Levilactobacillus brevis strains can be isolated from traditional Chinese pickles and used as the starter cultures to improve the nutritional profiles of fermented juices. Three L. brevis strains (LBG-29, LBG-24, LBD–14) that produce high levels of gamma-aminobutyric acid (GABA; >300 mg/L) were isolated from traditional Chinese pickles. The strains showed tolerance to low pH and high bile salts and exhibited safety in vitro. Litchi juice was fermented using each strain at 37 °C for 48 h. The litchi juice was determined to be a good substrate for fermentation as the process enhanced its functional profile. Overall, cell vitality increased (above 8.7 log₁₀ CFU/mL), the antioxidant activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric ion-reducing antioxidant power (FRAP) were significantly increased, and the antioxidant capacity of the 2,2′-amino-di(3-ethyl-benzothiazoline sulphonic acid-6)ammonium salt (ABTS) was decreased. There was also a significant increase in the GABA and acetic acid content after LBG-29 and LBG-24 fermentation. It was thus determined that the LBG-29 and LBG-24 strains could be used to improve beverage functionality and aid in the development of new products. This is the first report of litchi fermentation using L. brevis as a starter culture. Further research is required to elucidate the functional benefits for the human body and the nutritional and functional properties during its shelf life.

(1) Background: Ellagic acid (EA) acts as a product of gut microbiota transformation to prevent insulin resistance, which is limited by high-fat diet (HFD)-induced dysbiosis. The aim of this study was to investigate the synergistic effects and mechanisms of supplementation with the probiotic Weizmannia coagulans (W. coagulans) on the prevention of insulin resistance by EA; (2) Methods: C57BL/6J mice were divided into five groups (n = 10/group): low-fat-diet group, high-fat-diet group, EA intervention group, EA + W. coagulans BC77 group, and EA + W. coagulans BC2000 group; (3) Result: W. coagulans BC2000 showed a synergistic effect on EA’s lowering insulin resistance index and inhibiting high-fat diet-induced endotoxemia. The combined effect of BC2000 and EA activated the autophagy pathway in the mouse liver, a urolithin-like effect. This was associated with altered β-diversity of gut microbiota and increased Eggerthellaceae, a potential EA-converting family. Ellagic acid treatment alone and the combined use of ellagic acid and W. coagulans BC77 failed to activate the hepatic autophagy pathway; (4) Conclusions: W. coagulans BC2000 can assist EA in its role of preventing insulin resistance. This study provides a basis for the development of EA-rich functional food supplemented with W. coagulans BC2000.