Effect of fiber-modified kombucha tea on gut microbiota in healthy population: A randomized controlled trial (RCT)

The development of functional foods with health-promoting properties is a priority in addressing chronic diseases. Studying the effect of these foods on gut microbiota provides critical insights into the interplay between microorganisms, health, and disease.

This study aimed to evaluate the effects of fiber-enriched kombucha tea on biochemical parameters and gut microbiota composition in a healthy population.

A randomized, double-blind, parallel nutritional intervention trial was conducted with 60 participants (58 completed: 42 women and 16 men; mean ± SD age: 39.79 ± 14.58 years). Participants were randomized into two groups consuming either 250 mL/day of a control beverage (unfermented tea) or the fiber-enriched kombucha tea for six weeks. Lifestyle and biochemical data were collected, and gut microbiota composition and diversity were assessed using 16S rDNA sequencing.

Significant biochemical and microbiota-related improvements were observed in the study group compared to the control. The treatment significantly affected triglyceride levels (p-value = 0.031). In particular, the study group exhibited a reduction in triglyceride levels very close to significance (baseline mean ± SEM: 69.59 ± 6.98 mg/dL; post-intervention: 62.80 ± 5.14 mg/dL; p = 0.053), while the control group did not experience a significant variation. Additionally, fiber-enriched kombucha consumption led to a notable increase in Bifidobacterium abundance, recognized for its intestinal health benefits and immunomodulatory effects. A reduction in Ruminococcus torques, linked to inflammatory bowel diseases, was also observed.

The studied fiber-enriched kombucha drink demonstrated potential health benefits, including triglyceride modulation and positive alterations in gut microbiota composition. These findings suggest its promise as a functional beverage for improving metabolic and gut health in healthy individuals. However, further randomized controlled trials are warranted to confirm these benefits. This trial was registered at clinicaltrials.gov as NCT06626997.