Effects of replacing wheat bran with palm kernel cake or fermented palm kernel cake on the growth performance, intestinal microbiota and intestinal health of tilapia (GIFT, Oreochromis niloticus).

A nine-week feeding trial was conducted to evaluate the effects of replacing wheat bran (WB) with palm kernel cake (PKC) or fermented palm kernel cake (FPKC) on the growth performance, intestinal microbiota and intestinal health of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) (initial weight 7.00 ± 0.01 g). Eleven isonitrogenous and isolipidic experimental diets were formulated by replacing 0, 20, 40, 60, 80, and 100% of dietary WB with PKC or FPKC. Replacement of WB with PKC concentrations up to 80% had no significant effect on the growth rate of tilapia or feed utilisation (p > 0.05). FPKC improved the growth performance of tilapia, with optimum growth achieved at 40% replacement level (p < 0.05). Complete replacement with PKC significantly decreased the activity of lipase and trypsin, and reduced the height of muscularis and the height of villus (p < 0.05). However, FPKC significantly increased amylase activity and villus height (p < 0.05). The apparent digestibility of dry matter and energy decreased linearly with increasing levels of PKC substitution, while FPKC showed the opposite trend (p < 0.05). PKC replacement of WB by 20% significantly reduced serum diamine oxidase activity and endothelin levels and increased intestinal tight junctions (p < 0.05). However, FPKC significantly decreased diamine oxidase activity and increased intestinal tight junctions (p < 0.05). PKC completely replaced WB, up-regulating the expression of pro-inflammatory factors (il-1ß) (p < 0.05). When 40% of WB was replaced with FPKC, the expression of pro-inflammatory factors (il-1ß and il-6) was decreased significantly (p < 0.05). Completely replacement of WB with PKC reduced the abundance of Firmicutes and Chloroflexi, while FPKC reduced the abundance of Fusobacteriota and increased the levels of Actinobacteriota. WB can be replaced with PKC up to 80% in tilapia feeds. However, the high percentage of gluten induced intestinal inflammation, impaired gut health, and reduced dietary nutrient utilisation and growth performance. Complete replacement of WB with FPKC promoted intestinal immunity. It also improved dietary nutrient utilisation and growth performance. However, the optimal growth was achieved at a 40% replacement level.

Potential mechanisms of different methylation degrees of pectin driving intestinal microbiota and their metabolites to modulate intestinal health of Micropterus salmoides.

Four diets containing 8 % cellulose, low methyl-esterified pectin (LMP), high methyl-esterified pectin (HMP) and MMP (half LMP and half HMP) were designed to evaluate the potential mechanisms by which different esterification degrees of pectin drive intestinal microbiota and their metabolites modulating the intestinal health of Micropterus salmoides. The results showed that both dietary LMP and HMP consistently upregulated intestinal zonula occludens protein 1 (Zo-1), Caludin-1, and Caludin-4, and downregulated intestinal tumor necrosis factor-alpha (TNF-α), interleukin-8 (IL-8), and interleukin-1 beta (IL-1ß) gene expression (P < 0.05). Dietary HMP separately upregulated intestinal Occludin, nuclear factor erythroid2-related factor 2 (Nrf2), B-cell lymphoma-2 (Bcl-2), and Bcl-2 associated agonist of cell death (BAD) gene expression, as well as the digesta propionate content, OTUs, Sobs, Shannon, Chao, and ACE indices (P < 0.05), whereas dietary LMP decreased digesta arginine, 4-aminobutyric, L-tyrosine, and phenylalanine contents (P < 0.05). Moreover, dietary HMP decreased plasma lipopolysaccharide and d-lactic acid contents and increased intestinal superoxide dismutase and glutathione peroxidase activities and immunoglobulin (Ig) receptor and IgM levels (P < 0.05). Collectively, dietary HMP improves intestinal health by increasing intestinal flora α-diversity and enhancing intestinal mechanical barrier, anti-inflammatory, antioxidant, and immune functions. On the contrary, the interference of dietary LMP with butyrate, tyrosine, arginine, and 4-aminobutyric acid metabolism is the main reason for its detrimental effects on intestinal health.

Dietary Histamine Impairs the Digestive Physiology Function and Muscle Quality of Hybrid Grouper (Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂).

An 8-week feeding experiment was conducted to investigate the effect of dietary histamine on growth performance, digestive physiology function and muscle quality in a hybrid grouper (Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂). Seven isoproteic (50%) and isolipidic (11%) diets were prepared with various histamine inclusion levels of 0, 30, 60, 120, 240, 480 and 960 mg/kg in diets (actual contents were 72.33, 99.56, 138.60, 225.35, 404.12, 662.12 and 1245.38 mg/kg), respectively. Each diet was randomly assigned to triplicates of 30 juveniles (average body weight 14.78 g) per tank in a flow-through mariculture system. The increase in the dietary histamine level up to 1245.38 mg/kg made no significant difference on the growth rate and feed utilization of the grouper. However, the increased histamine content linearly decreased the activities of digestive enzymes, while no differences were observed in groups with low levels of histamine (≤404.12 mg/kg). Similarly, high levels of histamine (≥404.12 mg/kg) significantly damaged the gastric and intestinal mucosa, disrupted the intestinal tight junction structure, and raised the serum diamine oxidase activity and endotoxin level. Meanwhile, high doses of histamine (≥662.12 mg/kg) significantly reduced the activities of antioxidant enzymes, upregulated the relative expression of Kelch-like ECH-associated protein 1, and hardened and yellowed the dorsal muscle of grouper. These results showed that dietary histamine was detrimental to the digestive physiology function and muscle quality of the grouper, although it did compromise its growth performance.

Feeding Rainbow Trout with Different Types of Non-Starch Polysaccharides: Impacts on Serum Metabolome and Gut Microbiota.

A 70-day feeding trial investigated the effects of dietary inclusion of different types of non-starch polysaccharides (NSPs) on gut microbiota and serum metabolome of rainbow trout. Four practical feeds (42% crude protein, 17% crude lipid) were prepared with 8% insoluble NSP (INSP, cellulose), 16.8% soluble NSP (SNSP, composed of 1.12% ß-glucan, 1.28% mannan, 4.8% arabinoxylan, and 9.6% pectin), 24.8% NSPs (8% INSP + 16.8% SNSP), or no NSPs inclusion, respectively. Dietary NSPs inclusion had no significant influence on the Shannon, Simpson, ACE, and Chao1 indices of gut microbiota but induced a significant increase in the abundance of Pseudomonas aeruginosa and Photobacterium kishitanii, and a decrease in Firmicutes and Alistipes finegoldii. Besides, dietary SNSP upregulated the carnitine synthesis metabolic pathway. Our data suggest that dietary NSPs are detrimental to gut microbiota homeostasis and the health of rainbow trout, and dietary SNSP exhibit a stronger ability to interfere with physiological metabolism of rainbow trout than INSP. Therefore, the physiological effects of dietary NSPs, especially SNSP, should be carefully considered when designing the commercial feed formulations of rainbow trout.

High dietary non-starch polysaccharides detrimental to nutrient digestibility, digestive enzyme activity, growth performance, and intestinal morphology in largemouth bass, Micropterus salmoides.

An 8-weeks feeding trial was carried out to evaluate the effects of different levels of dietary non-starch polysaccharide on the growth, apparent nutrient digestibility, intestinal development, and morphology of largemouth bass (Micropterus salmoides). Seven isoproteic and isolipidic experimental diets were formulated (crude protein 47.00%, crude lipid 12.50%), containing 0, 3, 6, 9, 12, 15, and 18% non-starch polysaccharides (NSPs) (named Control, NSPs3, NSPs6, NSPs9, NSPs12, NSPs15, and NSPs18), respectively. Dietary inclusion of NSPs below 9% showed no negative impacts on fish growth and feed utilization efficiency, whereas dietary NSPs inclusion level above 9% decreased weight gain rate, specific growth rate, protein efficiency, protein deposition rate, apparent digestibility of dry matter and protein, and were accompanied by a reduction in intestinal protease, Na+/K+-ATPase and alkaline phosphatase activity and an increase in feed intake and feed coefficient. The activity of lipase was significantly decreased when dietary inclusion of 15 and 18% NSPs. Moreover, the lipid deposition rate and the apparent digestibility of lipids were significantly decreased since dietary inclusion of 9% NSPs. Dietary inclusion of NSPs above 12% significantly up-regulated intestinal GLP-2 gene's expression, and was accompanied by significant changes in hindgut morphology, including increases in villus length and width, muscularis thickness and number of goblet cell, as well as a decrease in crypt depth. Additionally, dietary inclusion of NSPs above 3% significantly increased intestinal length index, and the viserosomatic index was significantly increased when dietary NSPs exceeded 15%. The linear regression analysis based on weight gain rate and feed coefficient showed that the appropriate dietary NSPs level of juvenile largemouth bass should not above 5.51%. In conclusion, high dietary NSPs adversely affects digestive enzyme activity and intestinal morphology, which in turn reduced the apparent digestibility of dietary nutrients and growth of juvenile largemouth bass.

High Dietary Histamine Induces Digestive Tract Oxidative Damage in Juvenile Striped Catfish (Pangasianodon hypophthalmus).

A 56-day feeding trial investigated the effects of dietary histamine on the antioxidant capacity, gastric and intestinal barrier functions, and growth performance of striped catfish (Pangasianodon hypophthalmus). Seven isonitrogenous (34.0% crude protein) and isolipidic (10.5% crude lipid) diets were formulated with supplemental 0, 15, 30, 60, 120, 240, and 480 mg/kg of histamine, named H0, H15, H30, H60, H120, H240, and H480 group, respectively. Results showed that the weight gain rate, specific growth rate, relative intestinal length in the H240 and H480 groups, and the condition factors in the H480 group were significantly lower than those in the H0 group. Intestinal total antioxidant capacity, peroxidase, catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase activities in the H480 group were significantly lower than those in the H0 group, whereas intestinal malondialdehyde content exhibited the opposite trend. Intestinal complement 3, complement 4, immunoglobulin M, and Recombinant Mucin 2 in the H480 group were significantly lower than those in the H0 group, in contrast to intestinal lipopolysaccharide content. Intestinal IL-10 gene expression in the H480 group was significantly lower than that in the H0 group, whereas the TNF-α, IL-1, IL-6, and IL-8 gene expression exhibited opposite results. Scanning and transmission electron microscopic observation of the gastrointestinal tract revealed severe damage to the gastric mucosa and intestinal epithelium in the H480 group. The abundance of Treponema in the histamine groups was significantly higher than that in the H0 group. These results indicated that high dietary histamine decreases intestinal immunity and antioxidant capacity, inducing digestive tract oxidative damage and ultimately decreasing the growth of striped catfish.

Assessing effects of guar gum viscosity on the growth, intestinal flora, and intestinal health of Micropterus salmoides.

A 56-day feeding trial was conducted to assess the effects of different viscous guar gum on the growth, intestinal flora, and intestinal health of Micropterus salmoides. Four practical diets with 42.5 % crude protein and 13.7 % crude lipid were formulated to contain 8 % cellulose and three different viscosities (2500, 5200, and 6000 mPa·s) of guar gum. Dietary guar gum inhibits fish growth and feed utilization, decreases the α-diversity of the intestinal flora, and negatively alters the intestinal flora structure and metabolite composition. High viscous guar gum down-regulated the intestinal tight junction, anti-inflammatory, and anti-apoptotic related gene's expression, decreased digesta butyrate/histamine ratio; and increased the abundance of Plesiomonas shigelloides. These results suggest that dietary guar gum adversely affects intestinal health by disrupting intestinal flora structure and metabolite composition, and that viscosity should be considered when using guar gum as a binder in aquafeeds.

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

Dietary non-starch polysaccharides (NSPs) broadly influence fish intestinal flora and physiological metabolism, but limited information is available on grass carp (Ctenopharyngodon idella). This study investigated the effects of different types of NSPs on the growth, nutrient metabolism status, gut microbiota, and serum metabolome of grass carp. Fish were fed with diets containing 4.4% insoluble NSPs (INSP), 9.24% soluble NSPs (SNSP), 13.64% NSPs (4.4% INSP + 9.24% SNSP, NSP) and non NSPs (FM), respectively, for 9 weeks. Results showed that dietary SNSP decreased protein efficiency ratio and serum protein content, but increased feed coefficient ratio, feed intake, plasma blood urea nitrogen content, and plasma aspartate aminotransferase activity (AST); conversely, dietary INSP decreased plasma AST activity. Dietary INSP and SNSP increased serum free cholesterol content. Dietary NSPs altered the abundance of dominant bacteria and serum metabolite profiles. The differential metabolites between groups were significantly enriched in amino acid synthesis and metabolic pathways. In conclusion, dietary INSP exhibited a growth-promoting effect compared to SNSP. Dietary INSP is beneficial for improving nutrient metabolism and intestinal health. Moreover, dietary NSPs may regulate the physiological metabolism and feeding behavior of grass carp by altering amino acid synthesis and metabolism.

Effects of Different Viscous Guar Gums on Growth, Apparent Nutrient Digestibility, Intestinal Development and Morphology in Juvenile Largemouth Bass, Micropterus salmoides.

An 8-week feeding trial was conducted to investigate the effects of different viscous guar gums on the growth performance, apparent nutrient digestibility, intestinal development and morphology of juvenile largemouth bass. Four isoproteic and isolipidic diets (crude protein 42.5%, crude lipid 13.7%) were formulated to contain 8% cellulose (Control group), 8% low viscous guar gum with 2,500 mPa s (Lvs-GG group), 8% medium viscous guar gum with 5,200 mPa s (Mvs-GG group) and 8% high viscous guar gum with 6,000 mPa s (Hvs-GG group), respectively. Each diet was fed to quadruplicate groups of 40 fish (6.00 ± 0.01 g) per repetition. Dietary guar gum inclusion significantly decreased the weight gain rate, specific growth rate, protein efficiency ratio, protein productive value and lipid deposition rate, and these parameters decreased considerably with increasing guar gum viscous and were lowest in the Hvs-GG group. Dietary guar gum inclusion significantly decreased the apparent digestibility of dry matter, crude protein and crude lipid, and these parameters decreased considerably with increasing guar gum viscous and were lowest in the Hvs-GG group. Intestinal protease, lipase and creatine kinase activities in the guar gum groups were significantly lower than those in the control group, and intestinal protease and lipase activities decreased considerably with increased guar gum viscous. Intestinal alkaline phosphatase activity in the Hvs-GG group and intestinal Na+/K+-ATPase activity in the Mvs-GG and Hvs-GG groups were significantly lower than those in the Lvs-GG and control groups. Serum high-density lipoprotein, total cholesterol and triglyceride concentrations and superoxide dismutase activity in the guar gum groups were significantly lower than those in the control group. Intestinal villus height and muscular thickness in the guar gum groups were considerably higher than those in the control group, whereas the goblet cell relative number in the Mvs-GG and Hvs-GG groups and the microvillus height in the Lvs-GG and Hvs-GG groups were significantly lower than those in the control group. The expression level of IGF-1 in the guar gum groups and the expression level of GLP-2 in the Mvs-GG and Hvs-GG groups were significantly higher than those in the control group. These results indicated that guar gum diets adversely affected intestinal morphology, decreased intestinal digestive and absorptive enzyme activities, and caused poor nutrient digestibility and growth performance in juvenile largemouth bass. Moreover, the adverse effects of guar gum are closely related to its viscous, and high viscous guar gum produces more extreme negative impacts on juvenile largemouth bass.

Intestinal flora and immunity response to different viscous diets in juvenile largemouth bass, Micropterus salmoides.

An 8-weeks feeding trial was conducted to estimate the effects of different viscous cellulose on the intestinal flora and health in juvenile largemouth bass (Micropterus salmoides). Four isoproteic and isolipidic experimental diets were formulated (crude protein 42.50%, crude lipid 13.70%) to contain 8% cellulose (control group; 5.14 mPa s), 8% low viscous carboxymethyl cellulose (CMC) with 800 mPa s (Lvs-CMC group; 182.15 mPa s), 8% middle viscous CMC with 2000 mPa s (Mvs-CMC group; 320.48 mPa s) and 8% high viscous CMC with 5000 mPa s (Hvs-CMC group; 440.65 mPa s), respectively. The weight gain rate, specific growth rate, protein efficiency ratio, protein and lipid deposition rate in the CMC groups were dramatically lower than those in the control group, while feed conversion rate showed an opposite result. Plasma diamine oxidase activity, endothelin-1 and lipopolysaccharide concentrations in the Mvs-CMC and Hvs-CMC groups were significantly higher than in the control group, accompanied by a significant down-regulation of Occludin, Caludin-1 and Caludin-4. Intestinal glutathione concentration, superoxide dismutase and catalase activities in the CMC groups were significantly lower than in the control group, accompanied by a significant up-regulation of Keap1 and down-regulation of Nrf2. Moreover, CMC diets dramatically down-regulated the expression levels of IL-10 and TGF-ß1. Digesta total short chain fatty acid and acetate concentrations in the CMC groups were dramatically higher than in the control group, while butyrate concentration showed an opposite result. The OTU, Sobs, Shannon and Simpson indices of intestinal flora in the CMC groups were dramatically lower than in the control group. Notably, structural analysis showed that dietary CMC dramatically increased the abundance of C. somerae and P. shigelloides, but reduced the abundance of C. colicanis and C. perfringens. In summary, increasing dietary viscosity adversely affects the intestinal flora structure and diversity, increases acetate/butyrate-producing bacterial ratio and the abundance of pathogenic microorganisms, disrupting intestinal flora homeostasis, impairs mucosa barrier function, induces intestinal inflammation and epithelial cell apoptosis in juvenile largemouth bass. Our findings demonstrate that soluble cellulose is more detrimental to intestinal health and growth in juvenile largemouth bass compared to insoluble cellulose, and the adverse effects of soluble cellulose are mainly caused by its viscosity. Importantly, this study demonstrate that viscosity is the main characteristic of non-starch polysaccharides that are detrimental to the intestinal health of fish.

Network Pharmacology and Molecular Docking-Based Prediction of the Mechanism of Qianghuo Shengshi Decoction against Rheumatoid Arthritis.

Qianghuo Shengshi decoction (QHSSD) is a classical Chinese medicine formula, which is used in clinical practice for the treatment of rheumatoid arthritis (RA) in China. However, the pharmacological mechanism of QHSSD on RA has remained unclear by now. We collected and screened active compounds and its potential targets by the pharmacology platform of Chinese herbal medicines. In addition, the therapeutic targets of RA were obtained and selected from databases. Network construction analyzed that 128 active compounds may act on 87 candidate targets and identified a total of 18 hub targets. GO annotation and KEGG enrichment investigated that the action mechanism underlying the treatment of RA by QHSSD might be involved in cell proliferation, angiogenesis, anti-inflammation, and antioxidation. Finally, molecular docking verification showed that TP53, VEGFA, TNF, EGFR, and NOS3 may be related to the RA treatment and molecular dynamics simulation showed the stability of protein-ligand interactions. In this work, QHSSD might exert therapeutic effect through a multicomponent, multitarget, and multipathway in RA from a holistic aspect, which provides basis for its mechanism of action and subsequent experiments.