Weissella, a genus of Gram-positive, facultatively anaerobic lactic acid bacteria, has emerged as a significant component of human microbiota with diverse biotechnological and therapeutic applications. This narrative review examines the current state of knowledge regarding Weissella taxonomy, physiological characteristics, and functional properties based on research spanning from 1993 to present. Weissella species demonstrate remarkable versatility, producing bioactive metabolites including exopolysaccharides (EPS), bacteriocins, and organic acids that confer antimicrobial, antioxidant, and anti-inflammatory properties. These bacteria show significant potential in food fermentation, probiotic applications, and therapeutic interventions for gut health, obesity, and inflammatory conditions. However, challenges persist regarding strain-specific pathogenicity, particularly with W. confusa as an opportunistic pathogen, and the need for comprehensive safety evaluations. Current limitations include variability in probiotic efficacy, incomplete understanding of host-microbe interactions, and gaps in metabolic pathway characterization. This review provides a foundation for advancing Weissella research and applications while highlighting critical areas requiring further investigation to fully harness their biotechnological and therapeutic potential.

Objective: The aim of this experiment was to integrate production indices with omics sequencing to elucidate the systemic perturbations between hepatic metabolism and the gut microbiota during overfeeding.Methods: A total of 120 seven-week-old male Landes geese were floor-reared in a pen environment. Overfeeding commenced at week 8 using a corn-based diet containing 5% soybean oil. The feeding regimen consisted of three daily meals (150–180 g/meal) initially, gradually increasing to five meals (300–500 g/meal) after two weeks, and was maintained for a total overfeeding period of four weeks.Results: The results demonstrated that overfeeding significantly increased liver weight and serum lipid levels, accompanied by intracellular lipid droplet accumulation. Concurrently, the downregulation of taurine-conjugated bile acids and the upregulation of free bile acids disrupted cholesterol homeostasis. Crucially, overfeeding triggered gut microbial dysbiosis characterized by Escherichia–Shigella enrichment and norank_o_Clostridia_UCG-014 depletion.Conclusion: Our work demonstrated that the identification of the "gut microbiota‒bile acid‒liver axis" could serve as a pivotal signaling pathway driving overfeeding-induced foie gras formation while providing a theoretical foundation for overfeeding strategies to mitigate metabolic pathologies in waterfowl production.