Green tea kombucha, weight, inflammation and mouth bacteria
What it found
In adults with excess body weight following a calorie-reduced diet for 10 weeks, green tea kombucha did not boost weight loss but did lower a fat-related index and changed mouth bacteria.
It also appeared to blunt a rise in one inflammatory signal seen in the control group.
What they found
Studies in people
Weight and body fat
Both groups lost weight and body fat, but there was no difference between the kombucha group and the control group. The control group lost 2.29 kg on average and the kombucha group 3.02 kg.
Lipid accumulation product
The kombucha group had a significant reduction in lipid accumulation product, an index based on waist circumference and triglycerides. The control group did not.
Inflammatory markers
Both groups had lower levels of IL-1β and IL-8. IL-6 increased significantly only in the control group, and this rise was significantly different from the kombucha group.
Mouth bacteria diversity
The kombucha group showed higher alpha diversity at genus level and different beta diversity at species level after the intervention. The ratio of Bacillota to Bacteroidota was lower in the kombucha group.
Specific mouth bacteria
Several bacterial species, including Catonella morbi, Schaalia odontolytica and Veillonella dispar, were less abundant in the kombucha group compared to the control group.
BMI and bacteria
BMI was positively associated with the Bacillota phylum in saliva. IL-6 was not significantly correlated with any of the bacteria.
What the authors conclude
“GTK did not enhance weight loss, but it decreased the LAP. GTK helped in the inflammatory profile and induced positive changes in oral microbiota composition.”
Also in their conclusions
- They conclude that green tea kombucha did not enhance weight loss but decreased the lipid accumulation product.
- They state that green tea kombucha helped in the inflammatory profile and induced positive changes in oral microbiota composition.
- They suggest it as an option drink to be prescribed in weight loss strategies, noting it did not detrimentally affect health.
How it was done
The authors note that kombucha is a fermented drink with promising health benefits, but few studies have tested its impact on human health. They wanted to see its effect on weight loss, inflammation and mouth bacteria in people with excess body weight.
They ran a 10-week randomised controlled trial in 59 adults with excess body weight in Brazil. Both groups followed a diet with 500 kcal less per day; one group also drank 200 mL of green tea kombucha daily.
What it can’t tell you
- The study lasted only 10 weeks, so it cannot show what happens over a longer period.
- The participants were adults with excess body weight following a calorie-reduced diet, so the results may not apply to other groups.
- The authors note that the study had a limited sample size and could not be blinded.
Who paid
- Funding
- Funded by Fundação de Amparo à Pesquisa do Estado de Minas Gerais; Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition; Coordenação de Aperfeicoamento de Pessoal de Nível Superior (from the PubMed record).
- Conflicts
- The authors declare no conflicts of interest.
- Authors work at
- University of Navarra, Spain; Università degli Studi di Padova, Italy; Institute of Health Carlos III, Spain
The paper
- Title
- Green Tea Kombucha Impacts Inflammation and Salivary Microbiota in Individuals with Excess Body Weight: A Randomized Controlled Trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Fraiz GM, Bonifácio DB, Lacerda UV, et al (2024). Green Tea Kombucha Impacts Inflammation and Salivary Microbiota in Individuals with Excess Body Weight: A Randomized Controlled Trial. Nutrients. doi:10.3390/nu16183186Free full textPubMed 39339787DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error