Effects of Bacillus subtilis on hepatic lipid metabolism and oxidative stress response in grass carp (Ctenopharyngodon idellus) fed a high-fat diet

Abstract

Bacillus subtilis is widely used in aquaculture as a probiotic. However, few studies have been conducted to examine the effect of B. subtilis on liver lipid metabolism. A total of 135 healthy grass carp (50.24 ± 1.38 g) were randomly divided into three groups: control (Con), high-fat diet (HF), and high-fat diet + B. subtilis (HF + B. subtilis), and fed for 8 weeks. The results showed that compared with the HF group, the weight gain rate (WGR) significantly increased (P < 0.05) and the hepatic lipid content, serum low-density lipoprotein cholesterol (LDL-C), and aspartate aminotransferase (AST) decreased in the group supplemented with B. subtilis (P < 0.05). Moreover, the hepatic mRNA expression of fatty acid synthase (FAS) was significantly down-regulated and the carnitine palmitoyl transferases (CPT1α1a) were up-regulated in the HF + B. subtilis group compared to the HF group (P < 0.05), respectively. Additionally, in the HF + B. subtilis group, glutathione (GSH) significantly increased (P < 0.05), while hydrogen peroxide (H 2 O 2) and malondialdehyde (MDA) contents significantly decreased compared to the HF group (P < 0.05). B. subtilis may reduce the hepatic lipid content by inhibiting its synthesis and promoting β-oxidation of fatty acids. B. subtilis may also alleviate dyslipidaemia and prevent oxidative damage in the liver caused by the high-fat diet of grass carp. Hence, dietary supplementation with B. subtilis shows promise as a therapeutic or preventive tool against fatty liver disease.

Dietary Sodium Butyrate Supplementation Attenuates the Detrimental Effects of High‐Fat Diets on Growth Performance, Liver Health, and Disease Resistance in Grass Carp

“…Dietary inclusion of HF is known to induce oxidative stress and decrease antioxidant capacity in fish (Dai et al 2019;Zhao et al 2020;Zhou et al 2020). The present study confirmed this in Grass Carp that received the HF diet, as evidenced by lower activities of antioxidant enzymes (e.g., T-SOD and GPx) and a higher content of MDA, which is a biological marker of oxidative stress (Del Rio et al 2005).…”

“…However, Grass Carp farming in China has been encountering many serious problems, especially when high-fat (HF) diets are used (Gao et al 2011;Tang et al 2019). Dietary supplementation with excessive lipid (>9.6%) resulted in fatty liver syndrome (Du et al 2006), increased the liver oxidative stress response, and led to growth retardation and high mortality in Grass Carp (Zhao et al 2020;Liu et al 2021Liu et al , 2022. Consequently, there is an urgent need to solve the problems induced by HF diets in Grass Carp farming.…”

Dietary nano-selenium alleviated intestinal damage of juvenile grass carp (Ctenopharyngodon idella) induced by high-fat diet: Insight from intestinal morphology, tight junction, inflammation, anti-oxidization and intestinal microbiota

“…Grass carp ( Ctenopharyngodon idella ) is one of the most popular farmed fish species in China, with a production of 5.5 million tons in 2019 ( Zhang et al., 2020 ). However, in the last few years, the aquaculture of grass carp has faced more and more challenges, including the adverse effects caused by the increasing application of high-fat diet (HFD) ( Tang et al., 2019b ; Zhao et al., 2019 ). Dietary fats play a vital role in fish nutrition and provide essential fatty acids, fat-soluble vitamins, phospholipids and cholesterol needed for normal growth, development and health maintenance of fish ( Jobling, 2011 ).…”

“…Four percent of lipid in the diet showed the protein-sparing effect, but 6% of lipid in the diet negatively affected growth performance and body composition of juvenile grass carp ( Du et al., 2005 ). The HFD leads to unnecessary liver fat deposition ( Wang et al., 2013 ) and oxidative stress ( Huang et al., 2018 ; Ma et al., 2018 ), which might consequently affect the health of fish and reduce the yield of fish ( Zhao et al., 2019 ).…”

Surface-Displayed Amuc_1100 From Akkermansia muciniphila on Lactococcus lactis ZHY1 Improves Hepatic Steatosis and Intestinal Health in High-Fat-Fed Zebrafish

“…Fatty liver and intestinal barrier damage are widespread in most farmed fish, which severely restrict the development of aquaculture ( 1 , 2 ). Therefore, there is an urgent need to develop green feed additives to maintain host liver and intestinal health.…”