Ameliorative Effects of Fermented Gold Kiwi on Reflux Esophagitis in a Rat Model

Reflux esophagitis (RE) is characterized by the backflow of gastric contents, including acid, pepsin, and bile, into the esophagus. Fermented gold kiwi (FGK) has demonstrated protective effects against acute gastritis and efficacy in digestive disorders such as constipation, suggesting its potential potential therapeutic relevance for RE. In this study, we evaluated the protective effects of FGK, fermented with five probiotic strains, including two kiwi-derived stains, in a rats model of acute RE. Male Sprague-Dawley rats (6 weeks old, n=6 per group) were divided into six groups: normal control, negative control (vehicle, Veh), positive control, and FGK-treated groups (50, 125, and 250 mg/kg). After 24 h of fasting, test substances were orally administered, followed by pyloric ligation under isoflurane anesthesia 2 h later. Esophageal tissue and gastric juice were collected 4.5 h post-surgery for analysis. The evaluation parameters included the esophageal damage ratio; pH of the gastric content and pepsin activity; esophageal tissue glutathione (GSH) and malondialdehyde (MDA) levels; inflammatory cytokine expression [tumor necrosis factor-α; interleukin (IL)-1β; and IL-6]; and histological analysis of esophageal mucosa. FGK treatment significantly reduced esophageal damage and improved gastric pH and pepsin activity in a dose-dependent manner, compared to the Veh group. FGK also increased GSH levels, decreased MDA concentrations, suppressed IL-6 expression, and attenuated histopathological alterations in esophageal tissue. FGK demonstrates dose-dependent protective effects against RE-related esophageal damage and inflammation. These findings suggest that FGK may serve as a novel dietary intervention for the prevention and management of acute RE.