Regular black tea kombucha consumption is associated with improved insulin resistance and increased ADIPOQ expression in adults with obesity: a pre-post clinical trial

Clinical Snapshot

Key Findings

• P Value: ADIPOQ upregulation p=0.0481; correlations: BMI-PPARγ p=0.030, HOMA-IR-NFκB p=0.002

• Effect Size: Not clearly reported for primary outcomes

• Primary Outcome: Improved insulin resistance (HOMA-IR) and increased ADIPOQ expression in obesity group

• Nnt Or Sensitivity: Not calculable from available data

• Confidence Interval: Not provided for main outcomes

Clinical Application

Kombucha readily available but standardisation and quality control concerns exist Not TGA-regulated as therapeutic product; would be considered functional food. Limited relevance to PBS. RACGP obesity guidelines focus on evidence-based interventions with stronger study designs Adults with obesity seeking metabolic health improvements, though evidence limited

Abstract

Kombucha is a fermented beverage obtained by a Symbiotic Culture of Bacteria and Yeast (SCOBY). Although in vitro and animal studies suggest that kombucha has anti-inflammatory and anti-obesogenic properties, no clinical trials have confirmed that. In this pre-post clinical intervention study, we aimed to evaluate whether regular black tea kombucha consumption would impact metabolic, inflammatory, and oxidative stress markers; body weight and composition; and obesity-associated genes in individuals with and without obesity. This study follows the Transparent Reporting of Evaluations with Nonrandomized Designs (TREND) guidelines. Individuals with normal weight (Group 1; n = 20) and with obesity (Group 2; n = 16) received 200 mL of black tea kombucha for 8 consecutive weeks. Blood and subcutaneous adipose tissue (SAT) were collected at the baseline (T0) and after 8 weeks of intervention (T8). Most inflammatory (hs-CRP, IFN-γ, TNF-α, and IL-4, IL-6, IL-8, IL-10, and IL-12p70) and oxidative stress markers (FRAP, MDA, and NO) showed significant changes over time following the intervention. However, interaction analyses revealed that responses to kombucha consumption differed between groups for only a limited number of variables: body weight, conicity index, HOMA-IR, and hs-CRP. An upregulation of the gene ADIPOQ in the SAT (p = 0.0481) was also observed, alongside a positive correlation between the BMI and PPARγ (r = 0.58; p = 0.030), and between HOMA-IR and both NFκB (r = 0.73; p = 0.002) and SREBF1 (r = 0.66; p = 0.010). In conclusion, metabolic and inflammatory pathways may respond differently to kombucha consumption depending on the obesity status. The results are mainly attributed to the high number and diversity of phenolic compounds identified in the black tea kombucha, which confer a high antioxidant capacity to the beverage.

References

1. 1.de Campos Costa, M. A., Macedo Fraiz, G., Rezende Cardoso, R., da Silva, A., da Silva Duarte, V., Soares Gazzinelli Cruz, C. E., Rodrigues, E. G., Shaikh, M. W., Keshavarzian, A., Hamaker, B. R., Corich, V., Giacomini, A., Stampini Duarte Martino, H., Bressan, J., & Ribeiro de Barros, F. A. (2026). Regular black tea kombucha consumption is associated with improved insulin resistance and increased ADIPOQ expression in adults with obesity: a pre-post clinical trial. Food & Function. https://doi.org/10.1039/d5fo02226f