Kombucha’s clearest benefit in people is a change in gut bacteria. Six weeks of a fiber-enriched kombucha raised Bifidobacterium in a 60-person 2025 trial in Madrid, and eight weeks of black tea kombucha lowered fasting insulin in Brazilian volunteers with obesity.
Lower cholesterol and faster weight loss both failed when researchers tested them in people, and the detox, liver and cancer claims rest on rats and cell cultures.
I brew kombucha at home in 1-gallon glass jars under fine unbleached cheesecloth tied down with twine, and the tea and sugar run about $3 a gallon. Everything below comes from 13 human trials and intervention studies published through October 2026, drawn from 11 separate groups of volunteers. The largest enrolled 90 people, and the longest ran 12 weeks.
✦ Key Takeaways
- Gut bacteria shift in the human trials. Bifidobacterium rose in a 60-person Madrid trial, and Akkermansiaceae and Subdoligranulum rose in Brazilian volunteers with obesity.
- Blood sugar results are promising and thin. A 12-person Georgetown pilot cut average fasting glucose from 164 to 116 mg/dL, though the gap against placebo was not statistically significant (p = 0.265). An open-label Iranian trial of 75 people with Type 2 diabetes dropped A1C from 8.56% to 7.34% in six weeks.
- Cholesterol and weight loss did not improve in people. Green tea kombucha added nothing to a 10-week calorie-cut diet in a 59-person trial.
- Cancer, detox and immunity have no human trials measuring disease or infection. Memorial Sloan Kettering states that kombucha “has not been shown to treat cancer or AIDS in humans.”
- Daily dose in the trials ran from 100 to 473 mL (about 3.5 to 16 oz). At 16 oz a day, 31% of drinkers reported diarrhea or bloating.
- Alcohol ran from 0.04% to 1.3% in 47 store-bought samples tested at Cornell, and two of the six brands averaged above the 0.5% federal line.
- Pregnancy and weakened immunity are the two groups MD Anderson names for avoiding kombucha, because the drink carries live bacteria and yeast.
Kombucha Benefits Claim by Claim
| Claim | Best Human Evidence | Result |
|---|---|---|
| Healthier gut bacteria | Randomized trial, 58 adults, 6 weeks (Madrid, 2025); pre-post study, 36 adults, 8 weeks (Brazil, 2024) | Bifidobacterium up; Akkermansiaceae and Subdoligranulum up in obesity |
| Regularity | Randomized pilot, 40 women with IBS-C, 10 days (Russia, 2022) | Bowel movements up from 0.60 to 0.85 a day with an inulin-enriched kombucha drink |
| Blood sugar in Type 2 diabetes | Crossover pilot, 12 adults (Georgetown, 2023); open-label trial, 75 adults (Iran, 2025) | Fasting glucose fell within the kombucha phase; A1C fell 1.22 points |
| Insulin resistance | Pre-post study, 16 adults with obesity (Brazil, 2024) | HOMA-IR down from 3.75 to 2.78; healthy San Diego drinkers went up from 1.39 to 2.01 |
| Lower cholesterol | 2025 systematic review of 8 trials | No significant change in lipid profiles |
| Weight loss | Randomized trial, 59 adults, 10 weeks (Brazil, 2024) | Lost the same as diet alone |
| Antioxidant effect | Same 59-person trial; 90 beginner runners, 12 weeks (2026) | Hydrogen peroxide fell; antioxidant capacity unchanged in runners |
| Immune support | 90 beginner runners, 12 weeks (2026) | Neutrophil and lymphocyte counts shifted; no infection or illness data |
| Liver protection and detox | None | Rodent studies only |
| Cancer prevention | None | Cell and rodent studies only |
What Is in Kombucha
Kombucha is sweetened tea fermented by a SCOBY, a symbiotic culture of bacteria and yeast that grows as a rubbery disc on the surface. The yeasts turn sugar into alcohol, and acetic acid bacteria convert that alcohol into acetic, gluconic and glucuronic acids, which is why the finished drink tastes tart. Tea polyphenols carry through, and unpasteurized bottles hold living microbes.
A 2025 survey in FEMS Yeast Research of 23 starters from France found five taxa in nearly every one: the yeasts Brettanomyces bruxellensis and B. anomalus, and the bacteria Komagataeibacter, Lactobacillus and the Acetobacteraceae family. A 2021 sequencing study of a single Australian brand, The Good Brew, put Acetobacter at about 57% of bacterial reads and Komagataeibacter at 34%.
| Serving | Calories | Sugar | Caffeine |
|---|---|---|---|
| 8 fl oz (one glass) | 40 | 9.9 g | 27 mg |
| 12 fl oz (small bottle) | 60 | 14.8 g | 41 mg |
| 16 fl oz (large bottle) | 79 | 19.8 g | 55 mg |
Cornell food scientists J.H. Sogin and Randy Worobo measured 47 samples from six brands that together held more than half of U.S. kombucha sales, and total sugar ran from 15 to 48 grams per liter. Three of the six brands missed their own label sugar figure.
Caffeine lands at roughly half the level of the tea it was brewed from: 101 micrograms per mL in kombucha against 218 in black tea, in a 2019 Slovak study in Acta Alimentaria.
The origin story repeated through food-science reviews, including Rasu Jayabalan’s 2014 review in Comprehensive Reviews in Food Science and Food Safety, places kombucha in Manchuria around 220 B.C. and credits a physician named Kombu with carrying it to Japan in 414 A.D. None of those reviews cites a primary historical record for either date.
Kombucha and Gut Health
Fraiz and colleagues at the Universidade Federal de Viçosa pooled eight trials in a 2025 systematic review in Fermentation and found microbiome shifts and fewer constipation complaints, alongside “inconsistent findings on glucose metabolism,” and concluded that “while preclinical evidence is promising, the current clinical data remain inconclusive.”
Fiber-Enriched Kombucha in Madrid
Researchers at IMDEA Food in Madrid published a double-blind gut trial in June 2025. Sixty healthy adults were randomized to 250 mL a day of a fiber-modified kombucha or an unfermented tea for six weeks, and 58 finished. Bifidobacterium rose in the kombucha group and Ruminococcus torques, a species the authors link to inflammatory bowel disease, fell.
Triglycerides dropped too (treatment effect p = 0.031). The added fiber is a prebiotic in its own right, so the result belongs to the fiber and the fermented tea together.
Black Tea Kombucha and Obesity in Brazil
The Viçosa group gave 200 mL a day of house-brewed black tea kombucha to 46 adults for eight weeks, half with obesity, and 36 finished. With no kombucha-free control group, each person served as their own comparison. In the volunteers with obesity, stool sequencing showed more Bacteroidota, Akkermansiaceae and the butyrate producer Subdoligranulum, and less Ruminococcus and Dorea.
Normal-weight volunteers gained yeasts instead, mostly Pichia, Dekkera and Saccharomyces. Short-chain fatty acids and gut-permeability markers held steady in both groups. The house brew tested at 0.57% alcohol.
The San Diego Trial and Its Added Probiotic
Jack Gilbert’s lab at UC San Diego tested 16 oz a day of a commercial kombucha in 24 adults on a low-fiber Western diet, published in Scientific Reports in December 2024. GT’s Living Foods funded the study, and its drink contained added Bacillus coagulans, which microbiologists have since renamed Weizmannia coagulans. That added species rose in drinkers’ stool.
Bifidobacterium, Prevotella and other short-chain fatty acid producers also increased, while overall diversity fell, and the authors described the effect on the microbiome as “modest.”
Does Kombucha Make You Poop?
It did in women with constipation. In a Moscow pilot, 40 women with constipation-predominant IBS drank 220 mL a day of a pasteurized, non-alcoholic kombucha drink with 2.53 grams of inulin and B vitamins, or water, for 10 days.
Bowel movements rose from 0.60 to 0.85 a day (p = 0.004), stools moved from a 3.0 to a 4.4 on the Bristol scale, and the sense of incomplete emptying eased. Pain and bloating did not change.
In the 59-person Brazilian weight-loss trial, 200 mL of plain green tea kombucha a day for 10 weeks brought fewer hard stools and less reflux and stomach fullness than diet alone, and a 39-person 2026 study of 100 mL a day raised the share of normal, type 4 stools.
In the San Diego trial, 31% of the 16-oz drinkers reported diarrhea or bloating against 12.5% of controls, and one person quit over the bloating.
Is Kombucha a Probiotic?
Most U.S. kombucha is alive. Cornell found live acetic acid bacteria, lactic acid bacteria and yeast in most of its 47 retail samples, with yeast counts reaching 7.1 log, about 12 million cells per mL.
Live microbes alone do not make a probiotic, which requires a defined strain shown to benefit people, and the 2025 review says kombucha is “often promoted as a probiotic beverage on commercial labels… However, this probiotic health claim is not well-established.”
For antibiotics, my guide to which probiotic to take with which antibiotic matches strains to drugs.
Kombucha and Blood Sugar
The Georgetown Pilot
Dan Merenstein, a professor of family medicine at Georgetown, led the first kombucha trial in people with Type 2 diabetes, published in Frontiers in Nutrition in August 2023. Twelve adults drank 240 mL (8 oz) of kombucha with dinner for four weeks and a look-alike placebo for four more, with an eight-week washout between.
The kombucha came from Craft Kombucha in Washington, D.C., and tested at 1.5% alcohol.
Average fasting glucose fell from 164 to 116 mg/dL on kombucha (p = 0.035) and from 163 to 142 on placebo (p = 0.078). Only seven people finished every glucose measurement, and the difference between kombucha and placebo at four weeks was not statistically significant (p = 0.265).
In the five volunteers who started above 130 mg/dL, kombucha cut fasting glucose by 74 points against 16 on placebo.
“Some laboratory and rodent studies of kombucha have shown promise, and one small study in people without diabetes showed kombucha lowered blood sugar, but to our knowledge this is the first clinical trial examining effects of kombucha in people with diabetes,” Merenstein said in Georgetown’s announcement.
The Iranian Trial
A larger 2025 trial from Qazvin University of Medical Sciences, published in Clinical Diabetes, split 75 adults with Type 2 diabetes into three groups of 25: kombucha, reishi mushroom (Ganoderma lucidum) or neither, for six weeks. Everyone stayed on their usual diabetes medication, and kombucha drinkers worked up from 100 to 200 mL a day.
The trial was open-label with no placebo drink.
| Measure | Kombucha Before | Kombucha After | Control A1C |
|---|---|---|---|
| Fasting glucose (mg/dL) | 172.9 | 142.0 | |
| 2-hour glucose after a meal (mg/dL) | 230.9 | 184.1 | |
| A1C (%) | 8.56 | 7.34 | 8.18 to 8.10 |
Insulin Moved in Opposite Directions
In the Brazilian volunteers with obesity, eight weeks of 200 mL a day lowered fasting insulin from 15 to 12 and HOMA-IR, a measure of insulin resistance, from 3.75 to 2.78 (Fermentation, 2024).
The healthy San Diego drinkers on 16 oz a day went the other way, with insulin climbing from 6.15 to 9.30 and HOMA-IR from 1.39 to 2.01 (p = 0.021), though that change did not separate from the control group.
Kombucha drunk with a meal also blunted that meal’s glucose spike in an acute University of Sydney study of 11 healthy adults. Paired with 330 mL of The Good Brew kombucha, a jasmine rice meal scored a glycemic index of 68, against 86 with soda water (p = 0.041). One author consults for The Good Brew.
Kombucha, Cholesterol and Weight Loss
Rodents fed high-cholesterol diets show lower cholesterol and less weight gain on kombucha. The 2025 review found that the human trials “did not demonstrate significant improvements in lipid profiles.”
The reviewers credit the gap to “the highly controlled conditions of animal studies, which often do not reflect the complexity and variability of human clinical settings.”
A 2021 Viterbo University abstract gave 25 mostly lean adults 4 oz a day for four weeks and found no change in triglycerides (P = 0.958), HDL (P = 0.894), LDL (P = 0.424) or total cholesterol (P = 0.373).
In the Brazilian obesity study, total cholesterol in the normal-weight group rose from 166 to 177 mg/dL, a rise the authors traced to volunteers whose diet quality slipped during the study.
For weight, the Viçosa group put 59 adults with excess weight on a diet 500 calories a day below their needs for 10 weeks, and half added 200 mL of green tea kombucha. Both groups lost weight, BMI and body fat at the same rate, and the authors concluded that kombucha “did not enhance weight loss.”
A 2026 follow-up on the same volunteers found lipid markers improved within the kombucha group, with no difference from the diet-only group.
Antioxidant and Antimicrobial Claims
Tea polyphenols give kombucha measurable antioxidant activity in the lab. In people, the 59-person Brazilian trial saw blood hydrogen peroxide, a pro-oxidant marker, fall from 18.14 to 14.67 µmol/mL on kombucha against 16.5 to 15.09 on diet alone (P = 0.007), with no change in its other oxidative-stress markers.
A 2026 trial in 90 beginner runners found no effect on antioxidant capacity, its primary outcome, after 12 weeks.
In petri dishes, kombucha inhibits E. coli, Salmonella, Staphylococcus aureus, Helicobacter pylori and other pathogens, mostly through acetic acid. G. Sreeramulu’s group found some activity against E. coli and Salmonella survived neutralizing the acid and heating the sample, which points to polyphenols and other compounds as well. No trial has tested whether drinking kombucha prevents an infection.
Liver, Detox and Cancer Claims
Rodent studies show kombucha blunting liver damage from acetaminophen, carbon tetrachloride and the solvent trichloroethylene. The detox story leans on glucuronic acid, which the liver uses to tag toxins for excretion, but whether a glass of kombucha raises that pathway in a person has never been measured.
Across the eight human trials in the 2025 review, liver and kidney markers did not improve, apart from a 1-point GGT drop in the Brazilian volunteers with obesity.
Cancer research on kombucha stops at cell lines and animals, including breast, colon, prostate, kidney and bone cancer cells. Memorial Sloan Kettering states that “Kombucha has not been shown to treat cancer or AIDS in humans,” and advises that patients with suppressed immune systems avoid kombucha “produced in an uncontrolled environment,” citing reported Aspergillus contamination.
MSK also notes that kombucha’s acidity can change how the body absorbs drugs that depend on stomach pH.
How Much Kombucha Should You Drink a Day?
One 8 to 12 oz serving a day sits inside the range the human trials tested, and 16 oz is where side effects climbed.
| Study | Daily Amount | Length |
|---|---|---|
| Iran, Type 2 diabetes (2025) | 100 mL, then 200 mL | 6 weeks |
| Brazil, obesity cohort (2024) | 200 mL (6.8 oz) | 8 weeks |
| Georgetown, Type 2 diabetes (2023) | 240 mL (8 oz) | 4 weeks |
| Madrid, healthy adults (2025) | 250 mL (8.5 oz) | 6 weeks |
| Wales, healthy adults (2025) | 330 mL (11 oz) | 8 weeks |
| San Diego, healthy adults (2024) | 473 mL (16 oz) | 4 weeks |
| Liver injury case report (2023) | 32 oz, plus 10 to 15 oz of wine | About 3 months |
The Iranian trial reported no adverse events at 200 mL, and Georgetown logged one bloating case at 240 mL.
No study has compared drinking kombucha at different times of day. The Georgetown volunteers drank theirs with dinner, and the Sydney study, the only one tying timing to an outcome, served it alongside a carbohydrate meal.
Kombucha Side Effects and Risks
Liver Injury and Acidosis Case Reports
A 2023 case report in Gastro Hep Advances describes a previously healthy 42-year-old woman who drank 32 oz of kombucha a day for about three months, along with 10 to 15 oz of wine a day.
She arrived with an ALT of 634, a biopsy showed more than 95% liver cell death, and she recovered at a transplant center without needing a new liver. Her doctors judged the injury “most likely related to kombucha.”
Lactic acidosis, a dangerous buildup of acid in the blood, shows up in the older reports. In 1995 the CDC investigated two Iowa women who fell ill with severe acidosis after drinking home-brewed kombucha from the same parent culture; one, 59, died after cardiac arrest. Both drank about 4 oz a day, one having recently tripled to 12 oz, and the CDC did not establish that the tea caused the illness.
A 22-year-old newly diagnosed with HIV developed acidosis, kidney failure and a 103°F fever within 15 hours of drinking kombucha in a 2009 report, and a 54-year-old British woman who drank homemade kombucha daily for months recovered within about 18 hours in 2017.
Who Should Skip Kombucha
- Pregnant women. MD Anderson warns that kombucha’s live bacteria “could be harmful to immunocompromised or pregnant people.”
- People with weakened immune systems, including those on chemotherapy or living with HIV, given the live cultures, the Aspergillus reports and the 2009 acidosis case.
- Young children. No kombucha trial has enrolled children, and a 16-oz bottle can carry 55 mg of caffeine and, in some brands, more than 0.5% alcohol.
- Anyone with liver or kidney disease, given the necrosis and kidney-failure cases.
- People on drugs that depend on stomach acid, which kombucha’s acidity can affect, per MSK.
- Anyone avoiding alcohol for medical, religious or recovery reasons.
Kombucha Alcohol Content
Federal law treats kombucha as an alcoholic beverage once it reaches 0.5% alcohol “at any time,” according to the Alcohol and Tobacco Tax and Trade Bureau, which covers bottles that keep fermenting on the shelf. Cornell’s 47 retail samples ran from 0.04% to 1.3%, and two of the six brands averaged 0.84% and 0.75%.
The trial drinks ran higher than many store bottles: 1.5% at Georgetown and 0.57% in Brazil.
The KOMBUCHA Act, reintroduced on April 30, 2026 by Reps. Andrea Salinas and Adrian Smith and Sen. Ron Wyden, would raise the federal line to 1.25%. “A serving of kombucha contains about as much alcohol as an overripe banana,” Wyden said.
Lead From Ceramic Vessels
Kombucha’s acid pulls lead out of glazed ceramic. An Australian couple needed chelation therapy in 1998 after six months of drinking kombucha brewed in a ceramic pot, and in 2023 Spanish health officials traced a family’s lead poisoning to commercially made kombucha sold in ceramic containers, which tested at 47 mg of lead per kilogram.
Brewing Kombucha at Home Safely
My setup is glass from start to finish: 1-gallon fermentation jars with plastic lids for storage, fine unbleached cheesecloth tied on with twine to keep fruit flies out, and flip-top Grolsch-style bottles for the second fermentation. Metal lids rust in kombucha’s acid, and glazed ceramic leaches lead.
Fuzzy, colored mold growing on top of the SCOBY means the batch goes in the trash, culture included. The full equipment list and costs are in my kombucha brewing equipment guide.
Frequently Asked Questions
Is kombucha good for you?
Small human trials show kombucha shifting gut bacteria toward species linked to health, and early trials suggest it may help blood sugar in Type 2 diabetes. A 2025 systematic review of eight human trials called the clinical evidence inconclusive. Human trials found no effect on cholesterol or weight loss, and no trial has tested cancer or detox claims.
How much kombucha should you drink a day?
One 8 to 12 oz serving a day matches the amounts used in human trials, which ranged from 100 to 473 mL. At 16 oz a day, 31% of drinkers in a 2024 UC San Diego trial reported diarrhea or bloating. Case reports of liver injury involved 32 oz a day for months.
What is the best time to drink kombucha?
No study has compared times of day. In a 2023 University of Sydney study, kombucha drunk with a rice meal lowered that meal’s glycemic index from 86 to 68, and the Georgetown diabetes trial had volunteers drink it with dinner.
Does kombucha make you poop?
It increased bowel movements in a 2022 trial of 40 women with constipation-predominant IBS, from 0.60 to 0.85 a day over 10 days. That drink had added inulin, a fiber. A 16-oz daily dose brought diarrhea or bloating to 31% of a 2024 San Diego trial group.
Does kombucha help with bloating?
The trials do not show it. A 2022 constipation trial found no change in bloating, and in a 2024 UC San Diego trial 31% of people drinking 16 oz a day reported diarrhea or bloating against 12.5% of controls.
Is kombucha a probiotic?
Kombucha contains live bacteria and yeast unless pasteurized, and Cornell found live microbes in most of 47 U.S. retail samples. A 2025 systematic review called the probiotic claim on kombucha labels “not well-established,” because a probiotic requires a defined strain with proven benefit.
Can kids drink kombucha?
No kombucha trial has included children. A 16-oz bottle can hold about 55 mg of caffeine and 20 grams of sugar, and two of six major U.S. brands tested by Cornell averaged more than 0.5% alcohol.
Can you drink kombucha while pregnant?
MD Anderson Cancer Center advises against it, saying kombucha’s live bacteria “could be harmful to immunocompromised or pregnant people.” Kombucha also contains caffeine and can exceed 0.5% alcohol.
How much alcohol is in kombucha?
Store-bought kombucha tested at Cornell ran from 0.04% to 1.3% alcohol by volume across 47 samples. Federal rules treat it as alcohol once it reaches 0.5% at any time, and the KOMBUCHA Act reintroduced in April 2026 would raise that line to 1.25%.
Does kombucha lower cholesterol or help you lose weight?
Not in people. A 2025 systematic review of eight human trials found no significant improvement in lipid profiles, and a 10-week trial of 59 dieters found green tea kombucha “did not enhance weight loss.” The cholesterol results come from rodent studies.
Can kombucha treat cancer?
No. Kombucha has only been tested on cancer cells and in animals, and Memorial Sloan Kettering states it “has not been shown to treat cancer or AIDS in humans.” MSK advises patients with weakened immune systems to avoid kombucha not made under controlled conditions.
How long does it take for kombucha to work?
Gut bacteria changes appeared after four to eight weeks of daily drinking in the human trials. The Georgetown diabetes pilot measured lower fasting glucose after four weeks, and a single serving with a meal blunted that meal’s blood sugar spike within hours.
Sources
Systematic Review
- Fraiz GM, et al. “Benefits of Kombucha Consumption: A Systematic Review of Clinical Trials Focused on Microbiota and Metabolic Health.” Fermentation. 2025;11(6):353. https://www.mdpi.com/2311-5637/11/6/353
Earlier Reviews
- Kapp JM, Sumner W. “Kombucha: a systematic review of the empirical evidence of human health benefit.” Annals of Epidemiology. 2019;30:66-70. https://pubmed.ncbi.nlm.nih.gov/30527803/
- Costa MAC, et al. “Effect of kombucha intake on the gut microbiota and obesity-related comorbidities: A systematic review.” Critical Reviews in Food Science and Nutrition. 2023;63(19):3851-3866. https://pubmed.ncbi.nlm.nih.gov/34698580/
Human Trials
- Arce-López B, et al. “Effect of fiber-modified kombucha tea on gut microbiota in healthy population: A randomized controlled trial.” Current Research in Food Science. 2025;11:101130. https://pubmed.ncbi.nlm.nih.gov/40689297/
- Costa MAC, et al. “Regular Consumption of Black Tea Kombucha Modulates the Gut Microbiota in Individuals with and without Obesity.” Journal of Nutrition. 2025;155(5):1331-1349. https://www.sciencedirect.com/science/article/pii/S0022316624012392
- Fraiz GM, et al. “Black Tea Kombucha Consumption: Effect on Cardiometabolic Parameters and Diet Quality of Individuals with and without Obesity.” Fermentation. 2024;10(8):384. https://www.mdpi.com/2311-5637/10/8/384
- Ecklu-Mensah G, et al. “Modulating the human gut microbiome and health markers through kombucha consumption: a controlled clinical study.” Scientific Reports. 2024;14:31647. https://www.nature.com/articles/s41598-024-80281-w
- Isakov VA, Pilipenko VI, et al. Kombucha-based drink in women with constipation-predominant IBS: a randomized pilot study. Current Developments in Nutrition. 2023;7(12):102037. https://pubmed.ncbi.nlm.nih.gov/38149073/
- Mendelson C, et al. “Kombucha tea as an anti-hyperglycemic agent in humans with diabetes: a randomized controlled pilot investigation.” Frontiers in Nutrition. 2023;10:1190248. https://pmc.ncbi.nlm.nih.gov/articles/PMC10426908/
- Yekefallah L, et al. “Comparing the Effects of Ganoderma lucidum and Kombucha Mushrooms on Glycemic Control in Patients With Type 2 Diabetes: A Randomized Clinical Trial.” Clinical Diabetes. 2025;43(5):813-822. https://diabetesjournals.org/clinical/article/43/5/813/163688
- Atkinson FS, et al. Kombucha and postprandial glycemic response. Frontiers in Nutrition. 2023. https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2023.1036717/full
- Fraiz GM, et al. Green tea kombucha within an energy-restricted diet. Nutrients. 2024;16(18):3186. https://pubmed.ncbi.nlm.nih.gov/39339787/
- Bonifácio DB, et al. Green tea kombucha and oxidative stress markers. British Journal of Nutrition. 2025;134(1):70-78. https://pubmed.ncbi.nlm.nih.gov/40637142/
- Bonifácio DB, et al. Green tea kombucha in beginner runners: a randomized controlled trial. Journal of Food Science. 2026;91(9):e71505. https://pubmed.ncbi.nlm.nih.gov/42799570/
Composition and Safety
- Sogin JH, Worobo RW. “Primary Metabolites and Microbial Diversity in Commercial Kombucha Products.” Fermentation. 2024;10:385. https://doi.org/10.3390/fermentation10080385
- Ben Saad E, et al. Comprehensive survey of kombucha microbial communities. FEMS Yeast Research. 2025;25:foaf005. https://academic.oup.com/femsyr/article/doi/10.1093/femsyr/foaf005/7998921
- Sannapaneni S, et al. “Kombucha-Induced Massive Hepatic Necrosis: A Case Report and a Review of Literature.” Gastro Hep Advances. 2023;2(2):196-198. https://pmc.ncbi.nlm.nih.gov/articles/PMC11308232/
- “Kombucha: Can You Liver With or Without It?” American Journal of Gastroenterology. 2024;119(10S):S4456 (case abstract). https://journals.lww.com/ajg/fulltext/2024/10001/s4456_kombucha__can_you_liver_with_or_without_it_.4457.aspx
- “Fermented Danger: Metabolic Acidosis Triggered by Kombucha.” Journal of the American Society of Nephrology. 2025 (case abstract). https://journals.lww.com/jasn/fulltext/2025/10001/fermented_danger__metabolic_acidosis_triggered_by.674.aspx
- Centers for Disease Control and Prevention. “Unexplained Severe Illness Possibly Associated with Consumption of Kombucha Tea, Iowa, 1995.” MMWR. 1995;44(48). https://www.cdc.gov/mmwr/preview/mmwrhtml/00039742.htm
- Holbourn A, Hurdman J. “Kombucha: is a cup of tea good for you?” BMJ Case Reports. 2017. https://pmc.ncbi.nlm.nih.gov/articles/PMC5747697
- Memorial Sloan Kettering Cancer Center. “Kombucha.” https://www.mskcc.org/cancer-care/integrative-medicine/herbs/kombucha
- MD Anderson Cancer Center. “What are the benefits of drinking kombucha?” https://mdanderson.org/cancerwise/what-are-the-benefits-of-drinking-kombucha.h00-159542901.html
- Alcohol and Tobacco Tax and Trade Bureau. “Kombucha.” https://www.ttb.gov/regulated-commodities/beverage-alcohol/kombucha
- USDA FoodData Central. “Tea, kombucha.” https://fdc.nal.usda.gov/food-details/2710509/nutrients
Article Updates:
- October 18, 2026: Rewrote and reorganized the article around a claim-by-claim evidence table. Added five human trials published since February (Madrid fiber trial, Iranian diabetes trial, 2026 runners trial, Wales metabolome trial, 2026 Brazilian follow-ups), sections on daily dose, digestion, probiotics, alcohol content, lead from ceramic vessels and who should skip kombucha, and USDA nutrition figures. Corrections: the 2025 systematic review’s first author is Fraiz, not Gaggìa; the UC San Diego trial’s first author is Ecklu-Mensah, its drink contained an added probiotic, and GT’s Living Foods funded it; the Georgetown glucose drop was not significant against placebo; the review contains no contraindication list or toxicity statement, both previously attributed to it; the liver-necrosis patient also drank wine daily, and usnic acid has not been measured in kombucha; the Iowa patients drank about 4 oz a day, not large quantities; most U.S. commercial kombucha is unpasteurized; the 2025 SCOBY survey sampled French starters, not cultures worldwide. Removed claims that could not be verified against a primary source.
- February 3, 2026: Major revision incorporating 2024-2026 peer-reviewed research, including the 2025 systematic review, SCOBY microbiome research, the Brazilian cardiometabolic study and the Iranian RCT, plus expanded safety and sources sections.
- January 29, 2026: Complete revision adding clinical trial evidence for gut microbiome and blood sugar effects, safety case reports, the home-brewing section and a sources section.
- January 12, 2017: Original publication.
No company provided products or compensation for this article.
Wow. Thank you for such a well-researched piece. I’ve been wondering about Kombucha and whether or not to try it. I have all the information I need now! 🙂
Making your own kombucha is so easy guys! Don’t be afraid. If you can make sweet tea, you can brew kombucha. I even have my kids help me make it. (they are 2 and 9) I wrote up a little piece on my site. It’s not nearly as extensively researched as Mike’s here is, but it tells you how to make it. Seriously, it’s so easy. imsimplyadad.com/drink-kombucha-for-health/
Thank you so much for putting this article together! It was so interesting to read about the actual composition of kombucha. I’ve updated my own “how to brew kombucha” article to include a link to this article at the bottom. I think people who have unanswered questions about kombucha that are holding them back from brewing it themselves will really enjoy reading this detailed info that you’ve provided! Thanks for this wonderful article 🙂
Interesting read! Komucha has been very popular in my hometown, i had no idea it was suppose to be a fountain of youth!
xx nicole
http://www.nicoleparise.com
I used to drink it all the time but stopped. I need to get back into it since it’s so good for you!
Rachel | The Confused Millennial
This sounds amazing! I have RA and Fibromyalgia and I am always interested in learning new natural remedies to manage them. Great article!
Wow, what a well written article about Kombucha Health Benefits! I’ve seen Debbie posting about her Kombucha all the time, I need to try some! It might be a great tool to help with endurance training!
Excellent article. Sounds like I definitely should have had some kombucha on hand to help fight this awful flu I’ve had. I think I’m going to make my own through this article. Once I’m feeling better I’ll start the process.
Thanks!
I have seen this in multiple stores and was afraid to try it.. until now! Thanks for this! 🙂
I have made kombucha a regular part of my diet since reading up about pro and prebiotics. I am still too intimidated to attempt to make it myself! ha!
This is a spot-on post! I love Kombucha and have always believed in it’s beneficial properties!
I’m too afraid to make it myself but I definitely buy the drink in the stores!
It is so easy! Don’t be scared. Go for it
The “starter fluid”, a small amount of Kombucha to begin the fermentation with, raises the acidity of the sweet tea you start with and prevents any bad microorganisms from growing. The SCOBY forms a seal at the top of the mixture, and you keep it covered with a fine thread cloth, like Muslin, held in place with a rubber band, to keep anything bad out, like flies.
I was also leary of making it myself and spent a couple of years reading about it and watching youtube videos. The more I learned about it, the more I found out how safe it was, so I finally decided to give it a try.
The most surprising thing about starting to drink fresh homemade Kombucha is it seems to be stronger and more effective than any of the store-bought ones. None of the store bought ones made my stomach pain go away, but the homemade one did in only a couple of days.
Right now I have 2 continuous brews going using Black Tea (liptons), as some of the beneficial items in Kombucha don’t even start to be produced in less than 3 weeks; as well as a batch of Oolong, Green, and Black Tea (liptions). I noticed a difference in how fast and thick the SCOBY grew in each of these (Oolong the fastest and thickest; Black I’d say was “normal”; and Green the slowest and thinnest).
I’ve noticed a difference in how I feel when I drink the Kombucha depending on which tea it is made with, so now I’m looking for information on the difference in the bacteria that grows in each of them. I’ve found information stating that there is definitely a difference as to which beneficial bacteria grows and is present in different teas, but I want to know specifically which ones they are so I can look into them a bit more…
So, as the article said, Kombucha can SAFELY be prepared at home **WITHOUT pathogenic health risk**… after a while those $3-4 really start to add up, and brewing at home is ridiculously inexpensive once you’ve got the items to make your first batch… especially considering how safe it is…
Interesting research on the possibility that Kombucha may have positive effects on cancer treatment.
So much is unknown about cancer and there are so many kinds of cancer cells, more than I ever realized. Each cancer / cancer cell reacts differently to environmental factors, enzymes, and drugs. I checked to see if Kombucha was mentioned in the book I have on nutrition for cancer survivors. It isn’t.
I do believe there is much more research to be done with natural remedies for many diseases. At one point during cancer treatment, my white blood cell count dipped to a near dangerously low level. Someone suggested I drink pineapple juice with honey and I thought it was the most ridiculous suggestion – likely and old wives tale.
When I told my oncologist about the suggestion she said “Do it.” In other words, try it and see if it works. So I upped my intake of Vitamin C and PRESTO! my white blood cell count started going up. It sort of made me more of a believer that there may be something to the natural remedies that have been used for hundreds of years.
Now if they would only find a real “cure”.
I’ve seen this at the stores and have always been curious since it looks a little funny. I had been meaning to (eventually) look it up, so thank you for this post! 🙂
I have been reading up on how to make this and all the benefits. A friend made it and let me try some. Now I am really going to have to make my own.
Yeah! Kombucha is a very easy fermented drink to make. You can do it!