Bacillus amyloliquefaciens protects Nile tilapia against Aeromonas hydrophila infection and alleviates liver inflammation induced by high-carbohydrate diet. Issue 127 (August 2022)

• Record Type: Journal Article
• Authors: Xu, Rong; Ding, Fei-Fei; Zhou, Nan-Nan; Wang, Tong; Wu, Hong-Xia; Qiao, Fang; Chen, Li-Qiao; Du, Zhen-Yu; Zhang, Mei-Ling
• Is Part Of: Fish & shellfish immunology. Issue 127(2022)
• Page Start: 836
• Page End: 842
• Publication Date: 2022-08
• Subjects: Nile tilapia -- High-carbohydrate diet -- Bacillus amyloliquefaciens -- Inflammation -- Antioxidant activity; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2022.07.033
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Carbohydrates are widely distributed in nature as an important nutritional substance and energy source. However, the utilization efficiency of carbohydrates is very poor in fish. Over consumption of carbohydrates will cause excessive inflammatory response and result in lower pathogen resistance in fish. Probiotics have been widely used to prevent inflammation, but the underlying mechanism still needs more exploration. In this study, three diets, including a control diet (CD), a high-carbohydrate diet (HD) and the HD supplemented with Bacillus amyloliquefaciens SS1 (HDB) were used to feed Nile tilapia for 10 weeks. At the end of the feeding trial, fish were challenged with Aeromonas hydrophila ( A. hydrophila ) for 7 days. The data showed that the addition of Bacillus amyloliquefaciens SS1 ( B. amyloliquefaciens SS1) significantly increased the survival rate and enhanced the respiratory burst activity of head kidney leukocytes in Nile tilapia. B. amyloliquefaciens SS1 treatment significantly elevated the anti-oxidative capability, which was evidenced by higher activities of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC), and higher content of reduced glutathione (GSH) in the serum. Administration with B. amyloliquefaciens SS1 effectively suppressed inflammatory response in the liver by inhibiting nuclear factor kappa-B (NF-κB)/interleukin-1 beta (IL-1β) inflammatory signaling pathway. In vitro analysis suggested that intestinal bacteria derived-acetate has the antioxidant capability, which may account for the alleviation of inflammation. Overall, this study demonstrated that dietary supplementation with B. amyloliquefaciens SS1 protected Nile Tilapia against A. hydrophila infection and suppressed liver inflammation by enhancing antioxidant capability. Highlights: High-carbohydrate diet (HD) induces negative effects in Nile tilapia. The pathogen resistance is increased by B. amyloliquefaciens in HD-fed fish. The anti-oxidant capability is enhanced by B. amyloliquefaciens in HD-fed fish. The inflammatory response is alleviated by B. amyloliquefaciens in HD-fed fish.