Growth performance, lipid metabolism, and systemic immunity of weaned piglets were altered by buckwheat protein through the modulation of gut microbiota.

Tartary buckwheat protein (BWP) is well known for the wide-spectrum antibacterial activity and the lipid metabolism- regulating property; therefore, BWP can be applied as feed additives to improve the animal's nutritional supply. With the aim to investigate the bioactive actions of the BWP, growth performance, lipid metabolism and systemic immunity of the weaned piglets were measured, and the alterations of pig gut microbiota were also analyzed. According to the results, the growth performances of the weaned piglets which were calculated as the average daily gain (ADG) and the average daily feed intake (ADFI) were significantly increased when compared to the control group. Simultaneously, the serum levels of the total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) were decreased, while the levels of high-density lipoprotein cholesterol (HDL-C) were increased in the BWP group. Moreover, the relative abundances of Lactobacillus, Prevotella_9, Subdoligranulum, Blautia, and other potential probiotics in the gut microbiota of weaned piglets were obviously increased in the BWP group. However, the relative abundances of Escherichia-Shigella, Campylobacter, Rikenellaceae_RC9_gut_group and other opportunistic pathogens were obviously decreased in the BWP group. In all, BWP was proved to be able to significantly improve the growth performance, lipid metabolism, and systemic immunity of the weaned piglets, and the specific mechanism might relate to the alterations of the gut microbiota. Therefore, BWP could be explored as a prospective antibiotic alternative for pig feed additives.

Uncovering epigenetic and transcriptional regulation of growth in Douglas-fir: identification of differential methylation regions in mega-sized introns.

Tree growth performance can be partly explained by genetics, while a large proportion of growth variation is thought to be controlled by environmental factors. However, to what extent DNA methylation, a stable epigenetic modification, contributes to phenotypic plasticity in the growth performance of long-lived trees remains unclear. In this study, a comparative analysis of targeted DNA genotyping, DNA methylation and mRNAseq profiling for needles of 44-year-old Douglas-fir trees (Pseudotsuga menziesii (Mirb.) Franco) having contrasting growth characteristics was performed. In total, we identified 195 differentially expressed genes (DEGs) and 115 differentially methylated loci (DML) that are associated with genes involved in fitness-related processes such as growth, stress management, plant development and energy resources. Interestingly, all four intronic DML were identified in mega-sized (between 100 and 180 kbp in length) and highly expressed genes, suggesting specialized regulation mechanisms of these long intron genes in gymnosperms. DNA repetitive sequences mainly comprising long-terminal repeats of retroelements are involved in growth-associated DNA methylation regulation (both hyper- and hypomethylation) of 99 DML (86.1% of total DML). Furthermore, nearly 14% of the DML was not tagged by single nucleotide polymorphisms, suggesting a unique contribution of the epigenetic variation in tree growth.

Evaluating the probiotic effects of spraying lactiplantibacillus plantarum P-8 in neonatal piglets.

BACKGROUND: Gut microbes play an important role in the growth and health of neonatal piglets. Probiotics can promote the healthy growth of neonatal piglets by regulating their gut microbes. The study investigated the effects of spraying Lactiplantibacillus plantarum P-8 (L. plantarum P-8) fermentation broth on the growth performance and gut microbes of neonatal piglets. RESULTS: The animals were randomly divided into probiotics groups (109 neonatal piglets) and control groups (113 neonatal piglets). The probiotics group was sprayed with L. plantarum P-8 fermented liquid from 3 day before the expected date of the sow to the 7-day-old of piglets, while the control group was sprayed with equal dose of PBS. Average daily gain (ADG), immune and antioxidant status and metagenome sequencing were used to assess the changes in growth performance and gut microbiota of neonatal piglets. The results showed that L. plantarum P-8 treatment significantly improved the average daily gain (P < 0.05) of neonatal piglets. L. plantarum P-8 increased the activities of CAT and SOD but reduced the levels of IL-2 and IL-6, effectively regulating the antioxidant capacity and immunity in neonatal piglets. L. plantarum P-8 adjusted the overall structure of gut microflora improving gut homeostasis to a certain extent, and significantly increased the relative abundance of gut beneficial bacteria such as L. mucosae and L. plantarum. CONCLUSION: Spraying L. plantarum P-8 can be a feasible and effective probiotic intervention not only improving the growth of neonatal piglets, regulating the antioxidant capacity and immunity of neonatal piglets, but also improving the gut homeostasis to a certain extent.

Lactiplantibacillus argentoratensis AGMB00912 alleviates diarrhea and promotes the growth performance of piglets during the weaning transition.

BACKGROUND: Preventing post-weaning diarrhea (PWD) in weaned piglets is a crucial challenge in the swine production industry. The stress of weaning, dietary shifts from maternal milk to solid feed, and environmental changes lead to decreased microbial diversity, increased pathogen abundance, and compromised intestinal integrity. We have previously identified Lactiplantibacillus argentoratensis AGMB00912 (LA) in healthy porcine feces, which demonstrated antimicrobial activity against pathogens and enhanced short-chain fatty acid production. This research aimed to evaluate the efficacy of LA strain supplementation as a strategy to inhibit PWD and enhance overall growth performance in weaned piglets. RESULTS: LA supplementation in weaned piglets significantly increased body weight gain, average daily gain, and average daily feed intake. It also alleviated diarrhea symptoms (diarrhea score and incidence). Notably, LA was found to enrich beneficial microbial populations (Lactobacillus, Anaerobutyricum, Roseburia, Lachnospiraceae, and Blautia) while reducing the abundance of harmful bacteria (Helicobacter and Campylobacter). This not only reduces the direct impact of pathogens but also improves the overall gut microbiota structure, thus enhancing the resilience of weaned piglets. LA treatment also promotes the growth of the small intestinal epithelial structure, strengthens gut barrier integrity, and increases short-chain fatty acid levels in the gut. CONCLUSIONS: The study findings demonstrate the promising potential of LA in preventing PWD. Supplementation with the LA strain offers a promising feed additive for improving intestinal health and growth in piglets during the weaning transition, with the potential to significantly reduce the incidence and severity of PWD.

Productive Poplar Genotypes Exhibited Temporally Stable Low Stem Embolism Resistance and Hydraulic Resistance Segmentation at the Stem-Leaf Transition.

Breeding tree genotypes that are both productive and drought-resistant is a primary goal in forestry. However, the relationships between plant hydraulics and yield at the genotype level, and their temporal stabilities, remain unclear. We selected six poplar genotypes from I-101 (Populus alba) × 84 K (P. alba × Popolus tremula var. glandulosa) for experiments in the first and fourth years after planting in a common garden. Measurements included stem embolism resistance, shoot hydraulic resistance and its partitioning between stems and leaves, vessel- and pit-level anatomy, leaf carbon acquisition capacity, carbon allocation to leaves, and aboveground biomass (yield proxy). Significant genetic variations in hydraulic properties and yield were found among genotypes in both years. Productive genotypes had wide vessels, large thin pit membranes, small pit apertures, and shallow pit chambers. Hydraulic resistance was negatively correlated with yield, enabling high stomatal conductance and assimilation rates. Productive genotypes allocated less aboveground carbon and hydraulic resistance to leaves. Temporally stable trade-offs between stem embolism resistance and yield, and between hydraulic segmentation and yield, were identified. These findings highlight the tight link between hydraulic function and yield and suggest that stable trade-offs may challenge breeding poplar genotypes that are both productive and drought-resistant.

Impact of wheat processing on growth, serum biochemistry, and ruminal microbiota in sheep (Ovis aries).

This study investigated the impact of wheat processing methods (wheat flour vs wheat pellets) on the growth performance, serum biochemical parameters, and rumen microbiome composition in sheep. Results indicated that feeding of wheat flour resulted in significantly higher terminal weight and average daily gain (P < 0.05) and lower cholesterol and ALP04 levels (P < 0.05) in sheep compared to those fed wheat pellets. Analysis of 16s rDNA high-throughput sequencing data revealed significantly higher microbial richness (Chao1 index) in the rumen of sheep fed wheat flour (P < 0.05), even though the phylum-level composition dominated by Firmicutes, Bacteroidetes, and Proteobacteria was similar in both groups of sheep. Notably, sheep fed wheat flour were found to have a significantly higher relative abundance of Bacteroidetes (P < 0.05). At the genus level, Succinivibrionaceae_UCG-001 and Prevotella_1 were significantly more abundant in the rumen of sheep fed wheat flour (P < 0.05). Correlation analysis identified that both terminal weight and average daily gain were positively correlated with ruminal abundance of Bacteroidetes and Prevotella_1, while ALP04 was negatively correlated with the abundance of these taxa. Functional prediction using PICRUSt2 indicated enrichment of pathways related to the ABC-type glycerol-3-phosphate transport system, and periplasmic components in both wheat flour and pellet fed sheep. Overall, these findings suggest that dietary wheat flour modulates rumen microbiota composition, and improves growth performance in sheep.

Lactobacillus amylovorus Promotes Lactose Utilization in Small Intestine and Enhances Intestinal Barrier Function in Intrauterine Growth Restricted Piglets.

BACKGROUND: Intrauterine growth restriction (IUGR) resulted in high mortality and many physiological defects of piglets, causing huge economic loss in the swine industry. Lactobacillus amylovorus (L. amylovorus) was identified as one of the main differential bacteria between IUGR and normal piglets. However, the effects of L. amylovorus on the growth performance and intestinal health in IUGR piglets remained unclear. OBJECTIVES: This study aimed to investigate the promoting effects of L. amylovorus Mafic1501, a new strain isolated from normal piglets, on the growth performance and intestinal barrier functions in IUGR piglets. METHODS: Newborn mice or piglets were assigned into 3 groups: CON (normal birth weight, control), IUGR (low birth weight), and IUGR+L. amy (low birth weight), administered with sterile saline or L. amylovorus Mafic1501, respectively. Growth performance, lactose content in the digesta, intestinal lactose transporter, and barrier function parameters were profiled. IPEC-J2 cells were cultured to verify the effects of L. amylovorus Mafic1501 on lactose utilization and intestinal barrier functions. RESULTS: L. amylovorus Mafic1501 elevated body weight and average daily gain of IUGR mice and piglets (P < 0.05). The lactose content in the ileum was decreased, whereas gene expression of glucose transporter 2 (GLUT2) was increased by L. amylovorus Mafic1501 in IUGR piglets during suckling period (P < 0.05). Besides, L. amylovorus Mafic1501 promoted intestinal barrier functions by increasing the villus height and relative gene expressions of tight junctions (P < 0.05). L. amylovorus Mafic1501 and its culture supernatant decreased the lactose level in the medium and upregulated gene expressions of transporter GLUT2 and tight junction protein Claudin-1 of IPEC-J2 cells (P < 0.05). CONCLUSION: L. amylovorus Mafic1501 improved the growth performance of IUGR piglets by promoting the lactose utilization in small intestine and enhancing intestinal barrier functions. Our results provided the new evidence of L. amylovorus Mafic1501 for its application in the swine industry.

Effects of Dietary Glutamine Supplementation on the Modulation of Microbiota and Th17/Treg Immune Response Signaling Pathway in Piglets after Lipopolysaccharide Challenge.

BACKGROUND: Glutamine (Gln) has an important effect on the growth performance and immune function of piglets. However, the effect of Gln on intestinal immunity in piglets through modulating the signaling pathways of the helper T cells 17 (Th17)/regulatory T cells (Treg) immune response has not been reported. OBJECTIVE: This study aimed to determine the effect of Gln on piglet growth performance and immune stress response and its mechanism in piglets. METHODS: Twenty-four weaned piglets were randomly assigned to 4 treatments with 6 replicates each, using a 2 × 2 factorial arrangement: diet (basal diet or 1% Gln diet) and immunological challenge [saline or lipopolysaccharide (LPS)]. After 21 d, half of the piglets on the basal diet and 1% Gln diet received the intraperitoneal injection of LPS and the other half received the same volume of normal saline. RESULTS: The results showed that Gln increased average daily feed intake and average daily weight gain in comparison with the control group (P < 0.05). Dietary Gln increased the villus height, villus height-to-crypt depth ratio, and the abundance of Bacteroidetes, Lactobacillus sp., and Ruminococcus sp. while reducing the abundance of Firmicutes, Clostridium sensu stricto 1 sp., and Terrisporobacter sp. (P < 0.05). Furthermore, Gln increased the concentration of short-chain fatty acids in the colon and the expression of genes of interleukin (IL)-10, transforming growth factor-beta-1, forkhead box P3 while downregulating the expression of genes of IL-6, IL-8, IL-1ß, tumor necrosis factor-α, IL-17A, IL-21, signal transducer and activator of transcription 3, and rar-related orphan receptor c in ileum (P < 0.05). Correlation analysis demonstrated a strong association between colonic microbiota, short-chain fatty acids, and ileal inflammatory cytokines. CONCLUSIONS: These results suggest that dietary Gln could improve growth performance and attenuate LPS-challenged intestinal inflammation by modulating microbiota and the Th17/Treg immune response signaling pathway in piglets.

Hepatic transcriptomic analysis reveals differential regulation of metabolic and immune pathways in three strains of chickens with distinct growth rates exposed to mixed parasite infections.

During parasite infections, the liver may prioritise immune-related pathways over its metabolic functions. Intestinal infections caused by Ascaridia galli and Heterakis gallinarum impair feed intake, nutrient absorption, and weight gain. Histomonas meleagridis, vectored by H. gallinarum, can also damage liver tissues, potentially impairing liver functions. This study examined the hepatic gene expression in three strains of chickens: Ross-308 (R), Lohmann Brown Plus (LB), and Lohmann Dual (LD), 2 weeks after an experimental infection (n = 18) with both A. galli and H. gallinarum or kept as uninfected control (n = 12). Furthermore, H. gallinarum infection led to a co-infection with H. meleagridis. The mixed infections reduced feed intake and the average daily weight gain (P < 0.001). The infections also increased the plasma concentrations of alpha (1)-acid glycoprotein and the antibody titre against H. meleagridis (P = 0.049), with no strain differences (P > 0.05). For host molecular response, 1887 genes were differentially expressed in LD, while 275 and 25 genes were differentially expressed in R and LB, respectively. The up-regulated genes in R and LD were mostly related to inflammatory and adaptive immune responses, while down-regulated genes in LD were involved in metabolic pathways, including gluconeogenesis. Despite performance differences among the strains, worm burdens were similar, but hepatic molecular responses differed significantly. Moreover, there was an indication of a shift in hepatic functions towards immune-related pathways. We, therefore, conclude that the liver shifts its functions from metabolic to immune-related activities in chickens when challenged with mixed parasite species.

Effect of dietary heat-killed Lactiplantibacillus plantarum VSG3 on growth, immunity, antioxidant status, and immune-related gene expression in pathogen-aggravated Cyprinus carpio.

Heat-killed probiotics offer an alternative approach to enhance growth and disease resistance in farmed fish. In this study, we isolated Lactiplantibacillus plantarum VSG3 from the gut of Labeo rohita to investigate the effects of heat-killed L. plantarum (HK-LP) on the health and growth performance of Cyprinus carpio fingerlings. Different concentrations of HK-LP (0, 50, 100, 200, 300, and 400 mg/kg) were administered to the fish, followed by a challenge with Aeromonas hydrophila after 8 weeks of feeding. Notably, the LP200 group exhibited significantly improved percentage weight gain and specific growth rate, accompanied by the lowest feed conversion ratio. Post-challenge survival rates were considerably enhanced in the LP200 group, reaching 60.65%. Moreover, serum analysis indicated significantly higher levels of total protein and albumin in the LP200 group than in the control group. Although HK-LP had no substantial impact on certain serum parameters (glucose, total cholesterol, cortisol, and alanine aminotransferase), aspartate aminotransferase levels were considerably low in the LP200 group. Intestinal protease and trypsin activities significantly increased in the LP200 group, while no significant changes were observed in lipase and amylase activities post-pathogen challenge. Serum immunological indices, including lysozyme, alternative complement pathway, and phagocytic activity, improved considerably in the LP200 group. Additionally, serum antioxidant enzyme activities (superoxide dismutase [SOD], glutathione peroxidase [GPx], catalase [CAT], and myeloperoxidase) were significantly elevated in the LP200 group, while malondialdehyde level was reduced. Gene expression analysis in liver tissue indicated strong upregulation of antioxidant-related genes (SOD, CAT, nuclear factor erythroid 2 [NFE2]-related factor 2 [Nrf2], Kelch-like ECH-associated protein 1[Keap1]) in the LP100 and LP200 groups. Pro-inflammatory cytokines (IL-1ß and TNF-α) were considerably downregulated in the kidneys of the LP200 post-challenged fish, although the anti-inflammatory cytokine IL-10 showed an increased expression. Quadratic regression analysis identified the optimal dietary HK-LP level for maximizing growth and immune performance (200.381-270.003 mg/kg). In summary, our findings underscore the potential of HK-LP as a valuable dietary supplement for enhancing carp aquaculture, particularly at the appropriate concentration.

Preventive and reparative potentials of heat-inactivated and viable commensal Bacillus pumilus SE5 in ameliorating the adverse impacts of high soybean meal in grouper (Epinephelus coioides).

Probiotic Bacillus pumilus SE5, heat-inactivated (HSE5) or active (ASE5), were supplemented to high soybean meal (HSM) (36 %) diet at whole term (0-56 days) and middle term (29-56 days) to investigate the preventing and repairing effects of B. pumilus SE5 in ameliorating the adverse effects of HSM in Epinephelus coioides. The results suggested that the HSM significantly decreased the weight gain rate (WGR), specific growth rate (SGR), and increased the feed conversion rate (FCR) at day 56 (P < 0.05), while HSE5 and ASE5 promoted the growth performance. The HSE5 and ASE5 showed preventive and reparative functions on the antioxidant capacity and serum immunity, with significantly increased the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-PX) activities, and reduced malondialdehyde (MDA) level, and increased acid phosphatase (ACP), alkaline phosphatase (AKP), immunoglobulin M (IgM) and complement 3 (C3). The HSM impaired the intestinal health (destroyed the intestinal structure, significantly increased the contents of serum D-lactic acid and diamine oxidase, and reduced the expressions of claudin-3 and occludin), while HSE5 and ASE5 improved them at whole term and middle term. The HSM impaired the intestinal microbiota and reduced its diversity, and the HSE5 or ASE5 improved the intestinal microbiota (especially at whole term). HSE5 and ASE5 improved the intestinal mRNA expressions of anti-inflammatory genes (il-10 and tgf-ß1) and reduced the expressions of pro-inflammatory genes (il-1ß, il-8, il-12), and promoted the expressions of humoral immune factor-related genes (cd4, igm, mhcII-α) and antimicrobial peptide genes (ß-defensin, epinecidin-1 and hepcidin-1), and decreased the expressions of NF-κB/MAPK signaling pathway-related genes (ikk-α, nf-κb, erk-1), and improved the expressions of MAPK signaling pathway-related gene p38-α (P < 0.05). In conclusion, the heat-inactivated and active B. pumilus SE5 effectively prevented and repaired the suppressive effects of soybean meal in E. coioides, which underscored the potential of B. pumilus SE5 as a nutritional intervention agent in HSM diet in aquaculture.

Evaluation of four novel non-grain protein sources completely replacing soybean meal on growth performance, serum biochemistry, amino acid transport and intestinal health of grass carp (Ctenopharyngodon idella) at different water temperatures.

To investigate the effects of non-grain protein source and water temperature on growth and feed utilization differences of grass carp, the effects of different protein sources on the growth performance, serum biochemistry, digestive enzymes, amino acid transport and intestinal health of grass carp were studied at 24 °C, 28 °C and 32 °C. In this study, a total of 1350 grass carp (Ctenopharyngodon idella) (initial weight 5.00 ± 0.02 g) were selected, and Clostridium autoethanogenum protein (CAP), Tenebrio molitor meal (TMM), cottonseed protein concentrate (CPC) and Chlorella powder (CHP) were used as a single protein source to completely replace soybean meal for 56 days. The results showed that the final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR) and protein efficiency ratio (PER) of grass carp increased significantly with the increasing temperature (P < 0.001). The CHP and SBM groups showed no significant differences in FBW, WGR, SGR and PER (P > 0.05), which were higher than the CAP, TMM and CPC groups (P < 0.001). The alanine transaminase (ALT), aspartate aminotransferase (AST), total protein (TP) and triglyceride (TG) concentrations of grass carp at 32 °C were significantly lower than those at 24 °C and 28 °C (P < 0.001). The acid phosphatase (ACP) activity decreased significantly with the increase of temperature (P = 0.001). The amylase (AMS) activity of the TMM, CPC and CHP groups was significantly lower than that of the SBM and CAP groups (P < 0.001), and the ACP and lipase (LPS) activities in the TMM group were significantly lower than those in the SBM group (P < 0.001). In addition, the interaction between temperatures and protein sources significantly affected the gene expression levels of amino acid transport including solute carrier family 1 member 3 (SLC1A3), solute carrier family 7 member 1 (SLC7A1), solute carrier family 7 member 5 (SLC7A5), solute carrier family 15 member 1b (SLC15A1b), solute carrier family 7 member 7 (SLC7A7), target of rapamycin (TOR), 4E binding protein 1 (4E-BP1) and ribosomal protein S6 kinase 1 (S6K1), intestinal inflammatory including tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-8 (IL-8), interleukin-10 (IL-10) and tight junction proteins (occludin, claudin1, claudin3, claudin7 and claudin11) (P ≤ 0.001). Collectively, our results indicated that CHP could be a potential protein source in the case of complete replacement of soybean meal in grass carp.

Influence of increasing acclimation temperature on growth, digestion, antioxidant capacity, liver transcriptome and intestinal microflora of Ussruri whitefish Coregonus ussuriensis Berg.

For effective restoration, conservation of Ussruri whitefish Coregonus ussuriensis Berg and coping with global climate change, effects of environmental temperature on Ussruri whitefish urgently need to be explored. In current study, the effects of different acclimation temperatures on the growth, digestive physiology, antioxidant ability, liver transcriptional responses and intestinal microflora patterns of Ussruri whitefish were investigated. Ussruri whitefish (15.20 g ± 1.23 g) were reared for 42 days under different acclimation temperatures, i.e., 10, 13, 16, 19, 22 and 25 °C, respectively. Result first determined 28 °C as the semi-lethal temperature in order to design the temperature gradient test. Highest main gain rate (MGR) and specific growth rate (SGR) were observed in fish group having acclimation temperature of 19 °C. Significantly decrease (P < 0.05) in triglyceride (TG) content appeared at 19 °C as compared to the 10 °C and 13 °C temperature groups. 19 °C notablely increased protease activities of stomach and intestine and intestinal lipase and amylase activities. 19 °C group obtained the highest activities of chloramphnicol acetyltransferase (CAT) and total antioxidant capacity (T-AOC) and higher activities of superoxide dismutase (SOD). The intestinal microflora composition was most conducive to maintaining overall intestinal health when the temperature was 19 °C, compared to 10 °C and 25 °C. Ussruri whitefish exposed to 10 °C and 25 °C possessed the lower Lactobacillus abundance compared to exposure to 19 °C. Temperature down to 10 °C or up to 25 °C, respectively, triggered cold stress and heat stress, which leading to impairment in intestinal digestion, liver antioxidant capacity and intestinal microflora structure. Liver transcriptome response to 10 °C, 19 °C and 25 °C revealed that Ussruri whitefish might require the initiation of endoplasmic reticulum stress to correct protein damage from cold-temperature and high-temperature stress, and it was speculated that DNAJB11 could be regarded as a biomarker of cold stress response.Based on the quadratic regression analysis of MGR and SGR against temperature, the optimal acclamation temperature were, respectively, 18.0 °C and 18.1 °C. Our findings provide valuable theoretical insights for an in-depth understanding of temperature acclimation mechanisms and laid the foundation for conservation and development of Ussruri whitefish germplasm resources.

Fermented bile acids improved growth performance and intestinal health by altering metabolic profiles and intestinal microbiome in Micropterus salmoides.

A type of fermented bile acids (FBAs) has been produced through a biological method, and its effects on growth performance, metabolism, and intestinal microbiota in largemouth bass were investigated. The results demonstrated that incorporating 0.03 %-0.05 % FBAs diet could improve the final weight, weight gain and specific growth rate, and decrease the feed conversion ratio. Dietary FBAs did not significantly affect the levels of high-density lipoprotein, low-density lipoprotein, and triglycerides, but decreased the activities of α-amylase in most groups. Adding FBAs to the diet significantly increased the integrity of the microscopic structure of the intestine, thickened the muscular layer of the intestine, and notably enhanced its intestinal barrier function. The addition of FBAs to the diet increased the diversity of the gut microbiota in largemouth bass. At the phylum level, there was an increase in the abundance of Proteobacteria, Firmicutes, Tenericutes and Cyanobacteria and a significant decrease in Actinobacteria and Bacteroidetes. At the genus level, the relative abundance of beneficial bacteria Mycoplasma in the GN6 group and Coprococcus in the GN4 group significantly increased, while the pathogenic Enhydrobacter was inhibited. Meanwhile, the highest levels of AKP and ACP were observed in the groups treated with 0.03 % FBAs, while the highest levels of TNF-α and IL-10 were detected in the group treated with 0.04 % FBAs. Additionally, the highest levels of IL-1ß, IL-8T, GF-ß, IGF-1, and IFN-γ were noted in the group treated with 0.06 % FBAs. These results suggested that dietary FBAs improved growth performance and intestinal wall health by altering lipid metabolic profiles and intestinal microbiota in largemouth bass.

Preparation of valine-curcumin conjugate and its in vitro antibacterial and antitumor activity and in vivo biological effects on American eels (Anguilla rostrata).

Curcumin (Cur) exhibits diverse natural pharmacological activities, despite its limited water solubility (hydrophobicity) and low bioavailability. In this investigation, a valine-curcumin conjugate (Val-Cur) was synthesized through amino acid side chain modification, and its solubility increased to 1.78 mg/mL. In vitro experimental findings demonstrated that the antibacterial activity of Val-Cur against Escherichia coli, Staphylococcus aureus, Aeromonas hydrophila, and Vibrio parahaemolyticus was significantly superior to that of Cur. The inhibition rate of Val-Cur against HepG2 (human hepatocellular carcinoma) cells was higher than that of Cur at low concentrations (below 25 µmol/L), although the IC50 value of Val-Cur did not differ significantly from that of Cur. In vivo biological effects of Val-Cur were assessed by adding it into the feed (150 mg/kg) of American eels (Anguilla rostrata). Val-Cur significantly improved the growth performance (↑weight gain rate, ↑specific growth rate, and ↓feed conversion rate) and activities of intestinal digestive enzymes (amylase and lipase) and antioxidant enzymes (superoxide dismutase) in American eels. Additionally, Val-Cur significantly improved serum biochemical indices (↑high-density lipoprotein cholesterol, ↓low-density lipoprotein cholesterol, ↓aspartate and alanine aminotransferases). Furthermore, Val-Cur increased intestinal microbial diversity, reduced the abundance of potentially pathogenic bacteria (Spiroplasma, Clostridium, and Pseudomonas), and elevated the abundance of beneficial digestion-promoting bacteria (Romboutsia, Phyllobacterium, Romboutsia sedimentorum, and Clostridium butyricum) conducive to glucose metabolism (P < 0.05). To the best of our knowledge, this study is the first to explore water-soluble curcumin in aquaculture, and the findings will lay the groundwork for the potential application of water-soluble curcumin in the field of aquaculture.

Effects of dietary chitosan oligosaccharide on the growth, intestinal microbiota and immunity of juvenile red claw crayfish (Cherax quadricarinatus).

This study aimed to evaluate the potential benefits of chitosan oligosaccharide (COS) on red claw crayfish (Cherax quadricarinatus) and explore its underlying mechanisms. The crayfish were randomly divided into six groups, and the diets were supplemented with COS at levels of 0 (C0), 0.2 (C1), 0.4 (C2), 0.6 (C3), 0.8 (C4), and 1 (C5) g kg-1. Treatment with COS significantly improved the growth performance of the crayfish with a higher weight gain rate (WGR) and specific growth rate (SGR) in the C2 group compared to the C0 group. Additionally, the content of crude protein in the crayfish muscles in the C1 group was significantly higher than that of the C0 group. Regarding non-specific immunity, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and alkaline phosphatase (AKP), and the levels of expression of the genes related to immunity (SOD; anti-lipopolysaccharide factor [ALF]; thioredoxin1 [Trx1]; C-type lysozyme, [C-LZM]; and GSH-Px) in the hepatopancreas and hemolymph increased significantly (P < 0.05) after supplementation with 0.4 g kg-1 of COS, while the content of malondialdehyde (MDA) decreased (P < 0.05). The survival rate of C. quadricarinatus increased (P < 0.05) in the C2, C3, C4, and C5 groups after the challenge with Aeromonas hydrophila. This study found that COS has the potential to modulate the composition of the intestinal microbiota and significantly reduce the abundance of species of the phylum Proteobacteria and the genera Aeromonas and Vibrio in the gut of C. quadricarinatus, while the abundance of bacteria in the phylum Firmicutes and the genus Candidatus_Hepatoplasma improved significantly. This study suggests that the inclusion of COS in the diet of C. quadricarinatus can enhance growth, boost immunity, and increase resistance to infection with A. hydrophila, especially when supplemented at 0.4-0.8 g kg-1.

Effects of antimicrobial peptides from dietary Hermetia illucens larvae on the growth, immunity, gene expression, intestinal microbiota and resistance to Aeromonas hydrophila of juvenile red claw crayfish (Cherax quadricarinatus).

Antimicrobial peptides (AMPs), which are widely present in animals and plants, have a broad distribution, strong broad-spectrum antibacterial activity, low likelihood of developing drug resistance, high thermal stability and antiviral properties. The present study investigated the effects of adding AMPs from Hermetia illucens larvae on the growth performance, muscle composition, antioxidant capacity, immune response, gene expression, antibacterial ability and intestinal microbiota of Cherax quadricarinatus (red claw crayfish). Five experimental diets were prepared by adding 50 (M1), 100 (M2), 150 (M3) and 200 (M4) mg/kg of crude AMP extract from H. illucens larvae to the basal diet feed, which was also used as the control (M0). After an eight-week feeding experiment, it was discovered that the addition of 100-150 mg/kg of H. illucens larvae AMPs to the feed significantly improved the weight gain rate and specific growth rate of C. quadricarinatus. Furthermore, the addition of H. illucens larvae AMPs to the feed had no significant effect on the moisture content, crude protein, crude fat and ash content of the C. quadricarinatus muscle. The addition of 100-150 mg/kg of H. illucens larvae AMPs in the feed also increased the antioxidant capacity, nonspecific immune enzyme activity and related gene expression levels in C. quadricarinatus, thereby enhancing their antioxidant capacity and immune function. The H. illucens larvae AMPs improved the structure and composition of the intestinal microbiota of C. quadricarinatus, increasing the microbial community diversity of the crayfish gut. Finally, the addition of 100-150 mg/kg of H. illucens larvae AMPs in the feed enhanced the resistance of C. quadricarinatus against Aeromonas hydrophila, improving the survival rate of the crayfish. Based on the aforementioned findings, it is recommended that H. illucens larvae AMPs be incorporated into the C. quadricarinatus feed at a concentration of 100-150 mg/kg.

Effects of adding Bacillus subtilis natto NTU-18 in paste feed on growth, intestinal morphology, gastrointestinal microbiota diversity, immunity, and disease resistance of Anguilla japonica glass eels.

Japanese eel, Anguilla japonica, holds significant importance in Taiwanese aquaculture. With the intensification of eel farming, the impact of Edwardsiella tarda has become increasingly severe. Consequently, the abusive use of antibiotics has risen. Bacillus subtilis natto NTU-18, a strain of Bacillus with a high survival rate in feed processing, plays a crucial role in promoting intestinal health through competitive rejection, enhancing immune responses against bacterial pathogens, and improving intestinal health by modulating gastrointestinal microbiota to produce beneficial metabolites of mice and grass carp, Ctenopharyngodon idella. This study investigated the effects of different proportions (control, 0.25 %, 0.5 %, 1 %, and 2 %) of B. subtilis natto NTU-18 added to paste feed on the growth performance, intestinal morphology, and microbiota, expression of immune-related genes, and resistance to E. tarda in Japanese glass eel. The results indicated that the growth performance of all groups with B. subtilis natto NTU-18 added was significantly higher than that of the control group and did not impact the villi morphology. The expression of immune-related genes in the kidney, specifically HSP70 and SOD, was significantly higher from 0.5 % and above than the control; however, no significant differences were observed in CAT, POD, and HSP90. In the liver, significant differences were found in HSP70 and IgM above 0.25 % compared to the control group, with no significant differences in SOD, CAT, POD, and HSP90 among all groups. Additionally, intestinal microbiota analysis revealed that the 2 % additional group had significantly lower diversity than other groups, with Cetobacterium as the dominant species. The challenge test observed that the survival rates of the 0.5 % and 1 % groups were significantly higher. This research suggests that adding 0.5 % and 1 % of B. subtilis natto NTU-18 to the diet is beneficial for Japanese glass eel's immunity, growth performance, and disease resistance.

Effects of Lactobacillus acidophilus AC on the growth, intestinal flora and metabolism of zebrafish (Danio rerio).

The intensive aquaculture model has resulted in a heightened prevalence of diseases among farmed animals. It is imperative to identify healthy and efficacious alternatives to antibiotics for the sustainable progression of aquaculture. In this investigation, a strain of Lactobacillus acidophilus AC was introduced into the cultural water at varying concentrations (105 CFU/mL, 106 CFU/mL, 107 CFU/mL) to nourish zebrafish (Danio rerio). The findings revealed that L. acidophilus AC effectively increased the growth performance of zebrafish, improved the ion exchange capacity of gills, and enhanced hepatic antioxidant and immune-enzyme activities. Furthermore, L. acidophilus AC notably enhanced the intestinal morphology and augmented the activity of digestive enzymes within the intestinal tract. Analysis of intestinal flora revealed that L. acidophilus AC exerted a significant impact on the intestinal flora community, manifested by a reduction in the relative abundance of Burkholderiales, Candidatus_Saccharibacteria_bacterium, and Sutterellaceae, coupled with an increase in the relative abundance of Cetobacterium. Metabolomics analysis demonstrated that L. acidophilus AC significantly affected intestinal metabolism of zebrafish. PG (i-19:0/PGE2) and 12-Hydroxy-13-O-d-glucuronoside-octadec-9Z-enoate were the metabolites with the most significant up- and down-regulation folds, respectively. Finally, L. acidophilus AC increased the resistance of zebrafish to Aeromonas hydrophila. In conclusion, L. acidophilus AC was effective in enhancing the health and immunity of zebrafish. Thus, our findings suggested that L. acidophilus AC had potential applications and offered a reference for its use in aquaculture.

From growth promotion to intestinal inflammation alleviation: Unraveling the potential role of Lactobacillus rhamnosus GCC-3 in juvenile grass carp (Ctenopharyngodon idella).

Lactobacillus rhamnosus is a probiotic, which not only promotes the growth of animals, but also has anti-inflammatory effects. However, the mechanism by which Lactobacillus rhamnosus regulates intestinal immunity is not well comprehended. Hence, the study aimed to research how Lactobacillus rhamnosus affects the intestinal immunity using juvenile grass carp (Ctenopharyngodon idella) as a model. We selected 1800 juvenile grass carp for testing. They were divided into six treatments and fed with six gradients of Lactobacillus rhamnosus GCC-3 (0.0, 0.5, 1.0, 1.5, 2.0, 2.5 g/kg) for 70 days. Enteritis was subsequently induced with dextroside sodium sulfate. Results indicated that dietary Lactobacillus rhamnosus GCC-3 addition improved growth performance. Meanwhile, appropriate levels of Lactobacillus rhamnosus GCC-3 alleviated excessive inflammatory response by down-regulating the expression of TLR4 and NOD receptors, up-regulating the expression of TOR, and then down-regulating the expression of NF-κB. Additionally, appropriate Lactobacillus rhamnosus GCC-3 improved intestinal immunity by reducing pyroptosis triggered by NLRP3 inflammasome and mediated by GSDME. Furthermore, 16 S rRNA sequencing showing appropriate levels of Lactobacillus rhamnosus GCC-3 increased Lactobacillus and Bifidobacterium abundance and decreased Aeromonas abundance. These results suggest that Lactobacillus rhamnosus GCC-3 can alleviate intestinal inflammation through down-regulating NF-κB and up-regulating TOR signaling pathways, as well as by inhibiting pyroptosis.