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

Abstract

In recent years, high-fat diet (HFD) has been widely applied in aquaculture, which reduces the intestinal health of cultured fish. The current study evaluated the protective effects of nano-selenium (nano-Se) on intestinal health of juvenile grass carp ( Ctenopharyngodon idella ) fed with HFD. A total of 135 experimental fish were fed with a regular diet (Con), a HFD (HFD) and a HFD containing nano-Se at 0.6 mg/kg (HSe) for 10 weeks. The results showed that dietary nano-Se significantly improved the survival rate and feed efficiency which were reduced by HFD in juvenile grass carp ( P < 0.05). Also, nano-Se (0.6 mg/kg) supplement alleviated intestinal damage caused by the HFD, thus maintaining the integrity of the intestine. Moreover, it significantly up-regulated the expression of genes related to tight junction ( ZO-1 , c laudin-3 and o ccludin ), anti-oxidization ( GPx4a and GPx4b ), and the protein of ZO-1 in the intestine of juvenile grass carp, which were depressed by the HFD ( P < 0.05). Furthermore, nano-Se supplementation significantly suppressed the expressions of genes related to the inflammation, including inflammatory cytokines ( IL-8 , IL-1β , IFN-γ , TNF-α and IL-6 ), signaling molecules ( TLR4 , p38 MAPK and NF-κB p65 ), and protein expression of NF-κB p65 and TNF-α in the intestine of juvenile grass carp which were induced by the HFD ( P < 0.05). Besides, dietary nano-Se normalized the intestinal microbiota imbalance of juvenile grass carp caused by the HFD through increasing the abundance of the beneficial bacteria, e.g., Fusobacteria. Finally, dietary nano-Se increased the production of short chain fatty acids (SCFA) in the intestine, especially for butyric acid and caproic acid, which were negatively related to the increase of intestinal permeability and inflammation. In summary, supply of nano-Se (0.6 mg/kg) in HFD could effectively alleviate intestinal injury of juvenile grass carp by improving intestinal barrier function and reducing intestinal inflammation and oxidative stress. These positive effects may be due to the regulation of nano-Se on intestinal microbiota and the subsequently increased beneficial SCFA levels.

Different Types of Non-Starch Polysaccharides Alter the Growth, Intestinal Flora and Serum Metabolite Profile of Grass Carp, Ctenopharyngodon idella

“…Partially similar to these results, Fusobacterial, Bacteroidetes, Proteobacteria, and Firmicutes were the predominant phyla in this study. Our data was highly consistent with a study reported by Liu et al that found that Fusobacterial, Bacteroidetes, Proteobacteria, and Firmicutes are the main phyla in the gut of grass carp [ 67 ]. This evidence suggests that Fusobacterial, Bacteroidetes, Proteobacteria, and Firmicutes constitute the core flora of the grass carp.…”

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

“…2020; Liu et al. 2021, 2022). Consequently, there is an urgent need to solve the problems induced by HF diets in Grass Carp farming.…”

“…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.…”

Intestinal Microbiota Mediates Gossypol-Induced Intestinal Inflammation, Oxidative Stress, and Apoptosis in Fish

“…The present study used Nile tilapia as a model, and we found that gossypol reduced the intestinal microbiota richness and diversity according to the high-throughput sequencing technology. Mounting evidence in fish have shown that the disruption of intestinal microbial homeostasis and the loss of bacterial diversity in fish may lead to metabolic disorders and disease. , For example, a high-fat diet reduced the gut microbiota richness and diversity and caused intestinal inflammation and oxidative stress in juvenile grass carp ( Ctenopharyngodon idella ) . Additionally, it has been found that the secondary metabolites from Anoxybacillus kamchatkensis had immunomodulatory properties on carp, Cyprinus carpio .…”

“…33,34 For example, a high-fat diet reduced the gut microbiota richness and diversity and caused intestinal inflammation and oxidative stress in juvenile grass carp (Ctenopharyngodon idella). 35 Additionally, it has been found that the secondary metabolites from Anoxybacillus kamchatkensis had immunomodulatory properties on carp, Cyprinus carpio. 36 According to our heat map analysis, the proportions of Anoxybacillus, Clostridiaceae, and Hyphomicrobium were significantly reduced in the ML and MH treatments.…”