Effects of glucose oxidase on growth performance, immune function, and intestinal barrier of ducks infected with Escherichia coli O88

Dietary supplementation with a silicate clay mineral (palygorskite) alleviates inflammatory responses and intestinal barrier damage in broiler chickens challenged with Escherichia coli

This experiment aimed to explore the protective effects of dietary palygorskite (Pal) supplementation on inflammatory responses and intestinal barrier function of broiler chickens challenged with Escherichia coli (E. coli). A 2 × 2 factorial arrangement was designed to assess the effects of Pal administration (0 or 5 g/kg of feed) and E. coli challenge (E. coli or bacterial culture medium) on broilers in a 21-d feeding trial. Birds were randomly assigned into one of the 4 groups, and each group had 8 replicates with ten birds each. The challenged chickens were orally gavaged with E. coli suspended in Luria-Bertani broth on 14 d of age, while unchallenged birds were administrated with an equivalent amount of culture medium. The sampling was performed at 21 d of age. Compared with the normal birds, an oral E. coli challenge reduced final body weight, and decreased feed intake, weight gain, and feed efficiency during the challenge period (P < 0.05). E. coli challenge promoted colonization of E. coli in cecal content and their translocation to internal organs (heart, liver, and spleen) (P < 0.05). E. coli infection also increased levels of pro-inflammatory cytokines in jejunum and ileum possibly through activating the toll-like receptor-4-mediated signaling pathway (P < 0.05). Moreover, E. coli administration increased intestinal mucosal permeability (higher serum D-lactate level and diamine oxidase activity, and lower intestinal mucosal disaccharidase activities), altered intestinal morphology, and downregulated the gene expression of intestinal tight junction proteins (P < 0.05). In contrast, Pal supplementation enhanced growth performance, inhibited colonization of E. coli, reduced intestinal inflammation, decreased intestinal permeability, restored intestinal morphology, and normalized the expression of genes responsible for inflammatory processes and maintenance of intestinal mucosal barrier (P < 0.05), and most of these beneficial effects resulting from Pal administration were independent of bacterial challenge. The results indicated dietary Pal incorporation was effective in improving growth performance and alleviating inflammation and intestinal mucosal barrier damage in broilers challenged with E. coli.

The combination of macleaya extract and glucose oxidase improves the growth performance, antioxidant capacity, immune function and cecal microbiota of piglets

This study aims to investigate the effects of macleaya extract and glucose oxidase combination (MGO) on growth performance, antioxidant capacity, immune function, and cecal microbiota in piglets. A total of 120 healthy 28-day-old weaned piglets were randomly divided into two treatments of six replicates. Piglets were either received a basal diet or a basal diet supplemented with 250 mg/kg MGO (2 g/kg sanguinarine, 1 g/kg chelerythrine, and 1 × 106 U/kg glucose oxidase). The results showed that MGO supplementation increased average daily gain (ADG) and decreased feed:gain ratio (F/G) (p < 0.05). MGO increased serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity, and immunoglobulin G (IgG) content (p < 0.05), but decreased malondialdehyde (MDA) and interleukin 1β (IL-1β) content (p < 0.05). The jejunal mRNA expression of nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione peroxidase 1 (GPX1), and heme oxygenase 1 (HO-1) were increased in MGO group (p < 0.05), while that of kelch like ECH associated protein 1 (Keap1) was decreased (p < 0.05). The Firmicutes was significantly increased at phylum levels in MGO group (p < 0.05). In conclusion, 250 mg/kg MGO improved piglet growth, and regulated intestinal flora of piglets, which provided a theoretical basis for MGO as an alternative additive for antibiotics.

A potential anti-HIV-1 compound, Q308, inhibits HSV-2 infection and replication in vitro and in vivo

HSV-2 is a common human pathogen worldwide that causes genital herpes. Due to the lack of an effective HSV-2 vaccine in the foreseeable future, there is an urgent need to develop effective, safe and affordable anti-HSV-2 agents. Our previous studies confirmed that a small-molecule compound, Q308, effectively inhibits the reactivation of latent HIV and might be developed as an anti-HIV-1 agent. Patients infected with HSV-2 are generally more susceptible to HIV-1 infection than normal humans. In this study, we found that Q308 treatment had strong inhibitory activity against both HSV-2 and acyclovir-resistant HSV-2 strains in vitro and reduced the viral titers in tissue. And this treatment effectively ameliorated the cytokine storm and pathohistological changes caused by HSV-2 infection in HSV-2-infected mice. Unlike nucleoside analogs such as acyclovir, Q308 inhibited post-viral entry events by attenuating the synthesis of viral proteins. Furthermore, Q308 treatment blocked HSV-2-induced PI3K/AKT phosphorylation due to its inhibition on viral infection and replication. Overall, Q308 treatment exhibits potent anti-HSV-2 activity by inhibiting viral replication both in vitro and in vivo. Q308 is a promising lead compound for the development of new anti-HSV-2/HIV-1 therapies, particularly against acyclovir-resistant HSV-2 strains.

Bacillus subtilis DSM29784 attenuates Clostridium perfringens-induced intestinal damage of broilers by modulating intestinal microbiota and the metabolome

Necrotic enteritis (NE), especially subclinical NE (SNE), without clinical symptoms, in chicks has become one of the most threatening problems to the poultry industry. Therefore, increasing attention has been focused on the research and application of effective probiotic strains as an alternative to antibiotics to prevent SNE in broilers. In the present study, we evaluated the effects of Bacillus subtilis DSM29784 (BS) on the prevention of subclinical necrotic enteritis (SNE) in broilers. A total of 480 1-day-old broiler chickens were randomly assigned to four dietary treatments, each with six replicates pens of twenty birds for 63 d. The negative (Ctr group) and positive (SNE group) groups were only fed a basal diet, while the two treatment groups received basal diets supplemented with BS (1 × 109 colony-forming units BS/kg) (BS group) and 10mg/kg enramycin (ER group), respectively. On days 15, birds except those in the Ctr group were challenged with 20-fold dose coccidiosis vaccine, and then with 1 ml of C. perfringens (2 × 108) at days 18 to 21 for SNE induction. BS, similar to ER, effectively attenuated CP-induced poor growth performance. Moreover, BS pretreatment increased villi height, claudin-1 expression, maltase activity, and immunoglobulin abundance, while decreasing lesional scores, as well as mucosal IFN-γ and TNF-α concentrations. In addition, BS pretreatment increased the relative abundance of beneficial bacteria and decreased that of pathogenic species; many lipid metabolites were enriched in the cecum of treated chickens. These results suggest that BS potentially provides active ingredients that may serve as an antibiotic substitute, effectively preventing SNE-induced growth decline by enhancing intestinal health in broilers.

The replacement of bacitracin methylene disalicylate with Bacillus subtilis PB6 in the diet of male Cherry Valley Ducks reduces the feed conversion ratio by improving intestinal health and modulating gut microbiota

In this study, we compared the impacts of Bacillus subtilis PB6 (BS) and bacitracin methylene disalicylate (BMD) on the growth performance, intestinal morphology, expression of tight connection protein, and cecal microbiota community of male ducks through a 42-d trial. Three-hundred and sixty male Cherry Valley meat-type ducklings (1-day-old) were distributed into 3 groups of 6 replicates: CON group (control, basal diet), BMD group (basal diet + 45 mg/kg BMD, active ingredient dose in the feed), and BS group (basal diet + 2 × 107 CFU/kg BS in the feed). Results showed that supplementing the diet with BS reduced the average daily feed intake (ADFI) during d 15 to 42 and d 1 to 42 compared with the CON group (P = 0.032). It also reduced feed conversion ratio (FCR) during d 15 to 42 and d 1 to 42 (P < 0.05) relative to the other groups. The ileal villus height (VH) and villus height /crypt depth ratio (V/C) were increased (P < 0.05) in both the BS and BMD groups, and the jejunal VH and V/C ratio were increased in the BS group (P < 0.05). Relative to the CON, BS supplementation was associated with numerical augmentation of goblet cells in the jejunal mucosa and upregulation of jejunal zonula occludens (ZO-1) and ileal mucin2 (P < 0.05) mRNA levels. Analysis showed a negative correlation between FCR (d 0-42) and VH, V/C, and the number of goblet cells in the jejunum (P < 0.05). Additionally, BMD or BS supplementation altered the alpha diversity of colonic microbiota (P < 0.05). Correlation analysis revealed that Butyricimonas, Enterobacteriaceae, Clostridiaceae, and Tannerellaceae were positively associated with the acetic acid and butyrate concentrations (P < 0.05). Taken together, the supplementation of BS in the diet of male ducks was conducive to reducing FCR by meliorating intestinal morphology, upregulating ZO-1 and mucin2 mRNA levels, regulating the abundance of microbiota, and metabolites, and having a greater effect than BMD supplementation.

Escherichia coli O88 induces intestinal damage and inflammatory response through the oxidative phosphorylation and ribosome pathway in Pekin ducks

Colibacillosis is one of the major health threats in the poultry industry worldwide. Understanding the pathogenic mechanisms involved in Escherichia coli-induced inflammatory response may lead to the development of new therapies to combat the disease. To address this, a total of 96 1-day-old male lean Pekin ducklings were employed and randomly allocated to two treatments, each with six replicates of eight ducks. Ducks in the experiment group (EG) and the control group (CG) were separately orally administered with 0.2 ml of pathogenic E. coli O88 (3 × 109 CFU/ml) or equivalent volumes of 0.9% sterile saline solution on day 7, two times with an 8-h interval. Serum and intestinal samples were collected on days 9, 14, and 28. Results showed that ducks challenged with E. coli had lower average daily gain and higher feed intake/weight gain during days 9–14 and overall (P &lt; 0.05). Histopathological examination showed that E. coli decreased the villus height and the ratio of villus height/crypt depth in the jejunum (P &lt; 0.05) on days 9 and 14. The intestinal barrier was disrupted, presenting in E. coli ducks having higher serum DAO and D-LA on days 9 and 14 (P &lt; 0.05) and greater content of serum LPS on day 9 (P &lt; 0.05). Escherichia coli infection also triggered a systemic inflammatory response including the decrease of the serum IgA, IgM, and jejunal sIgA on day 14 (P &lt; 0.05). In addition to these, 1,062 differentially expressed genes were detected in the jejunum tissues of ducks by RNA-seq, consisting of 491 upregulated and 571 downregulated genes. Based on the KEGG database, oxidative phosphorylation and the ribosome pathway were the most enriched. These findings reveal the candidate pathways and genes that may be involved in E. coli infection, allow a better understanding of the molecular mechanisms of inflammation progression and may facilitate the genetic improvement of ducks, and provide further insights to tackle the drug sensitivity and animal welfare issues.

Dietary resistant starch alleviates Escherichia coli-induced bone loss in meat ducks by promoting short-chain fatty acid production and inhibiting Malt1/NF-κB inflammasome activation

Background

Escherichia coli (E. coli) infection in humans and animals usually comes with gut dysbiosis, which is potential culprit to skeletal health, it is still unclear to whether diet interfered gut microbiome changes can be a protective strategy to bone loss development. Here, the effects of resistant starch from raw potato starch (RPS), a type of prebiotic, on E. coli-induced bone loss and gut microbial composition in meat ducks were evaluated.

Results

The results showed that dietary 12% RPS treatment improved bone quality, depressed bone resorption, and attenuated the pro-inflammatory reaction in both ileum and bone marrow. Meanwhile, the 12% RPS diet also increased the abundance of Firmicutes in E. coli-treated birds, along with higher production of short-chain fatty acids (SCFAs) especially propionate and butyrate. Whereas addition of β-acid, an inhibitor of bacterial SCFAs production, to the drinking water of ducks fed 12% RPS diet significantly decreased SCFAs level in cecum content and eliminated RPS-induced tibial mass improvement. Further, treatment with MI-2 to abrogate mucosa-associated lymphoid tissue lymphoma translocation protein 1 (Malt1) activity replicated the protective role of dietary 12% RPS in E. coli-induced bone loss including reduced the inhibition on nuclear factor κB (NF-κB) inflammasome activation, decreased bone resorption, and improved bone quality, which were correlated with comparable and higher regulatory T cells (Treg) frequency in MI-2 and 12% RPS group, respectively.

Conclusions

These findings suggested that the diet with 12% RPS could alleviate E. coli-induced bone loss in meat ducks by changing the gut microbial composition and promoting concomitant SCFAs production, and consequently inhibiting Malt1/NF-κB inflammasome activation and Treg cells expansion.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00739-7.

Paternal transgenerational nutritional epigenetic effect: A new insight into nutritional manipulation to reduce the use of antibiotics in animal feeding

The use of antibiotics in animal feeding has been banned in many countries because of increasing concerns about the development of bacterial resistance to antibiotics and potential issues on food safety. Searching for antibiotic substitutes is essential. Applying transgenerational epigenetic technology to animal production could be an alternative. Some environmental changes can be transferred to memory-like responses in the offspring through epigenetic mechanisms without changing the DNA sequence. In this paper, we reviewed those nutrients and non-nutritional additives that have transgenerational epigenetic effects, including some amino acids, vitamins, and polysaccharides. The paternal transgenerational nutritional epigenetic regulation was particularly focused on mechanism of the substantial contribution of male stud animals to the animal industries. We illustrated the effects of paternal transgenerational epigenetics on the metabolism and immunity in farming animals and proposed strategies to modulate male breeding livestock or poultry.

Review of glucose oxidase as a feed additive: production, engineering, applications, growth-promoting mechanisms, and outlook

The regulation and prohibition of antibiotics used as growth promoters (AGP) in the feed field are increasing because they cause antimicrobial resistance and drug residue issues and threaten community health. Recently, glucose oxidase (GOx) has attracted increasing interest in the feed industry as an alternative to antibiotics. GOx specifically catalyzes the production of gluconic acid (GA) and hydrogen peroxide (H₂O₂) by consuming molecular oxygen, and plays an important role in relieving oxidative stress, preserving health, and promoting animal growth. To expand the application of GOx in the feed field, considerable efforts have been made to mine new genetic resources. Efforts have also been made to heterologously overexpress relevant genes to reduce production costs and to engineer proteins by modifying enzyme properties, both of which are bottleneck problems that limit industrial feed applications. Herein, the: different sources, diverse biochemical properties, distinct structural features, and various strategies of GOx engineering and heterologous overexpression are summarized. The mechanism through which GOx promotes growth in animal production, including the improvement of antioxidant capacity, maintenance of intestinal microbiota homeostasis, and enhancement of gut function, are also systematically addressed. Finally, a new perspective is provided for the future development of GOx applications in the feed field.

Effects of Dietary Glucose Oxidase Supplementation on the Performance, Apparent Ileal Amino Acids Digestibility, and Ileal Microbiota of Broiler Chickens

Simple Summary

Glucose oxidase was used as a potential additive to improve intestinal health in livestock and poultry industry. This study aimed to investigate the effects of glucose oxidase supplementation on performance, ileal microbiota, ileal short-chain fatty acids profile, and apparent ileal digestibility in grower broilers. Our findings will provide a valuable insight into the possibility of glucose oxidase as an alternative of antibiotic growth promoters in broiler diets.

Abstract

This study aimed to investigate the effects of glucose oxidase (GOD) supplementation on growth performance, apparent ileal digestibility (AID) of nutrients, intestinal morphology, and short-chain fatty acids (SCFAs) and microbiota in the ileum of broilers. Six hundred 1-day-old male broilers were randomly allotted to four groups of 10 replicates each with 15 birds per replicate cage. The four treatments included the basal diet without antibiotics (Control) and the basal diet supplemented with 250, 500, or 1000 U GOD/kg diet (E250, E500 or E1000). The samples of different intestinal segments, ileal mucosa, and ileal digesta were collected on d 42. Dietary GOD supplementation did not affect daily bodyweight gain (DBWG) and the ratio of feed consumption and bodyweight gain (FCR) during d 1-21 (p > 0.05); however, the E250 treatment increased DBWG (p = 0.03) during d 22–42 as compared to control. Dietary GOD supplementation increased the AIDs of arginine, isoleucine, lysine, methionine, threonine, cysteine, serine, and tyrosine (p < 0.05), while no significant difference was observed among the GOD added groups. The E250 treatment increased the villus height of the jejunum and ileum. The concentrations of secreted immunoglobulin A (sIgA) in ileal mucosa and the contents of acetic acid and butyric acid in ileal digesta were higher in the E250 group than in the control (p < 0.05), whereas no significant differences among E500, E1000, and control groups. The E250 treatment increased the richness of ileal microbiota, but E500 and E100 treatment did not significantly affect it. Dietary E250 treatment increased the relative abundance of Firmicutes phylum and Lactobacillus genus, while it decreased the relative abundance of genus Escherichina-Shigella (p < 0.05). Phylum Fusobacteria only colonized in the ileal digesta of E500 treated broilers and E500 and E1000 did not affect the relative abundance of Firmicutes phylum and Lactobacillus and Escherichina-Shigella genera as compared to control. These results suggested that dietary supplementation of 250 U GOD/kg diet improves the growth performance of broilers during d 22–42, which might be associated with the alteration of the intestinal morphology, SCFAs composition, and ileal microbiota composition.

Dietary glucose oxidase and/or catalase supplementation alleviates intestinal oxidative stress induced by diquat in weaned piglets

This study investigated the effects of dietary exogenous glucose oxidase (GOD) and/or catalase (CAT) on the intestinal antioxidant capacity and barrier function in piglets under oxidative stress. Sixty pigs assigned randomly to five treatment groups-CON: basal diet; DIQ: basal diet; GOD: basal diet + 40-U GOD/kg diet; CAT: basal diet + 50-U CAT/kg diet; and GC: basal diet + 40-U GOD/kg diet + 50-U CAT/kg diet-were analyzed. On Day 14, the CON group was injected with saline, and the others were treated with diquat. The results showed that in diquat-treated piglets, supplementation of dietary GOD and CAT elevated the superoxide dismutase and CAT activities and attenuated the malondialdehyde level in plasma and intestinal mucosa, enhanced the duodenal villus height and villus height/crypt depth ratio, upregulated ZO-1 mRNA level, and attenuated the apoptosis of the epithelial cells and caspase-3 mRNA level in the intestine. Additionally, the supplementation upregulated mRNA expression of the intestinal NF-E2-related factor 2-regulated genes in diquat-treated piglets. However, GOD combined with CAT could not alleviate oxidative damage better than supplementation of CAT or GOD alone under oxidative stress. Overall, the study provides a potential alternative that could relieve the weaning stress in piglets and help formulate antibiotic-free diets.

Effects of Lactobacillus acidophilus on the growth performance, immune response, and intestinal barrier function of broiler chickens challenged with Escherichia coli O157

We studied the effects of Lactobacillus acidophilus (L. acidophilus) on the growth performance, intestinal morphology, barrier function, and immune response of broilers challenged with Escherichia coli O157 (E. Coli). A total of 360 1-day-old Cobb male broilers were tested in a 3 × 2 factorial arrangement with 3 dietary L. acidophilus levels (0, 5 × 108 CFU/kg, and 10 × 108 CFU/kg of diet) and 2 disease challenge treatments (control or E. coli challenged). Results showed that E. coli challenge decreased the ADG, ADFI, and BW of broilers from 15 to 21 d (P < 0.05), increased the jejunum intestinal wall thickness, and significantly increased the mortality rate. E. coli challenge significantly (P < 0.05) decreased the serum IgA and IgM contents and peripheral blood CD3+ T cell counts (P < 0.05), increased the serum CRP, DAO, and LPS levels at 21 d; upregulated the mRNA expression of iNOS, IL-8, IL-1β in the jejunum and iNOS in the spleen, and downregulated the occludin and ZO-1 mRNA expression in the ileum at 21 d compared with uninfected birds (P < 0.05). Dietary L. acidophilus supplementation consistently showed higher BW, ADG, ADFI, and jejunum and ileum V:C ratio at 14 d and 21 d in the presence and absence of E. coli challenge (P < 0.05). L. acidophilus supplementation reduced the mortality rate caused by E. coli challenge (P < 0.05), decreased the serum CRP, DAO, and LPS levels at 14 d and 21 d; upregulated the mRNA expression of occludin and ZO-1 in the jejunum and ileum, and downregulated the mRNA expression of iNOS, IL-8, and IL-1β in the jejunum in E. coli challenged birds at 21 d (P < 0.05). Dietary supplementation with L. acidophilus can improve the growth performance, intestinal health, and survival of broilers challenged with E. coli.

Effects of dietary glucose oxidase, catalase, or both supplementation on reproductive performance, oxidative stress, fecal microflora and apoptosis in multiparous sows

Objective

The objective of this experiment was to investigate the effect of dietary glucose oxidase (GOD), catalase (CAT), or both supplementation on reproductive performance, oxidative stress, and apoptosis in sows.

Methods

A total of 104 multiparous sows were randomly assigned to four groups (n = 26) with each group given a basal diet, basal diet plus GOD at 60 U/kg, basal diet plus CAT at 75 U/kg, and basal diet plus GOD at 60 U/kg and CAT at 75 U/kg. Sows were fed the experimental diets throughout gestation and lactation.

Results

Dietary GOD supplementation increased average daily feed intake of sows and litter weight at weaning (p<0.05). Dietary CAT supplementation reduced the duration of parturition, stillbirth, and piglet mortality and increased growth performance of weaned piglets (p<0.05). Dietary GOD and CAT supplementation enhanced antioxidant enzyme activities and lessened oxidative stress product levels in plasma of sows and elevated antioxidant capacity of 14-day milk and plasma in weaned piglets (p<0.05). Dietary GOD supplementation increased fecal Lactobacillus counts and reduced Escherichia coli counts of sows (p<0.05). Compared with the basal diet, the GOD diet reduced fecal Escherichia coli counts of sows, but the addition of CAT did not reduce Escherichia coli counts in the GOD diet. Dietary GOD and CAT supplementation reduced the apoptosis rate of the liver, endometrium, and ovarian granulosa cells in sows (p<0.05). In the liver, uterus, and ovary of sows, the mRNA expression of caspase-3 and caspase-9 was downregulated by dietary GOD and CAT supplementation (p<0.05).

Conclusion

Dietary GOD and CAT supplementation could improve the antioxidant capacity of sows and weaned piglets, and alleviate hepatic, ovarian and uterine apoptosis by weakening apoptosis-related gene expression. Glucose oxidase regulated fecal microflora of sows, but supplementation of CAT to GOD could weaken the inhibitory effect of GOD on fecal Escherichia coli.

Dietary supplementation of Aspergillus niger-expressed glucose oxidase ameliorates weaning stress and improves growth performance in weaning pigs

Weaning is one of the most stressful events in the pig's life, which disrupts physiological balance and leads to oxidative stress. It is reported that glucose oxidase supplementation could alleviate oxidative stress in animals by increasing the concentration of antioxidant enzymes in vivo. The purpose of this study was to evaluate the effects of dietary supplementation of Aspergillus niger-expressed glucose oxidase (AN-GOX) on growth performance, nutrient digestibility, faecal microbiota, faecal gas emission and serum antioxidant enzyme parameters in weaning pigs. A total of 120 21-day-old weaning pigs [(Yorkshire ×Landrace) × Duroc] with an initial body weight of 6.54 ± 0.55 kg were used in a 21-day experiment (phase 1, days 1-7; phase 2, days 8-21) with a completely randomized block design. Pigs were randomly divided into 4 treatment groups with 6 replicate pens per treatment and 5 pigs per pen (2 barrows and 3 gilts). Dietary treatments were corn-soybean meal-based basal diet supplemented with 0, 0.01, 0.03 or 0.05% AN-GOX (1000 unit/g). The results of this study showed that average daily gain during days 1-7 and 1-21 and the concentrations of serum glutathione peroxidase and glutathione increased linearly at graduated doses of AN-GOX increased in the diet. However, dietary supplementation of AN-GOX had no effects on the apparent nutrient digestibility, faecal microbiota and faecal gas emission. In conclusion, supplementing AN-GOX to the diet of weaning pigs ameliorated weaning stress, which manifested as the increase in serum antioxidant enzyme levels, thus improving growth performance. The suitable dosage of AN-GOX used in the diet of weaning pigs was 0.05%.