Studies: The Health Benefits of Fermented Teas
Two studies highlight the varied health benefits of different types of teas used to make kombucha.
White, Green, and Black teas

Scientific Reports published a report by Thai researchers titled Functional metabolites and inhibitory efficacy of kombucha beverage on pathogenic bacteria, free radicals and inflammation. This comparative study of kombucha produced from white, green, and black tea focuses on microbial composition, evolving chemical profiles, and critical biological activities, including antioxidant, antibacterial, and anti-inflammatory properties. These findings underscore the considerable promise of kombucha tea as a functional beverage, offering diverse health benefits.
The research unequivocally demonstrates that fermentation profoundly enhances the functional attributes of kombucha. Distinct differences emerged based on the initial tea substrate: white tea kombucha exhibited superior antibacterial efficacy and high levels of specific organic acids like glucuronic acid, while green tea kombucha showed remarkable antioxidant and anti-inflammatory potential, with its anti-inflammatory effects linked to its elevated levels of catechins, epicatechins, and EGCG (epigallocatechin-3-gallate, a polyphenol found in green tea). All kombucha types developed a rich profile of organic acids, notably acetic acid, and demonstrated broad-spectrum antibacterial activity against common enteric pathogens. These findings underscore kombucha tea’s considerable promise as a functional beverage, offering diverse health benefits.
These distinct organic acid profiles are not random; they reflect the specific metabolic pathways favored by the microbial consortia in response to the unique phytochemicals present in white, green, and black teas. This provides a scientific basis for tailoring kombucha production for specific bioactive profiles. By selecting a particular tea base, producers can potentially guide the fermentation process to yield a kombucha rich in specific beneficial organic acids, thereby targeting particular health benefits, such as detoxification support with white tea or metabolic support with black tea, moving towards a more precision-nutrition approach.
The type of Camellia sinensis leaves used—white, green, or black—significantly influences the final organic acid composition and, consequently, the overall functional properties of the kombucha. Fermentation is a dynamic process that generally enhances the total phenolic content and antioxidant activity while simultaneously generating novel bioactive compounds, such as specific organic acids. The distinct processing methods of white, green, and black teas, such as the minimal oxidation in white and green tea, lead to different initial phytochemical profiles, which then interact uniquely with the symbiotic microbial culture (SCOBY) to produce varied metabolic outcomes.
Black tea

The Journal of Nutrition published the results of a clinical study titled Regular Consumption of Black Tea Kombucha Modulates the Gut Microbiota in Individuals with and without Obesity. It reveals that daily consumption of black tea kombucha can promote healthier gut bacteria, especially in individuals with obesity, by reducing harmful microbes and supporting beneficial ones.
Key findings include:
- Kombucha Composition: The kombucha was rich in 145 phenolic compounds, primarily flavonoids (81%) and phenolic acids (19%). It also contained various microorganisms, including acetic and lactic acid bacteria, as well as yeasts, which contributed to its low pH and increased acidity.
- Gut Microbiota Modulation: Kombucha consumption positively influenced gut microbiota in all individuals, with more pronounced effects observed among obese individuals. It favored commensal bacteria, such as Bacteroidota and Akkermansiaceae, especially in obese individuals. An increase in Subdoligranulum, a butyrate producer, was also observed in obese people.
- Reduction of Obesity-Associated Genera: Obesity-associated genera, such as Ruminococcus and Dorea, which were elevated in obese individuals at baseline, were reduced after kombucha consumption, becoming similar to those in the group of normal-weight individuals.
- Fungal Diversity Changes: Fungal diversity increased, with a higher abundance of Saccharomyces in both groups of people and a reduction in Exophiala and Rhodotorula, particularly in obese people. Pichia and Dekkera, key microorganisms in kombucha, were identified as biomarkers following the intervention.
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The content of this article is accurate to the best of our knowledge and is presented for general informational purposes only. The analysis was conducted with the help of Google Gemini. Please send corrections or questions to ian@boochnews.com. Comments are welcome.