View

The Study

Changes in gut microbiota composition following water kefir consumption in healthy adults

In simple terms

This study just watched what happened to 40 people's guts after they drank water kefir for two weeks. It didn't compare them to people who didn't drink it, so we can't say the kefir caused any changes — maybe their food, weather, or stress changed their guts instead.

20%

Analysis score

20/ 90

Maximum 90 for a randomized controlled trial.

Where the score came from

Reporting0
Methodology0
Publication100
Statistical0
Study type (basis of the score)
Randomized Controlled Trial
Level 1b - Individual RCT
What’s the bottom line?

People drank a homemade fizzy sweet drink made with sugar and tiny microbes for two weeks, and scientists checked if their gut bacteria changed.

Where does this study sit?

Reviews of RCTs (Meta-analyses)

Max 100

Randomized Trials

Max 90

Reviews of Cohort Studies

Max 85

Cohort Studies

Max 72

Reviews of Case-Control Studies

Max 63

Case-Control Studies

Max 58

Cross-Sectional & Case Series

Max 50

Expert Opinion

Max 5
StrongerWeaker
Randomized Trials
Level 1b
20

20 / 100

Quality score

Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.

Cannot establish causation

Save studies & get personalized insights

Create a free account to save this study, track new evidence as it comes in, and get breakdowns of studies in the topics you care about.

Key takeaways

Summary

Based on the study abstract and findings.

  1. 1The changes in bacteria are small and may not mean better health — we don’t know yet if they last or help with digestion or immunity.
  2. 2After drinking it, good bacteria like Blautia and Roseburia went up by 12-16%, bad bacteria like Firmicutes went down by 6.5%, and most people felt no big changes in their tummy.

Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data

Publication

Journal

Scientific Reports

Year

2026

Authors

Rumathi de Mel, Alia H. Al Khafaji, Saraladevi Muthusamy, Jie Xu, Å. Håkansson

Open Access
Analysis v5
Fit Body Science verdict — we translate health studies into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.