Gut Kombucha
CLINICAL STUDIES ON THE FOLLOWING INGREDIENTS:
Kombucha: A systematic review and meta-analysis of experimental evidence of its effects on blood glucose, dyslipidemia and body weight in diabetes mellitus
Abstract
Kombucha is a non-alcoholic fermented tea-based beverage produced by a symbiotic culture of bacteria and yeast. This growing popularity in the United States and developed countries has been part of the functional food’s movement in the use of plant infusions as a promising alternative to the benefits of the microbiome in the treatment of obesity and diabetes. However, recent studies show controversial information about the effects of Kombucha on health, often driven by different theories leading to the empirical use of the drink without standardization of quantity and forms, and preparation, which can cause harm to human health. Given that, we carried out this systematic review to evaluate the effect of Kombucha on health through pre-clinical studies with scientific evidence available in the literature, to enable future studies in humans.
Source: Mallmann M.M., Valderramas S., Garcia A.C., Petterle R.R., Duarte M.L. Ramos O. Jr. Kombucha: A systematic review and meta-analysis of experimental evidence of its effects on blood glucose, dyslipidemia and body weight in diabetes mellitus. 2022-05-05.
Health effects and probiotic and prebiotic potential of Kombucha: A bibliometric and systematic review
Abstract
Kombucha is a fermented beverage composed of a range of natural compounds such as sugars, ethanol, organic acids, and complex microbial communities of bacteria and yeasts. Based on this several biological properties are attributed to this drink. However, the production of kombucha is not standardized and the final composition of the beverage is highly dependent on the raw materials used and the physicochemical parameters adopted in the process. As a consequence, kombuchas not only vary from one producer to another but also from different batches of the same producer, making the assumptions of quality and properties questionable. In this review, we explore the largely unchecked relations between kombucha and its claimed health benefits. A systematic review was also performed to specifically discuss the potential probiotic and prebiotic effects of kombucha. Although several studies report that kombucha present antimicrobial, antioxidant, detoxifying, and hepatoprotective activities, among others, whereas others classify kombucha as a probiotic drink, there is a lack of scientific evidence about the content of probiotics in this drink and its possible role in the intestinal microbiota. These facts highlight the opportunities in researching and modifying the microbiome composition of kombucha, possibly improving the general qualities of this so-called functional drink.
Source: Bruna Krieger Vargas, Mariana Fensterseifer Fabricio, Marco Antônio Záchia Ayub, Health effects and probiotic and prebiotic potential of Kombucha: A bibliometric and systematic review, Food Bioscience, Volume 44, Part A, 2021, 101332, ISSN 2212-4292.
Effect of kombucha intake on the gut microbiota and obesity-related comorbidities: A systematic review
Abstract
Kombucha is a fermented nonalcoholic tea-based beverage produced through a symbiotic culture of bacteria and yeasts. In vitro studies have demonstrated antimicrobial, antioxidant, antiproliferative, and anti-carcinogenic properties of kombucha. However, no systematic reviews have evaluated the effects of kombucha in vivo. Thus, we aimed to evaluate the evidence that exists so far about kombucha consumption on comorbidities associated with obesity as well as on the gut microbiota. The search was conducted in accordance with PRISMA and the protocol was registered in PROSPERO (registration number: CRD42020158917). The MEDLINE/PubMed, Web of Science, LILACS, SciELO, Scopus, and Science Direct databases were used in the search considering the following terms: “kombucha” OR “kombucha tea” OR “kombucha teas” OR “tea, kombucha” OR “teas, kombucha” NOT “review.” Fifteen studies were included in this review. The results suggest that kombucha consumption attenuates oxidative stress and inflammation, improves the liver detoxification process, and reduces intestinal dysbiosis. There is evidence that kombucha consumption is beneficial for the control and treatment of obesity and associated comorbidities, as well as for the modulation of the gut microbiota in vivo.
Source: Costa, M. A. de C., Vilela, D. L. de S., Fraiz, G. M., Lopes, I. L., Coelho, A. I. M., Castro, L. C. V., & Martin, J. G. P. (2023). Effect of kombucha intake on the gut microbiota and obesity-related comorbidities: A systematic review. Critical Reviews in Food Science and Nutrition, 63(19), 3851–3866.
Kombucha tea as an anti-hyperglycemic agent in humans with diabetes – a randomized controlled pilot investigation
Introduction: Kombucha is a popular fermented tea that has attracted considerable attention due, in part, to its suggested health benefits. Previous results from animal models led us to hypothesize kombucha may reduce blood sugar levels in humans with diabetes. The objective of this pilot clinical study was to evaluate kombucha for its anti-hyperglycemic activities in adults with diabetes mellitus type II.
Methods: The study was organized as a prospective randomized double-blinded crossover study at a single-center urban hospital system. Participants (n = 12) were instructed to consume either a kombucha product or a placebo control (each 240 mL) for 4 weeks. After an 8-week washout period, participants consumed the alternate product. Fasting blood glucose levels were self-determined at baseline and at 1 and 4 weeks during each treatment period. Secondary health outcomes, including overall health, insulin requirement, gut health, skin health, mental health, and vulvovaginal health were measured by questionnaire at the same time points. The kombucha microbiota was assessed by selective culturing and 16S rRNA gene (bacteria) and ITS (fungi) sequencing. Fermentation end products were assessed by HPLC. Statistical significance of changes in fasting blood glucose was determined using paired, two-tailed student’s t-tests.
Results: Kombucha lowered average fasting blood glucose levels at 4 weeks compared to baseline (164 vs. 116 mg/dL, p = 0.035), whereas the placebo did not (162 vs. 141 mg/dL, p = 0.078). The kombucha microbiota, as assessed by cultural enumeration, was mainly comprised of lactic acid bacteria, acetic acid bacteria, and yeast, with each group present at about 106 colony forming units (CFU)/mL. Likewise, 16S rRNA gene sequencing confirmed that lactic acid and acetic acid bacteria were the most abundant bacteria, and ITS sequencing showed Dekkera was the most abundant yeast. The primary fermentation end products were lactic and acetic acids, both less than 1%. Ethanol was present at 1.5%.
Discussion: Although this pilot study was limited by a small sample size, kombucha was associated with reduced blood glucose levels in humans with diabetes. Larger follow-up studies are warranted.
Source: Mendelson C., Sparkes S., Merenstein D. J., Christensen C., Sharma V., Desale S., Auchtung J. M., Kok C. R., Hallen-Adams H. E., Hutkins R. Kombucha tea as an anti-hyperglycemic agent in humans with diabetes – a randomized controlled pilot investigation. Frontiers in Nutrition, Volume 10, 2023. DOI: 10.3389/fnut.2023.1190248, ISSN: 2296-861X.
Effect of regular green tea (Camellia sinensis) kombucha consumption on oxidative stress and endothelial health in individuals with excess body weight: a randomized controlled trial
Abstract
Kombucha is a fermented beverage rich in bioactive compounds. This beverage has demonstrated high antioxidant capacity in vitro and experimental animal studies. In this sense, this study aimed to evaluate the effect of daily consumption of green tea kombucha on oxidative stress and endothelial health in individuals with excess body weight. This is a randomized controlled clinical trial, lasting 10 weeks, during which the control group followed a healthy −500 kcal/d energy-restricted diet. In contrast, the kombucha group, in addition to the energy-restricted diet, consumed 200 ml of kombucha green tea daily. This study included men and women aged 18–45 years without chronic diseases. At the beginning and end of the study, fasting blood was collected, and colorimetric assays and immunoassay protocols evaluated markers of oxidative stress and endothelial health. Compared to the control group, kombucha consumption significantly reduced hydrogen peroxide (H2O2) levels (P = 0·007). Initial and final values were as follows: Control group (16·5 v. 15·09 µmol/ml; n 29) and Kombucha group (18·14 v. 14·67 µmol/ml; n 30). The other markers that were evaluated did not change after the kombucha consumption. In conclusion, daily consumption of 200 ml of green tea kombucha for 10 weeks reduces one pro-oxidant marker, without altering other markers of oxidative stress and endothelial health in individuals with excess body weight. Reducing a pro-oxidant marker suggests that kombucha is an antioxidant beverage with promising implications for human health. However, further studies are needed to elucidate other possible beneficial effects on health.
Source: Bonifácio DB, Macedo Fraiz G, Lacerda UV, et al. Effect of regular green tea (Camellia sinensis) kombucha consumption on oxidative stress and endothelial health in individuals with excess body weight: a randomized controlled trial. British Journal of Nutrition. 2025;134(1):70-78. doi:10.1017/S0007114525103838.
Benefits of Kombucha Consumption: A Systematic Review of Clinical Trials Focused on Microbiota and Metabolic Health
Background: Fermented foods rich in bioactive compounds have been proposed as potential strategy to combat non-communicable diseases. Among them is kombucha, a beverage fermented from sugared Camellia sinensis tea by a symbiotic culture of bacteria and yeasts (SCOBY). Recently, there has been an increased focus on assessing the actual effect of this beverage on human health. In this manner, this systematic review aimed to gather clinical evidence on the impact of kombucha consumption on human health.
Methods: The databases Cochrane CENTRAL, MEDLINE/PubMed, and Embase® were searched, and the risk of bias tool used was the Critical Appraisal Tools outlined in the Joanna Briggs Institute. This review followed the PRISMA guidelines and was registered on PROSPERO (CRD42024599464).
Results: Eight clinical trials were included (two pre- and post-interventions and six randomized controlled trials) with durations ranging from 10 days to 10 weeks. Two studies reported beneficial effects of kombucha on gastrointestinal symptoms, such as reduced intensity of constipation-related complaints. Two trials observed changes in gut microbiota composition, including increased abundance in Bacteroidota, Akkermansiaceae, Saccharomyces, and Weizmannia coagulans, alongside reductions in Ruminococcus, Dorea, and Rhodotorula. Moreover, five clinical trials evaluated glucose metabolism, evidencing inconsistent results, and other studies identified improvements in salivary microbiota composition and serum metabolomic profile.
Conclusion: These findings suggest that kombucha consumption may provide health benefits, particularly in alleviating gastrointestinal symptoms, and demonstrates a modest capacity for modulating gut and salivary microbiota, as well as metabolomic profiles. Although the results are promising, the heterogeneity of the studies and the limited number of available clinical trials highlight the need for further robust research to confirm these effects.
Source: Fraiz, G. M., Bonifácio, D. B., de Paulo, R. S., Teixeira, C. M., Martino, H. S. D., Barros, F. A. R. d., Milagro, F. I., & Bressan, J. (2025). Benefits of Kombucha Consumption: A Systematic Review of Clinical Trials Focused on Microbiota and Metabolic Health. Fermentation, 11(6), 353.
References:
- https://rsdjournal.org/index.php/rsd/article/view/29278
- https://www.sciencedirect.com/science/article/abs/pii/S2212429221004570?via%3Dihub
- https://www.tandfonline.com/doi/full/10.1080/10408398.2021.1995321
- https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2023.1190248/full
- https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/abs/effect-of-regular-green-tea-camellia-sinensis-kombucha-consumption-on-oxidative-stress-and-endothelial-health-in-individuals-with-excess-body-weight-a-randomized-controlled-trial/40944A1841B93BA6F330A56886E64A3A
- https://www.mdpi.com/2311-5637/11/6/353