Porcine small intestinal epithelial cell line (IPEC-J2) of rotavirus infection as a new model for the study of innate immune responses to rotaviruses and probiotics

The protective role of prebiotics and probiotics on diarrhea and gut damage in the rotavirus-infected piglets

Rotavirus is one of the pathogenic causes that induce diarrhea in young animals, especially piglets, worldwide. However, nowadays, there is no specific drug available to treat the disease, and the related vaccines have no obvious efficiency in some countries. Via analyzing the pathogenesis of rotavirus, it inducing diarrhea is mainly due to disturb enteric nervous system, destroy gut mucosal integrity, induce intracellular electrolyte imbalance, and impair gut microbiota and immunity. Many studies have already proved that prebiotics and probiotics can mitigate the damage and diarrhea induced by rotavirus infection in hosts. Based on these, the current review summarizes and discusses the effects and mechanisms of prebiotics and probiotics on rotavirus-induced diarrhea in piglets. This information will highlight the basis for the swine production utilization of prebiotics and probiotics in the prevention or treatment of rotavirus infection in the future.

Limosilactobacillus reuteri L26 BiocenolTM and its exopolysaccharide: Their influence on rotavirus-induced immune molecules in enterocyte-like cells

This study aimed to evaluate the immunomodulatory effect of the probiotic Limosilactobacillus reuteri L26 BiocenolTM (L26) and its purified exopolysaccharide (EPS) with respect to antiviral innate immune response. In our experiment, we used porcine epithelial IPEC-J2 cells as a model of the intestinal barrier in a homologous infection by porcine Rotavirus A strain OSU6 (RVA). The production of selected molecules of non-specific humoral immunity was evaluated at the mRNA level. The EPS alone significantly increased the level of interferon λ3 (IFN-λ3) mRNA in the non-infected IPEC-J2 cells (P < 0.001). We also tested whether the treatment of IPEC-J2 cells by L26 or EPS influences the replication of RVA by virus titration and real-time PCR. We found that a pre-treatment in combination with subsequent continuous stimulation has no influence on the RVA replication. However, both treatments significantly decreased the RVA-induced production of IFN-λ3 (P < 0.05) and the "SOS" cytokine interleukin 6 (IL-6; P < 0.01), already at the transcription level. In addition, the EPS treatment resulted in significantly increased IL-10 mRNA in the RVA-infected cells. In summary, we assume an immunoregulatory potential of L. reuteri L26 BiocenolTM and its EPS in the local intestinal antiviral immune response.

Microbial Community and Metabolome Analysis of the Porcine Intestinal Damage Model Induced by the IPEC-J2 Cell Culture-Adapted Porcine Deltacoronavirus (PDCoV) Infection

This study was conducted to elucidate the intestinal damage induced by the IPEC-J2 cell culture-passaged PDCoV. The results showed that PDCoV disrupted the intestinal structure and increased intestinal permeability, causing abnormalities in mucosal pathology. Additionally, PDCoV induced an imbalance in the intestinal flora and disturbed its stability. Microbial community profiling revealed bacterial enrichment (e.g., Proteobacteria) and reduction (e.g., Firmicutes and Bacteroidetes) in the PDCoV-inoculated piglet model. In addition, metabolomics analysis indicated that 82 named differential metabolites were successfully quantified, including 37 up-regulated and 45 down-regulated metabolites. Chenodeoxycholic acid, sphingosine, and oleanolic aldehyde levels were reduced in PDCoV-inoculated piglets, while phenylacetylglycine and geranylgeranyl-PP levels were elevated. Correlation analysis indicated a negative correlation between Escherichia-Shigella and choline, succinic acid, creatine, phenyllactate, and hippuric acid. Meanwhile, Escherichia-Shigella was positively correlated with acetylcholine, L-Glutamicacid, and N-Acetylmuramate. Roseburia, Lachnospiraceae_UCG-010, Blautia, and Limosilactobacillus were negatively and positively correlated with sphingosine, respectively. These data suggested PDCoV-inoculated piglets exhibited significant taxonomic perturbations in the gut microbiome, which may result in a significantly altered metabolomic profile.

Unraveling the Puzzle: Health Benefits of Probiotics-A Comprehensive Review

A growing number of probiotic-containing products are on the market, and their use is increasing. Probiotics are thought to support the health of the gut microbiota, which in turn might prevent or delay the onset of gastrointestinal tract disorders. Obesity, type 2 diabetes, autism, osteoporosis, and some immunological illnesses are among the conditions that have been shown to possibly benefit from probiotics. In addition to their ability to favorably affect diseases, probiotics represent a defense system enhancing intestinal, nutritional, and oral health. Depending on the type of microbial strain utilized, probiotics can have variable beneficial properties. Although many microbial species are available, the most widely employed ones are lactic acid bacteria and bifidobacteria. The usefulness of these bacteria is dependent on both their origin and their capacity to promote health. Probiotics represent a valuable clinical tool supporting gastrointestinal health, immune system function, and metabolic balance. When used appropriately, probiotics may provide benefits such as a reduced risk of gastrointestinal disorders, enhanced immunity, and improved metabolic health. Most popular probiotics, their health advantages, and their mode of action are the topic of this narrative review article, aimed to provide the reader with a comprehensive reappraisal of this topic matter.

Interferon-λ3 alleviates intestinal epithelium injury induced by porcine rotavirus in mice

Interferons are a group of glycoproteins that are expressed in various cell types in their inflammatory responses to infections. In this study, we explored the protective effects of porcine interferon-λ3 (PIFN-λ3) on intestinal inflammation and injury in mice induced by porcine rotavirus (PRV). BALB/c mice were administrated by PIFN-λ3 or phosphate buffer solution (PBS) for three days prior to PRV infection. We show that PRV infection caused acute inflammatory responses in mice, as indicated by increases in serum concentrations of inflammatory cytokines such as the interlukin-1β (IL-1β), interlukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) (P < 0.05). However, PIFN-λ3 administration not only decreased their concentrations but also elevated the concentrations of immunoglobulin (Ig) M and IgG in the PRV challenged mice (P < 0.05). PRV infection significantly decreased the jejunal villus height and the ratio of villus height to crypt depth (V/C); however, PIFN-λ3 treatment significantly elevated the villus height and the abundance of tight junction protein ZO-1 in the jejunum (P < 0.05). Moreover, PIFN-λ3 decreased the replication of PRV in the jejunal epithelium, but significantly increased the abundance of sIgA and the activities of maltase and sucrase in the PRV-challenged mice (P < 0.05). Interestingly, PIFN-λ3 elevated the expression levels of sodium/glucose cotransporter 1 (SGLT1) and mucin 2 (MUC2) in the PRV-challenged mice (P < 0.05). Moreover, PIFN-λ3 significantly increased the expression levels of IL-10, signal transducer and activator of transcription 1 (STAT1), and critical interferon-stimulated genes such as the 2'-5' oligoadenylate synthetase-like 1 (OASL1), interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) and radical S-adenosyl methionine domain containing 2 (RSAD2) in the jejunum upon PRV infection (P < 0.05). The anti-virus and anti-inflammatory effect of PIFN-λ3 should make it an attractive candidate to prevent various pathogen-induced bowel diseases.

Sodium butyrate protects against rotavirus-induced intestinal epithelial barrier damage by activating AMPK-Nrf2 signaling pathway in IPEC-J2 cells

Rotavirus (RV) mainly infects intestinal epithelial cells, which leads to diarrhea in newborn piglets with dysfunction in the intestinal mucosal mechanical barrier. Sodium butyrate (SB) is one of the metabolites excreted by gut microbes. However, the protective effect of SB on RV infection induced intestinal mucosal mechanical barrier injury and its potential mechanism has not been well elucidated. In the present study, IPEC-J2 cells with RV infection was a model of intestinal mucosal mechanical barrier injury. Our results demonstrated that the appropriate concentration of SB can effectively alleviate TJ structural damage and up-regulating the expression of TJ-related genes. Furthermore, the appropriate concentration of SB can effectively reverse the increase of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) level induced by RV infection. Meanwhile, the levels of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-px) and antioxidant proteins NAD(P)H dehydrogenase quinone 1 (NQO1) and heme oxygenase-1 (HO-1) were increased through SB treatment. In addition, we found that SB increased cellular antioxidant capacity by activating the adenosine monophosphate-activated protein kinase (AMPK)-nuclear factor erythroid 2-related factor (Nrf2) signaling pathway and the cytoprotective effect of SB is limited by GPR109A siRNA. Thus, our findings revealed that SB reduces oxidative stress caused by RV infection and restores the intestinal mucosal mechanical barrier function by activating the AMPK-Nrf2 signal pathway mediated by the receptor GPR109A.

Anti-rotavirus Properties and Mechanisms of Selected Gram-Positive and Gram-Negative Probiotics on Polarized Human Colonic (HT-29) Cells

Probiotics have been investigated to improve the universal rotavirus (RV) vaccination as well as to ameliorate the RV infection. However, underlying mechanisms how probiotics mediate beneficial effects needs more investigation. Thus, in the present study, we used polarized HT-29 cells to assess the anti-RV properties of Gram-positive, (Lactobacillus acidophilus, Lacticaseibacillus rhamnosus GG, and Bifidobacterium subsp. Lactis Bb12) and Gram negative, (Escherichia coli Nissle 1917) probiotics and study their underlying mechanisms. Our results showed that pre-treatment of HT-29 cells for 4 h with probiotics, significantly reduced (p < 0.05) human RV replication and this effect was most pronounced for E. coli Nissle followed by L. acidophilus and L. rhamnosus GG. Strikingly, only pre-treatment with live bacteria or their supernatants demonstrated anti-RV properties. Except Gram negative E. coli Nissle, the Gram-positive probiotics tested did not bind to RV. Ingenuity pathway analysis of tight junction (TJ)- and innate immune-associated genes indicated that E. coli Nissle or E. coli Nissle + RV treatments improved cell-cell adhesion and cell contact, while L. acidophilus or L. acidophilus + RV treatments also activated cell-cell contact but inhibited cell movement functions. RV alone inhibited migration of cells event. Additionally, E. coli Nissle activated pathways such as the innate immune and inflammatory responses via production of TNF, while RV infection activated NK cells and inflammatory responses. In conclusion, E. coli Nissle's ability to bind RV, modulate expression of TJ events, innate immune and inflammatory responses, via specific upstream regulators may explain superior anti-RV properties of E. coli Nissle. Therefore, prophylactic use of E. coli Nissle might help to reduce the RV disease burden in infants in endemic areas.

Decreased S100A9 expression alleviates Clostridium perfringens beta2 toxin-induced inflammatory injury in IPEC-J2 cells

Background

S100 calcium-binding protein A9 (S100A9) is a commonly known pro-inflammatory factor involved in various inflammatory responses. Clostridium perfringens (C. perfringens ) type C is known to cause diarrhea in piglets. However, the role of S100A9 in C. perfringens type C-induced infectious diarrhea is unclear.

Methods

Here, the S100A9 gene was overexpressed and knocked down in the IPEC-J2 cells, which were treated with C. perfringens beta2 (CPB2) toxin. The role of S100A9 in CPB2 toxin-induced injury in IPEC-J2 cells was assessed by measuring the levels of inflammatory cytokines, reactive oxygen species (ROS), lactate dehydrogenase (LDH), cell proliferation, and tight junction-related proteins.

Results

The results showed elevated expression of S100A9 in diarrhea-affected piglet tissues, and the elevation of S100A9 expression after CPB2 toxin treatment of IPEC-J2 was time-dependent. In CPB2 toxin-induced IPEC-J2 cells, overexpression of S100A9 had the following effects: the relative expression of inflammatory factors IL-6, IL8, TNF-α, and IL-1β was increased; the ROS levels and LDH viability were significantly increased; cell viability and proliferation were inhibited; the G0/G1 phase cell ratio was significantly increased. Furthermore, overexpression of S100A9 reduced the expression of tight junction proteins in CPB2-induced IPEC-J2 cells. The knockdown of S100A9 had an inverse effect. In conclusion, our results confirmed that S100A9 exacerbated inflammatory injury in CPB2 toxin-induced IPEC-J2 cells, inhibited cell viability and cell proliferation, and disrupted the tight junctions between cells. Thus, decreased S100A9 expression alleviates CPB2 toxin-induced inflammatory injury in IPEC-J2 cells.

Different Mechanisms Are Utilized by Coronavirus Transmissible Gastroenteritis Virus To Regulate Interferon Lambda 1 and Interferon Lambda 3 Production

Type III interferons (IFN-λ) are shown to be preferentially produced by epithelial cells, which provide front-line protection at barrier surfaces. Transmissible gastroenteritis virus (TGEV), belonging to the genus Alphacoronavirus of the family Coronaviridae, can cause severe intestinal injuries in porcine, resulting in enormous economic losses for the swine industry, worldwide. Here, we demonstrated that although IFN-λ1 had a higher basal expression, TGEV infection induced more intense IFN-λ3 production in vitro and in vivo than did IFN-λ1. We explored the underlying mechanism of IFN-λ induction by TGEV and found a distinct regulation mechanism of IFN-λ1 and IFN-λ3. The classical RIG-I-like receptor (RLR) pathway is involved in IFN-λ3 but not IFN-λ1 production. Except for the signaling pathways mediated by RIG-I and MDA5, TGEV nsp1 induces IFN-λ1 and IFN-λ3 by activating NF-κB via the unfolded protein responses (UPR) PERK-eIF2α pathway. Furthermore, functional domain analysis indicated that the induction of IFN-λ by the TGEV nsp1 protein was located at amino acids 85 to 102 and was dependent on the phosphorylation of eIF2α and the nuclear translocation of NF-κB. Moreover, the recombinant TGEV with the altered amino acid motif of nsp1 85-102 was constructed, and the nsp1 (85-102sg) mutant virus significantly reduced the production of IFN-λ, compared with the wild strain. Compared to the antiviral activities of IFN-λ1, the administration of IFN-λ3 showed greater antiviral activity against TGEV infections in IPEC-J2 cells. In summary, our data point to the significant role of IFN-λ in the host innate antiviral responses to coronavirus infections within mucosal organs and in the distinct mechanisms of IFN-λ1 and IFN-λ3 regulation. IMPORTANCE Coronaviruses cause infectious diseases in various mammals and birds and exhibit an epithelial cell tropism in enteric and respiratory tracts. It is critical to explore how coronavirus infections modulate IFN-λ, a key innate cytokine against mucosal viral infection. Our results uncovered the different processes of IFN-λ1 and IFN-λ3 production that are involved in the classical RLR pathway and determined that TGEV nsp1 induces IFN-λ1 and IFN-λ3 production by activating NF-κB via the PERK-eIF2α pathway in UPR. These studies highlight the unique regulation of antiviral defense in the intestine during TGEV infection. We also demonstrated that IFN-λ3 induced greater antiviral activity against TGEV replication than did IFN-λ1 in IPEC-J2 cells, which is helpful in finding a novel strategy for the treatment of coronavirus infections.

Comparison between Lactobacillus rhamnosus GG and LuxS-deficient strain in regulating gut barrier function and inflammation in early-weaned piglets

Background

Early weaning-induced stress impairs the intestinal barrier function and adversely affects the health of piglet. Probiotics can be used to prevent and treat various intestinal diseases. Lactobacillus rhamnosus GG (LGG) has an LuxS/AI-2 quorum sensing (QS) system that senses environmental changes through chemical signaling molecules. The aim of the study was to explore whether luxS mutant affects the protective role of LGG in the gut barrier of weaned piglets by comparing the luxS mutant (ΔluxS) with its wild-type (WT).

Methods

Newborn piglets were orally administered with WT and ΔluxS at dosage of 10⁹ CFU, respectively. Accordingly, newborn piglets in the Con group were orally administered with PBS. Piglets were weaned on day 21 and euthanized on day 24, three days following weaning.

Results

Supplementation of ΔluxS in advance significantly boosted the relative abundances of healthy microbes (including Catenibacterium, Eubacterium, Lachnospiraceae and Bifidobacterium). WT and ΔluxS maintain intestinal barrier function mainly by promoting intestinal villus to crypt ratio (VCR), occludin protein expression and mucus secretion (P<0.05). Furthermore, LGG reduces pro-inflammatory mediators by inhibiting TLR4 and MAPK signal transduction (P<0.05).

Conclusion

Both WT and ΔluxS were shown to resist weaning stress by enhancing the intestinal barrier function of piglets. It has to be said that the ability of ΔluxS to maintain intestinal tissue morphology and promote mucus secretion significantly decreased compared with that of WT.

TGF-β from the Porcine Intestinal Cell Line IPEC-J2 Induced by Porcine Circovirus 2 Increases the Frequency of Treg Cells via the Activation of ERK (in CD4+ T Cells) and NF-κB (in IPEC-J2)

Porcine circovirus 2 (PCV2) causes immunosuppression. Piglets infected with PCV2 can develop enteritis. Given that the gut is the largest immune organ, however, the response of the gut's immune system to PCV2 is still unclear. Here, IPEC-J2 cells with different treatments were co-cultured with PBMC or CD4⁺ T cells (Transwell). Flow cytometry and Western blotting revealed that PCV2-infected IPEC-J2 increased the frequency of CD4⁺ T cells among piglets' peripheral blood mononuclear cells (PBMCs) and caused CD4⁺ T cells to undergo a transformation into Foxp3⁺ regulatory T cells (Treg cells) via activating CD4⁺ T ERK. Cytokines production and an inhibitor assay showed that the induction of Tregs by PCV2-infected IPEC-J2 was dependent on TGF-β induced by PCV2 in IPEC-J2, which was associated with the activation of NF-κB. Taken together, PCV2-infected IPEC-J2 activated NF-κB to stimulate the synthesis of TGF-β, which enhanced the differentiation of CD4⁺ T cells into Treg cells through the activation of ERK in CD4⁺ T cells. This information sheds light on PCV2's function in the intestinal immune system and suggests a potential immunosuppressive mechanism for PCV2 infection.

Porcine deltacoronavirus E protein induces interleukin-8 production via NF-κB and AP-1 activation

Infection induces the production of proinflammatory cytokines and chemokines such as interleukin-8 (IL-8) and interleukin-6 (IL-6). Although they facilitate local antiviral immunity, their excessive release leads to life-threatening cytokine release syndrome, exemplified by the severe cases of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In the present study, we found that interleukin-8 (IL-8) was upregulated by PDCoV infection. We then demonstrated that PDCoV E protein induced IL-8 production and that the TM domain and the C-terminal domain of the E protein were important for IL-8 production. Subsequently, we showed here that deleting the AP-1 and NF-κB binding motif in porcine IL-8 promoter abrogated its activation, suggesting that IL-8 expression was dependent on AP-1 and NF-κB. Furthermore, PDCoV E induced IL-8 production, which was also dependent on the NF-κB pathway through activating nuclear factor p65 phosphorylation and NF-κB inhibitor alpha (IκBα) protein phosphorylation, as well as inducing the nuclear translocation of p65, eventually resulting in the promotion of IL-8 production. PDCoV E also activated c-fos and c-jun, both of which are members of the AP-1 family. These findings provide new insights into the molecular mechanisms of PDCoV-induced IL-8 production and help us further understand the pathogenesis of PDCoV infection.

Heat-labile enterotoxin enhances F4-producing enterotoxigenic E. coli adhesion to porcine intestinal epithelial cells by upregulating bacterial adhesins and STb enterotoxin

As one of the crucial enterotoxins secreted by enterotoxigenic Escherichia coli (ETEC), heat-labile enterotoxin (LT) enhances bacterial adherence both in vivo and in vitro; however, the underlying mechanism remains unclear. To address this, we evaluated the adherence of LT-producing and LT-deficient ETEC strains using the IPEC-J2 cell model. The expression levels of inflammatory cytokines and chemokines, and tight-junction proteins were evaluated in IPEC-J2 cells after infection with various ETEC strains. Further, the levels of adhesins and enterotoxins were also evaluated in F4ac-producing ETEC (F4 + ETEC) strains after treatment with cyclic AMP (cAMP). The adherence of the ΔeltAB mutant was decreased compared with the wild-type strain, whereas adherence of the 1836-2/pBR322-eltAB strain was markedly increased compared with the 1836-2 parental strain. Production of LT up-regulated the expression of TNF-α, IL-6, CXCL-8, and IL-10 genes. However, it did not appear to affect tight junction protein expression. Importantly, we found that cAMP leads to the upregulation of adhesin production and STb enterotoxin. Moreover, the F4 + ETEC strains treated with cAMP also had greater adhesion to IPEC-J2 cells, and the adherence of ΔfaeG, ΔfliC, and ΔestB mutants was decreased. These results indicate that LT enhances the adherence of F4 + ETEC due primarily to the upregulation of F4 fimbriae, flagellin, and STb enterotoxin expression and provide insights into the pathogenic mechanism of LT and ETEC.

The Growth Medium Affects the Viability of IPEC-J2 Animal Cell Line in the Presence of Probiotic Bacteria

Background: The IPEC-J2 cell line is frequently used as an in vitro model to study the bioactivity of live probiotics. However, lactic acid bacteria (LB) acidify the medium, and the impact of pH and lactic acid accumulation on cell viability seem to be underestimated. Methods: IPEC-J2 viability was assessed by neutral red and flow cytometry in the presence of eight probiotics at concentrations between 106 and 109 bacteria/mL in maintenance and buffered media. Results: It was shown that a high inoculation level led to higher cytotoxic effects on IPEC-J2 cells after 22 h of incubation and that viability losses were more related to a combination of low pH and lactic acid than to the probiotics themselves. Furthermore, with LB at 106 and 107 bacteria/mL, the addition of phosphates to the media significantly reduced the drop in the pH and preserved the IPEC-J2 viability between 100% and 69%, compared to a highly variable viability between 100% and 17.5% in the unbuffered media. Conclusions: Under certain in vitro conditions, probiotics can lead to the deterioration of animal cells, and pH neutralization is an essential parameter in the cell–probiotic system in order to preserve cell viability and to better evaluate the bioactive properties of live probiotics.

Effect of probiotic bacteria on porcine rotavirus OSU infection of porcine intestinal epithelial IPEC-J2 cells

Rotavirus infections in nursing or post-weaning piglets are known to cause diarrhea, which can lead to commercial losses. Probiotic supplementation is used as a prophylactic or therapeutic approach to dealing with microbial infections in humans and animals. To evaluate the effect of probiotic bacteria on porcine rotavirus infections, non-transformed porcine intestinal epithelial IPEC-J2 cells were used as an in vitro model, and three different procedures were tested. When cells were exposed to seven probiotics at concentrations of 105, 106, or 107 CFU/mL for 16 h and removed before rotavirus challenge, infection reduction rates determined by flow cytometry were as follows: 15% (106) and 18% (105) for Bifidobacterium longum R0175, 15% (107) and 16% (106) for B. animalis lactis A026, and 15% (105) for Lactobacillus plantarum 299V. When cells were exposed to three selected probiotic strains for 1 h at higher concentrations, that is, 108 and 5 × 108 CFU/mL, before infection with rotavirus, no significant reduction was observed. When the probiotic bacteria were incubated with the virus before cell infection, a significant 14% decrease in the infection rate was observed for B. longum R0175. The results obtained using a cell-probiotics-virus platform combined with flow cytometry analysis suggest that probiotic bacteria can have a protective effect on IPEC-J2 cells before infection and can also prevent rotavirus infection of the cells.

Probiotic as Adjuvant Significantly Improves Protection of the Lanzhou Trivalent Rotavirus Vaccine against Heterologous Challenge in a Gnotobiotic Pig Model of Human Rotavirus Infection and Disease

This preclinical study in the gnotobiotic (Gn) pig model of human rotavirus (HRV) infection and disease evaluates the effect of probiotic Lactobacillus rhamnosus GG (LGG) as a mucosal adjuvant on the immunogenicity and cross-protective efficacy of the Lanzhou live oral trivalent (G2, G3, G4) vaccine (TLV, aka LLR3). Gn pigs were immunized with three doses of TLV with or without concurrent administration of nine doses of LGG around the time of the first dose of the TLV vaccination, and were challenged orally with the virulent heterotypic Wa G1P[8] HRV. Three doses of TLV were highly immunogenic and conferred partial protection against the heterotypic HRV infection. LGG significantly enhanced the intestinal and systemic immune responses and improved the effectiveness of protection against the heterotypic HRV challenge-induced diarrhea and virus shedding. In conclusion, we demonstrated the immune-stimulating effects of probiotic LGG as a vaccine adjuvant and generated detailed knowledge regarding the cross-reactive and type-specific antibody and effector B and T cell immune responses induced by the TLV. Due to the low cost, ease of distribution and administration, and favorable safety profiles, LGG as an adjuvant has the potential to play a critical role in improving rotavirus vaccine efficacy and making the vaccines more cost-effective.

Probiotic as a Potential Gut Microbiome Modifier for Stroke Treatment: A Systematic Scoping Review of In Vitro and In Vivo Studies

BACKGROUND

Pharmacologic and non-pharmacologic treatments for stroke are essential but can be costly or harmful, whereas probiotics are a promising alternative. This scoping review aimed to synthesize the in vitro and in vivo evidence of probiotics on stroke-related neurological, biochemical, and histochemical outcomes.

METHODS

A systematic review was conducted in PubMed, Embase, and Cochrane Central Register of Clinical Trials (CENTRAL) up to 7 May 2021. Titles and abstracts were screened and assessed by two independent reviewers. The initial screening criteria aimed to include studies using probiotics, prebiotics, and symbiotics both in vitro and in vivo for the prevention and/or treatment of stroke.

RESULTS

Of 6293 articles, 4990 passed the initial screen after excluding duplication articles, of which 36 theme-related full texts were assessed and 13 were included in this review. No in vitro studies passed the criteria to be included in this review. Probiotics can ameliorate neurological deficits and show their anti-inflammation and anti-oxidative properties. Decreased loss of cerebral volume and inhibition of neuronal apoptosis were revealed in histopathological evidence.

CONCLUSIONS

There are potential cognitive benefits of probiotic supplementation, especially among animal models, on decreasing cerebral volume, increasing neurological score, and decreasing the inflammatory response. However, further investigation is needed to validate these conclusions in various populations.

Stromal Antigen 2 Deficiency Induces Interferon Responses and Restricts Porcine Deltacoronavirus Infection

Porcine deltacoronavirus (PDCoV) is a recently discovered enteropathogenic coronavirus and has caused significant economic impacts on the pork industry. Although studies have partly uncovered the molecular mechanism of PDCoV-host interaction, it requires further research. In this study, we explored the roles of Stromal Antigen 2 (STAG2) in PDCoV infection. We found that STAG2-deficient cells inhibited infection with vesicular stomatitis virus (VSV) and PDCoV, whereas restoration of STAG2 expression in STAG2-depleted (STAG2-/-) IPEC-J2 cells line restored PDCoV infection, suggesting that STAG2 is involved in the PDCoV replication. Furthermore, we found that STAG2 deficiency results in robust interferon (IFN) expression. Subsequently, we found that STAG2 deficiency results in the activation of JAK-STAT signaling and the expression of IFN stimulated gene (ISG), which establish an antiviral state. Taken together, the depletion of STAG2 activates the JAK-STAT signaling and induces the expression of ISG, thereby inhibiting PDCoV replication. Our study provides new insights and potential therapeutic targets for unraveling the mechanism of PDCoV replication.

Potential Substitutes of Antibiotics for Swine and Poultry Production

Early of the last century, it was detected that antibiotics added to the animal feeds at low doses and for a long time can improve technical performances such as average daily gain and gain-to-feed ratio. Since then, the antibiotics have been used worldwide as feed additives for many decades. At the end of the twentieth century, the consequences of the uses of antibiotics in animal feeds as growth promoters were informed. Since then, many research studies have been done to find other solutions to replace partly or fully to antibiotic as growth promoters (AGPs). Many achievements in finding alternatives to AGPs in which probiotics and direct-fed microorganism, prebiotics, organic acids and their salts, feed enzymes, bacteriophages, herbs, spices, and other plant extractives (phytogenics), mineral and essential oils are included.

Antiviral Activity of Porcine IFN-λ3 and IFN-α against Porcine Rotavirus In Vitro

Interferons (IFNs) play a major role in the host's antiviral innate immunity. In response to viral infection, IFNs bind their receptors and initiate a signaling cascade, leading to the accurate transcriptional regulation of hundreds of IFN-stimulated genes (ISGs). Porcine rotavirus (PoRV) belongs to genus Rotavirus of the Reoviridae family; the infection is a global epidemic disease and a major threat to the pig industry. In this study, we found that IFN-λ3 inhibited the replication of PoRV in both MA104 cells and IPEC-J2 cells, and this inhibition was dose-dependent. Furthermore, the antiviral activity of IFN-λ3 was more potent in IPEC-J2 cells than in MA104 cells. Further research showed that IFN-λ3 and IFN-α might inhibit PoRV infection by activating ISGs, i.e., MxA, OASL and ISG15, in IPEC-J2 cells. However, the co-treatment of IFN-λ3 and IFN-α did not enhance the antiviral activity. Our data demonstrated that IFN-λ3 had antiviral activity against PoRV and may serve as a useful antiviral candidate against PoRV, as well as other viruses in swine.

Porcine and Chicken Intestinal Epithelial Cell Models for Screening Phytogenic Feed Additives—Chances and Limitations in Use as Alternatives to Feeding Trials

Numerous bioactive plant additives have shown various positive effects in pigs and chickens. The demand for feed additives of natural origin has increased rapidly in recent years to support the health of farm animals and thus minimize the need for antibiotics and other drugs. Although only in vivo experiments can fully represent their effect on the organism, the establishment of reliable in vitro methods is becoming increasingly important in the goal of reducing the use of animals in experiments. The use of cell models requires strict control of the experimental conditions so that reliability and reproducibility can be achieved. In particular, the intestinal porcine epithelial cell line IPEC-J2 represents a promising model for the development of new additives. It offers the possibility to investigate antioxidative, antimicrobial, anti- or pro-proliferative and antiviral effects. However, the use of IPEC-J2 is limited due to its purely epithelial origin and some differences in its morphology and functionality compared to the in vivo situation. With regard to chickens, the development of a reliable intestinal epithelial cell model has attracted the attention of researchers in recent years. Although a promising model was presented lately, further studies are needed to enable the standardized use of a chicken cell line for testing phytogenic feed additives. Finally, co-cultivation of the currently available cell lines with other cell lines and the development of organoids will open up further application possibilities. Special emphasis was given to the IPEC-J2 cell model. Therefore, all publications that investigated plant derived compounds in this cell line were considered. The section on chicken cell lines is based on publications describing the development of chicken intestinal epithelial cell models.

Immunomodulation Potential of Probiotics: A Novel Strategy for Improving Livestock Health, Immunity, and Productivity

Over the past decade, the use of probiotics as feed supplements in animal production has increased considerably due to the ban on antibiotic growth promoters in livestock. This review provides an overview of the current situation, limitation, and prospects for probiotic formulations applied to livestock. Recently, the use of probiotics in livestock has been suggested to significantly improve their health, immunity, growth performance, nutritional digestibility, and intestinal microbial balance. Furthermore, it was reported that the use of probiotics in animals was helpful in equilibrating their beneficial microbial population and microbial turnover via stimulating the host immune response through specific secretions and competitive exclusion of potentially pathogenic bacteria in the digestive tract. Recently, there has been great interest in the understanding of probiotics targeted diet and its ability to compete with harmful microbes and acquire their niches. Therefore, the present review explores the most commonly used probiotic formulations in livestock feed and their effect on animal health. In summary, this article provides an in-depth knowledge about the formulation of probiotics as a step toward a better alternative to antibiotic healthy growth strategies.

Differential effects of orally administered <i>Lactobacillus acidophilus</i> L-55 on the gene expression of cytokines and master immune switches in the ileum and spleen of laying hen with an attenuated Newcastle disease virus vaccine

This study aimed to evaluate the benefits of oral administration of Lactobacillus acidophilus strain L-55 (LaL-55) to chickens inoculated with a Newcastle disease virus (NDV)-based live-attenuated vaccine by examining the mRNA expression of several genes related to viral infection in the spleen and ileum by quantitative reverse transcription polymerase chain reaction. In the spleen, interferon (IFN)-α was significantly higher in the low- and middle-dose LaL-55 groups at 6 weeks than at 4 weeks. IFN regulatory factor (IRF)-3 and IRF-7 expression was significantly higher in the low-dose LaL-55 group than in the middle- and high-dose LaL-55 groups. In the ileum, melanoma differentiation-associated gene 5 showed a dose-dependent increase at 4 weeks. IFN-γ and IRF-7 showed dose-dependent increases at 6 weeks. These results suggested that LaL-55 boosts the immune response to the NDV vaccine, albeit by different mechanisms in the spleen and ileum.

Nutritional and Health Potential of Probiotics: A Review

Several products consist of probiotics that are available in markets, and their potential uses are growing day by day, mainly because some strains of probiotics promote the health of gut microbiota, especially Furmicutes and Bacteroidetes, and may prevent certain gastrointestinal tract (GIT) problems. Some common diseases are inversely linked with the consumption of probiotics, i.e., obesity, type 2 diabetes, autism, osteoporosis, and some immunological disorders, for which the disease progression gets delayed. In addition to disease mitigating properties, these microbes also improve oral, nutritional, and intestinal health, followed by a robust defensive mechanism against particular gut pathogens, specifically by antimicrobial substances and peptides producing probiotics (AMPs). All these positive attributes of probiotics depend upon the type of microbial strains dispensed. Lactic acid bacteria (LAB) and Bifidobacteria are the most common microbes used, but many other microbes are available, and their use depends upon origin and health-promoting properties. This review article focuses on the most common probiotics, their health benefits, and the alleviating mechanisms against chronic kidney diseases (CKD), type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM), and obesity.

Low crude protein diets supplemented with casein hydrolysate enhance the intestinal barrier function and decrease the pro-inflammatory cytokine expression in the small intestine of pigs

To reduce nitrogen excretion and lower feeding costs, low crude protein (CP) diets are sometimes proposed, however, a great reduction of dietary CP concentration (>4% reduction vs. recommended concentration), even supplemented with essential and nonessential amino acids (AA) can detrimentally affect small intestinal barrier function and immunity, possibly due to the excessive lack of peptides. Here we hypothesize that with an extremely low CP concentration diet, protein-derived peptides, rather than AA supplementation, can improve intestinal barrier development and health. To test this hypothesis, 21 growing pigs (19.90 ± 1.00 kg body weight) were randomly assigned to 3 treatments with control diet (16% CP), or low CP diets (13% CP) supplemented with AA (LCPA) or casein hydrolysate (LCPC) for 28 days. In comparison with the control diet, the LCPA diet decreased the protein expression level of jejunal barrier factor zonula occludens-1 (ZO-1) and stem cell proliferation factor leucine-rich repeat-containing G-protein-coupled receptor-5, whereas the LCPC diet enhanced intestinal barrier function by increasing the protein expression level of jejunal occludin and ZO-1 and ileal mucin-2. The LCPA diet reduced Lactobacillus counts, whereas the LCPC diet increased Lactobacillus counts and reduced Escherichia coli counts in the ileum. The LCPA diet also increased protein expression levels of pro-inflammatory cytokine interleukin-6 (IL-6) and IL-22, whereas the LCPC diet decreased protein expression levels of pro-inflammatory IL-1β, IL-17A and tumor necrosis factor-α in the ileum. Collectively, the casein hydrolysate supplementation of low CP diets showed beneficial effects on the small intestinal barrier, bacterial community, and immunity in pigs, pointing to the important role of protein-derived peptides in small intestinal health in cases of low crude protein diets.

L-Leucine Promotes STAT1 and ISGs Expression in TGEV-Infected IPEC-J2 Cells via mTOR Activation

L-leucine (Leu), as one of the effective amino acids to activate the mTOR signaling pathway, can alleviate transmissible gastroenteritis virus (TGEV) infection. However, the underlying mechanism by which Leu alleviates the virus infection has not been fully characterized. In particular, how Leu impacts TGEV replication through mTOR signaling has yet to be elucidated. In the present study, we found that TGEV proliferated efficiently in intestinal porcine epithelial cells (IPEC-J2 cells) as evidenced by the increase in viral contents by flow cytometry, the inhibition of cell proliferation by CCK-8 assay as well as the reduction of PCNA level by western blot. Besides, western blot analysis showed that STAT1 expression was markedly reduced in TGEV-infected cells. The results of ELISA revealed the inhibition of ISGs (ISG56, MxA, and PKR) expressions by TGEV infection. TGEV-induced mTOR and its downstream p70 S6K and 4E-BP1, STAT1 and ISGs downregulation were blocked by an mTOR activator-MHY1485 but not by an mTOR inhibitor-RAPA. Concurrently, mTOR activation by MHY1485 reduced the contents of TGEV and vice versa. Furthermore, Leu reversed the inhibition of STAT1 and ISGs by activating mTOR and its downstream p70 S6K and 4E-BP1 in TEGV-infected cells. Our findings demonstrated that Leu promoted the expressions of STAT1 and ISGs via activating mTOR signaling in IPEC-J2 cells, aiming to prevent TGEV infection.

Protective effects of sodium butyrate on rotavirus inducing endoplasmic reticulum stress-mediated apoptosis via PERK-eIF2α signaling pathway in IPEC-J2 cells

BACKGROUND

Rotavirus (RV) is a major pathogen that causes severe gastroenteritis in infants and young animals. Endoplasmic reticulum (ER) stress and subsequent apoptosis play pivotal role in virus infection. However, the protective mechanisms of intestinal damage caused by RV are poorly defined, especially the molecular pathways related to enterocytes apoptosis. Thus, the aim of this study was to investigate the protective effect and mechanism of sodium butyrate (SB) on RV-induced apoptosis of IPEC-J2 cells.

RESULTS

The RV infection led to significant cell apoptosis, increased the expression levels of ER stress (ERS) markers, phosphorylated protein kinase-like ER kinase (PERK), eukaryotic initiation factor 2 alpha (eIF2α), caspase9, and caspase3. Blocking PERK pathway using specific inhibitor GSK subsequently reversed RV-induced cell apoptosis. The SB treatment significantly inhibited RV-induced ERS by decreasing the expression of glucose regulated protein 78 (GRP78), PERK, and eIF2α. In addition, SB treatment restrained the ERS-mediated apoptotic pathway, as indicated by downregulation of C/EBP homologous protein (CHOP) mRNA level, as well as decreased cleaved caspase9 and caspase3 protein levels. Furthermore, siRNA-induced GPR109a knockdown significantly suppressed the protective effect of SB on RV-induced cell apoptosis.

CONCLUSIONS

These results indicate that SB exerts protective effects against RV-induced cell apoptosis through inhibiting ERS mediated apoptosis by regulating PERK-eIF2α signaling pathway via GPR109a, which provide new ideas for the prevention and control of RV.

Modulatory Effects of Probiotics During Pathogenic Infections With Emphasis on Immune Regulation

In order to inhibit pathogenic complications and to enhance animal and poultry growth, antibiotics have been extensively used for many years. Antibiotics applications not only affect target pathogens but also intestinal beneficially microbes, inducing long-lasting changes in intestinal microbiota associated with diseases. The application of antibiotics also has many other side effects like, intestinal barrier dysfunction, antibiotics residues in foodstuffs, nephropathy, allergy, bone marrow toxicity, mutagenicity, reproductive disorders, hepatotoxicity carcinogenicity, and antibiotic-resistant bacteria, which greatly compromise the efficacy of antibiotics. Thus, the development of new antibiotics is necessary, while the search for antibiotic alternatives continues. Probiotics are considered the ideal antibiotic substitute; in recent years, probiotic research concerning their application during pathogenic infections in humans, aquaculture, poultry, and livestock industry, with emphasis on modulating the immune system of the host, has been attracting considerable interest. Hence, the adverse effects of antibiotics and remedial effects of probiotics during infectious diseases have become central points of focus among researchers. Probiotics are live microorganisms, and when given in adequate quantities, confer good health effects to the host through different mechanisms. Among them, the regulation of host immune response during pathogenic infections is one of the most important mechanisms. A number of studies have investigated different aspects of probiotics. In this review, we mainly summarize recent discoveries and discuss two important aspects: (1) the application of probiotics during pathogenic infections; and (2) their modulatory effects on the immune response of the host during infectious and non-infectious diseases.

Quantitative Proteomic Analysis of Porcine Intestinal Epithelial Cells Infected with Porcine Deltacoronavirus Using iTRAQ-Coupled LC-MS/MS

Porcine deltacoronavirus (PDCoV) is an emergent enteropathogenic coronavirus associated with swine diarrhea. Porcine small intestinal epithelial cells (IPEC) are the primary target cells of PDCoV infection in vivo. Here, isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantitatively identify differentially expressed proteins (DEPs) in PDCoV-infected IPEC-J2 cells. A total of 78 DEPs, including 23 upregulated and 55 downregulated proteins, were identified at 24 h postinfection. The data are available via ProteomeXchange with identifier PXD019975. To ensure reliability of the proteomics data, two randomly selected DEPs, the downregulated anaphase-promoting complex subunit 7 (ANAPC7) and upregulated interferon-induced protein with tetratricopeptide repeats 1 (IFIT1), were verified by real-time PCR and Western blot, and the results of which indicate that the proteomics data were reliable and valid. Bioinformatics analyses, including GO, COG, KEGG, and STRING, further demonstrated that a majority of the DEPs are involved in numerous crucial biological processes and signaling pathways, such as immune system, digestive system, signal transduction, RIG-I-like receptor, mTOR, PI3K-AKT, autophagy, and cell cycle signaling pathways. Altogether, this is the first study on proteomes of PDCoV-infected host cells, which shall provide valuable clues for further investigation of PDCoV pathogenesis.

Oral administration of the probiotic bacterium Lactobacillus acidophilus strain L-55 modulates the immunological parameters of the laying hen inoculated with a Newcastle disease virus-based live attenuated vaccine

Probiotic supplements containing living bacteria have attracted interest as a potential source of health benefits for humans and livestock. The aim of this study was to determine whether administration of Lactobacillus acidophilus strain L-55 (LaL-55) enhances the immune response among chicks exposed to a Newcastle disease virus (NDV)-based live attenuated vaccine. Oral administration of LaL-55 augmented the elevation in the total numbers of leukocytes and lymphocytes following inoculation with the NDV-based live attenuated vaccine. Monocyte counts increased after LaL-55 administration independent of inoculation with the NDV vaccine. Among chicks that were administered LaL-55, there was a dose-dependent increase in the NK cell activity measured by a ⁵¹Cr release assay at 2 weeks after the secondary NDV vaccine inoculation. Two weeks after the secondary inoculation with the NDV vaccine, interferon (IFN)-γ-mRNA expression was significantly elevated in mononuclear splenocytes from chicks that were administered LaL-55. Meanwhile, LaL-55 administration did not change the mRNA levels of IFN-α, IFN-β, and interleukin-1β. These results may suggest that coadministration of LaL-55 with an NDV vaccine augments the immune response against the virus. Therefore, LaL-55 may help protect against viral diseases in poultry.

Comparative Transcriptomic and Proteomic Analyses Prove that IFN-λ1 is a More Potent Inducer of ISGs than IFN-α against Porcine Epidemic Diarrhea Virus in Porcine Intestinal Epithelial Cells

Type III interferon (IFN-λ) is currently considered to be largely nonredundant to type I interferon (IFN-α) in antivirus infection, especially in epithelial cells. Previous studies reported that, compared with IFN-α, IFN-λ exhibited stronger induction of interferon-stimulated genes (ISGs) at the transcriptional level in intestinal epithelial cells and stronger inhibition of porcine epidemic diarrhea virus (PEDV). In this study, the different mechanisms of ISG upregulation induced by IFN-α and IFN-λ1 were compared at the mRNA and protein levels in the porcine intestinal epithelial cell model (IPEC-J2). It was proved that IFN-λ1 consistently exhibited stronger stimulation effects at both levels. At the mRNA level, 132 genes were significantly upregulated upon IFN-λ1 stimulation, while 42 genes upon IFN-α stimulation. At the protein level, 47 proteins were significantly upregulated upon IFN-λ1 stimulation, but only 8 proteins were upregulated upon IFN-α stimulation. The shared upregulated genes/proteins by IFN-λ1 in both transcriptional and translational omics, especially the regulation factors of ISG15, were involved in the JAK-STAT signaling pathway. Compared to IFN-α, IFN-λ1 could induce more consistent upregulation of the key ISGs (ISG15, USP18, OASL, and RSAD2) at 3-24 h postinduction as measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) validation. It was further confirmed through functional analysis that ISG15 and RSAD2 could inhibit PEDV infection in dose-dependent manners. This study provided solid evidence that IFN-λ1 could induce a more unique and higher ISG expression level, which exhibited anti-PEDV effects on porcine intestinal epithelial cells.

Antiviral Activity of Fecal Water Samples from HIV-1 Infected Subjects Treated with a Specific Probiotic Formulation

OBJECTIVES

The aim of the study was to investigate if the supplementation with multistrain probiotics may be able to modulate T cell response in HIV-1 infected patients and to evaluate the anti-HIV activity of probiotic by studying fecal water (FW) samples.

METHODS

Three HIV-1-positive patients (Pt1, Pt2 and Pt3) on long-term suppressive combined antiretroviral therapy (cART) received a specific multi-strain probiotic supplementation (Vivomixx ®), for six months (T6). Levels of T cell subsets were evaluated by flow cytometry. Anti- HIV activity of FW samples was evaluated in vitro.

RESULTS

CD4+ T cells levels increased in all HIV-1 infected patients whereas activation markers (CD38 and HLA-DR) were decreased both on CD4+ and CD8+ T cells. FW samples presented an increased inhibitory activity against HIV-1 compared to T0 (FW-Pt1: T0 =40%, T6 = 65% of reduction; FW Pt2: T0 = 26%, T6 = 46% of reduction; FW Pt3: T0 = 47%, T6 = 94% of reduction).

DISCUSSION

Our data suggest that the administration of the specific probiotic formulation improves the antiviral status of people living with HIV-1 under cART, also modulating T cell response.

CONCLUSION

Anti-HIV activity of FW may have several public health and social implications for sexually transmitted diseases that need to be further explored.

Strain-Specific Probiotic Properties of Bifidobacteria and Lactobacilli for the Prevention of Diarrhea Caused by Rotavirus in a Preclinical Model

Probiotic supplementation with different lactobacilli and bifidobacterial strains has demonstrated beneficial effects in infectious diarrhea caused by rotavirus (RV) in young children. Preclinical models of RV infection might be a good strategy to screen for the efficacy of new probiotic strains or to test their comparative efficacy. Neonatal Lewis rats were supplemented with Bifidobacterium breve M-16V, Lactobacillus acidophilus NCFM, Lactobacillus helveticus R0052, or Lactobacillus salivarius PS2 from days 2–14 of life. On day five, animals received RV SA-11 orally. Fecal samples were collected daily, weighed, and scored for the calculation of severity and incidence of diarrhea. In addition, fecal pH and fecal viral shedding were measured. Animals were sacrificed at the end of the study and their blood was obtained for the quantification of RV-specific immunoglobulins. RV infection was induced in ~90% of the animals. All probiotics caused a reduction of several clinical variables of severity and incidence of diarrhea, except L. salivarius PS2. L. acidophilus NCFM, B. breve M-16V, and L. helveticus R0052 seemed to be very effective probiotic strains. In addition, all Lactobacillus strains reduced the viral elimination one day post-inoculation. No differences were detected in the specific anti-RV humoral response. The present study highlights the strain-specific effects of probiotics and identifies promising probiotics for use in ameliorating and preventing RV-induced diarrhea in children, for example by including them in infant formulas.

Astragalus polysaccharides alleviates LPS-induced inflammation via the NF-κB/MAPK signaling pathway

Early weaning usually causes intestinal disorders, enteritis, and diarrhea in young animals and human infants. Astragalus polysaccharides (APS) possesses anti-inflammatory activity. To study the anti-inflammatory mechanisms of APS and its potential effects on intestinal health, we performed an RNA sequencing (RNA-seq) study in lipopolysaccharide (LPS)-stimulated porcine intestinal epithelial cells (IPEC-J2) in vitro. In addition, LPS-stimulated BALB/c mice were used to study the effects of APS on intestinal inflammation in vivo. The results from the RNA-seq analysis show that there were 107, 756, and 5 differentially expressed genes in the control versus LPS, LPS versus LPS+APS, and control versus LPS+APS comparison groups, respectively. The results of Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways play significant roles in the regulation of inflammatory factors and chemokine expression by APS. Further verification of the above two pathways by using western blot and immunofluorescence analysis revealed that the gene expression levels of the phosphorylated p38 MAPK, ERK1/2, and NF-κB p65 were inhibited by APS, while the expression of IκB-α protein was significantly increased (p < .05), indicating that APS inhibits the production of inflammatory factors and chemokines by the inhibition of activation of the MAPK and NF-κB inflammatory pathways induced by LPS stimulation. Animal experiments further demonstrated that prefeeding APS in BALB/c mice can alleviate the expression of the jejunal inflammatory factors interleukin 6 (IL-6), IL-Iβ, and tumor necrosis factor-α induced by LPS stimulation and improve jejunal villus morphology.

The protective effects of enriched citrulline fermented milk with Lactobacillus helveticus on the intestinal epithelium integrity against Escherichia coli infection

This study examined the protective effects of citrulline enriched-fermented milk with live Lactobacillus helveticus ASCC 511 (LH511) on intestinal epithelial barrier function and inflammatory response in IPEC-J2 cells caused by pathogenic Escherichia coli. Five percent (v/v) of fermented milk with live LH511 and 4 mM citrulline (5%LHFM_Cit-4mM) significantly stimulated the population of IPEC-J2 cells by 36% as determined by MTT assay. Adhesion level of LH511 was significantly increased by 9.2% when incubated with 5%LHFM_Cit-4mM and 5%LHFM_Cit-4mM reduced the adhesion of enterohemorrhagic (EHEC) and entero-invasive (EIEC) E. coli in IPEC-J2 cells by 35.79% and 42.74%, respectively. Treatment with 5%LHFM_Cit-4mM ameliorated lipopolysaccharide (LPS) from E. coli O55:B5 induced activated inflammatory cytokines expression (TNF-α, IL-6 and IL-8) and concentration (IL-6 and IL-8) and early apoptosis. It restored the transepithelial electrical resistance (TEER) and regulated the expression and distribution of tight junction (TJ) proteins (zonula occluden-1 (ZO-1), occludin and claudin-1), toll-like receptors (TLRs) (TLR2 and TLR4) and negative regulators of TLRs signalling pathway (A20 and IRAK-M). In conclusion, our findings suggested that 5%LHFM_Cit-4mM might have the positive effects on improving and maintaining the intestinal epithelial cell integrity and inflammatory response under both normal and pathogenic LPS-stimulated conditions.

Koumine Alleviates Lipopolysaccharide-Induced Intestinal Barrier Dysfunction in IPEC-J2 Cells by Regulating Nrf2/NF-κB Pathway

Gelsemium elegans Benth. (G. elegans), a traditional Chinese medicine, has great potential as an effective growth promoter in animals, however, the mechanism of its actin remains unclear. Here, we evaluated the protective effects of koumine extract from G. elegans against lipopolysaccharide (LPS)-induced intestinal barrier dysfunction in IPEC-J2 cells through alleviation of inflammation and oxidative stress. MTT and LDH assays revealed that koumine significantly reduced LPS cytotoxicity. Transepithelial electrical resistance (TEER) and cell monolayer permeability assays showed that koumine treatment attenuated the LPS-induced intestinal barrier dysfunction with no particularly different effects in tight junction proteins such as ZO-1, claudin-1, and occludin. LPS-triggered inflammatory response was also suppressed by koumine, as evidenced by the downregulated inflammatory factors, including TNF-α, IL-6, IL-1β, NO, iNOS, and COX-2, which was closely connected with the inhibition of NF-κB pathway for the decrease of phosphorylation of IκBα and NF-κB and nuclear translocation of p-p65. Amount of reactive oxygen species (ROS) and MDA induced by LPS was also reduced by koumine through activation of Nrf2 pathway, and increased in the levels of Nrf2 and HO-1 degradation of keap-1 to promote anti-oxidants, including superoxide dismutase (SOD) and catalase (CAT). To summarize, koumine-reduced the oxidative stress and inflammatory reaction triggered by LPS through regulation of the Nrf2/NF-κB signaling pathway and preventing intestinal barrier dysfunction.

The Role of Innate Immunity in Regulating Rotavirus Replication, Pathogenesis, and Host Range Restriction and the Implications for Live Rotaviral Vaccine Development

Rotaviruses (RVs) are important causative agents of viral gastroenteritis in the young of most mammalian species studied, including humans, in which they are the most important cause of severe gastroenteritis worldwide despite the availability of several safe and effective vaccines. Replication of RVs is restricted in a host species-specific manner, and this barrier is determined predominantly by the host interferon (IFN) signaling and the ability of different RV strains to successfully negate IFN activation and amplification pathways. In addition, viral attachment to the target intestinal epithelial cells also regulates host range restriction. Several studies have focused on the role of the innate immune response in regulating RV replication and pathogenesis. The knowledge accrued from these efforts is likely to result in rational attenuation of RV vaccines to closely match circulating (and host species-matched) virus strains. In this chapter, we review prevalent models of RV interactions with innate immune factors, viral strategies employed to regulate their function, and the implications of these findings for improved RV vaccine development.

Porcine rotavirus mainly infects primary porcine enterocytes at the basolateral surface

Intestinal epithelium functions as a barrier to protect multicellular organisms from the outside world. It consists of epithelial cells closely connected by intercellular junctions, selective gates which control paracellular diffusion of solutes, ions and macromolecules across the epithelium and keep out pathogens. Rotavirus is one of the major enteric viruses causing severe diarrhea in humans and animals. It specifically infects the enterocytes on villi of small intestines. The polarity of rotavirus replication in their target enterocytes and the role of intestinal epithelial integrity were examined in the present study. Treatment with EGTA, a drug that chelates calcium and disrupts the intercellular junctions, (i) significantly enhanced the infection of rotavirus in primary enterocytes, (ii) increased the binding of rotavirus to enterocytes, but (iii) considerably blocked internalization of rotavirus. After internalization, rotavirus was resistant to EGTA treatment. To investigate the polarity of rotavirus infection, the primary enterocytes were cultured in a transwell system and infected with rotavirus at either the apical or the basolateral surface. Rotavirus preferentially infected enterocytes at the basolateral surface. Restriction of infection through apical inoculation was overcome by EGTA treatment. Overall, our findings demonstrate that integrity of the intestinal epithelium is crucial in the host's innate defense against rotavirus infection. In addition, the intercellular receptor is located basolaterally and disruption of intercellular junctions facilitates the binding of rotavirus to their receptor at the basolateral surface.

Parenterally Administered P24-VP8* Nanoparticle Vaccine Conferred Strong Protection against Rotavirus Diarrhea and Virus Shedding in Gnotobiotic Pigs

Current live rotavirus vaccines are costly with increased risk of intussusception due to vaccine replication in the gut of vaccinated children. New vaccines with improved safety and cost-effectiveness are needed. In this study, we assessed the immunogenicity and protective efficacy of a novel P24-VP8* nanoparticle vaccine using the gnotobiotic (Gn) pig model of human rotavirus infection and disease. Three doses of P24-VP8* (200 μg/dose) intramuscular vaccine with Al(OH)₃ adjuvant (600 μg) conferred significant protection against infection and diarrhea after challenge with virulent Wa strain rotavirus. This was indicated by the significant reduction in the mean duration of diarrhea, virus shedding in feces, and significantly lower fecal cumulative consistency scores in post-challenge day (PCD) 1-7 among vaccinated pigs compared to the mock immunized controls. The P24-VP8* vaccine was highly immunogenic in Gn pigs. It induced strong VP8*-specific serum IgG and Wa-specific virus-neutralizing antibody responses from post-inoculation day 21 to PCD 7, but did not induce serum or intestinal IgA antibody responses or a strong effector T cell response, which are consistent with the immunization route, the adjuvant used, and the nature of the non-replicating vaccine. The findings are highly translatable and thus will facilitate clinical trials of the P24-VP8* nanoparticle vaccine.

Significant Interference with Porcine Epidemic Diarrhea Virus Pandemic and Classical Strain Replication in Small-Intestine Epithelial Cells Using an shRNA Expression Vector

Porcine epidemic diarrhea (PED) re-emerged in China in 2010 and is now widespread. Evidence indicates that highly virulent porcine epidemic diarrhea virus (PEDV) strains belonging to genotype G2 caused a large-scale outbreak of diarrhea. Currently, vaccines derived from PEDV classical strains do not effectively prevent infection by virulent PEDV strains, and no specific drug is available to treat the disease. RNA interference (RNAi) is a novel and effective way to cure a wide range of viruses. We constructed three short hairpin RNA (shRNA)-expressing plasmids (shR-N307, shR-N463, and shR-N1071) directed against nucleocapsid (N) and determined their antiviral activities in intestine epithelial cells infected with a classical CV777 strain and LNCT2. We verified that shR-N307, shR-N463, and shR-N1071 effectively inhibited the expression of the transfected N gene in vitro, comparable to the control shRNA. We further demonstrated the shRNAs markedly reduced PEDV CV777 and LNCT2 replication upon downregulation of N production. Therefore, this study provides a new strategy for the design of antiviral methods against coronaviruses by targeting their processivity factors.

Effects of Lactobacillus plantarum on the intestinal morphology, intestinal barrier function and microbiota composition of suckling piglets

This study investigated the effect of Lactobacillus plantarum strain 299v on gut health in suckling piglets. Sixty newborn piglets were assigned to control and probiotic treatments, with three litters per treatment (ten piglets/litter). From days 1 to 20 of life, piglets were orally administered a placebo of 0.1% peptone or 1.0 ×  10¹⁰  CFU L. plantarum 299v daily. Six piglets per treatment were sacrificed on day 20, and intestinal tissues (including duodenum, jejunum, ileum and colon) and the intestinal contents from colon segments were collected. The results demonstrated that piglets treated with L. plantarum 299v had a lower diarrhoea incidence than the controls. L. plantarum 299v administration significantly increased the ratio of the villus height to the crypt depth in the jejunum and ileum, as well as the mRNA expression of jejunal occludin and ileal zonula occludens 1 (ZO-1). The L. plantarum treatment also increased the mRNA abundance of porcine β-defensin 2 (pBD2) and pBD3 in the jejunum and ileum and of toll-like receptors (TLRs), such as TLR2, TLR4, TLR6 and TLR9 in the ileum, and significantly upregulated the mRNA abundances of ileal pBD1 and colonic TLR4. Additionally, the L. plantarum 299v treatment significantly changed the structure of the colonic microbiota, as evidenced by the obvious increases in the relative abundances of the phyla Firmicutes and Actinobacteria and of the genus Lactobacillus. Our findings indicate that L. plantarum 299v facilitates the gut health of suckling piglets, probably by improving the intestinal morphology and intestinal barrier function and by modifying the structure of the gut microbiota.

Effects of Saccharomyces cerevisiae on alleviating cytotoxicity of porcine jejunal epithelia cells induced by deoxynivalenol

Deoxynivalenol (DON) is one of the mycotoxins most frequently encountering in cereal-based foods throughout the world. Saccharomyces cerevisiae was used to alleviate porcine jejunal epithelia cell (IPEC-J2) injury induced by DON in this study. The results indicated that cell viability and proliferation rates were significantly decreased when DON concentrations were increased from 0 to 64 µM after 24 h incubation (p < 0.05). The longer incubation time and higher DON concentrations would cause more serious effects on cell viability. S. cerevisiae could significantly degrade DON and decrease lactic dehydrogenase (LDH) release in the cells induced by DON (p < 0.05). DON (4 µM) could increase necrotic and apoptotic cell rates as well as decrease viable cell rates, compared with the control group (p < 0.05). However, S. cerevisiae addition in the DON group could decrease necrotic, late apoptotic and early apoptotic cell rates by 38.05%, 46.37% and 44.78% respectively, increase viable cell rates by 2.35%, compared with the single DON group (p < 0.05). In addition, S. cerevisiae addition could up-regulate mRNA abundances of IL-6, IL-8 and IL-10 in IPEC-J2 cells (p < 0.05), but down-regulate mRNA abundances of tight junction proteins (TJP-1) and occludin by 36.13% and 50.18% at 1 µM of DON (p < 0.05). It could be concluded that S. cerevisiae was able to alleviate IPEC-J2 cell damage exposed to DON.

Interferon gamma inhibits transmissible gastroenteritis virus infection mediated by an IRF1 signaling pathway

Interferon gamma (IFN-γ) is best known for its ability to regulate host immune responses; however, its direct antiviral activity is less well studied. Transmissible gastroenteritis virus (TGEV) is an economically important swine enteric coronavirus and causes acute diarrhea in piglets. At present, little is known about the function of IFN-γ in the control of TGEV infection. In this study, we demonstrated that IFN-γ inhibited TGEV infection directly in ST cells and intestine epithelial IPEC-J2 cells and that the anti-TGEV activity of IFN-γ was independent of IFN-α/β. Moreover, IFN-γ suppressed TGEV infection in ST cells more efficiently than did IFN-α, and the combination of IFN-γ and IFN-α displayed a synergistic effect against TGEV. Mechanistically, using overexpression and functional knockdown experiments, we demonstrated that porcine interferon regulatory factor 1 (poIRF1) elicited by IFN-γ primarily mediated IFN-γ signaling cascades and the inhibition of TGEV infection by IFN-γ. Importantly, we found that TGEV elevated the expression of poIRF1 and IFN-γ in infected small intestines and peripheral blood mononuclear cells. Thus, IFN-γ plays a crucial role in curtailing enteric coronavirus infection and may serve as an effective prophylactic and/or therapeutic agent against TGEV infection.

Vitamin D Alleviates Rotavirus Infection through a Microrna-155-5p Mediated Regulation of the TBK1/IRF3 Signaling Pathway In Vivo and In Vitro

(1) Background: Vitamin D (VD) plays a vital role in anti-viral innate immunity. However, the role of VD in anti-rotavirus and its mechanism is still unclear. The present study was performed to investigate whether VD alleviates rotavirus (RV) infection through a microRNA-155-5p (miR-155-5p)-mediated regulation of TANK-binding kinase 1 (TBK1)/interferon regulatory factors 3 (IRF3) signaling pathway in vivo and in vitro. (2) Methods: The efficacy of VD treatment was evaluated in DLY pig and IPEC-J2. Dual-luciferase reporter activity assay was performed to verify the role of miR-155-5p in 1α,25-dihydroxy-VD₃ (1,25D3) mediating the regulation of the TBK1/IRF3 signaling pathway. (3) Results: A 5000 IU·kg^–1 dietary VD₃ supplementation attenuated RV-induced the decrease of the villus height and crypt depth (p < 0.05), and up-regulated TBK1, IRF3, and IFN-β mRNA expressions in the jejunum (p < 0.05). Incubation with 1,25D3 significantly decreased the RV mRNA expression and the RV antigen concentration, and increased the TBK1 mRNA and protein levels, and the phosphoprotein IRF3 (p-IRF3) level (p < 0.05). The expression of miR-155-5p was up-regulated in response to an RV infection in vivo and in vitro (p < 0.05). 1,25D3 significantly repressed the up-regulation of miR-155-5p in vivo and in vitro (p < 0.05). Overexpression of miR-155-5p remarkably suppressed the mRNA and protein levels of TBK1 and p-IRF3 (p < 0.01), while the inhibition of miR-155-5p had an opposite effect. Luciferase activity assays confirmed that miR-155-5p regulated RV replication by directly targeting TBK1, and miR-155-5p suppressed the TBK1 protein level (p < 0.01). (4) Conclusions: These results indicate that miR-155-5p is involved in 1,25D3 mediating the regulation of the TBK1/IRF3 signaling pathway by directly targeting TBK1.

Immunobiotic Strains Modulate Toll-Like Receptor 3 Agonist Induced Innate Antiviral Immune Response in Human Intestinal Epithelial Cells by Modulating IFN Regulatory Factor 3 and NF-κB Signaling

Many studies have demonstrated that immunobiotics with immunoregulatory functions improve the outcomes of several bacterial and viral infections by modulating the mucosal immune system. However, the precise mechanisms underlying the immunoregulatory and antiviral activities of immunobiotics have not yet been elucidated in detail. The present study was conducted to determine whether selected lactic acid bacteria (LAB) modulate toll-like receptor 3 (TLR3) agonist polyinosinic:polycytidylic acid (PolyI:C) induced viral response in human intestinal epithelial cells (IECs). PolyI:C increased the expression of interferon-β (IFN-β), interleukin-6 (IL-6), interleukin-8 (IL-8), monocyte chemoattractant protein (MCP-1), and interleukin-1β (IL-1β) in HCT116 cells, and these up-regulations were significantly altered when cells were pre-stimulated with LAB isolated from Korean fermented foods. LAB strains were capable to up-regulate IFN-β but down-regulated IL-6, IL-8, MCP-1, and IL-1β mRNA levels as compared with PolyI: C. HCT-116 cell treatment with LABs beneficially modulated the mRNA levels of C-X-C motif chemokine 10 (CXCL-10), 2-5A oligoadenylate synthetase 1 (OSA1), myxovirus resistance protein (MxA), TLR3, and retinoic acid inducible gene-I (RIG-I), and TLR negative regulators. In addition, LABs increased IFN-β, IFN-α, and interleukin-10 (IL-10) and decreased tumor necrosis factor-α (TNF-α) and IL-1β protein/mRNA levels in THP-1 cells. LABs also protected the cells by maintaining tight-junction proteins (zonula occludens-1 and occludin). The beneficial effects of these LABs were mediated via modulation of the interferon regulatory factor 3 (IRF3) and nuclear factor-kappa B (NF-κB) pathways. Overall, the results of this study indicate that immunobiotics have potent antiviral and anti-inflammatory activities that may use as antiviral substitutes for human and animal applications.

Growth, health, rumen fermentation, and bacterial community of Holstein calves fed Lactobacillus rhamnosus GG during the preweaning stage1

The aim of this study was to determine if feeding Lactobacillus rhamnosus GG (GG, ATCC 53013) to neonatal calves would alter their growth, health, rumen fermentation, and bacterial community composition during the preweaning stage; we hypothesized that it would. Twenty-four male Holstein calves were blocked and randomly assigned to 1 of 2 treatment groups: 1) untreated control (CON), or 2) treated with 1 × 1010 cfu/d of a GG suspension (GG). Calves received GG daily, mixed with the milk replacer in the morning feed for 6 wk. Starter and alfalfa hay intakes, as well as feces and respiratory scores, were recorded daily, while body weight and structures were measured weekly. Blood, rumen fluid, and feces samples were collected, from which relevant indicators were detected. The results showed that the administration of GG significantly increased voluntary starter intake (P = 0.023) and ADG (P = 0.035) of the calves. The fecal score (P = 0.018) was lower and the β-hydroxybutyric concentration in the plasma tended to increase (P = 0.092) in calves treated with GG. The pH of the rumen fluid in calves fed GG was lower (P = 0.007), which might be attributable to the tendency (P = 0.083) for total volatile fatty acids concentration to increase. Administration of GG significantly increased the amylase, protease activity, and the microbial protein concentrations (P = 0.043, P = 0.036, and P = 0.044, respectively) in the rumen fluids. Furthermore, GG treatment altered the dominant bacteria order and relative abundance of the bacteria families in the rumen fluids. The microbial diversity indices were significantly affected by GG administration. In conclusion, the neonatal calves fed GG before weaning increased their voluntary starter intake and growth performance, improved the rumen fermentation, and regulated the pattern to normally increase the propionate and butyrate concentrations. Administration of GG also diversified the bacterial community composition in the rumen, and regulated the balance of rumen and intestinal microorganisms. These results indicated that feeding calves GG were beneficial to the rumen development and early weaning.

Effect of Compound Probiotics and Mycotoxin Degradation Enzymes on Alleviating Cytotoxicity of Swine Jejunal Epithelial Cells Induced by Aflatoxin B₁ and Zearalenone

Zearalenone (ZEA) and aflatoxin B₁ (AFB₁) are two main kinds of mycotoxins widely existing in grain and animal feed that cause a lot of economic loss and health problems for animals and humans. In order to alleviate the cytotoxic effects of AFB₁ and ZEA on swine jejunal epithelial cells (IPEC-J2), the combination of a cell-free supernatant of compound probiotics (CFSCP) with mycotoxin degradation enzymes (MDEs) from Aspergillus oryzae was tested. The results demonstrated that coexistence of AFB₁ and ZEA had synergetic toxic effects on cell viability. The cell viability was decreased with mycotoxin concentrations increasing, but increased with incubation time extension. The necrotic cell rates were increased when 40 µg/L AFB₁ and/or 500 µg/L ZEA were added, but the addition of CFSCP + MDE suppressed the necrotic effects of AFB₁ + ZEA. The viable cell rates were decreased when AFB₁ and/or ZEA were added: However, the addition of CFSCP + MDE recovered them. The relative mRNA abundances of Bcl-2, occludin, and ZO-1 genes were significantly upregulated, while Bax, caspase-3, GLUT2, ASCT2, PepT1, and IL6 genes were significantly downregulated by CFSCP + MDE addition, compared to the groups containing 40 µg/L AFB₁ and 500 µg/L ZEA. This research provided an effective strategy in alleviating mycotoxin cytotoxicity and keeping normal intestinal cell structure and animal health.

Probiotic Bacillus enhance the intestinal epithelial cell barrier and immune function of piglets

Bacillus is widely used in the livestock industry. This study was designed to evaluate the effects of probiotic Bacillus amyloliquefaciens SC06 (Ba), originally isolated from soil, in piglets diet as an alternative to antibiotics (aureomycin), mainly on intestinal epithelial barrier and immune function. Ninety piglets were divided into three groups: G1 (containing 150 mg/kg aureomycin in the diet); G2 (containing 75 mg/kg aureomycin and 1×108 cfu/kg Ba in the diet); G3 (containing 2×108 cfu/kg Ba in the diet without any antibiotics). The results showed that, compared with the antibiotic group (G1), villus length, crypt depth and villus length/crypt depth ratio of intestine significantly increased in the G2 and G3 groups. In addition, intestinal villi morphology, goblet-cell number, mitochondria structure and tight junction proteins of intestinal epithelial cells in G2 and G3 were better than in G1. The relative gene expression of intestinal mucosal defensin-1, claudin3, claudin4, and human mucin-1 in G3 was significantly lower, while the expression of villin was significantly higher than in the antibiotic group. Probiotic Ba could significantly decrease serum interferon (IFN)-α, IFN-γ, interleukin (IL)-1β, and IL-4 levels, whereas increase tumour necrosis factor (TNF)-α and IL-6 secretion. Ba could also significantly decrease cytokines TNF-α, IFN-γ, IL-1β, and IL-4 level in liver, whereas it significantly increased IFN-α. Furthermore, replacing antibiotics with Ba also significantly down-regulated gene expression of TNF and IL-1α in intestinal mucosa, but up-regulated IL-6 and IL-8 transcription. Dietary addition of Ba could significantly reduce the gene expression of nuclear factor kappa beta (NFκB)-p50 and Toll-like receptor (TLR)6, while there was no significant difference for that of myeloid differentiation primary response 88, TNF receptor-associated factor-6, nucleotide-binding oligomerisation domain-containing protein 1, TLR2, TLR4, and TLR9. Taken together, our findings demonstrated that probiotic Ba could increase the intestinal epithelial cell barrier and immune function by improving intestinal mucosa structure, tight junctions and by activating the TLRs signalling pathway.

In vitro free radical scavenging capacity of dimethylglycine sodium salt and its protective ability against oleic acid hydroperoxide-induced oxidative damage in IPEC-J2 cells

The aim of the present study was to evaluate the in vitro free radical scavenging capacity of dimethylglycine sodium (DMG‑Na) and its protective ability against oleic acid hydroperoxide (OAHPx)‑induced oxidative damage in IPEC‑J2 cells. Initially, the free radical scavenging activities of water‑soluble pigments (DMG‑Na, betalain, capsanthin and cyanidin‑3‑rutinoside) were measured and compared with those of Trolox. Subsequently, freshly collected swine blood was mixed with heparin and centrifuged to obtain erythrocytes. In order to induce the free radical chain oxidation in erythrocytes, the aqueous peroxyl radicals were generated by thermal decomposition of 2,2'‑azobis(2‑amidinopropane) dihydrochloride (AAPH) in oxygen. A 2% suspension of porcine erythrocytes in PBS buffer were pre‑incubated for 30 min at 37˚C with DMG‑Na (32 µM), followed by incubation with or without AAPH (75 mM) for 5 h with gentle shaking. Additionally, IPEC‑J2 cells were randomly assigned to four groups (n=6 per group): Cells treated with phosphate buffered saline (PBS); cells treated with DMG‑Na (32 µM); cells treated with oleic acid hydroperoxides (OAHPx, 20 µM; TO group); cells treated with DMG‑Na (32 µM) followed by OAHPx (20 µM; DTO group). The cells were cultured in Dulbecco's modified Eagle's medium, Ham's F‑12 mixture, 1.5 mM HEPES, 5% (v/v) fetal bovine serum, 1% (v/v) insulin‑transferrin‑selenium mixture, 1% (v/v) penicillin‑streptomycin mixture and 2.5 µg/ml fungizone (37˚C, 5% CO2). The results showed that DMG‑Na exerted the strongest free radical scavenging capacity at 0.32 M from 0.08‑0.64 M, and that it could prevent AAPH‑induced porcine erythrocyte hemolysis by increasing its antioxidant capacity (P<0.05). The results also demonstrated that antioxidant capacity and antioxidant‑associated gene expression increased in the DTO group relative to the TO group (P<0.05), indicating that DMG‑Na prevented the OAHPx‑induced oxidative damage in IPEC‑J2 cells by improving the antioxidant capacity and antioxidant‑associated gene expression.