This study aimed to verify the possible positive effects of feeding the commercial probiotic Bioplus 2BC^® [Bacillus subtilis (1.6 × 10¹⁰ CFU/g) and Bacillus licheniformis (1.6 × 10¹⁰ CFU/g)] to Nile tilapia on its growth performance, nutrient digestibility, gut microbiology, haematology (hematimetric index, erythrocyte, leucocyte and thrombocyte counts) and innate immunology (lysozyme, burst respiratory and phagocyte activities). For this purpose, one in vivo assay was performed following a completely randomized design, with four treatments (0.00%; 0.02%; 0.04%; and 0.08% of probiotic inclusion on ratio) and four replicates. The fish fed with diets containing 0.04% and 0.08% of probiotics presented higher weight gain than the control group, as well as higher thrombocyte counts in the bloodstream. The positive effect of the probiotics on the gut microbiota was illustrated by the higher richness and habitability indexes, soaring genetic variability. On the contrary of control, the groups fed with probiotic had Firmicutes, Fusobacteria and Bacteroidetes phyla, and a lower percentage of Proteobacteria. The inclusion of 0.04% and 0.08% of B. subtilis and B. licherniformis in the fed provides better growth performance and modifies the intestinal microbiota, reducing the class of potential pathogen agent species. The establishment of a beneficial microorganism population may improve host health.

中文翻译：

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尼罗罗非鱼（Oreochromis niloticus）日粮中的枯草芽孢杆菌和地衣芽孢杆菌：对生长性能，肠道菌群调节和先天免疫学的影响

本研究旨在验证喂养商业益生菌Bioplus 2BC的可能积极效果^® [枯草芽孢杆菌（1.6×10 ¹⁰  CFU / g）和地衣芽孢杆菌（1.6×10 ¹⁰ CFU / g）]对尼罗罗非鱼的生长性能，养分消化率，肠道微生物学，血液学（血液学指标，红血球，白血球和血小板计数）和先天免疫学（溶菌酶，呼吸道和吞噬细胞的活动）。为此，在完全随机设计之后进行了一项体内测定，采用四种治疗方法（0.00％； 0.02％； 0.04％； 0.08％的益生菌包埋率）和四次重复。饲喂含有0.04％和0.08％益生菌的饲料的鱼比对照组具有更高的体重增加，并且血液中的血小板计数更高。益生菌对肠道菌群的积极作用可以通过较高的丰富度和适居性指数来证明，其遗传变异性也随之飙升。与对照相反，喂食益生菌的组有Firmicutes，Fusobacteria和Bacteroidetes phyla，以及Proteobacteria的百分比较低。包含0.04％和0.08％的饲料中的枯草芽孢杆菌和地衣芽孢杆菌可提供更好的生长性能，并改善肠道菌群，减少潜在病原体的种类。有益微生物种群的建立可以改善宿主健康。