Lactobacillus paracasei fermentation enhances the aroma profile and antidiabetic efficacy of goji berry juice.

Goji berry (Lycium barbarum L.) is rich in bioactive compounds, and its functional efficacy can be further enhanced through fermentation. This study evaluated the impact of Lactobacillus paracasei-fermentation on the quality attributes of goji berry juice and its in vivo antihyperglycemic efficacy. Fermentation significantly increased total flavonoids (+31.8%) and polysaccharides (+5.4%), enhanced antioxidant activity, and enriched the volatile aroma profile relative to unfermented juice. In a type II diabetic mouse model, four weeks of gavage with fermented goji berry juice alleviated weight loss and polydipsia, reduced fasting blood glucose by 33%, improved glucose tolerance, and corrected dyslipidemia. Histopathological examination revealed partial restoration of liver, kidney, and pancreatic integrity, accompanied by reduced malondialdehyde and elevated superoxide dismutase activity. Moreover, the intervention modulated gut microbiota by increasing the abundance of Akkermansia and Bacteroidetes while suppressing Desulfovibrionaceae, alongside elevated cecal propionic acid and butyric acid. Correlation analyses further revealed that the fermentation-enhanced antioxidants and gut microbiota-derived short-chain fatty acids were significantly correlated with the improvement in key diabetic phenotypes, suggesting a potential mechanism mediated by the microbiota-metabolite axis. These findings provide a scientific basis for developing fermented goji berry products as functional foods or adjuvant therapies for diabetes management.