Effect of chito-oligosaccharide on growth performance, intestinal barrier function, intestinal morphology and cecal microflora in weaned pigs

Multiple omics integration analysis reveals the regulatory effect of chitosan oligosaccharide on testicular development

Infertility is a global health problem affecting millions of people of reproductive age worldwide, with approximately half caused by males. Chitosan oligosaccharide (COS) has strong antioxidant capacity, but its impact on the male reproductive system has not been effectively evaluated. To address this, we integrated RNA-seq, serum metabolomics and intestinal 16 S rDNA analysis to conduct a comprehensive investigation on the male reproductive system. The results showed that COS has potential targets for the treatment of oligospermia, which can promote the expression of meiotic proteins DDX4, DAZL and SYCP1, benefit germ cell proliferation and testicular development, enhance antioxidant capacity, and increase the expression of testicular steroid proteins STAR and CYP11A1. At the same time, COS can activate PI3K-Akt signaling pathway in testis and TM3 cells. Microbiome and metabolomics analysis suggested that COS alters gut microbial community composition and cooperates with serum metabolites to regulate spermatogenesis. Therefore, COS promotes male reproduction by regulating intestinal microorganisms and serum metabolism, activating PI3K-Akt signaling pathway, improving testicular antioxidant capacity and steroid regulation.

Enhancing immune response, antioxidant capacity, and gut health in growing beagles through a chitooligosaccharide diet

Chitooligosaccharides (COS) have attracted significant attention due to their unique biological activities, water solubility, and absorbable properties. The objective of the present study was to investigate the impact of COS-supplemented diets on the immune response, antioxidative capacity, hematology, serum biochemistry, and modulation of intestinal microbiota in growing beagles. Twelve weaning male beagles (6 weeks old; weighing 3.6 ± 0.6 kg) were fed either a control diet (food without COS, n = 6) or a COS-supplemented diet (n = 6) twice daily for 7 weeks. Blood samples collected at weeks 4 and 7 indicated that hematology and serum biochemistry remained unaffected by COS supplementation. Compared with the control group, the test group showed higher levels of serum antibodies against the canine distemper virus and parvovirus, higher levels of immunoglobulin A, G, and M, and increased activities of superoxide dismutase, glutathione peroxidase, and catalase. In addition, COS was observed to modulate the intestinal flora by enhancing the presence of probiotics, such as Muribaculaceae, Prevotellaceae_Ga6A1_group, Lactobacillus, Collinsella, Blautia, and Lachnospiraceae_NK4A136_group. In summary, a COS-supplemented diet could effectively improve dog health by regulating immune function and antioxidant responses and modulating intestinal microbiota. This study highlights the potentiality of using COS as a valuable nutraceutical for growing dogs.

Engineering polysaccharide hydrolases in the product-releasing cleft to alter their product profiles

Polysaccharide hydrolases are enzymes capable of hydrolyzing polysaccharides to generate oligosaccharides that have diverse applications in the food, feed and pharmaceutical industries. However, the detailed mechanisms governing the compositions of their hydrolysates remain poorly understood. Previously, we identified a novel neopullulase Amy117, which exclusively converts pullulan to panose by specifically cleaving α-1,4-glycosidic bonds. Yet, several enzymes with high homology to Amy117 produce a mixture of glucose, maltose and panose during pullulan hydrolysis. To explore this particular phenomenon, we compared the sequences and structures between Amy117 and the maltose amylase ThMA, and identified a specific residue Thr299 in Amy117 (equivalent to His294 in ThMA) within the product-releasing cleft of Amy117, which might be responsible for this characteristic feature. Using structure-based rational design, we have successfully converted the product profiles of pullulan hydrolysates between Amy117 and ThMA by simply altering this key residue. Molecular docking analysis indicated that the key residue at the product-releasing outlet altered the product profile by affecting the panose release rate. Moreover, we modeled the long-chain pullulan substrate G8 to examine its potential conformations and found that G8 might undergo a conformational change in the narrow cleft that allows the Amy117 variant to specifically recognize α-1,6-glycosidic bonds.

Protective Effects of Alginate and Chitosan Oligosaccharides against Clostridioides difficile Bacteria and Toxin

Clostridioides difficile infection is expected to become the most common healthcare-associated infection worldwide. C. difficile-induced pathogenicity is significantly attributed to its enterotoxin, TcdA, which primarily targets Rho-GTPases involved in regulating cytoskeletal and tight junction (TJ) dynamics, thus leading to cytoskeleton breakdown and ultimately increased intestinal permeability. This study investigated whether two non-digestible oligosaccharides (NDOs), alginate (AOS) and chitosan (COS) oligosaccharides, possess antipathogenic and barrier-protective properties against C. difficile bacteria and TcdA toxin, respectively. Both NDOs significantly reduced C. difficile growth, while cell cytotoxicity assays demonstrated that neither COS nor AOS significantly attenuated the TcdA-induced cell death 24 h post-exposure. The challenge of Caco-2 monolayers with increasing TcdA concentrations increased paracellular permeability, as measured by TEER and LY flux assays. In this experimental setup, COS completely abolished, and AOS mitigated, the deleterious effects of TcdA on the monolayer's integrity. These events were not accompanied by alterations in ZO-1 and occludin protein levels; however, immunofluorescence microscopy revealed that both AOS and COS prevented the TcdA-induced occludin mislocalization. Finally, both NDOs accelerated TJ reassembly upon a calcium-switch assay. Overall, this study established the antipathogenic and barrier-protective capacity of AOS and COS against C. difficile and its toxin, TcdA, while revealing their ability to promote TJ reassembly in Caco-2 cells.

Chitosan Enhances Intestinal Health in Cats by Altering the Composition of Gut Microbiota and Metabolites

The interaction between gut microbiota and the health of the host has gained increasing attention. Chitosan is a natural alkaline polysaccharide with a wide range of beneficial effects. However, rare studies have been observed on the effects of dietary chitosan supplementation on intestinal health in cats. A total of 30 cats with mild diarrhea were divided into three groups, receiving a basic diet with 0 (CON), 500 (L-CS) or 2000 (H-CS) mg/kg chitosan. Samples of blood and feces were collected and analyzed for serology and gut microbiota composition. The results demonstrated that chitosan alleviated symptoms of diarrhea, with enhanced antioxidant capability and decreased inflammatory biomarker levels in serum. Chitosan reshaped the composition of gut microbiota in cats that the beneficial bacteria Allobaculum was significantly increased in the H-CS group. Acetate and butyrate contents in feces were significantly higher in the H-CS group in comparison to the CON group (p < 0.05). In conclusion, the addition of dietary chitosan in cats enhanced intestinal health by modulating their intestinal microbes and improved microbiota-derived SCFA production. Our results provided insights into the role of chitosan in the gut microbiota of felines.

Chitosan oligosaccharide alleviates and removes the toxicological effects of organophosphorus pesticide chlorpyrifos residues

The abuse of chlorpyrifos (CHP), a commonly used organophosphorus pesticide, has caused many environmental pollution problems, especially its toxicological effects on non-target organisms. First, CHP enriched on the surface of plants enters ecosystem circulation along the food chain. Second, direct inflow of CHP into the water environment under the action of rainwater runoff inevitably causes toxicity to non-target organisms. Therefore, we used rats as a model to establish a CHP exposure toxicity model and studied the effects of CHP in rats. In addition, to alleviate and remove the injuries caused by residual chlorpyrifos in vivo, we explored the alleviation effect of chitosan oligosaccharide (COS) on CHP toxicity in rats by exploiting its high water solubility and natural biological activity. The results showed that CHP can induce the toxicological effects of intestinal antioxidant changes, inflammation, apoptosis, intestinal barrier damage, and metabolic dysfunction in rats, and COS has excellent removal and mitigation effects on the toxic damage caused by residual CHP in the environment. In summary, COS showed significant biological effects in removing and mitigating blood biochemistry, antioxidants, inflammation, apoptosis, gut barrier structure, and metabolic function changes induced by residual CHP in the environment.

Dietary chitooligosaccharide supplementation improves mineral deposition, meat quality and intramuscular oxidant status in broilers

BACKGROUND

The present study aimed at evaluating the in vitro adsorption capability of chitooligosaccharide (COS) with some metal elements (Fe, Zn, Cd, Pb) at different pH values along with potential effects of dietary COS supplementation on growth performance, mineral content, meat quality and oxidant status in broilers. Day-old male chicks were randomly distributed into two groups and offered a basal diet supplemented with or without 30 mg kg^-1 COS for 42 days.

RESULTS

In vitro trials demonstrated that Fe levels were higher (P < 0.001) in the COS-treated group compared with the non-treated group at pH of 2.5. However, these levels became lowered when pH values were raised to 5 (P < 0.01) or 6 (P < 0.001). Similarly, COS adsorbed more (P < 0.05) Zn at pH values of 2.5 and 6, and Cd contents at pH of 2.5 for 70 min when compared with the control. For in vivo trial, the feed-to-gain ratio, serum Cu (P < 0.01), hepatic Mn, Cr (P < 0.05) and intramuscular Cd (P < 0.01) were lower in response to COS treatment. Supplementation of COS improved (P < 0.05) meat quality of broilers in terms of lower drip loss, cooking loss and malondialdehyde content with a concomitant increase (P < 0.01) in the pH of breast meat at 24 h post mortem.

CONCLUSION

COS adsorbed heavy metal ions not only in vitro but also in broilers, and dietary supplementation with 30 mg kg^-1 COS improved growth performance, breast meat quality and oxidant status in broilers. © 2022 Society of Chemical Industry.

Fabrication of bio-engineered chitosan nanoformulations to inhibition of bacterial infection and to improve therapeutic potential of intestinal microflora, intestinal morphology, and immune response in infection induced rat model

Overdosage of antibiotics used to prevent bacterial infections in the human and animal gastrointestinal tract would result in disturbing of intestinal barrier, significant misbalancing effects of intestinal microflora and persuading bacterial resistance. The main objective of the present investigation is to design and develop novel combinations of organic curcumin (Cur) and antimicrobial peptide (Amp) loaded chitosan nanoformulations (Cur/Amp@CS NPs) to improve significant effects on antibacterial action, immune response, intestine morphology, and intentional microflora. The antibacterial efficiency of the prepared nanoformulations was evaluated using Escherichia coli (E. coli) induced bacterial infections in GUT of Rat models. Further, we studied the cytocompatibility, inflammatory responses, α-diversity, intestinal morphology, and immune responses of treated nanoformulations in rat GUT models. The results indicated that Cur/Amp@CS NPs are greatly beneficial for intestinal microflora and could be a prodigious alternative of antibiotics.

Direct Action of Non-Digestible Oligosaccharides against a Leaky Gut

The epithelial monolayer is the primary determinant of mucosal barrier function, and tight junction (TJ) complexes seal the paracellular space between the adjacent epithelial cells and represent the main "gate-keepers" of the paracellular route. Impaired TJ functionality results in increased permeation of the "pro-inflammatory" luminal contents to the circulation that induces local and systemic inflammatory and immune responses, ultimately triggering and/or perpetuating (chronic) systemic inflammatory disorders. Increased gut leakiness is associated with intestinal and systemic disease states such as inflammatory bowel disease and neurodegenerative diseases such as Parkinson's disease. Modulation of TJ dynamics is an appealing strategy aiming at inflammatory conditions associated with compromised intestinal epithelial function. Recently there has been a growing interest in nutraceuticals, particularly in non-digestible oligosaccharides (NDOs). NDOs confer innumerable health benefits via microbiome-shaping and gut microbiota-related immune responses, including enhancement of epithelial barrier integrity. Emerging evidence supports that NDOs also exert health-beneficial effects on microbiota independently via direct interactions with intestinal epithelial and immune cells. Among these valuable features, NDOs promote barrier function by directly regulating TJs via AMPK-, PKC-, MAPK-, and TLR-associated pathways. This review provides a comprehensive overview of the epithelial barrier-protective effects of different NDOs with a special focus on their microbiota-independent modulation of TJs.

Multifunctional role of chitosan in farm animals: a comprehensive review

The deacetylation of chitin results in chitosan, a fibrous-like material. It may be produced in large quantities since the raw material (chitin) is plentiful in nature as a component of crustacean (shrimps and crabs) and insect hard outer skeletons, as well as the cell walls of some fungi. Chitosan is a nontoxic, biodegradable, and biocompatible polygluchitosanamine that contains two essential reactive functional groups, including amino and hydroxyl groups. This unique chemical structure confers chitosan with many biological functions and activities such as antimicrobial, anti-inflammatory, antioxidative, antitumor, immunostimulatory and hypocholesterolemic, when used as a feed additive for farm animals. Studies have indicated the beneficial effects of chitosan on animal health and performance, aside from its safer use as an antibiotic alternative. This review aimed to highlight the effects of chitosan on animal health and performance when used as a promising feed additive.

Probiotics and Synbiotics Addition to Bama Mini-Pigs' Diet Improve Carcass Traits and Meat Quality by Altering Plasma Metabolites and Related Gene Expression of Offspring

This study evaluated the effects of maternal probiotics and synbiotics addition on several traits and parameters in offspring. A total of 64 Bama mini pigs were randomly allocated into the control (basal diet), antibiotic (50 g/t virginiamycin), probiotics (200 mL/day probiotics), or synbiotics (500 g/t xylo-oligosaccharides and 200 mL/day probiotics) group and fed with experimental diets during pregnancy and lactation. After weaning, two piglets per litter and eight piglets per group were selected and fed with a basal diet. Eight pigs per group were selected for analysis at 65, 95, and 125 days of age. The results showed that the addition of probiotics increased the average daily feed intake of the pigs during the 66- to 95-day-old periods and backfat thickness at 65 and 125 days of age, and that the addition of synbiotics increased backfat thickness and decreased muscle percentage and loin-eye area at 125 days of age. The addition of maternal probiotics increased the cooking yield and pH45min value at 65 and 95 days of age, respectively, the addition of synbiotics increased the meat color at 95 days of age, and the addition of probiotics and synbiotics decreased drip loss and shear force in 65- and 125-day-old pigs, respectively. However, maternal antibiotic addition increased shear force in 125-day-old pigs. Dietary probiotics and synbiotics addition in sows' diets increased several amino acids (AAs), including total AAs, histidine, methionine, asparagine, arginine, and leucine, and decreased glycine, proline, isoleucine, α-aminoadipic acid, α-amino-n-butyric acid, β-alanine, and γ-amino-n-butyric acid in the plasma and longissimus thoracis (LT) muscle of offspring at different stages. In the LT muscle fatty acid (FA) analysis, saturated FA (including C16:0, C17:0, and C20:0) and C18:1n9t contents were lower, and C18:2n6c, C16:1, C20:1, and unsaturated FA contents were higher in the probiotics group. C10:0, C12:0, and C14:0 contents were higher in 65-day-old pigs, and C20:1 and C18:1n9t contents were lower in the synbiotics group in 95- and 125-day-old pigs, respectively. The plasma biochemical analysis revealed that the addition of maternal probiotics and synbiotics decreased plasma cholinesterase, urea nitrogen, and glucose levels in 95-day-old pigs, and that the addition of synbiotics increased plasma high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total cholesterol concentrations in 65-day-old pigs and triglyceride concentration in 125-day-old pigs. The addition of maternal probiotics and synbiotics regulated muscle fiber type, myogenic regulation, and lipid metabolism-related gene expression of LT muscle in offspring. In conclusion, the addition of maternal probiotics and synbiotics improved the piglet feed intake and altered the meat quality parameters, plasma metabolites, and gene expression related to meat quality.

Dietary Supplementation of Chitosan Oligosaccharide–Clostridium butyricum Synbiotic Relieved Early-Weaned Stress by Improving Intestinal Health on Pigeon Squabs (Columba livia)

According to a previous study, we had found that early weaning causes harm to growth performance, intestinal morphology, activity of digestive enzymes, and antioxidant status in pigeon squabs (Columba livia). Chitosan oligosaccharides (COS) and Clostridium butyricum have been reported to have great potential to improve the growth performance and intestinal health of early-weaned animals. Therefore, the aim of this study is to explore whether dietary supplementation with COS-C. butyricum synbiotic could relieve early-weaned stress by evaluating its effects on growth performance and intestinal health in pigeon squabs. A total of 160 squabs (weaned at 7 days of age) were randomly divided into 5 groups: the control group, fed with artificial crop milk; the COS supplementation group, fed with artificial crop milk + 150 mg/kg COS; and three synbiotic supplementation groups, fed with artificial crop milk + 150 mg/kg COS + 200, 300, and 400 mg/kg C. butyricum. The results showed that a diet supplemented with COS-C. butyricum synbiotic benefitted the growth performance of early-weaned squabs; even so the differences were not significant among the five groups (p > 0.05). In addition, dietary supplementation of 150 mg/kg COS + 300~400 mg/kg C. butyricum significantly improved the intestinal morphology (especially villus surface area and the ratio of villus height to crypt depth), the activity of digestive enzymes (lipase, trypsin, and leucine aminopeptidase) in duodenum contents, and the production of total short-chain fatty acids and acetic acid in ileum content (p < 0.05). Additionally, dietary supplementation of 150 mg/kg COS + 400 mg/kg C. butyricum benefitted gut health by improving the antioxidant capacity (glutathione peroxidase and total antioxidant capacity) and cytokine status (IL-4 and IL-10) (p < 0.05), as well as by improving the intestinal microbiota diversity. In conclusion, our results revealed that dietary supplementation with synbiotic (150 mg/kg COS + 300~400 mg/kg C. butyricum) could relieve early-weaned stress by maintaining intestinal health in pigeon squabs.

Bifidobacterium castoris strains isolated from wild mice show evidence of frequent host switching and diverse carbohydrate metabolism potential

Members of the gut microbiota genus Bifidobacterium are widely distributed human and animal symbionts believed to exert beneficial effects on their hosts. However, in-depth genomic analyses of animal-associated species and strains are somewhat lacking, particularly in wild animal populations. Here, to examine patterns of host specificity and carbohydrate metabolism capacity, we sequenced whole genomes of Bifidobacterium isolated from wild-caught small mammals from two European countries (UK and Lithuania). Members of Bifidobacterium castoris, Bifidobacterium animalis and Bifodobacterium pseudolongum were detected in wild mice (Apodemus sylvaticus, Apodemus agrarius and Apodemus flavicollis), but not voles or shrews. B. castoris constituted the most commonly recovered Bifidobacterium (78% of all isolates), with the majority of strains only detected in a single population, although populations frequently harboured multiple co-circulating strains. Phylogenetic analysis revealed that the mouse-associated B. castoris clades were not specific to a particular location or host species, and their distribution across the host phylogeny was consistent with regular host shifts rather than host-microbe codiversification. Functional analysis, including in vitro growth assays, suggested that mouse-derived B. castoris strains encoded an extensive arsenal of carbohydrate-active enzymes, including putative novel glycosyl hydrolases such as chitosanases, along with genes encoding putative exopolysaccharides, some of which may have been acquired via horizontal gene transfer. Overall, these results provide a rare genome-level analysis of host specificity and genomic capacity among important gut symbionts of wild animals, and reveal that Bifidobacterium has a labile relationship with its host over evolutionary time scales.

Feeding of cuticles from Tenebrio molitor larvae modulates the gut microbiota and attenuates hepatic steatosis in obese Zucker rats

Insect biomass obtained from large-scale mass-rearing of insect larvae has gained considerable attention in recent years as an alternative and sustainable source of food and feed. A byproduct from mass-rearing of insect larvae is the shed cuticles - the most external components of insects which are a relevant source of the polysaccharide chitin. While it has been shown that chitin modulates the gut microbiota and ameliorates lipid metabolic disorders in obese rodent models, feeding studies dealing with isolated insects' cuticles are completely lacking. Thus, the present study tested the hypothesis that dietary insects' cuticles modulate the gut microbiome and improve hepatic lipid metabolism in obese Zucker rats. To test this hypothesis, three groups of obese Zucker rats were fed a nutrient-adequate, semisynthetic basal diet which was supplemented with either 0% (group O), 1.5% (group O1.5) or 3.0% (group O3.0) Tenebrio molitor cuticles at the expense of cellulose. Oil red O-stained liver sections showed a marked lipid accumulation, but lipid accumulation was clearly less in group O3.0 than in groups O and O1.5. In line with this, hepatic lipid concentrations were 30% lower in group O3.0 than in group O (p < 0.05). No differences were observed across the obese groups regarding liver concentrations of methionine, S-adenosylmethionine and homocysteine. Analysis of cecal microbial community at the family level revealed that the relative abundances of Bifidobacteriaceae, Coriobacteriaceae Erysipelotrichaceae, Lactobacillaceae, Prevotellaceae, Sutterellaceae, unknown Deltaproteobacteria and unknown Firmicutes were higher and those of Anaeroplasmataceae, Desulfovibrionaceae, Eubacteriaceae, Ruminococcaceae, Saccharibacteria and unknown Clostridiales were lower in group O3.0 compared to group O (p < 0.05). Cecal digesta concentrations of total short-chain fatty acids, acetate and butyrate were higher in group O3.0 than in group O (p < 0.05). Targeted plasma metabolomics revealed 53 metabolites differing between groups, amongst which two indole metabolites, indole-3-propionic acid and 3-indoxylsulfate, were markedly elevated in group O3.0 compared to groups O1.5 and O. Regarding that increased abundances of bacteria of the Actinobacteria phylum and Lactobacillaceae family in the gut have been reported to be associated with antisteatotic, hepatoprotective and antiinflammatory effects, the pronounced increases of Bifidobacteriaceae and Coriobacteriaceae (both Actinobacteria), and of Lactobacillaceae in group O3.0 might have contributed to the amelioration of fatty liver.

Fructooligosaccharide Reduces Weanling Pig Diarrhea in Conjunction with Improving Intestinal Antioxidase Activity and Tight Junction Protein Expression

This study was to illustrate the effects of fructooligosaccharide (FOS) on the antioxidant capacity, intestinal barrier function, and microbial community of weanling pigs. Results showed that FOS reduced the incidence of diarrhea (6.5 vs. 10.8%) of pigs (p < 0.05) but did not affect growth performance when compared with the control group. A diet supplemented with FOS increased ileal mRNA expression of occludin (1.7 vs. 1.0), claudin-1 (1.9 vs. 1.0), claudin-2 (1.8 vs. 1.0), and claudin-4 (1.7 vs. 1.0), as well as colonic mRNA expression of ZO-1 (1.6 vs. 1.0), claudin-1 (1.7 vs. 1.0), occludin (1.9 vs. 1.0), and pBD-1 (1.5 vs. 1.0) when compared with the control group (p < 0.05). FOS supplementation improved the anti-oxidase activity and expression of nuclear factor erythroid-2 related factor 2 (Nrf2), and decreased concentrations of D-lactate (3.05 U/L vs. 2.83 U/L) and TNF-α (59.1 pg/mL vs. 48.0 pg/mL) in the serum when compared with the control group (p < 0.05). In addition, FOS increased Sharpea, Megasphaera, and Bacillus populations in the gut when compared with the control group (p < 0.05). Association analysis indicated that mRNA expression of occludin and claudin-1 in the ileal mucosa were correlated positively with populations of Sharpea and Bacillus (p < 0.05). Furthermore, mRNA expression of occludin and claudin-1 in the colonic mucosa were correlated positively with abundances of Sharpea, Lactobocillus, and Bifidobacterium (p < 0.05). In conclusion, FOS activated Nrf2 signaling and increased the expression of specific tight junction proteins, which were associated with reduced diarrhea incidence.

Dietary supplementation of fructooligosaccharides alleviates enterotoxigenic E. coli-induced disruption of intestinal epithelium in a weaned piglet model

Diarrhea caused by pathogens such as enterotoxigenic E. coli (ETEC) is a serious threat to the health of young animals and human infants. Here, we investigated the protective effect of fructooligosaccharides (FOS) on the intestinal epithelium with ETEC-challenge in a weaned piglet model. Twenty-four weaned piglets were randomly divided into three groups: (1) non-ETEC-challenged control (CON), (2) ETEC-challenged control (ECON), and (3) ETEC challenge + 2.5 g/kg FOS (EFOS). On day 19, the CON pigs were orally infused with sterile culture, while the ECON and EFOS pigs were orally infused with active ETEC (2.5 × 109 colony-forming units). On day 21, pigs were slaughtered to collect venous blood and small intestine. Result showed that the pre-treatment of FOS improved the antioxidant capacity and the integrity of intestinal barrier in the ETEC-challenged pigs without affecting their growth performance. Specifically, comparing with ECON pigs, the level of GSH-Px (glutathione peroxidase) and CAT (catalase) in the plasma and intestinal mucosa of EFOS pigs was increased (P<0.05), and the intestinal barrier marked by ZO-1 and plasmatic DAO was also improved in EFOS pigs. A lower level (P<0.05) of inflammatory cytokines in the intestinal mucosa of EFOS pigs might be involved in the inhibition of TLR4/MYD88/NF-κB pathway. The apoptosis of jejunal cells in EFOS pigs was also lower than that in ECON pigs (P<0.05). Our findings provide convincing evidence of possible prebiotic and protective effect of FOS on the maintenance of intestinal epithelial function under the attack of pathogens.

Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 9: Polymyxins: colistin

The specific concentrations of colistin in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels of colistin in feed that showed to have an effect on growth promotion/increased yield were reported. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these antimicrobials.

Morchella importuna Flavones Improve Intestinal Integrity in Dextran Sulfate Sodium-Challenged Mice

Morchella importuna, as an edible fungus, has various health benefits. However, the effects of M. importuna on intestinal health are rarely investigated. Hence, this study aims to ascertain the influences of flavones from the fruiting bodies of M. importuna (hereinafter abbreviated as MIF) on dextran sulfate sodium (DSS)-induced damage to intestinal epithelial barrier in C57BL/6J mice. In this (14-day) study, 144 C57BL/6J mice were divided into four groups: (1) Control; (2) DSS treatment; (3) DSS treatment + 100 mg/kg MIF (LMIF); (4) DSS treatment + 200 mg/kg MIF (HMIF). On days 8-14, mice in the challenged groups were challenged with 3.5% DSS, while the control group received an equal volume of normal saline. Then, serum and intestinal samples were obtained from all mice. The results showed that MIF ingestion enhanced intestinal integrity in DSS-challenged mice, as evinced by the elevated (p < 0.05) abundances of occludin, claudin-1, and zonula occludens-1 proteins. Meanwhile, MIF ingestion reduced (p < 0.05) the colonic interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) concentrations and increased the superoxide dismutase and catalase activities and Shannon and Simpson indices in DSS-challenged mice. Moreover, MIF ingestion reduced (p < 0.05) the abundance of phospho-nuclear factor (NF)-κB and increased the abundance of phospho-Nrf2 in DSS-challenged mice. Taken together, MIF protects against intestinal barrier injury in C57BL/6J mice via a mechanism that involves inhibiting NF-κB activation and promoting Nrf2 activation, as well as regulating intestinal microbiota.

Chitosan-chelated zinc modulates ileal microbiota, ileal microbial metabolites, and intestinal function in weaned piglets challenged with Escherichia coli K88

This study was to investigate the effects of chitosan-chelated zinc on ileal microbiota, inflammatory response, and barrier function in weaned piglets challenged with Escherichia coli K88. Piglets of the chitosan-chelated zinc treatment (Cs-Zn; 100 mg zinc + 766 mg chitosan/kg basal diet, from chitosan-chelated zinc) and the chitosan treatment (CS, 766 mg chitosan/kg basal diet) had significantly increased ileal villus height and the ratio of villi height to crypt depth. CS-Zn group piglets had a higher abundance of Lactobacillus in the ileal digesta, while the abundance of Streptococcus, Escherichia shigella, Actinobacillus, and Clostridium sensu stricto 6 was significantly decreased. The concentrations of propionate, butyrate, and lactate in the CS-Zn group piglets were significantly increased, while the pH value was significantly decreased. Furthermore, the concentrations of IL-1β, TNF-α, MPO, and INF-γ in the ileal mucosa of the CS-Zn and the H-ZnO group (pharmacological dose of 1600 mg Zn/kg basal diet, from ZnO) were significantly lower than those of the control group fed with basal diet, and the mRNA expression of TLR4, MyD88, and NF-κB of the CS-Zn group was also reduced. In addition, the mRNA expression of IGF-1 was increased, the protein expression of occludin and claudin-1 was enhanced, while the mRNA expression of caspase 3 and caspase 8 was decreased in the CS-Zn group. These results suggest CS-Zn treatment could help modulate the composition of ileal microbiota, attenuate inflammatory response, and maintain the intestinal function in weaned piglets challenged with Escherichia coli K88. KEY POINTS: • Chitosan-chelated zinc significantly modulated ileal microbiota. • Chitosan-chelated zinc can improve ileal health. • The ileal microbiota plays an important role in host health.

Chitosan oligosaccharide attenuates endoplasmic reticulum stress-associated intestinal apoptosis via the Akt/mTOR pathway

Endoplasmic reticulum stress (ERS) and apoptosis are widely considered as essential factors associated with intestinal disorders, whereas nutritional therapeutic approaches targeting ERS may control disease activity. Thus, we focus on the potential benefit of chitosan oligosaccharide (COS) on repressing ERS and ERS-induced apoptosis. In this study, we used the ERS model with tunicamycin (TM)-induced IPEC-J2 cells in vitro and nutrient deprivation-induced ERS in piglets to evaluate the protective mechanism of COS against ERS and ERS-induced apoptosis. The results showed that cells were characterized by activation of the unfolded protein response (UPR) and increased epithelial apoptosis upon exposure to TM. However, these changes were significantly attenuated by COS and the expressions of Akt and mTORC1 were inhibited. Furthermore, a specific inhibitor of mTOR confirmed the suppression of Akt and reduced the activation of the UPR and apoptosis. In vivo, COS protected against nutrient deprivation-induced ERS in the jejunum of piglets, in which the overexpression of the UPR and apoptosis was rescued. Consistently, COS attenuated nutrient deprivation-induced disruption of intestinal barrier integrity and functional capacity. Together, we provided the first evidence that COS could protect against intestinal apoptosis through alleviating severe ERS, which may be related to the inhibition of the Akt/mTOR signaling pathway.

Ultrasound-assisted extraction of boulardii yeast cell wall polysaccharides: Characterization and its biological functions on early-weaned lambs

Firstly, this study was designed to determine the optimal ultrasound-assisted extraction parameters of Saccharomyces boulardii yeast wall polysaccharides (BYWP). Besides, the molecular weight and the ratio of mannose to glucose in compositions of BYWP were determined. Also, the effects of BYWP on the gain feed ratio, diarrhea frequency, intestinal morphology, intestinal immunity, and intestinal microbial flora of early-weaned lambs were investigated. Single-factor tests and Response surface optimization analysis (RSA) were used to obtain the optimal ultrasound-assisted extraction conditions. Sephadex G-100 column chromatography and liquid chromatography were used to analyze the molecular weight and ratio of mannose to glucose. The feeding trial was used to observe the biological functions of BYWP on early-weaned lambs. A total of 72 36-day-old crossbred early-weaned lambs were randomly divided into 4 groups with 3 replicates per group and 6 lambs per replicate. Lambs in the four treatments were fed basal milk replacer without supplement (Group I), basal milk replacer+0.1% BYWP (Group II), basal milk replacer+0.3% BYWP (Group III), and basal milk replacer+0.5% BYWP (Group IV), respectively. The optimal ultrasound-assisted extraction parameters were as follows: NaOH addition: 52.63%, ultrasonic power: 143.15 W, ultrasonic time: 86.20 min, and the optimized extraction yield reached 37.54%. The molecular weights of main components BLC-1 and BLC-2 were 164.68 KDa and 13.21 KDa, and their proportions in BYWP were 24.57% and 66.08%, respectively. The proportions of glucose, mannose in BLC-1 and BLC-2 were 47.68%, 39.18%, and 76.59%, 6.86%, respectively. The addition of 0.3% and 0.5% BYWP in basal milk replacer significantly increased the average daily gain and feed conversion rate, and decreased the average fecal index and diarrhea rate of early-weaned lambs. The addition of 0.3% and 0.5% BYWP significantly enhanced the intestinal morphology (villus height, crypt depth, and V/C value) of jejunum, ileum (p < .05). The addition of 0.3% and 0.5% BYWP significantly improved the levels of SIgA and IL-10, but significantly decreased the level of IL-1 in the ileum (p < .05). The addition of 0.3% and 0.5% BYWP significantly increased the number of Lactobacillus, but significantly suppressed the growth of Salmonella and Clostridium perfringens (p < .05). The results of the present study suggest that the supplementation of BYWP in the diet of early-weaned lambs could increase feed utilization rate, and enhance intestinal morphology, immunological competence, microbial flora balance, and decrease the rate of diarrhea occurrence.

Fructooligosaccharides improve growth performance and intestinal epithelium function in weaned pigs exposed to enterotoxigenic Escherichia coli

To explore the protective effect of Fructooligosaccharides (FOS) against Enterotoxigenic Escherichia coli (ETEC)-induced inflammation and intestinal injury, twenty-four weaned pigs were randomly assigned into three groups: (1) non-challenge (CON, fed with basal diet), (2) ETEC-challenge (ECON, fed with basal diet), and (3) ETEC challenge + FOS treatment (EFOS, fed with basal diet plus 2.5 g kg-1 FOS). On day 19, the CON group was orally infused with sterilized culture while pigs in the ECON group and EFOS group were orally infused with ETEC (2.5 × 1011 colony-forming units). After 3 days, pigs were slaughtered for sample collection. We showed that ETEC challenge significantly reduced average daily gain (ADG); however, FOS improved the ADG (P < 0.05), apparent digestibility of crude protein (CP), gross energy (GE), and ash and reduced the diarrhea incidence (P < 0.05). FOS reduced plasma concentrations of IL-1β and TNF-α and down-regulated (P < 0.05) the mRNA expression of IL-6 and TNF-α in the jejunum and ileum as well as IL-1β and TNF-α in the duodenum. The concentrations of plasma immunoglobulin A (IgA), immunoglobulin M (IgM) and secreted IgA (SIgA) in the jejunum (P < 0.05) were elevated. Interestingly, FOS elevated the villus height in the duodenum, and elevated the ratio of villus height to crypt depth in the duodenum and ileum in the EFOS group pigs (P < 0.05). Moreover, FOS increased lactase activity in the duodenum and ileum (P < 0.05). The activities of sucrase and alkaline phosphatase (AKP) were higher in the EFOS group than in the ECON group (P < 0.05). Importantly, FOS up-regulated the expressions of critical genes in intestinal epithelium function such as zonula occludens-1 (ZO-1), L-type amino acid transporter-1 (LAT1), and cationic amino acid transporter-1 (CAT1) in the duodenum and the expressions of ZO-1 and glucose transporter-2 (GLUT2) in the jejunum (P < 0.05). FOS also up-regulated the expressions of occludin, fatty acid transporter-4 (FATP4), sodium glucose transport protein 1 (SGLT1), and GLUT2 in the ileum (P < 0.05). FOS significantly increased the concentrations of acetic acid, propionic acid and butyric acid in the cecal digesta. Additionally, FOS reduced the populations of Escherichia coli, but elevated the populations of Bacillus and Bifidobacterium in the caecal digesta (P < 0.05). These results suggested that FOS could improve the growth performance and intestinal health in weaned pigs upon ETEC challenge, which was associated with suppressed inflammatory responses and improved intestinal epithelium functions and microbiota.

Pollution by Antibiotics and Antimicrobial Resistance in LiveStock and Poultry Manure in China, and Countermeasures

The demand for animal protein has increased considerably worldwide, especially in China, where large numbers of livestock and poultry are produced. Antibiotics have been widely applied to promote growth and prevent diseases. However, the overuse of antibiotics in animal feed has caused serious environmental and health risks, especially the wide spread of antimicrobial resistance (AMR), which seriously affects animal and human health, food safety, ecosystems, and the sustainable future development of animal protein production. Unfortunately, AMR has already become a worldwide challenge, so international cooperation is becoming more important for combatting it. China’s efforts and determination to restrict antibiotic usage through law enforcement and effective management are of significance. In this review, we address the pollution problems of antibiotics; in particular, the AMR in water, soil, and plants caused by livestock and poultry manure in China. The negative impact of widespread and intensive use of antibiotics in livestock production is discussed. To reduce and mitigate AMR problems, we emphasize in this review the development of antibiotic substitutes for the era of antibiotic prohibition.

Exploring Effects of Chitosan Oligosaccharides on the DSS-Induced Intestinal Barrier Impairment In Vitro and In Vivo

Intestinal barrier dysfunction is an essential pathological change in inflammatory bowel disease (IBD). The mucus layer and the intestinal epithelial tight junction act together to maintain barrier integrity. Studies showed that chitosan oligosaccharide (COS) had a positive effect on gut health, effectively protecting the intestinal barrier in IBD. However, these studies usually focused on its impact on the intestinal epithelial tight junction. The influence of COS on the intestinal mucus layer is still poorly understood. In this study, we explored the effect of COS on intestinal mucus in vitro using human colonic mucus-secreted HT-29 cells. COS relieved DSS (dextran sulfate sodium)-induced mucus defects. Additionally, the structural characteristics of COS greatly influenced this activity. Finally, we evaluated the protective effect of COS on intestinal barrier function in mice with DSS-induced colitis. The results indicated that COS could manipulate intestinal mucus production, which likely contributed to its intestinal protective effects.

Effects of chitosan oligosaccharides on intestinal oxidative stress and inflammation response in heat stressed rats

This study was to verify the effects of chitosan oligosaccharides (COS) on intestinal integrity, oxidative status, and inflammatory response in a heat-stressed rat model. A total of 24 male Sprague Dawley rats were randomly divided into 3 treatment: CON, the control group; HS, the heat stress group; HSC, the heat stress group with 200 mg/kg COS. Rats in the HS and HSC group exposed to a cyclical heat stress for 7 consecutive days. The CON and HS group provided basal diet, and the HSC group provided the same diet with 200 mg/kg COS. Compared with the HS group, rats in the HSC group had lower serum diamine oxidase and D-lactate acid level, higher villus height of jejunum and ileum, lower malondialdehyde (MDA) content in duodenum, jejunum, and ileum mucosa, higher glutathione peroxidase (GSH-Px), catalase (CAT) and total antioxidant capacity (T-AOC) activity in duodenum mucosa, higher T-AOC activity in jejunum mucosa, and higher glutathione (GSH) level in ileum mucosa. Compared with the HS group, rats in the HSC group had higher interleukin-10 (IL-10) level, but lower tumor necrosis factor-α (TNF-α) level in duodenum, jejunum, and ileum mucosa. These results indicated that COS may alleviate intestinal damage under heat stress condition, probably by modulating intestinal inflammatory response and oxidative status.

Effectiveness of inulin-type on the iron bioavailability in anemic female rats fed bio-yogurt

It is well-documented that iron deficiency leads to anemia, which is the utmost critical problem of nutrition worldwide. Inulin, indigestible polysaccharides, or prebiotic agents may act as vehicles to enhance the iron bioavailability through the formation of the polysaccharide-iron complex. The present study was undertaken to evaluate the therapeutic effects of yogurt fortified with iron and supplemented by long- or short-chain inulin on the growth status, blood parameters, antioxidant capacity, and liver function enzymes in anemic rats. Five animal groups were assigned as the control (G1), which were fed a standard diet and there were four anemic groups, in which haemolytic anemia was induced by phenylhydrazine. The anemic rats were divided into 4 groups according to the regime of feeding as G2: control anemic group fed low-iron diet while the remaining anemic groups were fed yogurt fortified with Fe2(SO4)3 without inulin (G3) or with either long- (G4) or short-chain (G5) inulin. The results showed that the animals subjected to treatment G4 had the highest (P ≤ 0.05) weight gain and organ coefficient compared with other anemic groups (G2, G3, and G5). Among the anemic groups, the animals that belonged to G4 showed a significant restorative effect by returning the hemoglobin and hematocrit levels and the red blood cell count to the normal control liver. Also, the liver iron content, enzymatic activities, and antioxidant capacities improved in the animals subjected to G4 and G5 treatment groups. The histological structures of the liver tissues of the animals that belonged to G4 and G5 were extremely close to that of the normal control liver. Long-chain inulin-containing yogurt exhibited the best effects in terms of iron supplementation, bioavailability, and antioxidant activities. This formula might be a potential new iron supplement and a good functional food candidate.

Intestinal Population in Host with Metabolic Syndrome during Administration of Chitosan and Its Derivatives

Chitosan and its derivatives can alleviate metabolic syndrome by different regulation mechanisms, phosphorylation of AMPK (AMP-activated kinase) and Akt (also known as protein kinase B), suppression of PPAR-γ (peroxisome proliferator-activated receptor-γ) and SREBP-1c (sterol regulatory element–binding proteins), and translocation of GLUT4 (glucose transporter-4), and also the downregulation of fatty-acid-transport proteins, fatty-acid-binding proteins, fatty acid synthetase (FAS), acetyl-CoA carboxylase (acetyl coenzyme A carboxylase), and HMG-CoA reductase (hydroxy methylglutaryl coenzyme A reductase). The improved microbial profiles in the gastrointestinal tract were positively correlated with the improved glucose and lipid profiles in hosts with metabolic syndrome. Hence, this review will summarize the current literature illustrating positive correlations between the alleviated conditions in metabolic syndrome hosts and the normalized gut microbiota in hosts with metabolic syndrome after treatment with chitosan and its derivatives, implying that the possibility of chitosan and its derivatives to serve as therapeutic application will be consolidated. Chitosan has been shown to modulate cardiometabolic symptoms (e.g., lipid and glycemic levels, blood pressure) as well as gut microbiota. However, the literature that summarizes the relationship between such metabolic modulation of chitosan and prebiotic-like effects is limited. This review will discuss the connection among their structures, biological properties, and prebiotic effects for the treatment of metabolic syndrome. Our hope is that future researchers will consider the prebiotic effects as significant contributors to the mitigation of metabolic syndrome.

Dietary chitosan oligosaccharides alleviate heat stress-induced intestinal oxidative stress and inflammatory response in yellow-feather broilers

The purpose of this study was to evaluate the effects of chitosan oligosaccharides (COS) on intestinal permeability, morphology, antioxidant status, and inflammatory response in heat-stressed broilers. A total of 108 thirty-five-day-old Chinese yellow-feather broilers (body weight 470.31 ± 13.15 g) were randomly allocated to 3 dietary treatments as follows: CON group, basal diet and raised under normal temperature (24°C); HS group, basal diet and raised under cycle heat stress (34°C from 10:00–18:00 and 24°C for the rest time); HSC group, basal diet with 200 mg/kg COS supplementation and raised under cycle heat stress. Each treatment had 6 replication pens and 6 broilers per pen. Compared with the CON group, heat stress decreased (P < 0.05) the relative weight of duodenum and jejunum; the relative length and villus height (VH) of duodenum, jejunum, and ileum; the ileum VH to crypt depth ratio; duodenum mucosal catalase (CAT) activity; and jejunum mucosal glutathione peroxidase (GSH-Px) and CAT activity, whereas it increased (P < 0.05) serum diamine oxidase (DAO) activity and D-lactate acid (D-LA) content, duodenum and jejunum mucosal malondialdehyde (MDA) and interleukin-1β (IL-1β) content, and ileum mucosal tumor necrosis factor-α content. Compared to the HS group, dietary COS supplementation increased (P < 0.05) the relative length of duodenum, jejunum, and ileum; the VH of jejunum and ileum; and duodenum and jejunum mucosal GSH-Px activity, whereas it decreased (P < 0.05) serum DAO activity and D-LA concentration and duodenum and jejunum mucosal MDA and IL-1β content. These results suggested that dietary COS supplementation had beneficial effects on intestinal morphology by increasing jejunum and ileum VH; permeability by decreasing serum DAO activity and D-LA content; antioxidant capacity by decreasing duodenum and jejunum mucosal MDA content and by increasing duodenum and jejunum GSH-Px activity; and inflammatory response by decreasing duodenum and jejunum mucosal IL-1β content.

Butyrate-mediated autophagy inhibition limits cytosolic Salmonella Infantis replication in the colon of pigs treated with a mixture of Lactobacillus and Bacillus

Probiotics as an effective and safe strategy for controlling Salmonella infection are much sought after, while autophagy is a central issue in eliminating intracellular pathogens of intestinal epithelial cells. In this study, an animal model of colitis has been developed by infecting weaned pigs orally with a strain of Salmonella Infantis in order to illuminate the potential efficacy of a mixture of Lactobacillus and Bacillus (CBB-MIX) in the resistance to Salmonella infection by regulating butyrate-mediated autophagy. We found that CBB-MIX alleviated S. Infantis-induced colitis and tissue damage. Autophagy markers ATG5, Beclin-1, and the LC3-II/I ratio were significantly enhanced by S. Infantis infection, while treatment with CBB-MIX suppressed S. Infantis-induced autophagy. Additionally, S. Infantis-induced colonic microbial dysbiosis was restored by this treatment, which also preserved the abundance of the butyrate-producing bacteria and the butyrate concentration in the colon. A Caco-2 cell model of S. Infantis infection showed that butyrate had the same effect as the CBB-MIX in restraining S. Infantis-induced autophagy activation. Further, the intracellular S. Infantis load assay indicated that butyrate restricted the replication of cytosolic S. Infantis rather than that in Salmonella-containing vacuoles. Suppression of autophagy by knockdown of ATG5 also attenuated S. Infantis-induced cell injury. Moreover, hyper-replication of cytosolic S. Infantis in Caco-2 cells was significantly decreased when autophagy was inhibited. Our data demonstrated that Salmonella may benefit from autophagy for cytosolic replication and butyrate-mediated autophagy inhibition reduced the intracellular Salmonella load in pigs treated with a probiotic mixture of Lactobacillus and Bacillus.

Effects of dietary chitosan on growth rate, small intestinal morphology, nutrients apparent utilization and digestive enzyme activities of growing Huoyan geese

Dietary chitosan (CS) supplementation could improve the growth rate, small intestinal morphology, nutrients apparent digestibility and digestive enzyme activities in pigs, broiler chickens, rats and fish, whereas no data has been reported about the effect of CS on the growing Huoyan geese. Therefore, this study was designed to investigate the effects of CS on growth rate, small intestinal morphology, nutrients apparent utilization and digestive enzyme activities of growing Huoyan geese. Three hundred and twenty (28 days of age, gender balance) Huoyan geese were randomly divided into control, CS100, CS200 and CS400 groups (based on BW) with 20 geese per pen and 4 replicates pen per group, and the feeding experiment lasted for 4 weeks. The 4 diets contained 0, 100, 200 and 400 mg CS per kg feed, respectively. The results showed that CS200 groups had higher average daily gain, final BW, apparent utilization of DM and CP, and lower feed/gain ratio compared with the control group (P < 0.05). Meanwhile, CS100 and CS200 groups had higher villus height, villus height/crypt depth ratio and lower crypt depth in duodenum and jejunum than those in the control group (P < 0.05). The geese in CS100 and CS200 groups had higher villus height, villus height/crypt depth ratio and lower crypt depth of ileum compared with those in control and CS400 groups (P < 0.05). In addition, compared with the control group, CS200 group has higher trypsin activities and lower lipase activities in duodenal, jejunal and ileal contents (P < 0.05). The results suggested that addition of 200 mg/kg CS had positive effects on growth rate, small intestinal morphology, nutrients apparent utilization and digestive enzyme activities of growing Huoyan geese.

Effect of chitooligosaccharides on human gut microbiota and antiglycation

Chitooligosaccharides (COS) have garnered great attention in the field of human healthcare. The prebiotic activities and antiglycation of COS were investigated using a combination of in vitro and in vivo studies. COS supplementation dramatically increased the levels of acetic acid, while reducing the concentrations of propionic and butyric acids. It also decreased the total bacterial population; however, it did not affect diversity and richness of the gut microbiota. In addition, COS modulated the gut microbiota composition by increasing Bacteroidetes, decreasing Proteobacteria and Actinobacteria, and lowering the Firmicutes/Bacteroidetes ratio. COS promoted the generation of beneficial Bacteroides and Faecalibacterium genera, while suppressing the pathogenic Klebsiella genus. The antiglycation activity of COS and acetic acid was dose-dependent. Furthermore, COS prevented the decrease of serum N^ε-(carboxymethyl) lysine (CML) level caused by CML ingestion in a mouse model of diet-induced obesity. To improve host health, COS could be potential prebiotics in food products.

Digestive abilities, amino acid transporter expression, and metabolism in the intestines of piglets fed with spermine

This study evaluated the effects of spermine supplementation on the digestion, transport, and metabolism of nutrients in the jejuna of piglets. Of the 80 piglets examined, 40 received 0.4 mmol/kg body weight spermine, and the other half were randomly distributed such that the restricted nutrient intake supplemented with the saline solution for 7 hr and 3, 6, or 9 days in pairs. Spermine supplementation increased the lipase and trypsin activities (p < .05), and spermine increased the mRNA levels of maltase, sucrase, and aminopeptidase N (APN) but decreased the lactase gene expression (p < .05). Moreover, spermine increased the mRNA expression levels of amino acid transporters (p < .05). Spermine increased the jejunum glycerolphosphocholine, lipid, and taurine levels and decreased the choline and amino acids levels (p < .05). In summary, spermine can promote the digestion, transport, and metabolism of nutrients in piglets. PRACTICAL APPLICATIONS: Meat, fish, dairy products, and fruits contain polyamines (i.e., spermine, spermidine, and putrescine). Spermine plays an important role in the cell proliferation, growth, and differentiation, and spermine supplementation can improve the growth of broilers, growth performance of early weaning piglets, and intestinal maturation. The results of this study suggest that spermine can improve the digestion, transport, and metabolism of nutrients in piglets.

Effects of dietary supplementation of chitosan on immune function in growing Huoyan geese

This present experiment was performed to investigate the effects of dietary supplementation of chitosan (CS) on immune function in growing Huoyan geese. A total of 320 28-day-old healthy growing Huoyan geese (sex balance) with similar body weight were randomly allotted into control, CS100, CS200, and CS400 groups. Each group includes 4 replicates with 20 geese per replicate, and the feeding trial lasted for 4 wk. The 4 diets contained 0, 100, 200, and 400 mg CS per kg feed, respectively. The results showed that compared with the control group, the relative weight of thymus, serum concentrations of IGF-I, INS, GH, T3, T4, IgM, IgG, IgA, complement C3, and IL-2 in CS200 group were significantly higher at both 42 and 56 D of age, respectively (P < 0.05). In addition, relative weight of bursa of fabricius (BF), spleen, serum complement C4, and TNF-a concentrations in CS200 group were higher at 56 D of age (P < 0.05), no differences were observed at 42 D of age (P > 0.05). These results indicated that addition of 200 mg/kg CS enhanced immune organs weight, serum concentrations of immunoglobulins, complements, hormone, as well as cytokines, and improved immune function of growing Huoyan geese.

Effects of spermine on ileal physical barrier, antioxidant capacity, metabolic profile and large intestinal bacteria in piglets

Spermine, a polyamine, exerts important roles in alleviating oxidative damage, improving immunity, increasing antioxidant status and digestive enzyme activities, and promoting the development of small intestine. However, information is not available regarding the effects of spermine supplementation on gut barrier function, intestinal microbiota and metabolic profile in piglets. Therefore, this study was designed to explore the effect of spermine administration on these parameters. The experiment was conducted on twenty 12 day-old suckling piglets, which were allocated either to the group fed basal formula milk (control group) or to that fed a basal formula milk that contained spermine (0.4 mmol kg⁻¹ BW per day) for 3 days. Caecal and colonic digesta and ileal tissues were collected at the end of the three-day feeding experiment. The results were as follows: (1) supplementation with spermine increased glutathione S-transferase (GST) capacity by 27.84% and glutathione content by 18.68% in the ileum (P < 0.05). (2) Glutathione peroxidase 1 (GPx1), catalase (CAT), GST, nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein1 (Keap1) mRNA levels in ileum were increased in the spermine-supplemented group in contrast to those in the control group (P < 0.05). (3) The spermine-supplemented group increased zonula occludens-1 (ZO-1) (by 42.0%), ZO-2 (by 101.0%), occludin (by 84.0%), claudin 2 (by 98.0%), claudin 3 (by 121.0%), claudin 12 (by 47.0%), claudin 14 (by 68.0%) and claudin 16 (by 73.0%) mRNA levels in ileum relative to the control group (P < 0.05). (4) Supplementation with spermine increased ZO-2 and occludin mRNA levels in ileum by reducing myosin light chain kinase (MLCK) (by 23.0%) mRNA level. (5) Spermine supplementation increased choline, glycerolphosphocholine, creatine and serine levels, and decrease alanine, glutamate, lysine, phenylalanine, threonine, lactate, tyrosine levels in ileum (P < 0.05). (6) The population of Lactobacilli, Bifidobacteria and total bacteria increased, but the number of Escherichia coli decreased in the caecal and colonic digesta after spermine supplementation (P < 0.05). In summary, dietary spermine supplementation promotes ileal health by enhancing antioxidant properties, improving ileal barrier function, modulating metabolic profiles, and maintaining large intestinal microbial homeostasis.

Spermine, a polyamine, exerts important roles in alleviating oxidative damage, improving immunity, increasing antioxidant status and digestive enzyme activities, and promoting the development of small intestine.

Effects of chitosan nanoparticle supplementation on growth performance, humoral immunity, gut microbiota and immune responses after lipopolysaccharide challenge in weaned pigs

In this study, we aimed to determine the effects of dietary supplementation with chitosan nanoparticles (CNP) on growth performance, immune status, gut microbiota and immune responses after lipopolysaccharide challenge in weaned pigs. A total of 144 piglets were assigned to four groups receiving different dietary treatments, including basal diets supplemented with 0, 100, 200 and 400 mg/kg CNP fed for 28 days. Each treatment group included six pens (six piglets per pen). The increase in supplemental CNP concentration improved the average daily gain (ADG) and decreased the feed and gain (F/G) and diarrhoea rate (p < .05). However, significant differences in the average daily feed intake (ADFI) among different CNP concentrations were not observed. CNP also increased plasma immunoglobulin (Ig)A and IgG, and C3 and C4 concentrations in piglets in a dose-dependent manner on day 28, whereas IgM concentration was not affected by CNP. A total of 24 piglets in the control diet and control diet with 400 mg/kg CNP supplementation groups were randomly selected for the experiment of immunological stress. Half of the pigs in each group (n = 6) were injected i.p. with Escherichia coli lipopolysaccharide (LPS) at a concentration of 100 μg/kg. The other pigs in each group were injected with sterile saline solution at the same volume. Plasma concentrations of cortisol, prostaglandin E2 (PEG2), interleukin (IL)-6, tumour necrosis factor (TNF)-α and IL-1β dramatically increased after LPS challenge. However, CNP inhibited the increase in cortisol, PEG2, IL-6 and IL-1β levels in plasma, whereas TNF-α level slightly increased. Moreover, the effects of CNP on the gut microbiota were also evaluated. Our results showed that dietary supplementation with CNP modified the composition of colonic microbiota, where it increased the amounts of some presumably beneficial intestinal bacteria and suppressed the growth of potential bacterial pathogens. These findings suggested CNP supplementation improved the growth performance and immune status, alleviated immunological stress and regulated intestinal ecology in weaned piglets. Based on these beneficial effects, CNP could be applied as a functional feed additives supplemented in piglets diet.

Dietary Chitooligosaccharide Inclusion as an Alternative to Antibiotics Improves Intestinal Morphology, Barrier Function, Antioxidant Capacity, and Immunity of Broilers at Early Age

Simple Summary

At early an age, broilers are susceptible to exterior stressors and therefore have a higher disease incidence rate. Antibiotic growth promoters have been forbidden in animal production by the European Union and other countries since their usage has caused potentially adverse effects such as antibiotic residues in livestock, environmental pollution, and the generation of drug-resistant bacteria. The search for safe and environmentally friendly alternatives to antibiotics to prevent disease and promote growth has become necessary in poultry production. Chitooligosaccharide (COS), a natural alkaline polymer of glucosamine with a number of bioactive groups, is easily obtained by chemical and enzymatic hydrolysis of chitosan, which is the second most abundant carbohydrate polymer in nature. Our results indicated that dietary supplementation with chitooligosaccharide, at a dosage of 30 mg/kg, enhanced the feed conversion ratio, benefited the intestinal morphology and barrier function, and improved antioxidant capacity and immunity in broilers at 21 days of age. These effects were similar with those observed as a result of chlortetracycline inclusion. Therefore, dietary COS supplementation can be used as a potential alternative to antibiotics in broilers.

Abstract

This study aimed to investigate the effects of chitooligosaccharide (COS) inclusion as an alternative to antibiotics on growth performance, intestinal morphology, barrier function, antioxidant capacity, and immunity in broilers. In total, 144 one-day-old Arbor Acres broiler chicks were randomly assigned into 3 groups and fed a basal diet free from antibiotics (control group) or the same basal diet further supplemented with either chlortetracycline (antibiotic group) or COS, for 21 days. Compared with the control group, inclusion of COS reduced the feed to gain ratio, the jejunal crypt depth, the plasma diamine oxidase activity, and the endotoxin concentration, as well as jejunal and ileal malondialdehyde contents, whereas increased duodenal villus height, duodenal and jejunal ratio of villus height to crypt depth, intestinal immunoglobulin G, and jejunal immunoglobulin M (IgM) contents were observed, with the values of these parameters being similar or better to that of the antibiotic group. Additionally, supplementation with COS enhanced the superoxide dismutase activity and IgM content of the duodenum and up-regulated the mRNA level of claudin three in the jejunum and ileum, when compared with the control and antibiotic groups. In conclusion, dietary COS inclusion (30 mg/kg), as an alternative to antibiotics, exerts beneficial effects on growth performance, intestinal morphology, barrier function, antioxidant capacity, and immunity in broilers.

Effects of isomaltooligosaccharide and Bacillus supplementation on sow performance, serum metabolites, and serum and placental oxidative status

This study investigated the effects of isomaltooligosaccharide (IMO) and Bacillus supplementation on sow performance, serum metabolites, and serum and placental oxidative status. Multiparous gestating sows (n = 130) with similar body conditions were randomly allocated to five groups (n = 26) receiving a basal diet (CON group) or a basal diet supplemented with 0.5% IMO (IMO group); 0.5% IMO and 0.02% Bacillus subtilis (IMO + S group); 0.5% IMO and 0.02% Bacillus licheniformis (IMO + L group); or 0.5% IMO, 0.02% Bacillus subtilis, and 0.02% Bacillus licheniformis (IMO + S+L group). There were no significant differences in the litter sizes among all dietary groups. The average piglet birth weight was improved in all treatment groups, and the placental efficiency was greater in the IMO + S and IMO + S+L groups than in the CON group (P < 0.05). The IMO + S+L group had increased the low-density lipoprotein cholesterol and reduced the total cholesterol in umbilical venous serum (P <  0.05). Additionally, the malondialdehyde concentrations were greater in umbilical venous serum of piglets in all treatment groups relative to that in the CON piglets (P <  0.05). The placental total antioxidant capacity was increased in the IMO+L and IMO+S+L groups (P <  0.05). Furthermore, the growth hormone concentration in umbilical venous serum was greater (P <  0.05) in all treatment groups. Overall, IMO and Bacillus supplementation during late gestation resulted in a changed metabolism of sows, improved the placental antioxidant capacity, and increased the growth hormone concentrations in umbilical venous serum, which ultimately improved the piglet birth weight and placental efficiency.

Biological Effects and Applications of Chitosan and Chito-Oligosaccharides

The numerous functional properties and biological effects of chitosan and chito-oligosaccharides (COS) have led to a significant level of interest, particularly with regard to their potential use in the agricultural, environmental, nutritional, and pharmaceutical fields. This review covers recent studies on the biological functions of COS and the impacts of dietary chitosan and COS on metabolism. The majority of results suggest that the use of chitosan as a feed additive has favorable biological effects, such as antimicrobial, anti-oxidative, cholesterol reducing, and immunomodulatory effects. The biological impacts reviewed herein may provide a new appreciation for the future use of COS.

Effectiveness of AOS-iron on iron deficiency anemia in rats

Iron deficiency anemia (IDA) is one of the most serious nutritional problems. This study aimed to evaluate the therapeutic effects of a novel agar oligosaccharide-iron complex (AOS-iron) on rats with IDA, such as iron supplementation and recovery of antioxidant ability. Eighty-four weaned male SD rats were randomly divided into a normal control group (n = 12), which was fed with a standard diet, and an anemia model group (n = 72), which was fed with an iron-deficient diet for 4 weeks to establish a model of IDA. After the model was established, the rats with IDA were divided into six groups, namely, an anemia model group, a ferrous gluconate group, a ferrous sulfate (FeSO4) group, and low-dose (LD), medium-dose (MD) and high-dose (HD) AOS-iron groups, and fed with an iron-deficient diet and different iron supplements for 4 weeks, respectively. The results showed that HD AOS-iron exerted a significant restorative effect by returning blood parameters to normal levels in rats with IDA, including hemoglobin, red blood cells, hematocrit, mean cell volume, mean cell hematocrit, mean cell hemoglobin concentration, serum iron, total iron binding capacity, transferrin saturation, and serum ferritin. A histological analysis suggested that the liver morphology in the MD and HD AOS-iron groups was similar to that in the normal group. Furthermore, MD and HD AOS-iron improved antioxidant activities in the serum and liver. In general, high-dose (the same dose as those of ferrous gluconate and FeSO4) AOS-iron exhibited the best effects in terms of iron supplementation and antioxidant activities. The present findings showed that AOS-iron might be a potential new iron supplement.

Exploring Effects of Chitosan Oligosaccharides on Mice Gut Microbiota in in vitro Fermentation and Animal Model

Chitosan oligosaccharides (COS) have shown positive effects on host gut health and influence on intestinal microbial community. However, the bioactivity and mechanism of COS on gut microbiota is still poorly understood. Here, we presented systematic studies of COS on mice fecal/gut microbiota. During in vitro fermentation of COS by mice gut microbiota, total bacterial population significantly decreased after 8-h COS treatment but was returned to the normal level after extended incubation. Consumption of COS and production of SCFAs suggested that COS were utilized by the microbe, although the consumption of chitosan pentasaccharides was obviously slower than others. COS treatments on mice fecal samples caused the decrease of potential pathogenic genera Escherichia/Shigella and the increase of genus Parabacteroides. In vivo animal study indicated that COS reduced population of probiotic genera Lactobacillus, Bifidobacterium and harmful genus Desulfovibrio, and increased abundance of genus Akkermansia. Phylum Proteobacteria was significantly inhibited by COS both in the animal model and in vitro fermentation. Our findings suggested that COS could reform the community structure of gut microbiota. The relationship among COS, gut microbiota and host health deserve further study.

Effect of probiotics and xylo-oligosaccharide supplementation on nutrient digestibility, intestinal health and noxious gas emission in weanling pigs

OBJECTIVE

This study was conducted to evaluate the effect of probiotics (Bacillus subtilis and Enterococcus faecium) and xylo-oligosaccharide (XOS) supplementation on growth performance, nutrient digestibility, serum profiles, intestinal health, fecal microbiota and noxious gas emission in weanling pigs.

METHODS

A total of 240 weanling pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 6.3±0.15 kg were used in this 28-day trial. Pigs were randomly allocated in 1 of the following 4 dietary treatments in a 2×2 factorial arrangement with 2 levels of probiotics (0 and 500 mg/kg probiotics) and XOS (0 and 200 mg/kg XOS) based on the BW and sex.

RESULTS

Administration of probiotics or XOS improved average daily gain (p<0.05) during 0 to 14 d and the overall period, while pigs that were treated with XOS had a greater average daily gain and feed efficiency (p<0.05) compared with unsupplemented treatments throughout 15 to 28 d and the whole experiment. Either probiotics or XOS treatments increased the apparent total tract digestibility of nutrients (p<0.05) during 0 to 14 d. No effects on serum profiles were observed among treatments. The XOS increased villus height: crypt depth ratio in jejunum (p<0.05). The supplementation of probiotics (500 mg/kg) or XOS (200 mg/kg) alone improved the apparent total tract digestibility of dry matter, nitrogen and gross energy on d 14, the activity of trypsin and decreased fecal NH3 concentration (p<0.05). Administration of XOS decreased fecal Escherichia coli counts (p<0.05), while increased lactobacilli (p<0.05) on d 14. There was no interaction between dietary supplementation of probiotics and XOS.

CONCLUSION

Inclusion of XOS at 200 mg/kg or probiotics (Bacillus subtilis and Enterococcus faecium) at 500 mg/kg in diets containing no antibiotics significantly improved the growth performance of weanling pigs. Once XOS is supplemented, further providing of probiotics is not needed since it exerts little additional effects.