Occludin Gene Expression Research Articles

Lithospermum erythrorhizon Alleviates Atopic Dermatitis-like Skin Lesions by Restoring Immune Balance and Skin Barrier Function in 2.4-Dinitrochlorobenzene-Induced NC/Nga Mice.

The incidence of atopic dermatitis (AD), a disease characterized by an abnormal immune balance and skin barrier function, has increased rapidly in developed countries. This study investigated the anti-atopic effect of Lithospermum erythrorhizon (LE) using NC/Nga mice induced by 2,4-dinitrochlorobenzene. LE reduced AD clinical symptoms, including inflammatory cell infiltration, epidermal thickness, ear thickness, and scratching behavior, in the mice. Additionally, LE reduced serum IgE and histamine levels, and restored the T helper (Th) 1/Th2 immune balance through regulation of the IgG1/IgG2a ratio. LE also reduced the levels of AD-related cytokines and chemokines, including interleukin (IL)-1β, IL-4, IL-6, tumor necrosis factor-α (TNF-α), thymic stromal lymphopoietin, thymus and activation-regulated chemokine, macrophage-derived chemokine, regulated on activation, normal T cell expressed and secreted, and monocyte chemoattractant protein-1 in the serum. Moreover, LE modulated AD-related cytokines and chemokines expressed and secreted by Th1, Th2, Th17, and Th22 cells in the dorsal skin and splenocytes. Furthermore, LE restored skin barrier function by increasing pro-filaggrin gene expression and levels of skin barrier-related proteins filaggrin, involucrin, loricrin, occludin, and zonula occludens-1. These results suggest that LE is a potential therapeutic agent that can alleviate AD by modulating Th1/Th2 immune balance and restoring skin barrier function.

Effects of zinc dosage and particle size on gut morphology, tight junctions and TNF-α expression in broiler breeder hens.

This study was performed to evaluate the effects of different amounts and particle size of zinc oxide (ZnO) on villus height (VH), villus width (VW), crypt depth (CD) and VH to CD ratio (VH: CD), and expression of zonula occludens-1 (ZO-1), occludin (OC) and tumour necrosis factor-α (TNF-α) in broiler breeders. A total of 350 (Ross 308) broiler breeder hens of 54weeks randomly assigned to seven treatments, included control basal diet (C) without added Zn, C+ 100, and 130mg Zn per kg of diet from Large (L) (100-1000nm) and Small (S) (<100nm) particle size ZnO (LZnO100 and 130; SZnO100 and 130), C and SZnO100 challenged with lipopolysaccharide (C+LPS and SZnO100+LPS). Each diet was fed to five replicates consisting of ten birds each. The middle part of the duodenum, jejunum and ileum was used for morphological assessments. To assess the gene expression of ZO-1, OC and TNF-α in the jejunum samples were excised. Results showed that the supplementing 130ppm SZnO increased VH:CD in the duodenum (p<0.05). VW in the duodenum and all the evaluated morphometric indices in jejunum and ileum were not affected by the dietary treatment (p>0.05). ZO-1mRNA abundance in C+LPS group compared to SZnO100+LPS group was significantly decreased and increased by LPS and SZnO100 respectively. The SZnO-100 increased OC gene expression in compare to C+LPS group. The expression of TNF-α in C+LPS treatment was higher than other groups (p<0.05). The lowest and the highest litter moisture and foot-pad dermatitis (FPD) were observed in LZnO-130 and C treatments respectively (p<0.05). Improving the physical properties of ZnO affect on VH:CD. Broiler breeder diet with ZnO enhance ZO-1, OC and mitigate TNF-α gene expression in jejunum maintenance of gut health in broiler breeders.

Infection Heterogeneity and Microbiota Differences in Chicks Infected by Salmonella enteritidis.

This study was conducted to compare the infection heterogeneity and cecal microbiota in chicks infected by S. enteritidis. Forty-eight 8-d-old female Arbor Acres chicks were challenged with S. enteritidis and euthanized 24 h later. The eight chicks with the highest Salmonella tissue loads were assigned to group S (S. enteritidis-susceptible), and the eight chicks with the lowest Salmonella tissue loads were assigned to group R (S. enteritidis-resistant). Chicks in group S showed a higher liver index (p < 0.05), obvious liver lesions, and an decreasing trend for the villus height-to-crypt depth ratio (p < 0.10), compared with those in group R. Gene expression of occludin, MUC2, and IL10 was higher, whereas that of iNOS and IL6 was lower (p < 0.05), in chicks of group R relative to those in group S. Separation of the cecal microbial community structure has been found between the two groups. The S. enteritidis-susceptible chicks showed higher abundance of pathogenic bacteria (Fusobacterium and Helicobacter) in their cecal, while Desulfovibrio_piger was enriched in the cecal of S. enteritidis-resistant chicks. In summary, chicks showed heterogeneous responses to S. enteritidis infection. Enhanced intestinal barrier function and cecal microbiota structure, especially a higher abundance of Desulfovibrio_piger, may help chicks resist S. enteritidis invasion.

Dietary Yeast Cell Wall Improves Growth Performance and Prevents of Diarrhea of Weaned Pigs by Enhancing Gut Health and Anti-Inflammatory Immune Responses

Simple SummaryPost-weaning stress can substantially affect performance of weaned pigs as well as overall pig production, and thus, a practical approach is needed to improve their performance by alleviating the stress that can cause intestinal barrier dysfunction of weaned pigs. There are potential ways to solve the concern in swine production, but dietary yeast cell wall in weaner diets may be one possible solution. The results of the present study suggest that dietary yeast cell wall improves growth performance of weaned pigs by enhancing gut health and provide its potential mechanism.Dietary yeast cell wall products (YCW) are recognized as a feed additive due to multifunctional benefits by the biological response modulators. Thus, this study was conducted to verify a potential advantage of YCW for improving growth performance, nutrient digestibility, immune responses, and intestinal health and microbiota of weaned pigs. A total of 112 weaned pigs (7.99 ± 1.10 kg of body weight; 28 days old) were arbitrarily allocated to two experimental treatments with eight pigs (four barrows and four gilts) per pen and seven replicate pens per treatment in a completely randomized block design (block = BW and sex): (1) a basal diet based on corn and soybean meal (CON) and (2) CON + 0.05% YCW. The experimental period was for 4 weeks. There were no differences in final body weight, average daily feed intake, and gain-to-feed ratio between dietary treatments. In contrast, pigs fed YCW had higher average daily gain (p = 0.088) and apparent ileal digestibility of DM (p < 0.05) and energy (p = 0.052) and lower diarrhea frequency (p = 0.083) than those fed control diet (CON). Pigs fed YCW also had a higher (p < 0.05) ratio between villus height and crypt depth, villus width and area, and goblet cell counts in the duodenum and/or jejunum than those fed CON. Dietary YCW decreased (p < 0.05) serum TNF-α and IL–1β of weaned pigs on day 7 and 14, respectively, compared with CON. Furthermore, pigs fed YCW had higher (p < 0.05) ileal gene expression of claudin family, occludin, MUC1, INF-γ, and IL-6 and lower (p < 0.05) that of TNF-α than those fed CON. Lastly, there were no differences in the relative abundance of bacteria at the phylum level between CON and YCW. However, dietary YCW increased (p < 0.05) the relative abundance of genera Prevotella and Roseburia compared with CON. This study provided that dietary YCW improved growth rate, nutritional digestibility, and intestinal health and modified immune responses and intestinal microbiota of weaned pigs.

Wine Pomace Product Inhibit Listeria monocytogenes Invasion of Intestinal Cell Lines Caco-2 and SW-480.

Red wine pomace products (WPP) have antimicrobial activities against human pathogens, and it was suggested that they have a probable anti-Listeria effect. This manuscript evaluates the intestinal cell monolayer invasive capacity of Listeria monocytogenes strains obtained from human, salmon, cheese, and L. innocua treated with two WPP (WPP-N and WPP-C) of different polyphenol contents using Caco-2 and SW480 cells. The invasion was dependent of the cell line, being higher in the SW480 than in the Caco-2 cell line. Human and salmon L. monocytogenes strains caused cell invasion in both cell lines, while cheese and L. innocua did not cause an invasion. The phenolic contents of WPP-N are characterized by high levels of anthocyanin and stilbenes and WPP-C by a high content of phenolic acids. The inhibitory effect of the WPPs was dependent of the strain and of the degree of differentiation of the intestinal cells line. The inhibition of Listeria invasion by WPPs in the SW480 cell line, especially with WPP-C, were higher than the Caco-2 cell line inhibited mainly by WPP-N. This effect is associated with the WPPs’ ability to protect the integrity of the intestinal barrier by modification of the cell–cell junction protein expression. The gene expression of E-cadherin and occludin are involved in the L. monocytogenes invasion of both the Caco-2 and SW480 cell lines, while the gene expression of claudin is only involved in the invasion of SW480. These findings suggest that WPPs have an inhibitory L. monocytogenes invasion effect in gastrointestinal cells lines.

Effects of Wheat Germ and Its Combination With Antibiotics on Metabolic and Gut Health Outcomes in Western Diet-Fed Mice

Abstract Objectives This study evaluated whether wheat germ (WG) alone or in combination with antibiotics (Ab) will ameliorate metabolic and gut integrity and inflammatory markers in mice fed a Western diet (WD). Methods Six-wk-old male C57BL/6 mice were randomly assigned (n = 7–8/group) to three dietary treatement groups: WD (60% fat kcal), WD + WG (10% wt/wt) and WD + WG + Ab (1 mg/mL ampicillin, metronidazole, neomycin, and ampothericin B plus 0.5 mg/mL vancomycin cocktail added in drinking water) for 4 wks. Food intake and body weights were assessed daily throughout the study. Tissues were collected and assessments included clinical chemistry parameters, intaperitoneal glucose tolerance test (IPGTT), body composition by dual-energy x-ray absorptiometry, and gut integrity and inflammatory markers by qPCR. Effects of treatment were analyzed with one-way ANOVA using SPSS software and P &amp;lt; 0.05 was considered significant. Results Food intake differed significantly (P &amp;lt; 0.0001) between groups, with the WD + WG having the highest and WD + WG + Ab having the lowest intake. Final body weight (P &amp;lt; 0.0001) and fat mass (P &amp;lt; 0.0001) was lowest in the WD + WG + Ab and similar for WD and WD + WG groups. There was no difference in lean mass among the groups. IPGTT area under the curve (P &amp;lt; 0.0001) and serum total cholesterol (P = 0.023) were significantly reduced and fasting glucose tended (P = 0.091) to be lower in the WD + WG + Ab group. Mice in the WD + WG + Ab group also had higher cecal tissue and cecal content weights (P &amp;lt; 0.0001) as well as the ileal gene expression of the tight junction protein occludin (P = 0.008) compared to the other groups. On the other hand, WD + WG fed mice had significantly higher ileal gene expression of the anti-inflammatory cytokine, interleukin (IL)-10, compared to WD (P = 0.05) and WD + WG + Ab (P = 0.035). Conclusions Although WG alone promoted a gut anti-inflammatory response, it was not as effective as the combination of WG and antibiotics at improving metabolic outcomes. These positive effects of WD + WG + Ab on metabolic outcomes were likely due to a reduction in food intake resulting in lower body weight and body fat. Future studies should investigate the contribution of antibiotics, the role of the gut microbiota, and the impact of long-term antibiotic use. Funding Sources Oklahoma Agriculture Experiment Station and the Jim and Lynn Williams Professorship.

The Bile Acids Specifically Modulate Colonic MUC2 and Tight Junction Protein Expression in the Human Colon Cancer Cell Line

Abstract Objectives Alterations to mucin secretion and epithelial tight junctions can compromise the ability of the epithelium to act as a barrier for the host to prevent pathogenic attack. Bile acids are synthesized in hepatocytes and released into the intestine, further modified by gut bacteria. Although many studies have investigated the changes of intestinal bile acids in the pathogenesis of various immune disorders, there are few reports about its function in preventing or interventing the dysfunction of the intestinal barrier. In this study, we sought to investigate the effects of the colonic bile acids on MUC2 and tight junction protein expression, which are crucial to colonic barrier. Methods Regulation of MUC2 and tight junction protein expression was assayed in the human colon cancer LS174T and T84 cells. The cells were treated with deoxycholic acid (DCA), lithocholic acid (LCA), 3-oxo-DCA, 3-oxo-LCA, isoDCA and isoLCA (100 μM or 200 μM), respectively. Proliferation of the cells was investigated with the MTT assay. mRNA expression of MUC2, ZO-1, occludin, claudin1 were measured by RT-PCR. Nuclear bile acid receptor FXR and TGR5, toll-like receptors and TLR adaptor MyD88, and genes (CDX2, AGR2, MyD88) related to mucin synthesis and secretion were also measured. Results In comparison with the untreated control, DCA, 3-oxo-DCA, isoDCA and isoLCA (100 μM) significantly upregulated the ZO-1, occludin and bile acid receptor FXR gene expression in the T84 cell. LCA, 3-oxo-LCA and isoLCA upregulated MUC2 expression at 200 μM, but showed no significant effect at 100 μM. DCA only significantly upregulated MUC2 expression at 200 μM, but isoDCA upregulated MUC2 expression independent of concentration in the LS174T cell. The expression of CDX2, AGR2, MyD88 was consistent with MUC2. Conclusions Bile acids at various concentrations specifically modulate MUC2 and tight junction protein expression, and thereby alter the colonic barrier function. This regulatory effect of bile acids could be mediated by activating bile acid receptors FXR. Funding Sources This work was financially supported by Ministry of Science and Technology of China (10000 Talent Project).

Microscopic Colitis Patients Possess a Perturbed and Inflammatory Gut Microbiota.

Microscopic colitis (MC), an inflammatory disease of the colon, is characterized by chronic non-bloody diarrhea with characteristic inflammation and for some, collagen deposits in mucosal biopsies. The etiology of MC is unclear, although previous findings implicate luminal factors and thus the gut microbiome. However, the relationships between fecal microbiota and MC are relatively unexplored. Stool microbiota of MC (n = 15) and healthy controls (HC; n = 21) were assessed by 16S rRNA V4 amplicon sequencing and analysis performed in QIIME. Gut microbiota functions were predicted using Piphillin and inflammatory potential assessed using an in vitro HT29 colonocyte cell assay. MC patient fecal microbiota were less diverse (Faiths index; p < 0.01) and compositionally distinct (PERMANOVA, weighted UniFrac, R2 = 0.08, p = 0.02) compared with HC subjects. MC microbiota were significantly depleted of members of the Clostridiales, enriched for Prevotella and more likely to be dominated by this genus (Chi2 = 0.03). Predicted pathways enriched in MC microbiota included those related to biosynthesis of antimicrobials, and sphingolipids, to glycan degradation, host defense evasion, and Th17 cell differentiation and activation. In vitro, exposure of cultured colonocytes to cell-free products of MC patient feces indicates reduced gene expression of IL-1B and occludin and increased GPR119 and the lymphocyte chemoattractant CCL20. MC gut microbiota are distinct from HC and characterized by lower bacterial diversity and Prevotella enrichment and distinct predicted functional pathways. Limited in vitro experiments indicate that compared with cell-free products from healthy fecal microbiota, MC microbiota induce distinct responses when co-cultured with epithelial cells, implicating microbiota perturbation in MC-associated mucosal dysfunction.

Effect of roasted peanut allergen Ara h 3 protein on the sensitization of Caco-2 cells.

Roasted peanut is widely loved as a kind of food with rich taste. However, peanut allergy is one of the major threats to human health, which affects about 5% of children and 1.4-2% of adults in the world. To evaluate the sensitization mechanism of peanut allergen Ara h 3, Caco-2 cells as the model, which has the similar structure and function to differentiated small intestinal epithelial cells. Compared with Ara h 3-raw (purified from raw peanut) group, more significant results such as the inhibited Caco-2 cell viability and proliferation, the increased secretion of reactive oxygen species (ROS) and the decreased transepithelial electrical resistance were obtained in Ara h 3-roasted (purified from roasted peanut) group. Accordingly, oxidative stress and NF-κB signaling pathway were more imbalanced, which lead to the increased of thymic stromal lymphopoietin (TSLP), interleukin 6 (IL-6), IL-8 and monocyte chemotactic protein 1 (MCP-1). Then, the gene expression of tight junction proteins ZO-1, occludin and JAM-1 were reduced, which proved that the integrity of the Caco-2 monolayer barrier is severely damaged. These finding identify the mechanisms of the allergenicity of roasted peanut allergy proteins are probably associated with intestinal uptake and cytokine dependent allergies. The aggravated allergic reaction might be caused by the increment of TSLP, IL-6, IL-8 and MCP-1 due to the activated NF-κB signaling pathway, and the enhanced transport of Ara h 3-roasted protein by Caco-2 monolayer. © 2021 Society of Chemical Industry.

Long Term High Protein Diet Feeding Alters the Microbiome and Increases Intestinal Permeability, Systemic Inflammation and Kidney Injury in Mice.

This study evaluates the effects of a chronic high protein diet (HPD) on kidney injury, intestinal permeability and gut microbiota perturbations in a mouse model. Mice are fed a diet containing either 20% or 52% energy from protein for 24 weeks; protein displaced an equivalent amount of wheat starch. The HPD does not alter glycemic control or body weight. The HPD induces kidney injury as evidenced by increase in albuminuria, urinary kidney injury molecule-1, blood urea nitrogen, urinary isoprostanes and renal cortical NF-κB p65 gene expression. HPD decreases intestinal occludin gene expression, increases plasma endotoxin and plasma monocyte chemoattractant protein-1, indicating intestinal leakiness and systemic inflammation. Cecal microbial analysis reveals that HPD feeding does not alter alpha diversity; however, it does alter beta diversity, indicating an altered microbial community structure with HPD feeding. Predicted metagenome pathway analysis demonstrates a reduction in branched-chain amino acid synthesis and an increase of the urea cycle with consumption of a HPD. These results demonstrate that long term HPD consumption in mice causes albuminuria, systemic inflammation, increase in gastrointestinal permeability and is associated with gut microbiome remodeling with an increase in the urea cycle pathway, which may contribute to renal injury.

Dietary Glutamic Acid Modulates Immune Responses and Gut Health of Weaned Pigs

Simple SummaryWeaning stress can lead to intestinal barrier dysfunction, immune system destruction, and intestinal microbiota disruption, thereby reducing the absorption of nutrients and causing intestinal diseases. Glutamic acid is a non-essential amino acid that is abundantly present in the body and plays an essential function in cellular metabolism and immune responses. In this study, the effects of dietary glutamic acid on the growth performance, nutrient digestibility, immune responses, and intestinal health of weaned pigs were evaluated. Based on the results, dietary glutamic acid increased growth performance, nutrient digestibility, intestinal morphology, and ileal gene expression of tight junction proteins of weaned pigs and modified immune responses and gut microbiota. This study provides information to understand the functional use of dietary glutamic acid as a feed additive for improving the growth performance and intestinal health of weaned pigs.Dietary glutamic acid (GLU) is used as a feed additive because of its functional characteristics that may affect the growth performance and health of pigs. This study was carried out to determine the effects of dietary GLU on growth performance, nutrient digestibility, immune responses, and intestinal health of weaned pigs. A total of ninety-six weaned pigs (8.07 ± 1.17 kg of body weight; 28 days of age) were assigned to two dietary treatments (8 pigs/pen; 6 replicates/treatment) in a randomized complete block design (block: body weight): (1) a typical weaner diet (CON) and (2) CON supplemented with 0.5% GLU. The experimental period was for 4 weeks. All data and sample collections were performed at the specific time points during the experimental period. Pigs fed GLU had higher average daily gain and average daily feed intake for the first two weeks and nutrient digestibility than pigs fed CON. In addition, dietary GLU increased villus height to crypt depth ratio, number of goblet cells, and ileal gene expression of claudin family and occludin compared with CON, but decreased serum TNF-α and IL-6 and ileal gene expression of TNF-α. Moreover, pigs fed GLU had increased relative composition of bacterial communities of genus Prevotella and Anaerovibrio and decreased genus Clostridium and Terrisporobacter compared with those fed CON. This study suggests that dietary GLU influences growth performance and health of weaned pigs by modulating nutrient digestibility, intestinal morphology, ileal gene expression of tight junction proteins and cytokines, immune responses, and microbial community in the gut.

Tight junction proteins in the small intestine and prefrontal cortex of female rats exposed to stress of chronic isolation starting early in life.

Simultaneous evaluation of barrier protein expression in the gut and the brain and their modulation under stress conditions have not been studied before now. As the permeability and function of the gut and blood-brain barrier are different and both express the MRs, we hypothesized that stress of post-weaning social isolation induces changes in tight junction protein expression in the gut which are (1) independent of changes in the brain and (2) are mediated via the mineralocorticoid receptor (MR). First, using UPLC-MS/MS we have successfully validated and selected a dose (1.2mg/rat/day) of the MR antagonist spironolactone to treat female rats exposed to stress of chronic isolation or control conditions from postnatal day 21 for 9weeks. Isolation stress caused an enhancement of gene expression of occludin and ZO-1 and a decrease in claudin-5 and MR expression in both the small intestine and prefrontal cortex. Isolation stress failed to decrease claudin-5 (small intestine) and MR (prefrontal cortex) gene expression in spironolactone-treated rats. MR blockade resulted in a decrease in claudin-15 expression in the small intestine. Anxiogenic effect of chronic stress, measured in elevated plus-maze test, was partly prevented by spironolactone treatment. Claudins, the main regulators of intestinal barrier permeability responded to chronic stress of social isolation and/or simultaneous blockade of MR in female rats by alterations independent of changes in the brain cortex. The results suggest a physiological role of MR in the control of claudin expression in the small intestine, but not in the brain cortex.

Study on the mechanisms of the intestinal tight-junction destruction caused by Blastocystis hominis infection in rats

To explore the mechanism of the intestinal barrier damage caused by Blastocystis hominis infections in rats. Thirty SD rats were randomly divided into the control group, and the 1-, 3-, 6- and 9-week-infection groups, of 6 rats in each group. Rats in each infection group were orally infected with B. hominis trophozoites at a density of 2 × 108 parasites per rat, and the control group was given an equal volume of phosphate buffered saline solution. The 7-hour urine samples were collected 1, 3, 6 and 9 weeks post-infection for the measurement of the intestinal permeability. Then, rats were sacrificed using the cervical dislocation method, and the cecum specimens were collected for the detection of the intestinal epithelial cell permeability. The expression of tight junction-related Occludin and Claudin - 1 genes and apoptosis-related Bcl - 2 and Bax genes was quantified in cecum epithelial cells using the real-time fluorescent quantitative PCR (qPCR) assay, and cell apoptosis was detected in the rat cecum using the TdT-mediated dUTP nick-end labeling (TUNEL) assay. The median urinary lactolose to mannitol ratios were 0.29, 0.72, 0.44, 0.46 and 0.38 in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 12.09, P < 0.05). B. hominis invasion and epithelial injury were observed in intestinal epithelial cells of rats infected with B. hominis, and transmission electron microscopy displayed the destruction of tight junctions between intestinal epithelial cells. The relative expression of Occludin, Claudin-1, Bcl-2 and Bax genes was 1.04, 0.62, 0.71, 0.68 and 0.96; 1.03, 0.61, 0.63, 0.76 and 0.86; 1.08, 0.70, 0.75, 0.74 and 1.03; and 1.00, 1.57, 1.33, 1.35 and 1.10 in the control group and the 1-, 3-, 6- and 9-week-infection groups, respectively, and all differences were statistically significant (F = 2.86, 2.85, 3.37 and 4.45, all P values < 0.05). The median number of positive staining cells were 1.00, 13.00, 9.00, 3.50 and 1.00 in rat cecum specimens in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 22.95, P < 0.01). B. hominis infection may cause an increase in the rat intestinal permeability through triggering the apoptosis of intestinal epithelial cells to destroy the tight junction between intestinal epithelial cells, thereby destroying the intestinal barrier function.

Influence of Glycyrrhiza glabra Extract on Growth, Gene Expression of Gut Integrity, and Campylobacter jejuni Colonization in Broiler Chickens.

Phytogenic feed additives have been gaining considerable interest due to their ability to improve gut health and thereby performance of broiler chickens. The impact of Glycyrrhiza glabra (licorice) extract (GE) on expression of genes coding for tight junction proteins and gut protection and Campylobacter jejuni colonization in broilers has not been discussed until now. Thus, the current study assessed the effective dose of GE for maximum growth in broiler chickens, clear-cut molecular mechanisms related to integrity and health of intestine, and controlling C. jejuni colonization. Over a 35-day feeding period, a total of 500 Ross broiler chicks were allocated to five groups; the first group was fed a control diet without GE and the second group to the fifth group were fed a control diet with GE (0.25, 0.5, 1, and 2 g/kg of diet); each group comprised 100 chicks with 10 replicates (10 birds/replicate). Birds fed GE had an improved body weight gain and feed conversion ratio. Furthermore, the highest body weight gain was observed in the group that received 1 g/kg of GE (P < 0.05). The expression of genes coding for tight junction proteins [occludin and junctional adhesion molecules (JAM)] was upregulated in all groups supplemented with GE. Moreover, birds fed 1 g/kg of GE exhibited the maximum gene expression of occludin and JAM [0.2 and 0.3 fold change, respectively (P < 0.05)]. In relation to enterocyte protective genes [glucagon-like peptide (GLP-2) and fatty acid-binding protein (FABP-6)], use of GE significantly upregulated expression of GLP-2 gene with 0.8 fold change in 2 g/kg of the GE supplemented group (P < 0.05) while the expression of FABP-6 gene was not affected by GE supplementation (P > 0.05). After challenge with C. jejuni, the expression of mucin (MUC-2) gene was upregulated and the inflammatory markers such as Toll-like receptors (TLR-4) and interleukin (IL-1β) were downregulated with increasing level of supplemented GE (P < 0.05). The mean log10 count of C. jejuni in cecal samples after 7 days post-infection by culture and real-time qPCR was decreased in groups fed GE in a dose-dependent manner (P < 0.05). In addition, the highest reduction of C. jejuni count in cecal samples by culture and real-time qPCR was observed in the group fed 2 g/kg of GE (2.58 and 2.28 log10 CFU/g, respectively). Results from this study suggested that G. glabra extract (1 g/kg) improved growth performance of broiler chickens, as well as influenced the maintenance of intestinal integrity and reduced C. jejuni shedding from infected birds.

Effect of cereal type and plant extract addition on the growth performance, intestinal morphology, caecal microflora, and gut barriers gene expression of broiler chickens

Feeding broiler chickens on diets based on cereal grains of high non-starch polysaccharides content such as wheat and barley can negatively impact their performance and gut health. Plant extracts can be used as a potential tool to alleviate these negative effects. The present study assessed the effects of dietary cereal type and the inclusion of a plant extract blend (PEB) on the growth performance, intestinal histomorphology, caecal microflora, and gene expression of selected biomarkers for gut integrity in broiler chickens in a 42-d experiment. Ross-308 male broilers were assigned into different dietary treatments and fed on two cereal types (corn- vs. wheat/barley-based) with/without added graded concentrations of a PEB (0, 250, 500, 1000, and 2000 mg/kg diet). There were no significant differences in the growth performance parameters, intestinal histomorphology, and caecal microflora due to the impact of dietary cereal type. However, lactobacilli count in the caecal microflora was increased in the group fed on a corn-based diet. The PEB supplementation especially at a level of 500 to 1000 mg/kg diet significantly increased the average BW and decreased the feed conversion ratio. It also increased the villi length of duodenum, jejunum, and ileum, decreased the duodenal crypt depth, and increased the villi length to crypt depth ratio in the duodenum, jejunum and ileum. Supplementation of the PEB decreased the total bacterial and coliform count and increased the lactobacilli count in a linear pattern. Gene expression of Occludin and Junction Adhesion Molecule was significantly increased in the PEB supplemented diets, whereby no influence was observed on mucin expression. In conclusion, supplementation of a PEB at levels of 500–1000 mg/kg can be used as a tool to improve broiler performance and gut health.

Maternal dietary linoleic acid altered intestinal barrier function in domestic pigeons (Columba livia).

Linoleic acid (LA) is predominantly essential for poultry. Poultry lacking LA show retarded growth and reduced disease resistance. Intestinal barrier function plays an important role in pigeon squab growth, whereas research on the effects of LA on intestinal health in altrices is scant. Considering that squabs are fed by their parents, the study aimed to explore the effects of maternal dietary LA on intestinal morphology, tight junction proteins, immune cytokines and microbial flora in squabs. A completely randomised design with a control group, 1 % LA supplementation group, 2 % LA supplementation group and 4 % LA supplementation group was used. Six squabs from each treatment were randomly sampled at 21 d post-hatching. The results indicated that LA supplementation improved intestinal morphology, as reflected by increased villus height, villus area and the ratio of villi to crypts. Also, 1 % LA supplementation elevated the density of goblet cells in the intestine and strengthened tight junctions by up-regulating claudin-3 and occludin gene expression but down-regulating claudin-2 gene expression. Moreover, 1 % LA supplementation reduced the secretion of proinflammatory cytokines and partly increased anti-inflammatory cytokines. The intestinal microbial diversity in the 1 % LA supplementation group was higher than that in the other groups. As beneficial bacteria, Butyrivibrio was the biomarker of 1 % LA supplementation. However, excessive (4 %) LA supplementation led to adverse impacts on intestinal immunity and microbiota. In conclusion, maternal dietary LA might alter intestinal barrier function in pigeon squabs in a dose-dependent manner. Supplementation with 1 % LA was suggested in parental pigeons.

Differential expression of intestinal genes in necrotic enteritis challenged broiler chickens with 2 different Clostridium perfringens strains

The primary cause of necrotic enteritis (NE) disease in chickens is the NetB-positive Clostridium perfringens bacterium. Many factors are known to affect the severity of NE in the challenge models of broiler chickens, and one of these factors is the virulence of C. perfringens strain. This study was conducted to evaluate the effect of 2 pathogenic C. perfringens strains in a NE challenge model on gut health and mRNA expression of genes encoding apoptosis, tight junction, immunity, and nutrient transporters in broilers. Day-old Ross-308 male broilers (n = 468) were allocated in a 2 × 3 factorial arrangement of treatments with in-feed antibiotics (no or yes) and challenge (Non, C. perfringens strain NE18, and C. perfringens strain NE36) as the factors. The birds in the challenged groups were inoculated with Eimeria species on day 9 and with a fresh suspension of C. perfringens NE18 or NE36 on day 14 and 15. Sample collection was performed on 2 birds of each pen on day 16. Necrotic enteritis challenge, impaired feed conversion ratio during day 0 to 16 compared with the control group where the effect of the NE36 challenge was more severe than that with NE18 (P < 0.001). The mRNA expression of mucin-2, immunoglobulin-G, occludin (P < 0.001), and tight junction protein-1 (P < 0.05) genes were downregulated in both challenged groups compared with the nonchallenged counterparts. Antibiotic supplementation, on the other hand, increased weight gain, and feed intake in all challenged birds (P < 0.01), but upregulated mucin-5ac and alanine, serine, cysteine, and threonine transporter-1 (P < 0.05) only in the NE18 challenged birds. The challenge with NE36 significantly upregulated caspase-8 and claudin-1 (P < 0.001), but downregulated glucose transporter-2 (P < 0.001) compared with the NE18 challenge. These results suggest that NE challenge is detrimental to the performance of broilers through compromised intestinal health, and different C. perfringens strains can affect the severity of the disease through modulating the expression of intestinal genes encoding proteins responsible for apoptosis, gut integrity, immunity, mucus production, and nutrient transporters.

The Antimicrobial Peptide Cecropin AD Supplement Alleviated Soybean Meal-Induced Intestinal Inflammation, Barrier Damage, and Microbial Dysbiosis in Juvenile Turbot, Scophthalmus maximus

This study aimed to investigate the benefit of dietary cecropin AD (CAD) on the intestinal health of turbot (Scophthalmus maximus) fed diets with a high level of soybean meal. A 12-week feeding trial was conducted with four isonitrogenous and isolipidic diets: a fishmeal-based diet (FM), a diet replacing 40% fish meal protein of FM diet with soybean meal protein (SBM), and the SBM diet supplemented with 0.5 g/kg (C1) and 1.0 g/kg (C2) CAD, respectively. The results of histology of distal intestine (DI) showed that turbots fed the SBM diet exhibited distinct symptoms of enteritis. However, fish fed diets with CAD supplementation kept the normal appearance of the DI which was similar to that in FM group. Compared with the SBM group, diet with CAD supplementation significantly decreased the gene expression of intestinal pro-inflammatory cytokines tumor necrosis factor-α (tnf-α), interleukin-1β (il-1β), interferon-gamma (ifn-γ), and nuclear factor-kappa B p65 (nf-κb p65), while up-regulated the gene expression of intestinal tight junction proteins claudin-3, claudin-4, occludin, and zonula occludens-1 (zo-1). Besides, diet C1 shaped the intestinal microbiota profile toward an anti-inflammatory phenotype represented by the increased abundance of Blutia, Firmicutes/Bacteroides ratio, and decreased Prevotellaceae. In conclusion, dietary CAD could positively modulate the intestinal health of turbot from the impairment induced by soybean meal, which expands its application to help fish better adapt to the increasing plant protein level in aquafeed.

Highly nutritious diet resists Salmonella Typhimurium infections by improving intestinal microbiota and morphology in broiler chickens

Salmonella Typhimurium (S. Typhimurium) infection in broiler chickens threatens public health and livestock production. In this study, we explored the effects of highly nutritious (crude protein 21.8%, metabolizable energy 3.16 Mcal/kg) and lowly nutritious (crude protein 18.1%, metabolizable energy 2.98 Mcal/kg) diets on S. Typhimurium infection by altering the intestinal morphology and environment in broiler chickens. The highly nutritious diet significantly increased the body weight gain and reduced feed conversion ratio on day 1 to 21 (P < 0.01). The highly nutritious diets promoted the intestinal villus height, crypt depth, and their ratio to improve the intestinal epithelial maturation (P < 0.05). Highly nutritious diets significantly increased the expression of claudin-1, occludin, and NF-κB genes in the intestinal epithelium on the days of 14 and 21 (P < 0.05). S. Typhimurium activated the expression of TLR4, MyD88, and NF-κB genes to cause an inflammatory response. The S. Typhimurium can increase the activity of myeloperoxidase, which cause an inflammatory response. The S. Typhimurium significantly reduced the diversity indexes of the ileal microbiota (P < 0.05), increased the abundance of Cyanobacteria which can synthesize toxins. The highly nutritious diet group challenged with S. Typhimurium can increase the abundance of Lactobacillus in the ileum, which lead to improved intestinal health (P < 0.05). It is concluded that increasing the nutritional level of dietary is beneficial to improve the resistance to S. Typhimurium infection by altering the intestinal bacterial community.

Dietary administration of Enterococcus faecalis affects the growth, disease resistance and immune function of tilapia (Oreochromis niloticus)

The present study aimed to investigate the growth, disease resistance and immune function of tilapia (Oreochromis niloticus) fed diets containing Enterococcus faecalis at levels of 0 (CG), 1 × 105 (EF1), 1 × 106 (EF2), 1 × 107 (EF3) or 1 × 108 CFU/g diet (EF4) for 56 days. The results showed that the EF3 group exhibited significantly increases in the final weight, weight gain and specific growth rate and a significantly decreased feed conversion ratio compared with those obtained from the CG group. The cumulative mortality was significantly decreased in the EF2, EF3 and EF4 groups. Serum alkaline phosphatase activity and tumour necrosis factor α gene expression in the hindgut were significantly increased in the EF1, EF2 and EF3 groups, and the serum complement 3 (C3) and C4 contents were significantly increased in the EF2, EF3 and EF4 groups. The gene expression of interleukin receptor-associated kinase-4, Toll-like receptor 2 and myeloid differentiation factor 88, claudin1 and interleukin 8 were significantly upregulated in all EF groups, and the activity of diamine oxidase was significantly reduced in the EF3 and EF4 groups. The gene expression of occludin was significantly upregulated in the EF1 and EF3 groups, and that of interleukin 10 was significantly upregulated in the EF3 group. No differences in serum lysozyme, d- lactic acid or endotoxin were found among the groups. These results showed that the optimal level of dietary E. faecalis enhanced the growth performance and disease resistance, and those effects might be related to increased humoural and intestinal immunity in tilapia. The optimal supplementation level of dietary E. faecalis for tilapia was found to be 1 × 107 CFU/g.