mRNA Expression Of Occludin Research Articles

Protective effects of methylsulfonylmethane (MSM) on barrier function injury of porcine intestinal epithelial cells (IPEC-J2) induced by lipopolysaccharide (LPS)

Methylsulfonylmethane (MSM) is a natural organic sulfur component that has anti-inflammatory and antioxidant properties. In this study, injury of porcine intestinal epithelial cell (IPEC-J2) models were used to investigate the effect of MSM on lipopolysaccharide (LPS)-induced porcine intestinal epithelium barrier damage. The results of the cell cycle showed that the cells in the G2/M phase decreased significantly with the supplementation of 300 mmol/L MSM ( P < 0.05). The ELISA assay revealed that MSM could significantly inhibit the expression of tumor necrosis factor-alpha, interleukin-1, and interleukin-6 ( P < 0.01). Meanwhile, MSM could significantly increase the value of cell monolayer transepithelial electrical resistance while reducing the FITC-dextran flux permeability and lactate dehydrogenase activity in IPEC-J2 cells ( P < 0.01). Additionally, 300 mmol/L MSM significantly increased both mRNA and protein expression of occludin, claudin-1, and ZO-1 ( P < 0.05). Furthermore, MSM prevented the downregulation of epidermal growth factor receptor (EGFR) by LPS, indicating that MSM might enhance tight junction function through mechanisms of activation of EGFR-mediated protein synthesis in IPEC-J2 cells. Therefore, our findings suggested that MSM has protective effects on inflammation and epithelial barrier injury in LPS-induced IPEC-J2 cells, indicating that MSM might be used as a potential therapeutic agent in the pig industry.

Resveratrol alleviates oxidative stress induced by oxidized soybean oil and improves gut function via changing gut microbiota in weaned piglets

BackgroundOxidized soybean oil (OSO) has been shown to impair growth and exacerbate inflammation, leading to intestinal barrier injury in animals. Recent evidence suggests important roles for resveratrol (RES) in the promoting growth performance, antioxidant capacity, anti-inflammatory, and regulate intestinal barriers in animals. Therefore, The objectives of this study are to investigate the effects of dietary RES (purity 98%) supplementation on the growth performance, antioxidant capacity, inflammatory state, and intestinal function of weaned piglets challenged with OSO.MethodsA total of 28 castrated weaned male piglets with a similar body weight of 10.19 ± 0.10 kg were randomly assigned to 4 dietary treatments for 28-d feeding trial with 7 replications per treatment and 1 piglet per replicate. Treatments were arranged as a 2 × 2 factorial with oil type [3% fresh soybean oil (FSO) vs. 3% OSO] and dietary RES (0 vs. 300 mg/kg).ResultsThe results showed that relative to the FSO group, OSO stress tended to decrease the average daily feed intake (ADFI), and decreased the activity levels of lipase, villus/crypt ratio (VCR), the mRNA expression of FABP1, SOD2, IL-10 and ZO-1 in the jejunum, and SOD2, GPX1, occludin and ZO-1 in the colon, the levels of acetic acid in the colonic digesta, whereas up-regulated the mRNA expression of IL-1β and TNF-α in the jejunum (P < 0.05). Moreover, dietary supplementation with RES increased ether extract (EE), the activity levels of sucrase, lipase, α-amylase, villus height (VH) and VCR, the mRNA expression of FABP1, SOD2, IL-10 and occludin in the jejunum, and FABP1, PPAR-γ, GPX1, occludin and ZO-1 in the colon, and the abundance of Firmicutes, acetic and propionic acid, but decreased the levels of D-lactic acid in the plasma, the abundance of Bacteroidetes in the colonic digesta of weaned piglets compared to the non-RES group (P < 0.05). Meanwhile, in the interaction effect analysis, relative to the OSO group, dietary RES supplementation in the diets supplemented with OSO increased the activity levels of trypsin, VH in the jejunum, the abundance of Actinobacteria, the levels of butyric acid of weaned piglets, but failed to influence the activity levels of trypsin and VH, Actinobacteria abundance, the levels of butyric acid when diets were supplemented with FSO (interaction, P < 0.05). Relative to the OSO group, dietary RES supplementation in the diets supplemented with OSO decreased the activity levels of DAO in the plasma of weaned piglets but failed to influence the activity levels of DAO when diets were supplemented with FSO (interaction, P < 0.05). Relative to the FSO group, dietary RES supplementation in the diets supplemented with FSO decreased the level of propionic acid, whereas RES supplementation failed to influence the level of propionic acid when the diet was supplemented with OSO (interaction, P < 0.01).ConclusionsInclusion of OSO intensified inflammatory states and impaired the intestinal health characteristics of weaned piglets. Dietary RES supplementation improved the antioxidant capacity, anti-inflammatory activity, and intestinal morphology. Further studies showed that the protective effects of RES on gut health could be linked to the decreased abundance of Prevotella_1, Clostridium_sensu_stricto_6, and Prevotellaceae_UCG003 and increased levels of acetic and propionic acid.

Use of fermented Chinese medicine residues as a feed additive and effects on growth performance, meat quality, and intestinal health of broilers.

The purpose of this research was to investigate how dietary supplementation with fermented herbal residues (FCMR) affected birds' development capacity, quality of meat, gut barrier, and cecum microbiota. 540 cyan-shank partridge birds aged 47 days were chosen and divided into two groups of six replicates each and 45 birds for each replicate. The control group (CON) received a basal diet, while the trial group decreased a basic diet containing 5% FCMR. The findings revealed that the addition of FCMR decreased FCR and increased ADG in broilers (P < 0.05). Adding FCMR increased steaming loss in broiler chicken breasts (p < 0.05). Supplementation with FCMR significantly enhanced VH/CD and VH in the bird's intestine (jejunum, duodenum, and ileum) (p < 0.05). In addition, the addition of FCMR significantly down-regulated mRNA expression of INF-γ, IL-6, IL-1β, and TNF-α and up-regulated mRNA expression of ZO-1, Occludin, and Claudin (P < 0.05). Microbial 16S rDNA high-throughput sequencing study revealed that supplements with FCMR modified the cecum microbiota, and α-diversity analysis showed that supplementation with FCMR reduced the cecum bacterial abundance in broilers (P < 0.05). At the phylum level, the relative abundance of Spirochaetota increased considerably following FCMR supplementation (P < 0.05). The broiler cecum's close lot of Prevotellaceae_UCG-001 (P < 0.05), Desulfovibrio, Muribaculaceae, and Fusobacterium (p < 0.05) reduced when FCMR was supplemented. Supplementation with FCMR can promote growth capacity and maintain intestinal health in birds by enhancing gut barrier function and modulating the inflammatory response and microbial composition.

Colitis induced by PD-1 inhibitor combined with platinum-containing dual drug chemotherapy in Lewis mice and its mechanism.

To explore the occurrence and possible mechanism of colitis in Lewis mice treated with PD-1 inhibitor combined with platinum-containing dual drug chemotherapy. A Lewis lung cancer model of C57BL/6 mice was established, randomly divided into the treatment group (group C, PD-1 inhibitor + Carboplatin (CARB) + Pemetrexed (PEM)) and model group (group B, normal saline), and a control group (group A, normal saline) was set up. Observe the changes in tumor-free weight, tumor volume, disease activity index (DAI), colon histopathology, identify serum interleukin (IL)-10, interferon (IFN)-γ, the expression of claudin-1, and occludin mRNA in the colon in each animals. Compared with group A, the tumor-free weight of mice in B decreased (P < 0.001), the content of IL-10 in serum increased (P < 0.01), the content of IFN-γ in serum decreased (P < 0.01). Compared with group B, the transplanted tumor volume in C was reduced (P < 0.05), DAI scores of D4 (P < 0.001), and D7 (P < 0.001) were increased, colonic histopathology analysis showed that colitis occurred, serum IL-10 content was decreased (P < 0.05), IFN-γ content was increased (P < 0.05), and the mRNA expression of claudin-1 (P < 0.05) and occludin (P < 0.05) was reduced. This treatment can inhibit the growth of transplanted tumors but will cause colitis in Lewis mice. The impairment of intestinal barrier function following administration cause an imbalance in the expression of pro-inflammatory and anti-inflammatory factors in the colon, thus causing colitis.

Inflammation of Mesenteric Adipose Tissue Correlates with Intestinal Injury and Disease Severity in Rats with Severe Acute Pancreatitis.

Visceral adipose tissue (VAT) is related to SAP prognosis. As a depot of VAT, mesenteric adipose tissue (MAT) resides between pancreas and gut, which might affect SAP and the secondary intestinal injury. To investigate the changes of MAT in SAP. 24 SD rats were randomly divided into four groups. 18 rats in SAP group were euthanized in time gradients (6h, 24h, and 48h after modeling) and the others in control group. Blood samples and tissues of pancreas, gut, and MAT were taken for analysis. Compared to the control group, SAP rats appeared MAT inflammation, presenting higher mRNA expression of TNF-α and IL-6 and lower IL-10, and histological changes after 6h of modeling, which became worse over time. Flow cytometry showed that B lymphocytes increased in MAT after 24h of SAP modeling and lasted up to 48h, earlier than the changes of T lymphocytes and macrophages. The intestinal barrier integrity was damaged after 6h of modeling, presenting lower mRNA and protein expression of ZO-1 and occludin, higher serum levels of LPS and DAO, with pathological changes, which gradually aggravated after 24h and 48h. SAP rats had higher serum levels of inflammatory indicators and revealed histological inflammation of pancreas, the severity of which increased with the passage of modeling time. MAT appeared inflammation in early-stage SAP, and became worse over time, with the same trend as the intestinal barrier injury and the severity of pancreatitis. B lymphocytes infiltrated early in MAT, which might promote the MAT inflammation.

Dietary grape pomace extract supplementation improved meat quality, antioxidant capacity, and immune performance in finishing pigs.

In pig production, reducing production costs and improving immunity are important. Grape pomace, a good agricultural by-product, has been thrown away as food waste for a long time. Recently, we found that it could be used as a new source of pig feed. We investigated the effect of grape pomace on inflammation, gut barrier function, meat quality, and growth performance in finishing pigs. Our results indicated that treatment samples showed a significant decrease in water loss, IL-1β, DAO, ROS, and MDA content (p < 0.05). IgA, IgG, IgM, CAT, T-AOC, SOD, and IFN-γ significantly increased compared with those in control samples (p < 0.05). Meanwhile, the relative mRNA expression of the tight junction protein occludin showed a significant difference (p < 0.05). Analysis of metagenomic sequencing indicated that grape pomace significantly decreased the relative abundance of Treponema and Streptococcus (p < 0.05). In summary, our results demonstrated that grape pomace could improve meat quality, alleviate inflammation, and decrease oxidative stress.

Immunological effect of Lactic acid bacteria adjuvant on in ovo injection of Newcastle disease vaccine

In ovo immunization of chicken embryos with live vaccines is an effective strategy to protect chickens against various viral pathogens. The immunogenic efficacies of in ovo administration of lactic acid bacteria (LAB) in combination with live Newcastle disease (ND) vaccine were investigated in this study. Four hundred healthy 1-day-old fertilized specific pathogen-free (SPF) eggs of similar weights were randomly assigned to one of four treatments, with five replicates of each treatment and a total of 20 for each replicate. On day 18.5 of incubation, in ovo injections were given. The treatment groups are as follows: (I) no injection, (II) 0.9% physiological saline injection, (III) ND vaccine injection, and (IV) LAB as an adjuvant for ND vaccine injection. The ND vaccine adjuvanted with LAB significantly increased the daily weight gain, immune organ index, and small intestine histomorphological development in layer chicks while decreasing the feed conversion ratio (FCR). The results suggested that the LAB-adjuvant group significantly affected the relative expression of mucosal mucin protein (mucin-1) and zoccluding small circle protein-1 (ZO-1) (P < 0.05), whereas the relative expression of occludin mRNA was not significantly affected (P > 0.05) compared with the non-injected group. Meanwhile, we indicated that intra-amniotic synbiotic injection significantly maintained the balance of flora (P < 0.05). Compared with the non-injected group, the ND vaccine adjuvanted with the LAB group exhibited significant promotion of the HI and SIgA antibody titers in serum on day 21 (P < 0.05), induction of higher production of cytokines (IL-2, IL-4, IL-6, IFN-γ) in serum. In summary, in ovo injection of ND vaccine adjuvanted with LAB has a positive impact on the growth performance, immune function, and microbiome of growing chicks.

Oligosaccharides isolated from Rehmannia glutinosa protect LPS-induced intestinal inflammation and barrier injury in mice.

We investigated the protective effect of Rehmannia glutinosa oligosaccharides (RGO) on lipopolysaccharide (LPS)-induced intestinal inflammation and barrier injury among mice. RGO is prepared from fresh rehmannia glutinosa by water extraction, active carbon decolorization, ion exchange resin impurity removal, macroporous adsorption resin purification, and decompression drying. LPS could establish the model for intestinal inflammation and barrier injury in mice. Three different doses of RGO were administered for three consecutive weeks. Then the weight, feces, and health status of the mice were recorded. After sacrificing the mice, their colon length and immune organ index were determined. The morphological changes of the ileum and colon were observed using Hematoxylin-eosin (H&E) staining, followed by measuring the villus length and recess depth. RT-qPCR was utilized to detect the relative mRNA expression of intestinal zonula occludens-1 (ZO-1) and occludin. The expression of inflammatory factors and oxidation markers within ileum and colon tissues and the digestive enzyme activities in the ileum contents were detected using ELISA. The content of short-chain fatty acids (SCFAs) in the colon was determined with GC. The gut microbial composition and diversity changes were determined with 16S-rRNA high-throughput sequencing. The association between intestinal microorganisms and SCFAs, occludins, digestive enzymes, inflammatory factor contents, and antioxidant indexes was also analyzed. RGO significantly increased the weight, pancreatic index, thymus index, and colon length of mice compared with the model group. Moreover, it also improved the intestinal tissue structure and increased the expression of intestinal barrier-related junction proteins ZO-1 and Occludin. The contents of IL-6, IL-17, IL-1β, and TNF-α in the intestinal tissues of mice were significantly reduced. Additionally, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were elevated. In contrast, the malondialdehyde (MDA) content decreased. Trypsin and pancreatic lipase activities in the ileum enhanced, and the SCFA contents such as acetic acid, propionic acid, and butyric acid in the colon increased. The study on intestinal flora revealed that RGO could enhance the abundance of intestinal flora and improve the flora structure. After RGO intervention, the relative abundance of Firmicutes, Lactobacillus, and Akkermania bacteria in the intestinal tract of mice increased compared with the model group, while that of Actinomycetes decreased. The intestinal microbiota structure changed to the case, with probiotics playing a dominant role. The correlation analysis indicated that Lactobacillus and Ackermann bacteria in the intestinal tract of mice were positively associated with SCFAs, Occludin, ZO-1, pancreatic amylase, SOD, and CAT activities. Moreover, they were negatively correlated with inflammatory factors IL-6, IL-17, IL-1β, and TNF-α. RGO can decrease LPS-induced intestinal inflammation and intestinal barrier injury in mice and protect their intestinal function. RGO can ameliorate intestinal inflammation and maintain the intestinal barrier by regulating intestinal flora.

Effects of Hydrogen Peroxide-Induced Oxidative Stress on Intestinal Morphology, Redox Status, and Related Molecules in Squabs

The purpose of this study was to evaluate the potential effect of oxidative stress on the intestine of squabs, and to explore the molecular mechanisms. A total of 360 1-day-old squabs were divided evenly into five different groups (n = 72/group): control, negative control, low, medium, and high dose groups. On the 3rd, 5th, and 7th days, squabs in the control group were not effectively treated and the negative control group were intraperitoneally injected with normal saline, whereas the H2O2 group was injected with H2O2 of 2.0, 2.5, and 3.0 mmol/kg BW respectively. On the 21st day, the serum and duodenum were collected for further analysis. The results indicated that, compared with the control group, H2O2 caused squabs weight loss and intestinal morphology damage, and these effects were enhanced with an increase in dose. Further examination revealed that the contents of oxidative stress markers in both the serum and duodenum of the H2O2 group were significantly enhanced as the dose was increased. In addition, H2O2 exposure also resulted in the lower mRNA expression of Occludin, ZO-1, Beclin1, Atg5, and Caspase-3, but the expression of Claudin2 and Bcl-2 was decreased in comparison to the control group. These findings suggested that duodenal oxidative damage was accompanied by weight loss, changes in intestinal morphology, redox status imbalance, apoptosis as well as autophagy of intestinal cells, with, effects of 3.0 mmol/kg BW of H2O2 being the most severe.

Restorative effects of Acetobacter ghanensis on the pathogenicity of gliadin-induced modulation of tight junction-associated gene expression in intestinal epithelial cells

Background/Aim: At present, a gluten-free diet is the only efficient way to treat celiac disease (CD). The development of novel approaches to lessen or counteract the pathogenic effects of gluten remains crucial for the treatment of CD. The aim in this investigation was to examine the restorative effects of Acetobacter ghanensis as a novel probiotic against gliadin-induced modulation in the barrier integrity of an intestinal epithelial cell (IEC) model (Caco-2). Methods: Fully differentiated Caco-2 cell monolayers were subjected to enzymatically digested gliadin with a pepsin and trypsin (PT) in the presence or absence of A. ghanensis for 90 min. The relative amounts of zonulin, zonula occludens-1 (ZO-1), claudin-1, and occludin mRNA expression were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Transepithelial electrical resistance (TEER) was evaluated to monitor the barrier integrity of cell monolayers. Statistical analyses were carried out using one- or two-way ANOVA followed by Tukey’s post-hoc analysis for multiple pairwise comparisons. Results: A significant upregulation (4.7-fold) of zonulin was noted in the PT-gliadin treated Caco-2 cells in comparison with the untreated controls (P&lt;0.001). Conversely, gliadin-induced zonulin expression was markedly downregulated in the Caco-2 cells following exposure to A. ghanensis in the presence of PT-gliadin (P&lt;0.001). Furthermore, prominent decreases in the mRNA expression levels of ZO-1 (45%) and occludin (40%) were seen in the PT-gliadin exposed Caco-2 cells compared to the untreated control cells (P&lt;0.001). PT-gliadin in the Caco-2 cells did not significantly alter the mRNA levels of claudin-1 (P=0.172). Similarly to zonulin expression, the decreasing effect of PT-gliadin on ZO-1 was completely attenuated in the PT-gliadin-administrated Caco-2 cells following exposure to A. ghanensis (P&lt;0.001). Conclusion: A. ghanensis restored the pathogenicity of PT-gliadin on intestinal barrier integrity.

Effect of Dietary Supplemented with Mulberry Leaf Powder on Growth Performance, Serum Metabolites, Antioxidant Property and Intestinal Health of Weaned Piglets

Background: The study aimed to explore the effect of mulberry leaf powder (MP) on the performance, serum metabolites and antioxidant property, as well as intestinal health, of weaned piglets. A total of 120 healthy piglets weighing 8.43 ± 1.91 kg (Duroc × (Landrace × Yorkshire); weaned at 28 d) were chosen and classified into four treatments with three replicates of 10 piglets each based on a randomized complete block design (barrow:gilt = 1:1). The diet treatments were a corn-soybean meal basal diet added with 0% (Ctrl), 2% (MP_2), 4% (MP_4) and 6% MP (MP_6), respectively. The feeding experiment was 28 days in total. The feeding period lasted for 28 days in total. Results: The diet supplemented with 2% MP had no detrimental effects on the growth performance, immunity, enzyme capacity and inflammatory factors, as well as intestinal barrier function. MP_2 is capable of decreasing the levels of serum D-lactic acid and lactate dehydrogenase, enhancing the superoxide dismutase capacity in the liver and diminishing the potential pathogenic bacteria Allisonella in the colon. However, compared with MP_2, MP_6 had unfavorable effects on the average daily gain and average daily feed intake; the concentration of serum non-esterified fatty acids; the activities of superoxide dismutase and glutathione peroxidase and the capacity of lipase and amylase, as well as the intestinal barrier function-related mRNA expression of occludin, claudin-1 and mucin-2 in piglets. Conclusion: Taken together, piglets fed with 2% MP had no adverse effect and was capable of improving the serum metabolites, enhancing the antioxidant capacity (SOD) and lowering the potential pathogenic bacteria of the hindgut (Allisonella). However, the highest concentration of MP (6%) may cause detrimental effects for piglets, which are probably associated with the higher antinutritional factors and fiber. Therefore, the dietary supplementation of 2% MP for piglets may be advisable.

Encapsulated Essential Oils Improve the Growth Performance of Meat Ducks by Enhancing Intestinal Morphology, Barrier Function, Antioxidant Capacity and the Cecal Microbiota.

The objective of this study was to evaluate the effects of encapsulated essential oils (EOs) on the gut microbiota, growth performance, intestinal morphology, antioxidant properties and barrier function of meat-type ducks. A total of 320 male Cherry Valley ducks (1 day old), were randomly assigned to four dietary experimental groups with eight replicates of ten ducks each. The groups consisted of the CON group (basal diet), the HEO group (basal diet + EO 1000 mg/kg), the LEO group (basal diet + EO 500 mg/kg), and the ANT group (basal diet + chlortetracycline 50 mg/kg). Our findings indicated that ducks fed with EO 1000 mg/kg had greater average daily feed intake (ADFI), average daily gain (ADG), and body weight (BW) and a lower feed conversion ratio (FCR) than the other groups. The serum concentration of TG reduced in the HEO (p > 0.05) and LEO (p < 0.05) groups on day 42, while the concentration of CHOL increased with the EO concentration in the LEO (p > 0.05) and HEO (p < 0.05) groups. No differences were observed in the ileal mucosa for the activities of SOD, MPO and GSH-PX after EO dietary treatment. Dietary supplementation with EOs significantly increased the villus heights (p < 0.01) and the ratio of villus height to crypt depth (c/v) in the duodenum and jejunum of ducks. Moreover, the mRNA expressions of Claudin1 and Occludin in the jejunal mucosa were observed to be higher in the LEO and HEO groups rather than the CON and ANT groups on d 42. The α diversity showed that the HEO group improved the bacterial diversity and abundance. The β diversity analysis indicated that the microbial structures of the four groups were obviously separated. EO dietary supplementation could increase the relative abundance (p < 0.01) of the Bacteroidetes phylum, Bacteroidaceae family, and Bacteroides, Desulfovibrio, Phascolarctobacterium, and Butyricimonas genera in the cecal microbiota of ducks. We demonstrated significant differences in the bacterial composition and functional potential of the gut microbiota in ducks that were fed either an EO diet or a basal diet. Therefore, supplemented EOs was found to have a positive effect on the growth performance and intestinal health of ducks, which was attributed to the improvement in cecal microbiota, intestinal morphology, and barrier function.

Lactiplantibacillus plantarum BW2013 protects mucosal integrity and modulates gut microbiota of mice with colitis.

This study explored the effects of Lactiplantibacillus plantarum (previously Lactobacillus plantarum) BW2013 on mucosal integrity and gut microbiota of mice with dextran sulfate sodium (DSS)-induced colitis. The results show that the clinical symptoms in DSS-modelled ulcerative colitis (UC) were improved by L. plantarum BW2013 via decreasing disease activity index scores and suppressing inflammatory cell infiltration. Furthermore, L. plantarum BW2013 decreased the levels of diamine oxidase activity, myeloperoxidase, and D-lactic acid. The mRNA expression of ZO-1, occludin, and claudin-1 was upregulated by L. plantarum BW2013, which also increased IL-10 and reduced TNF-α, IL-1β, and IL-6 in the colon. 16S rDNA sequencing showed that L. plantarum BW2013 enhanced α-diversity. L. plantarum BW2013 upregulated significantly the abundance of unidentfied Lachnospiraceae, Lactococcus, Rikenella, Lactobacillus, and Odoribacter, which had an inhibitory effect on inflammation and a protective effect on the integrity of the mucosa. These results demonstrate that L. plantarum BW2013 alleviates DSS-modelled UC by protecting mucosal integrity and ameliorating the composition of gut microbiota.

Green tea extract and Piper retrofractum attenuate deoxycholic acid-induced damage and enhance the tight junction barrier: An analysis in a Caco-2 cell culture model and a DSS coinduced mouse model

This study investigated the effect of green tea extract (GTE) and green tea–Piper retrofractum complex (GPX), on tight junctions (TJs) in a cellular model of deoxycholic acid (DCA)-induced intestinal barrier disruption and a mouse DSS + DCA-induced colitis model. Green tea and P. retrofractum were extracted and coadministered to examine the bioavailability and effects of combined catechins and piperine on colonic TJ damage. The ability of GPX to alleviate TJ damage was determined by comparing the transepithelial electrical resistance (TEER), FITC-dextran flux, and mRNA expression of TJ-related components and target expression pathway in the GTE and GPX groups. Compared with the DCA-treated group, the GTE- and GPX-treated groups showed significantly enhanced TEER, FITC-dextran flux, and TJ-related mRNA expression (p < 0.05). Cell treatment also downregulated the mRNA encoding bile acid receptor and decreased ERK1/2 phosphorylation. Compared with the GTE-treated group, the GPX-treated group showed higher mRNA expression of zonula occludens-1, occludin, claudin-3, and claudin-4; greater restoration of TJs, as determined by immunofluorescence; and better modulation of ERK1/2 activation. In the in vivo model, GPX-pretreated mice showed an improved intestinal damage index and colon length compared with mice in the other colitis-induced groups. Both extracts recovered the distal colon mRNA expression of zonula occludens-1 and claudin-1. These results suggest that GTE improves intestinal health by protecting TJs from secondary bile acid damage and that P. retrofractum may potentiate the bioactivity of green tea catechins.

Compound probiotics can improve intestinal health by affecting the gut microbiota of broilers.

Probiotics, as a widely used additive, have played a unique advantage in replacing antibiotic products. As a result, the probiotic effects on broiler development, intestinal flora, intestinal barrier, and immunity were assessed by this investigation. Four hundred and eighty 1-day-old Arbor Acres broilers were randomly allotted to 4 groups of 5 replicates with 24 broilers each. The control was fed only a basal corn-soybean meal diet. Probiotics I, probiotics II, and probiotics III were fed basal diet and 1, 5, and 10 g/kg compound probiotics (Lactobacillus casei: Lactobacillus acidophilus: Bifidobacterium = 1:1:2), respectively. We found that broilers in the compound probiotic group exhibited better growth performance and carcass characteristics compared with control, especially among probiotics III group. The intestinal barrier-related genes relative expression of Claudin, Occludin, MUC2, and ZO-1 mRNA in the probiotic group increased at 21 and 42 d compared with control, especially among probiotics III group (P < 0.05). The early gut immune-related genes (TLR2, TLR4, IL-1β, and IL-2) mRNA increased compared with control, while the trend at 42 d was completely opposite to that in the earlier stage (P < 0.05). Among them, probiotics III group showed the most significant changes compared to probiotics II group and probiotics I group. Select probiotics III group and control group for 16S rDNA amplicon sequencing analysis. The 16S rDNA amplicon sequencing results demonstrated that probiotics increased the relative abundance of beneficial microbes such as o_Bacteroidales, f_Rikenellaceae, and g_Alistipes and improved the cecum's gut microbiota of 42-day-old broilers. Additionally, adding the probiotics decreased the relative abundance of harmful microbes such as Proteobacteria. PICRUSt2 functional analysis revealed that most proteins were enriched in DNA replication, transcription, and glycolysis processes. Therefore, this study can provide theoretical reference value for probiotics to improve production performance, improve intestinal barrier, immunity, intestinal flora of broilers, and the application of probiotics.

Shoseiryuto Promotes the Formation of a Tight-Junction Barrier in Cultured Human Bronchial Epithelial Cells.

Shoseiryuto (SST) (Xiao-Qing-Long-Tang in Chinese) is an effective treatment for respiratory diseases, such as bronchial asthma and allergic rhinitis, but its effects on the bronchial tight-junction (TJ) barrier have not been clarified. This study aimed to evaluate the effect of SST on TJ-barrier function in human bronchial epithelial (16HBE) cells. The 16HBE cells were cultured in a culture medium without (control) and with SST in the absence and presence of bacterial endotoxin lipopolysaccharide (LPS) in transwell chambers. Transepithelial electrical resistance (TEER) and sodium fluorescein (Na-F) permeability of the cultured-cell monolayer were measured as TJ integrity markers. In addition, immunofluorescence staining and quantitative real-time polymerase chain reaction analysis were used to measure the expression of the TJ protein, occludin. SST increased TEER and decreased Na-F permeability of the 16HBE cell monolayers. Furthermore, SST increased both occludin mRNA and immunostained protein expressions, suggesting that SST has the effect of directly promoting epithelial TJ-barrier function. LPS decreased TEER, increased Na-F permeability, and decreased both occludin mRNA and protein expression. LPS-induced barrier dysfunction was completely blocked by pre/co- and posttreatment with SST. These results suggest that SST has protective and therapeutic effects against LPS-induced TJ-barrier damage. To our knowledge, these are the first results to demonstrate the protective and therapeutic effects conferred by TJ-barrier promoting, which may be a novel mechanism contributing to the efficacy of SST for respiratory diseases.

Aflatoxin B1 Induces Intestinal Barrier Dysfunction by Regulating the FXR-Mediated MLCK Signaling Pathway in Mice and in IPEC-J2 Cells

Aflatoxin B1 (AFB1) is a widespread mycotoxin in food and feed. Although the liver is the main target organ of AFB1, the intestine is the first exposure organ to AFB1. However, the mechanism by which AFB1 induced intestinal barrier dysfunction via regulating the farnesoid X receptor (FXR)-mediated myosin light chain kinase (MLCK) signaling pathway has rarely been studied. In vivo, AFB1 exposure significantly decreased the small intestine length and increased the intestinal permeability. Meanwhile, AFB1 exposure markedly suppressed the protein expressions of FXR, ZO-1, occludin, and claudin-1 and enhanced the protein expression of MLCK. In vitro, AFB1 exposure induced intestinal barrier dysfunction by the elevation in the FITC-Dextran 4 kDa flux and inhibition in the transepithelial electrical resistance in a dose-dependent manner. In addition, AFB1 exposure downregulated the mRNA and protein expressions of FXR, ZO-1, occludin, and claudin-1, redistributed the ZO-1 protein, and enhanced the protein expressions of MLCK and p-MLC. However, fexaramine (Fex, FXR agonist) pretreatment markedly reversed the AFB1-induced FXR activity reduction, MLCK protein activation, and intestinal barrier impairment in vitro and in vivo. Moreover, pretreatment with the inhibition of MLCK with ML-7 significantly alleviated the AFB1-induced intestinal barrier dysfunction and tight junction disruption in vitro. In conclusion, AFB1 induced intestinal barrier impairment via regulating the FXR-mediated MLCK signaling pathway in vitro and in vivo and provided novel insights to prevent mycotoxin poisoning in the intestine.

Synbiotic Intervention Ameliorates Oxidative Stress and Gut Permeability in an In Vitro and In Vivo Model of Ethanol-Induced Intestinal Dysbiosis

Alcoholic liver disease (ALD) alters gut microbiota and tight junctions, causing bacterial components to enter the portal vein and induce oxidative stress-induced inflammation in the liver. Only corticosteroids and liver transplants are treatment options for severe alcoholic hepatitis. ALD's pathophysiology is unknown. However, acetaldehyde's toxic effects cause oxidative stress and intestinal permeability. This study investigates the influence of a synbiotic (a combination of aged garlic extract (AGE) and Lactobacillus rhamnosus MTCC1423) on colonic oxidative stress and inflammation in ALD male Wistar rats and Caco2 cells. MDA measurement by HPLC in CaCo2 cells, blood serum, and colon tissue demonstrated that synbiotic treatment in the ALD model reduces oxidative stress. Further, fecal high-throughput 16S rRNA gene sequencing revealed the microbiome's shift towards Firmicutes in the synbiotic group compared to ethanol. In addition, DCFDA labeling and H/E staining demonstrate that the synbiotic is beneficial in inhibiting the development of ALD. In the colon, the synbiotic reduces the activation of CYP2E1 and the inflammatory markers TNF-a and IL-6 while elevating the mRNA expression of ZO-1, occludin, and IL-10. Synbiotics colonize Lactobacillus to restore barrier function and microbiota and reduce colon oxidative stress. Thus, a synbiotic combination can be used in ALD treatment.

Quercetin alleviates intestinal inflammation and improves intestinal functions via modulating gut microbiota composition in LPS-challenged laying hens

Quercetin, a well-known flavonoid, has been demonstrated to exert beneficial effects on intestinal functions and gut microbiota in birds. In this study, we investigated the effects of quercetin supplementation on inflammatory responses, intestinal barrier functions and gut microbial community in LPS-challenged laying hens. A total of two hundred eighty-eight 32-wk-old Jingfen No.6 laying hens were randomly assigned to 3 groups, the CON group, the LC group and the LQ group. LQ group was fed with 0.4 mg/kg quercetin and at the end of 12 wk, LC and LQ groups were challenged intraperitoneally with lipopolysaccharide (LPS). After LPS challenge, 8 birds of each group were randomly selected and sampled. LPS challenge induced an obvious intestinal mucosal injury, necrosis and shedding, while quercetin intervention maintained its structure. Quercetin significantly decreased the elevated malondialdehyde contents (P < 0.05), and increased the activity of total antioxidant capacity and glutathione peroxidase (P < 0.05) in intestinal mucosa of LPS-challenged laying hens. Quercetin rescued the LPS-induced decreases in goblet cell density and mucin2 expression levels (P < 0.05). There was a significant decline (P < 0.05) in the mRNA expression of Claudin1 and Occludin in intestinal mucosa of LPS-challenged layers, which could be alleviated (P < 0.05) by dietary quercetin. LPS challenge induced the increased expression levels (P < 0.05) of IL-1β and TLR-4 in intestinal mucosa, while these rises could be reversed (P < 0.05) following dietary quercetin supplementation. LPS challenge induced a shift in gut microenvironment, and quercetin addition could elevate the relative abundance of some short chain fatty acids (SCFA)-producing or health-promoting bacteria such as Phascolarctobacterium, Negativicutes, Selenomonadales, Megamonas, Prevotellaceae, and Bacteroides_salanitronis. In conclusion, dietary quercetin addition ameliorated the LPS challenge-induced intestinal inflammation and improved intestinal functions, possibly associated with its modulation on gut microbiota, particularly the increased population of SCFA-producing bacteria.

Dietary glycine supplementation prevents heat stress-induced impairment of antioxidant status and intestinal barrier function in broilers

This study tested the hypothesis that glycine improves intestinal barrier function through regulating oxidative stress in broilers exposed to heat stress. A total of 300 twenty-one-day-old female Arbor Acres broilers (600 ± 2.5g) was randomly allocated to 5 treatments (6 replicate of 10 birds each). The 5 treatments were as follows: the control group (CON) was kept under thermoneutral condition (24 ± 1°C) and was fed a basal diet. Broilers fed a basal diet and reared under high ambient temperature (HT) were considered as the HT group (34 ± 1°C for 8 h/d). Broilers fed a basal diet supplemented with 0.5%, 1.0%, and 2.0% glycine and exposed to HT were regarded as the HT+glycine treatments. The results exhibited that heat stress reduced growth performance, serum total antioxidant capacity (T-AOC), and glutathione (GSH) concentration (P < 0.05); increased activity of serum catalase (CAT) and the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) (P < 0.05). HT exposure led to downregulating the mRNA expression of NAD(P)H quinone dehydrogenase 1 (NQO1), Occludin, and zonula occludens-1 (ZO-1) (P < 0.05); enhanced the mRNA levels of Kelch-like ECH-associated protein 1 (Keap1), CAT, glutathione synthetase (GSS), and glutamate-cysteine ligase modifier subunit (GCLM) (P < 0.05); impaired the intestinal morphology (P < 0.05); and altered the diversity and community of gut microbiota (P < 0.05). The final body weight (FBW), ADFI, ADG, and gain-to-feed ratio (G: F) increased linearly or quadratically, and the antioxidant capacity was improved (P < 0.05) with glycine supplementation. Glycine treatment increased the villus height (VH), and villus height to crypt depth ratio (V/C) of the duodenum linearly or quadratically, and linearly increased the VH of jejunum and ileum. The mRNA expression of Occludin, and ZO-1 were increased linearly in the ileum mucosa of broilers subjected to HT. Collectively, these results demonstrated that glycine supplementation alleviates heat stress-induced dysfunction of antioxidant status and intestinal barrier in broilers.