Dual role of Leuconostoc mesenteroides in crayfish aquaculture: Improve meat quality and enhance disease resistance

The red swamp crayfish ( Procambarus clarkii ) represents an economically significant aquaculture species that enjoys widespread consumer preference. However, intensive culture practices and bacterial pathogens frequently compromise product quality and pose food safety concerns. To mitigate these challenges, the present study evaluated the potential of Leuconostoc mesenteroides (LM) as a probiotic dietary supplement. Our findings demonstrated that LM modulated the gut microbiota by enriching beneficial taxa and suppressing pathogens, thereby significantly improving digestive enzyme activity and nutrient absorption efficiency. The enhanced nutrient metabolism not only directly promoted growth performance but also provided the substrate for high-quality muscle synthesis, as reflected in improved myofiber architecture, enhanced texture parameters, and elevated nutrient content . Moreover, LM secretes antimicrobial and antioxidant metabolites that effectively inhibit growth and disrupt biofilm formation of pathogenic Vibrio fluvialis , reduce its intestinal colonization burden, and ameliorate infection-induced tissue damage and inflammation. Furthermore, LM supplementation significantly elevated hemolymph immune enzyme activities and enhanced hemocyte phagocytic capacity. Taken together, these improvements in intestinal and hemocyte immunity synergistically strengthened the crayfish’s pathogen defense. LM thus emerges as a promising functional feed additive for sustainable crustacean aquaculture.