Kombucha modulates the gut microbiota and promotes insulin secretion and pancreatic beta cell recovery during diabetes.

Abstract

Kombucha is fermented tea brewed by the introduction of a symbiotic culture of bacteria and yeasts (SCOBY) into a sweetened tea substrate. Kombucha consumption has been anecdotally linked to the treatment of multiple diseases including diabetes. Even though the medicinal capabilities of Kombucha have been associated to its anti-inflammatory and antioxidant properties, the precise mode of action is not fully understood. The aim of this study was to investigate the antidiabetic effect of Kombucha in rat models. Diabetes was induced in adult male Wistar rats by a single intraperitoneal injection of 150 mg/kg body weight of alloxan monohydrate. Rats were grouped and administered different doses of Kombucha (5, 25 and 100 mg/kg), and standard drugs (glibenclamide and metformin). Blood samples were collected weekly to determine glucose and insulin levels. To determine the physiological effect of Kombucha treatment on beta pancreatic cells, we performed histological analysis on the pancreas after hematoxylin-eosin staining. Finally, 16S metagenomics sequencing was performed on stool samples to evaluate the temporal gut microbiota changes. We showed that alloxan injection induced diabetes characterized by hyperglycemia, hypoinsulinemia and pancreatic beta cells damage. Notably, treatment with kombucha significantly reduced blood glucose levels, increased insulin secretion and showed better-preserved pancreatic beta cells characterized by reduced inflammation and increased viable cell mass. Additionally, our analysis of gut microbiome revealed shifts in microbial taxonomical composition characterized by the relatively high abundance of Lactobacillaceae in kombucha treated rats, in contrast, these bacteria populations were diminished in the alloxan control. Altogether, our data provide evidence that the antidiabetic mode of action of kombucha involves restoration of proper glycemic control by ameliorating pancreatic beta cell damage, improving insulin secretion and modulating the gut microbiome. Thus, kombucha could offer a positive outcome for the management of diabetes mellitus.