification ability. All biochemical reactions within phase 1 and 2 of the liver detoxification pathways depend on availability and adequate levels of specific nutrients such as proteins, vitamins, essential minerals, antioxidants, enzymes and other organic compounds. Further to this, it is certain that many detoxification processes, such as glucuronidation (key phase 2 biochemical reaction), are reduced in elderly people. These deficiencies can decrease the body’s ability to synthesize the bio transforming enzymes essential for proper detoxification. All these elements impair proper liver function and consequently lead to development of fatty liver disease (liver steatosis). Fatty liver disease is one of the most frequent and sadly most underappreciated diseases today. The latest data from the World’s Health Organization for gastroenterology show that 1/5 of the world’s population on average suffers from liver steatosis, or non-alcoholic fatty liver disease. If the condition of liver steatosis is not treated for a longer period of time it can lead to destruction of the hepatocytes, their replacement with fibrosis-connective tissue and development of liver cirrhosis, a life threatening condition with detrimental effect. 

The Kombucha extract is one of the best and most concentrated, natural sources of glucuronic acid. This acid plays a key role in the phase 2 of the liver detoxification metabolic reactions, such as the process of glucuronidation . It conjugates - it binds to toxic metabolites and exogenous chemicals called xenobiotics (such as pharmaceuticals, environmental pollutants, toxins such as pesticides) present in the human body and modifies them into compounds that have better solubility, which ensures flushing out of these toxic compounds from the liver, with gallbladder secretion, through the intestines out of the body. Emphasis should be put on the notion that the process of glucuronidation accounts for up to 60% of the metabolization of the analgesic and antipyretic medications. In that regard, it can be stated that by supporting the process of glucuronidation, the intake of kombucha has been shown to prevent hepatotoxicity caused by overuse of paracetamol or acetaminophen, (chemically named N-acetyl-p-aminophen) which was measured by reduced plasma levels of specific liver enzymes (glutamic oxaloacetate transferase, serum glutamic pyruvate transferase, LDHE, and MDA). Kombucha has also demonstrated hepatoprotective and curative properties against toxicity induced by carbon tetrachloride (CCl4 xenobiotic) and aflatoxin (mold toxin). In conclusion, the Kombucha intake in the presented experimental studies has resulted in reduced number of fatty droplets in the hepatocytes, which signifies inhibition of the accumulation of triglycerides and total cholesterol within the hepatocytes, as well as greatly increased productivity of the hepatic cells, due to the presence of glucuronic acid as a detoxifier, as well as the presence of polyphenolics. (9, 10, 11, 12, 13, 14, 18, 28, 30, 52)

Oxidative stress - cumulative damage free radicals cause to the cells (cell’s membrane, mitochondria and other organelles, as well as the nucleus (the molecule of DNA)) results in reduced nutrient transport, weakened energy and molecule production and altered replication of the cell, which leads to impaired cellular function and metabolism. Without proper antioxidant defense, which serves the purpose of effective neutralization of the scavenging free radicals, the continual oxidative damage creates inflammations on a cellular level that creates systemic inflammation, tissue and organ damage and development of an illness. The phenolic and other compounds in the Kombucha (that originate from the tea) have potent antioxidant abilities to prevent free radical molecules and tissue damage, in particular to prevent lipid peroxidation (in the blood plasma and the vascular epithelial lining) which leads to creation of arterial plaque and development of atherosclerosis (frequent cardiovascular disease that can result in formation of arterial blockages, hearth failures and brain strokes). Medical studies conducted on patients with atherosclerosis, patients with high plasma cholesterol, reported significant reduction of atherosclerosis symptoms. Specifically, in addition to preventing lipid peroxidation, Kombucha could lower cholesterol level in the body through the inhibition of cholesterol synthesis enzyme HMG (3hydroxy 3-metilglutaril CoA reductase) activity in liver and/ or through the mechanism of increased excretion of cholesterol. The glucuronic acid found in Kombucha can neutralize cholesterol deposits supporting liver and kidneys in excreting the excess sterols (types of lipid molecules cholesterol belongs to) from the body. The results that were obtained in the studies demonstrated the ability of the Kombucha to decrease blood plasma total cholesterol by up to 52%, also reducing triglyceride values up to 27%, LDL-Ch up to 91%, while increasing HDL-Ch levels up to 27%. (9,12, 13, 20, 18, 24, 26, 36)

It has also been reported that Kombucha potentiates the hepatic glutathione antioxidant/detoxification system. Glutathione is the master endogenous antioxidant which together with its antioxidant enzymes (glutathione peroxidase, glutathione transferase and glutathione reductase) have essential role in the body’s detoxification capacity. By preventing oxidative damage the consumption of Kombucha prevents development of a wide number of systemic inflammation and chronic conditions such as cardiovascular diseases, kidney insufficiencies, eye diseases, degenerative cognitive diseases of the nervous system, etc. Secondary to this, Kombucha’s antioxidant properties and the ability to prevent oxidative stress, also give support to the immune system and better controlled inflammatory response. (16, 17 - 19)

Regular consumption of Kombucha also provides protection against anemia and has an energizing effect. Kombucha intake increases the energy level by improving significant aspects of the energy metabolism. Iron is the essential part for the formation of hemoglobin, which is an oxygen carrying protein present in the red blood cells. The increased hemoglobin levels directly increases the oxygen carrying capacity of the red blood cells, which improves the tissues’ supply with oxygen, which in turn allows for greater energy production inside the cells (by stimulatating ATP synthesis in the mitochondria). More specifically the Kombucha’s ability to prevent anemia and increase the levels of energy come from the formation of the iron and gluconic acid synthesized chelating complex (ability to chelate-bind to metals). The organic acids in the Kombucha, can improve the plant-derived (non-heme)) iron absorption, by reducing trivalent iron compounds from plant sources to divalent iron ions, and forming chelate compounds with them that dissolve well in an acidic medium. Also present B vitamins support the energy regeneration by enzymatic activation of lipid and protein metabolism. Consumption of Kombucha is particularly recommended for elderly people and vegetarians because it enhances the absorption of plant source iron and helps prevent iron deficiency and anemia caused by it. (9,10,12,13,17 - 20, 23 - 41)

Regular intake of Kombucha in form of fermented tea or as extract has also shown the ability to provide beneficial effect to the health and function of the gastrointestinal system. The overuse of nonsteroidal anti-inflammatory pharmaceuticals has gastro toxic effect that often leads to gastric ulceration and delayed healing. The research conducted until now shows several mechanisms of action that make Kombuca intake beneficial. It prevents oxidative stress, particularly peroxidation of lipids in the epithelial cells of the stomach, which in addition to acid secretion, also contributes to stomach ulceration. It also better regulates gastric and intestinal function (such as contraction of the stomach and intestines). Further to this, the healing ability of the Kombucha extract is mainly attributed to its capability to protect the mucin content (the first guarding line-mucin and bicarbonates barrier). Study has confirmed that Kombucha extract preparation (15mg/kg) is as effective in ulcer healing as the positive control omeprazole (3mg/kg). (23)

Diabetes mellitus is one of most prevalent chronic metabolic diseases in the world. Either as dysfunction of endogenous insulin secretion (type 1) or as a result of different metabolic misbalances (such as insulin resistance in type 2) the condition of diabetes melitus affects nearly half a billion people worldwide and is one of the leading causes for development of cardiovascular diseases, eye diseases, kidney insufficiencies, limb amputations and other serious complications. The antidiabetic property of the Kombucha was first mentioned as early as 1929. Several studies conducted on animals demonstrate strong ability of the Kombucha to lower blood sugar levels and to keep low, stabile blood sugar levels. Kombucha has the ability to inhibit the digestion of starches (starch hydrolysis) by influencing the activity of the enzyme pancreatic amylase as well as to decrease the action of the pancreatic lipase, which in turn decreases the digestion and uptake of lipids, decreasing the level of blood glucose. In addition the consumption of Kombucha provides protection of the liver-kidney functions, evidenced by significant decreases in key enzymes such as aspartate transaminase (ASAT), alanine transaminase (ALAT), and other as well as the urea contents (all of which are normally increased by hyperglycemia). By regulating the digestion and uptake of starches (carbohydrates) and lipids Kombucha demonstrates an antiobesity effects and it has been mentioned that regular Kombucha ingestion contributes to better weight control and inhibition of weight gain. (13, 24, 25, 26)

Beside liver, kidneys have an important role in blood filtration and elimination of toxins, which makes them particularly prone to oxidative stress and damages induced by toxins and increased metabolic waste product present in the blood. The Kombucha’s intake contribution to eliminate the damage caused by environmental pollutants is already reported in studies and could be of significance to patients suffering from renal impairment or patients with kidney stones. The unique blend of acids, particularly present in the Kombucha extract, such as glucuronic acid and other, increases water-solubility and improves transport and bioavailability of steroid hormones and fat-soluble vitamins, prevents an accumulation of heavy metals, insoluble` oxalates, inorganic salts of calcium, phosphorus, and uric acid. The regular intake of Kombucha has the potential to reduce kidney calcification and has been proven repeatedly to prevent kidney stone formation prevention. (11, 13, 20, 44)

Increased oxidative stress and unbalanced blood sugar levels are also associated with induction of neurodegenerative diseases. The unique nutritional profile of the Kombucha, presented by the specific combination of acids, amino acids, vitamins and other bioactive molecules provide nutrients required for normal function of the nervous system. The consumption of Kombucha may help in prevention of headaches, nervousness, depression in elderly and epilepsy. (9, 13 20, 24, 54, 55)

The glucuronic acid found in abundance in Kombucha can be used and converted by the body to glucosamine, chondroitin-sulphate, other acidic mucopolysaccharides and glucoproteins present in the cartilage, collagen and the fluid that lubricates joints. This demonstrates the ability to use Kombucha as resource to obtain many key elements necessary for the cartilage and joint’s overall health and function. The possibility of Kombucha’s consumption to relieve arthritis and be used as dietary supplement for osteoarthritis has been successfully demonstrated in clinical tests in the USA, Russia, Sweden, and Germany. Further to this, Kombucha’s detoxifying abilities (mainly established by the support for the process of glucuronidation has been proven remedial against rheumatism and gout, in addition to arthritis (all 3 conditions characterized by accumulation of toxins in the joints). (20,58, 59, 60) 

It has been reported that incidence of cancer in population that regularly consumes Kombucha tea or Kombucha extract is extremely rare. Several researches demonstrate Kombucha’s ability to inhibit cancer formation and growth by several mechanisms. Initially, by neutralizing free radical damage it preserves healthy cell metabolism, preventing abnormal cellular cycles and potential development of malignant cells. Furthermore, long-term Kombucha consumption increases immune system’s anticancer defensive properties by preventing cancer cell’s proliferation in particular, at early stages of tumor growth, due to synergetic action of the glucuronic, lactic and acetic acid, and antibiotic compounds found in Kombucha. In recent studies, it was also shown that Kombucha significantly reduced cancer cell’s development and metastasis, by inhibiting growth of blood vesicles in the cancer tissue (downregulation of angiogenesis) especially in hormone-dependent tumors. (13, 18, 20, 22, 34, 62)

Last but not list, Kombucha has demonstrated antimicrobial and antibiotic activities that can offer alternative to current synthetic antimicrobial pharmaceuticals (considering the increasingly important challenge of resistance to antibiotics). Precisely, many studies proved that Kombucha with high total acidity, as a result of high concentration of glucuronic, gluconic, lactic and other acids, exert antibacterial activity against a broad range of pathogenic bacteria, in particular, against Helicobacter pylori, Salmonella typhimurium, Staphylococcus aureus, Bacillus cereus, etc. This antimicrobial activity of Kombucha is contributed to the acids and low pH of the Kombucha which inhibits bacterial growth, by disrupting the bacterial wall membrane, inhibiting essential metabolic reactions and accumulation of toxins inside the cell of the bacteria. (2,8,17,19, 36–41, 60-75)

Conclusion

Regular consumption of kombucha, in particularly kombucha extract has demonstrated beneficial health properties in broad range of metabolic conditions and disorders. These properties to support specific organ functions and metabolic pathways and to prevent development of diseases are atrubuted to the unique nutritional and chemical composition, predominately represented by the specific profile of acids (glucuronic, gluconic, lactic and other) and other bioactive molecules present in the Kombucha.

Large number of studies and research, bot conducted on animals and humans have confirmed Kombucha’s properties to:

  • - provides efficient detoxification of the liver and cleaning up of the blood of all toxins, by supporting key segments of the liver detoxification pathways;
  • - prevent liver diseases by metabolizing pharmaceuticals known to cause liver toxicity and enhancing the activity of liver hepatocytes;
  • - regulate blood lipids (by downregulating i.e. reducing the levels of blood triglycerides, total cholesterol and oxidized LDL cholesterol);
  • - regulate blood sugar levels by decreasing the absorption of starches and better regulating carbohydrate metabolism controlled by the liver;
  • - prevent oxidative stress and cellular and tissue damage caused by oxidative stress;
  • - provide protection of the cardiovascular system by preventing damages to arterial walls and cholesterol deposits that lead to development of atherosclerosis, hence providing prevention from heart attacks and stroke;
  • - clean out blood metabolic waster products such as metal ions, glycated proteins, fibrin, etc. which provides support in metabolizing thrombus and hematomas;
  • - prevent formation of kidney stones and support kidney function by metabolizing harmful substances ;
  • - provide nutrients and support toxin removals, hence preserving joint function and preventing inflammations in individuals with arthritis;
  • - prevent anemia, improve hemoglobin levels and energy (by increasing oxygen delivery to tissues);
  • - has antimicrobial action that prevents the growth ad kills a range of pathogenic bacteria that cause infections and diseases;
  • - prevent growth and proliferation of cancer (malignant) cells;

REFERENCES

1. Liu CH, Hsu WH, Lee FL, Liao CC: The isolation and identification of microbes from a fermented tea beverage, Haipao, and their interactions during Haipao fermentation. Food Microbiol 1996;13:407–415. 

2. Greenwalt CJ, Steinkraus KH, Ledford RA: Kombucha, the fermented tea: microbiology, composition, and claimed health effects. J Food Prot 2000;63:976–981. 

3. Kurtzman CP, Robnett CJ, Basehoar-Powers E: Zigosaccharomyces kombuchaensis, a new ascosporogeneous yeast from ‘kombucha tea’. FEMS Yeast Res 2001;1:133–138. 

4. Yang Z, Zhou F, Ji B, Li B, Luo Y, Yang L, Li T: Symbiosis between microorganisms from kombucha and kefir: potential significance to the enhancement of kombucha function. Appl Biochem Biotechnol 2010;2:446–455. 

5. U.S. Food and Drug Administration (1995). FDA Talk Paper: FDA cautions consumers on ‘‘kombucha mushroom tea.’’ National Press Office, Rockville, MD, USA, Talk Paper, T95–T15. 

6. Allen CM: Kombucha unveiled. Kombucha FAQ. Part six— Research and Test Results. http://users.bestweb.net/*om/FAQ/ part06.html (accessed Jan 2013). 

7. Vijayaraghavan R, Singh M, Rao PV, Bhattacharya R, Kumar P, Sugendran K, Kumar O, Pant SC, Singh R: Subacute (90 days) oral toxicity studies of kombucha tea. Biomed Environ Sci 2000;13:293–299. 

8. Greenwalt CJ, Ledford RA, Steinkraus KH: Determination and characterization of the antimicrobial activity of the fermented tea kombucha. Lebenson Wiss Technol 1998;31:291–296. 

9. Adriani L, Mayasari N, Kartasudjana RA: The effect of feeding fermented kombucha tea on HLD, LDL and total cholesterol levels in the duck bloods. Biotechnol Anim Husb 2011;27:1749– 1755. 

10. Pauline T, Dipti P, Anju B, Kavimani S, Sharma SK, Kain AK, Sarada SKS, Sai Ram M, Ilavazhagan G, Kumar D, Selvamurthy W: Studies on toxicity; anti-stress and hepatoprotective properties of kombucha tea. Biomed Environ Sci 2001;14:207–213. 

11. Vı na I, Semjonovs P, Linde R, Patetko A: Glucuronic acid containing fermented functional beverages produced by natural yeasts and bacteria associations. Int J Res Rev Appl Sci 2013;14:17–25. 

12. Suhartatik N, Karyantina M, Marsono Y, Rahayu ES, Kuswanto KR: Kombucha as anti hypercholesterolemic agent (in vitro study using SD rats). Proceedings of the 3rd International Conference of Indonesian Society for Lactic Acid Bacteria (3rd IC- ISLAB): Better Life with Lactic Acid Bacteria: Exploring Novel Functions of Lactic Acid Bacteria, 2011, Yogyakarta, Indonesia. 

13. Danielian LT: Kombucha (Kombucha) and Its Biological Features. Meditsina, Moscow, 2005. (In Russian.) 

14. Naland H: Kombucha: Teh dengan Seribu Khasiat. Agromedia Pustaka. Jakarta, 2008. (In Indonesian.) 

15. Sies H, Stahl W: Vitamins E and C, B-carotene and other carotenoids as antioxidants. Am J Clin Nutr 1995;62:1315S–1321S.

16. Dufresne CJ, Farnworth ER: A review of latest research findings on the healthpromotion properties of tea. J Nutr Biochem 2001;12:404–421. 

17. Dipti P, Yogesh B, Kain AK, Pauline T, Anju B, Sai Ram M, Singh B, Mongia SS, Kumar GI, Selvamurthy W: Lead induced oxidative stress: beneficial effects of kombucha tea. Biomed Environ Sci 2003;16:276–282. 

18. Yang Z-W, Ji B-P, Zhou F, Li B, Luo Y, Yang L, Li T: Hypocholesterolaemic and antioxidant effects of kombucha tea in high-cholesterol fed mice. J Sci Food Agric 2009;89: 150–156. 

19. Sai Ram M, Anju B, Pauline T, Dipti P, Kain AK, Mongia SS, Sharma SK, Singh B, Singh R, Ilavazhagan G, Kumar D, Selvamurthy W: Effect of kombucha tea on chromate(VI)-induced oxidative stress in albino rats. J Ethnopharmacol 2010;71:235– 240.

20. Dufresne C, Farnworth E: Tea, kombucha and health: a review. Food Res Int 2000;33:409–421. 

21. Meydani SN, Wu D, Santos MS, Hayek MG: Antioxidants and immune status in aged persons: overview of present evidence. Am J Clin Nutr 1995;62:1462S–1476S. 

22. McCord JM: The evolution of free radicals and oxidative stress. Am J Med 2000;108:652–659. 

23. Banerjee D, Hassarajani SA, Maity B, Narayan G, Bandyopadhyay SK, Chattopadhyay S: Comparative healing property of kombucha tea and black tea against indomethacin-induced gastric ulceration in mice: possible mechanism of action. Food Funct 2010;1:284–293. 

24. Kallel L, Desseaux V, Hamdi M, Stocker P, Ajandouz EH: Insights into the fermentation biochemistry of kombucha teas and potential impacts of kombucha drinking on starch digestion. Food Res Int 2012;49:226–232. 

25. Shenoy C: Hypoglycemic activity of bio-tea in mice. Indian J Exp Biol 2000;38:278–279. 

26. Aloulou A, Hamden K, Elloumi D, Ali MB, Hargafi K, Jaouadi B, Ayadi F, Elfeki A, Ammar E: Hypoglycemic and antilipidemic properties of kombucha tea in alloxan-induced diabetic rats. BMC Complement Altern Med 2012;12:63. 

27. Gharib OA: Effects of kombucha on oxidative stress induced nephrotoxicity in rats. Chin Med 2009;4:23. 

28. Jayabalan R, Malini K, Sathishkumar M, Swaminathan K, Yun S: Biochemical characteristics of tea fungus produced during kombucha fermentation. Food Sci Biotechnol 2010;3:843–847. 

29. Jalil A, Amin D, Mohammad HF, Saeid H: Protective effect of kombucha tea against acetaminophen-induced hepatotoxicity in mice: a biochemical and histopathological study. Comp Clin Path 2012;21:1243–1248. 

30. Murugesan GS, Sathishkumar M, Jayabalan R, Binupriya AR, Swaminathan K, Yun SE: Hepatoprotective and curative properties of kombucha tea against carbon tetrachloride-induced toxicity. J Microbiol Biotechnol 2009;19:397–402. 

31. Bhattacharya S, Manna P, Gachhui R, Sil PC: Protective effect of kombucha tea against tertiary butyl hydroperoxide induced cytotoxicity and cell death in murine hepatocytes. Indian J Exp Biol 2011;49:511–524. 

32. Yapar K, Cavusoglu K, Oruc E, Yalcin E: Protective effect of kombucha mushroom (KM) tea on phenol-induced cytotoxicity in albino mice. J Environ Biol 2010;31:615–621. 

33. Abshenas J, Derakhshanfar A, Ferdosi MH, Hasanzadeh S: Protective effect of kombucha tea against acetaminophen induced hepatotoxicity in mice: a biochemical and histopathological study. Comp Clin Path 2012;21:1243–1248. 

34. Sriharia T, Arunkumarb R, Arunakaranb J, Satyanarayanac U: Downregulation of signalling molecules involved in angiogenesis of prostate cancer cell line (PC-3) by kombucha (lyophilized). Biomed Prev Nutr 2012;3:53–58. 

35. Jayabalan R, Chen P-N, Hsieh Y-S, Prabhakaran K, Pitchai P, Marimuthu S, Thangaraj P, Swaminathan K, Yun SE: Effect of solvent fractions of kombucha tea on viability and invasiveness of cancer cells—characterization of dimethyl 2-(2-hydroxy-2methoxypropylidine) malonate and vitexin. Indian J Biotechnol 2011;10:75–82. 

36. Jayabalan R, Subathradevi P, Marimuthu S, Sathishkumar M, Swaminathan K: Changes in free-radical scavenging ability of kombucha tea during fermentation. Anal Methods 2008;109:227–234. 

37. Steinkraus KH, Shapiro KB, Hotchkiss JH, Mortlock RP: Investigations into the antibiotic activity of tea fungus/kombucha beverage. Acta Biotechnol 1996;16:199–205. 

38. Battikh H, Bakhrouf A, Ammar E: Antimicrobial effect of kombucha analogues. LWT Food Sci Technol 2012;47:71–77. 

39. Sreeramulu G, Zhu Y, Knol W: Characterization of antimicrobial activity in kombucha fermentation. Acta Biotechnol 2001;21: 49–56. 

40. Chu SC, Chen CS: Effects of origins and fermentation time on the antioxidant activities of kombucha. Food Chem 2006;98: 502–507. 

41. Talawat S, Ahantharik P, Laohawiwattanakul S, Premsuk A, Ratanapo S: Efficacy of fermented teas in antibacterial activity. Kasetsart J Nat Sci 2006;40:925–933. 

42. Skuja N, Danilans A, Geldnere G: Praktiska gastroenterolog ´ija un hepatolog ´. Zvaigzne, Riga, Latvija, 1999. (In Latvian.) 

43. Frank GW: Fascination of kombucha. Am Raum Zeit 1991;2: 51–56. 

44. Roussin, M: Kombucha Consumer Research Group. www.kom bucha-research.com/kcrg/aboutus.htm (accessed January 2013). 

45. Grundy SM, Balady GJ, Criqui MH, Fletcher G, Greenland P, Hiratzka LF, Houston-Miller N, Kris-Etherton P, Krumholz HM, LaRosa J, Ockene IS, Pearson TA, Reed J, Washington R, Smith SC, Jr.: Primary prevention of coronary heart disease: guidance from Framingham: a statement for healthcare professionals from the AHA Task Force on Risk Reduction. Circulation 1998;97: 1876–1887. 

46. Hartmann AM, Burleson LE, Holmes AK, Geist CR: Effects of chronic kombucha ingestion on open-field behaviors, longevity, appetitive behaviors, and organs in C57-BL/6 mice: a pilot study. Nutrition 2000;16:755–761. 

47. Cook JD, Redd MB: Effect of ascorbic acid intake on newborn iron absorption from a complete diet. Am J Clin Nutr 2001;73:93–98. 

48. Halberg L, Hulthen L: Prediction of dietary iron absorption: an algorithm for calculating absorption and bio-availability of dietary iron. Am J Clin Nutr 2000;71:1147–1160. 

49. Jacob RA: Vitamin C. In: Modern Nutrition in Health and Disease (Shils ME, Olson JA, Shike M, eds.) Lea & Febiger, Philadelphia, PA, USA, 1994; 432–448. 

50. Nelson LH, Neal AL, Howland MA, Hoffman RS, Goldfrank LR, Flomenbaum NE: Goldfrank’s Toxicologic Emergencies. McGraw-Hill, New York, USA, 2010. 

51. JeonTI,HwangSG,ParkNG,JungYR,ShinSI,ChoiSD,ParkDK: Antioxidative effects of chitosan on chronic carbon tetrachloride induced hepatic injury in rats. Toxicology 2003;187:67–73.

52. Kumaravelu P, Dakshinamoorthy DP, Subramaniam S, Devaraj H, Devaraj NS: Effect of eugenol on drug-metabolizing enzymes of carbon tetrachloride-intoxicated rat liver. Biochem Pharm 1995;49:1703–1707. 

53. Scalbert A, Manach C, Morand C, Re ´me ´sy C, Jime ´nez L: Dietary polyphenols and the prevention of diseases. Crit Rev Food Sci Nutr 2005;45:287–306. 

54. Kleene R, Schachner M: Glycans and neural cell interactions. Nat Rev Neurosci 2004;5:195–208. 

55. Roche J: The History and Spread of Kombucha. http://w3.trib .com/*kombu/roche.html (accessed Jan 2013). 

56. Pasha C, Reddy G: Nutritional and medicinal improvement of black tea by yeast fermentation. Food Chem 2005;89:449–453. 

57. Motaff AC: Clarkes Isolation and Identification of Drugs. The Pharmaceutical Press, London, United Kingdom, 1992. 

58. Jayabalan R, Marimuthu S, Swaminathan K: Changes in content of organic acids and tea polyphenols during kombucha tea fermentation. Food Chem 2007;102:392–398. 

59. Yavari N, Assadi MM, Larijani K, Moghadam MB: Response surface methodology for optimization of glucuronic acid production using kombucha layer on sour cherry juice. Aust J Basic Appl Sci 2010;4:3250–3256. 

60. Deal CL, Moskowitz RW: Nutraceuticals as therapeutic agents in osteoarthritis. The role of glucosamine, chondroitin sulfate, and collagen hydrolysate. Rheum Dis Clin North Am 1999;25:379–395. 

61. Korkina LG, De Luca C, Kostyuk VA, Pastore S: Plant polyphenols and tumors: from mechanisms to therapies, prevention, and protection against toxicity of anti-cancer treatments. Curr Med Chem 2009;16:3943–3965. 

62. Figueiredo JC, Grau MV, Haile RW, Sandler RS, Summers RW, Bresalier RS, Burke CA, McKeown-Eyssen GE, Baron JA: Folic acid and risk of prostate cancer: results from a randomized clinical trial. J Natl Cancer Inst 2009;101: 432–435. 

63. Mo H, Zhu Y, Chen Z: Microbial fermented tea—a potential source of natural food preservatives. Trends Food Sci Technol 2008;19:124–130. 

64. Balentine DA: Special issue: tea and health. Crit Rev Food Sci Nutr 1997;8:691–692. 

65. Steiger KE, Steinegger E: On the tea fungus. Pharm Acta Helv 1957;32:88–93. 

66. Stadelman E: Der Teepilz und seine antibiotische Wirkung. In: Zentralblatt fu ¨r Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene, Erste Abteilung/Referate. Allgemeine Medizinische Mikrobiologie, Chemotherapie und Chemotherapeutica, 1961, pp. 401–435. (In German.) 

67. Hauser SP: Dr. Sklenar’s kombucha mushroom infusion—a biological cancer therapy. Schweiz Rundsch Med Prax 1990;79: 243–246. 

68. Blanc PhJ: Characterization of the tea fungus metabolites. Biotechnol Lett 1996;18:139–142. 

69. Freese E, Sheu CW, Galliers E: Function of lipophilic acids as antimicrobial food additives. Nature 1973;241:321–325. 

70. Stratford M, Anslow PA: Evidence that sorbic acid does not inhibit yeast as a classic ‘weak acid preservative’. Lett Appl Microbiol 1998;27:203–206. 

71. Bracey D, Holyoak CD, Coote PJ: Comparison of the inhibitory effect of sorbic acid and amphotericin B on Saccharomyces cerevisiae: is growth inhibition dependent on reduced intracellular pH? J Appl Microbiol 1998;85:1056–1066.

72. Krebs HA, Wiggins D, Stubs M, Sols A, Bedoya F: Studies on the mechanism of the antifungal action of benzoate. Biochem J 1983;214:657–663. 

73. Salmond CV, Kroll RG, Booth IR: The effects of food preservatives on pH homeostasis in Escherichia coli. J Gen Microbiol 1984;130:2845–2850.

74. Cole MB, Keenan MHJ: A quantitative method for predicting shelf life of soft drinks using a model system. J Ind Microbiol 1987;2:59–62. 

75. Eklund T: The effect of sorbic acid and esters of para-hydroxybenzoic acid on the proton motive force in Escherichia coli membrane vesicles. J Gen Microbiol 1985;131:73–76.

All comments

Leave a Reply