Blueberry kombucha and gut symptoms in 39 adults
What it found
In a 28-day trial in 39 adults, those who drank live blueberry kombucha reported softer, more normal stools and fewer gut symptoms than those who drank a sterilised version.
The authors call the results preliminary.
What they found
Studies in people
Stool consistency
In the live kombucha group, hard stools (types 1 and 2) decreased and normal smooth stools (type 4) increased over 28 days. The sterilised group showed no significant changes.
Abdominal symptoms
People drinking live kombucha reported less abdominal pain and bloating. About 90% said their bowel function felt better.
Satisfaction with bowel habits
The live kombucha group had more people saying they were very satisfied with their bowel movements. The sterilised group did not show this improvement.
Animal and lab studies
Microbes in the drink
The live kombucha contained yeasts, lactic acid bacteria and acetic acid bacteria. Adding blueberry did not significantly affect their numbers. After 28 days of storage, yeast and lactic acid bacteria counts dropped slightly, while acetic acid bacteria stayed more stable.
Antioxidants and compounds
The blueberry kombucha had higher levels of flavonoids, anthocyanins and total phenolic compounds than the plain kombucha, and stronger antioxidant activity in lab tests. The blueberry syrup itself had even higher levels.
Alcohol content
The blueberry kombucha contained 0.20% alcohol and the version without blueberry contained 0.10%. The sterilised controls had no detectable alcohol.
What the authors conclude
- They say the blueberry kombucha is a promising functional beverage with favourable bioactive characteristics and the potential to support gastrointestinal health.
- They advise that the clinical findings should be interpreted with caution because the evaluation was exploratory and need confirmation in larger clinical studies involving clinically characterised populations.
- They recommend future work to identify the microbes at strain level, test the drink against foodborne pathogens, and run longer clinical interventions.
How it was done
The authors say there is a lack of clinical studies on how kombucha affects gut function, especially when combined with fruits rich in phenolic compounds. They also wanted to compare live kombucha with sterilised kombucha to separate the effects of live microbes from those of stable fermentation compounds.
They made a blueberry-flavoured kombucha from green tea and sucrose, fermented with a SCOBY, then added blueberry syrup and fermented again. They gave 39 healthy adults 100 mL a day for 28 days: one group got the live kombucha and the other got a sterilised version. Stool consistency and gut symptoms were recorded at the start and end.
What it can’t tell you
- The trial was small and used healthy people with self-reported gut symptoms, not people diagnosed with a gut disorder. So the results may not apply to other groups.
- The study cannot prove that the live kombucha caused the improvements, because other factors like diet, exercise, hydration and medication were not controlled.
- The authors did not identify the exact strains of microbes in the SCOBY, so they cannot say which specific microbes might be responsible for any effects.
Who paid
- Funding
- Funded by National Council for Scientific and Technological Development; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (from the PubMed record).
- Conflicts
- The authors declare no conflicts of interest.
The paper
- Title
- Physicochemical, Bioactive, and Clinical Evaluation of Blueberry-Enriched Kombucha as a Functional Beverage
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Anselmini AM, Lorandi G, Peruzzolo M, et al (2026). Physicochemical, Bioactive, and Clinical Evaluation of Blueberry-Enriched Kombucha as a Functional Beverage. Journal of food science. doi:10.1111/1750-3841.71337Free full textPubMed 42757640DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error