Cascara kombucha potential as a functional food for fasting glucose regulation, cholesterol control, and liver function modulation: <i>in vitro</i> and <i>in vivo</i> study

Abstract Unhealthy dietary patterns are a major contributor to obesity worldwide, leading to various adverse metabolic effects such as elevated liver enzyme levels and increased cholesterol concentrations. This study investigates the potential of cascara kombucha as a functional beverage to provide health benefits in both in vitro and in vivo models. Our results indicate that kombucha fermentation enhances the bioactive compounds in cascara, including polyphenols and flavonoids. The in vitro study found that cascara kombucha effectively decreased free radicals (DPPH and ABTS) levels, α-amylase, and lipase activity, suggesting its potential to act as an antioxidant and modulate carbohydrate and lipid metabolism. In a mouse model, oral administration of cascara kombucha at a dose of 300 mg/kg body weight for 28 days successfully decreased fasting blood glucose levels, improved liver health by reducing aspartate transaminase and alanine transaminase levels, and lowered serum cholesterol content induced by a fat-enriched diet compared to the untreated group. The levels of superoxide dismutase and catalase, suppressed by the fat-enriched diet, were restored to normal. Additionally, cascara kombucha downregulated genes associated with inflammation induced by a fat-enriched diet, including tnf-α, IL-6, IL-1β, and cox-2. It also positively affected the balance of intestinal microflora in mice by reducing coliform density and enhancing probiotic populations. These findings highlight the potential of cascara kombucha as a promising approach to addressing health issues caused by poor dietary habits and metabolic imbalances.