Toxicity and Antioxidant Activity of Black Tea Kombucha in Wistar Rats: A 28-Day Repeated Dose Oral Study

Kombucha is a fermented beverage produced from sweetened black tea using a symbiotic culture of bacteria and yeasts. While studies suggest potential health benefits, such as antioxidant activity, its toxicological profile must be thoroughly evaluated to ensure safe consumption. This study aimed to assess the subacute oral toxicity of kombucha over 28 days in Wistar rats and evaluate its effects on oxidative stress markers. Forty female Wistar rats were divided into four groups: a control group receiving saline (1 mL/100 g), and three treatment groups-T1 (1 mL/100 g) and T2 (2 mL/100 g) receiving kombucha fermented for 7 days, and T3 (1 mL/100 g) receiving kombucha fermented for 14 days. All treatments were administered daily for 28 days. No signs of toxicity, mortality, or histopathological changes in tissue morphology were observed. However, significant behavioral changes, including increased exploration and self-care, were noted. Additionally, kombucha administration modulated the activity of antioxidant enzymes, specifically superoxide dismutase and catalase, and reduced tissue lipid peroxidation. These findings suggest that kombucha fermented for 7 and 14 days is non-toxic and exhibits antioxidant properties by modulating oxidative stress markers in Wistar rats.