Skin mucosal lymphoid tissues of fish are the first line of defence against pathogen invasion. We investigated the effects of Lactiplantibacillus plantarum subsp. plantarum L7, singularly or in combination with Limosilactobacillus reuteri P16, on mucosal immunity and diseases resistance of carp Cyprinus carpio. C. carpio (average weight: 26.28 ± 1.02 g) were divided into five experimental groups. Fish in each group were fed with one of the following potential probiotic-supplemented diets: control (0 – basal diet), D1 (10⁷ CFU/g L7), D2 (10⁸ CFU/g L7), D3 (10⁹ CFU/g L7), and D4 (10⁸ CFU/g L7 + 10⁸ CFU/g P16). Eight weeks post-feeding, growth performance was higher in D4, with a final weight gain of 67.18 ± 1.47 g. Results showed a significantly higher skin mucosal lysozyme, alkaline phosphatase, mucus protein level, superoxide dismutase, and catalase activities in D2 and D4 compared to the control. However, potential probiotics had no significant effect on skin mucosal immunoglobulin level. Skin mucus of D4 exhibited stronger inhibition zones against pathogenic bacterial strains. Moreover, digestive enzyme activities (protease, lipase) were highest in D4. Intesinal lactic acid bacterial counts of fish fed combind probiotics (i.e. D4) was significantly higher than the control. Further, supplementation of potential probiotics altered the expression of IL-1β, TNF-α, and IL-10 cytokines. Fish from D4 exhibited significantly higher relative post-challenge survival (69.7%) against Aeromonas hydrophila, followed by D2 (66.67%). Therefore, the inclusion of L. plantarum subsp. plantarum L7 at 10⁸ CFU/g or in combination with L. reuteri P16 could enhance the growth performance, mucosal immune responses, and disease resistance of C. carpio.

鱼类皮肤黏膜淋巴组织是抵御病原体入侵的第一道防线。我们研究了植物乳杆菌亚种的影响。植物L7，单用或与罗伊氏乳杆菌P16合用，对鲤鱼Cyprinus carpio的黏膜免疫和抗病性的影响。C. carpio（平均重量：26.28 ± 1.02 g）分为五个实验组。给每组鱼喂食以下一种可能添加益生菌的日粮：对照（0 - 基础日粮）、D1（10 ⁷  CFU/g L7）、D2（10 ⁸  CFU/g L7）、D3（10 ⁹  CFU） /g L7) 和 D4 (10 ⁸  CFU/g L7 + 10 ⁸ CFU/g P16)。喂食后 8 周，D4 的生长性能更高，最终体重增加 67.18 ± 1.47 g。结果显示，与对照相比，D2 和 D4 中的皮肤粘膜溶菌酶、碱性磷酸酶、粘液蛋白水平、超氧化物歧化酶和过氧化氢酶活性显着提高。然而，潜在的益生菌对皮肤黏膜免疫球蛋白水平没有显着影响。D4 的皮肤粘液对致病菌株表现出更强的抑制区。此外，消化酶活性（蛋白酶、脂肪酶）在 D4 最高。喂食组合益生菌（即D4）的鱼的肠道乳酸菌计数显着高于对照。此外，潜在益生菌的补充改变了 IL-1β、TNF-α 和 IL-10 细胞因子的表达。嗜水气单胞菌，其次是 D2 (66.67%)。因此，包括L. plantarum subsp。10 ⁸  CFU/g的植物L7或与罗伊氏乳杆菌P16联合使用可增强鲤鱼的生长性能、黏膜免疫反应和抗病性。