Abstract Lactobacillus pentosus HC-2 is a lactobacillus previous isolated and identified from aquatic animals (such as the goby, Acanthogobius hasta), which has shown a positive effect on growth and disease resistance in the Pacific white shrimp, Penaeus vannamei. Aflatoxin B1 (AFB1) is a highly carcinogenic and teratogenic toxin found in moldy feeds. This study aims to investigate the positive effect of L. pentosus on protecting the intestine of P. vannamei affected by AFB1 toxicity. Shrimp were respectively fed with formulated feed containing AFB1 (500 μg/kg), AFB1 (500 μg/kg) + L. pentosus HC-2 (5 × 108 CFU/g feed), and a basal commercial diet (Control group). After feeding for 6 weeks, the survival rate (AFB1 group: 37%, AFB1+ L. pentosus HC-2 group: 49%，Control group:61%) and the percent weight gain (AFB1 group: 98.28%, AFB1+ L. pentosus HC-2 group: 112.40%，Control group:111.27%) in the AFB1 + L. pentosus HC-2 group were higher than the AFB1 group. The intestinal morphology of the AFB1 + L. pentosus HC-2 group was more complete than that of the AFB1 group. The relative expression of immune-related genes including Rab, GST, mucin-like-PM, Dorsal, Relish and Pro-PO was detected. Expression in the experimental group significantly decreased compared with the control group, while the expression levels of immune genes (Rab, GST, mucin-like-PM, Dorsal and Pro-PO) in AFB1+ L. pentosus HC-2 group was higher than the AFB1 group. Intestinal microbiota analysis demonstrated that the community structure of intestinal microbiota was markedly different between the control group and experimental group. Comparing different genera of bacteria, the abundance of Proteobacteria in the AFB1 + L. pentosus HC-2 group increased significantly compared with the control group, while the abundance of Firmicutes and Bacteroidetes decreased. These results indicated that L. pentosus HC-2 had a positive effect on the growth performance and resistance of P. vannamei affected by AFB1 according to regulate the structure of intestinal flora. In breeding practice, probiotics can be used to reduce the harm of aflatoxin. This may be related to the probiotic's contribution to maintaining the structural integrity of the intestinal mucosa, promoting the expression of immune related genes and regulating the composition of intestinal microflora.

中文翻译：

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戊糖乳杆菌HC-2对黄曲霉毒素B1影响的南美白对虾生长性能、肠道形态、免疫相关基因及肠道菌群的影响

摘要 Lactobacillus pentosus HC-2 是先前从水生动物（如虾虎鱼、Acanthogobius hasta）中分离鉴定的乳酸菌，对南美白对虾的生长和抗病性显示出积极作用。黄曲霉毒素 B1 (AFB1) 是一种在发霉的饲料中发现的高度致癌和致畸的毒素。本研究旨在探讨戊糖乳杆菌对受AFB1毒性影响的南美白对虾肠道保护的积极作用。对虾分别饲喂含有AFB1（500 μg/kg）、AFB1（500 μg/kg）+戊糖乳杆菌HC-2（5×108 CFU/g饲料）的配合饲料和基础商业饲料（对照组）。喂养6周后，存活率（AFB1组：37%，AFB1+L. pentosus HC-2组：49%，对照组：61%​​）和体重增加百分比（AFB1组：98.28%，AFB1+ L. pentosus HC-2 组：112.40%，对照组：111.27%）在 AFB1+L. pentosus HC-2 组中高于 AFB1 组。AFB1+L. pentosus HC-2组肠道形态比AFB1组更完整。检测Rab、GST、粘蛋白样PM、Dorsal、Relish、Pro-PO等免疫相关基因的相对表达量。实验组与对照组相比表达明显降低，而AFB1+戊糖乳杆菌HC-2组免疫基因（Rab、GST、粘蛋白样PM、Dorsal和Pro-PO）的表达水平高于对照组。 AFB1 组。肠道菌群分析表明，对照组和实验组肠道菌群的群落结构存在显着差异。比较不同属的细菌，AFB1+L. pentosus HC-2组Proteobacteria丰度较对照组显着增加，而Firmicutes和Bacteroidetes丰度降低。这些结果表明戊糖乳杆菌HC-2通过调节肠道菌群结构，对受AFB1影响的南美白对虾的生长性能和抗性具有积极作用。在养殖实践中，可以使用益生菌来降低黄曲霉毒素的危害。这可能与益生菌对维持肠黏膜结构完整性、促进免疫相关基因表达和调节肠道菌群组成的贡献有关。这些结果表明戊糖乳杆菌HC-2通过调节肠道菌群结构，对受AFB1影响的南美白对虾的生长性能和抗性具有积极作用。在养殖实践中，可以使用益生菌来降低黄曲霉毒素的危害。这可能与益生菌对维持肠黏膜结构完整性、促进免疫相关基因表达和调节肠道菌群组成的贡献有关。这些结果表明戊糖乳杆菌HC-2通过调节肠道菌群结构，对受AFB1影响的南美白对虾的生长性能和抗性具有积极作用。在养殖实践中，可以使用益生菌来降低黄曲霉毒素的危害。这可能与益生菌对维持肠黏膜结构完整性、促进免疫相关基因表达和调节肠道菌群组成的贡献有关。