Dietary Lactobacillus rhamnosus GG Supplementation Improves the Mucosal Barrier Function in the Intestine of Weaned Piglets Challenged by Porcine Rotavirus

Host-derived lactic acid bacteria alleviate short beak and dwarf syndrome by preventing bone loss, intestinal barrier disruption, and inflammation

Short-beak and dwarf syndrome (SBDS) is caused by novel goose parvovirus (NGPV) infection, which leads to farm economic losses. Our research aimed to investigate the potential of administering isolated lactic acid bacteria (LAB) in alleviating SBDS in ducks. Eight wild LAB strains were isolated from duck feces and their biosecurity was investigated in both duck embryo fibroblast (DEF) and live ducks. Moreover, the LAB strains exhibited no detrimental effects on bone metabolism levels and facilitated the tight junction proteins (TJPs) mRNA expression, and contributing to the mitigation of inflammation in healthy ducks. Subsequently, we conducted in vitrol and in vivo experiments to assess the impact of LAB on NGPV infection. The LAB strains significantly reduced the viral load of NGPV and downregulated the mRNA levels of pro-inflammatory factors in DEF. Additionally, LAB treatment alleviated SBDS in NGPV-infected ducks. Furthermore, LAB treatment alleviated intestinal damage, and reduced the inflammatory response, while also mitigating bone resorption in NGPV-infected ducks. In conclusion, the LAB strains isolated from duck feces have favorable biosecurity and alleviate SBDS in ducks, and the mechanism related to LAB improves intestinal barrier integrity, alleviates inflammation, and reduces bone resorption. Our study presents a novel concept for the prevention and treatment of NGPV, thereby establishing a theoretical foundation for the future development of probiotics in the prevention and treatment of NGPV.

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.

Nutritional strategies to reduce intestinal cell apoptosis by alleviating oxidative stress

The gut barrier is the first line of defense against harmful substances and pathogens in the intestinal tract. The balance of proliferation and apoptosis of intestinal epithelial cells (IECs) is crucial for maintaining the integrity of the intestinal mucosa and its function. However, oxidative stress and inflammation can cause DNA damage and abnormal apoptosis of the IECs, leading to the disruption of the intestinal epithelial barrier. This, in turn, can directly or indirectly cause various acute and chronic intestinal diseases. In recent years, there has been a growing understanding of the vital role of dietary ingredients in gut health. Studies have shown that certain amino acids, fibers, vitamins, and polyphenols in the diet can protect IECs from excessive apoptosis caused by oxidative stress, and limit intestinal inflammation. This review aims to describe the molecular mechanism of apoptosis and its relationship with intestinal function, and to discuss the modulation of IECs' physiological function, the intestinal epithelial barrier, and gut health by various nutrients. The findings of this review may provide a theoretical basis for the use of nutritional interventions in clinical intestinal disease research and animal production, ultimately leading to improved human and animal intestinal health.

Dietary supplementation with Lactiplantibacillus plantarum P-8 improves the growth performance and gut microbiota of weaned piglets

Weaning is a stressful event in the pig life cycle. We hypothesized that probiotics could be potential alternatives to antibiotics for promoting growth and ameliorating stress in weaning piglets via gut microbiota modulation and, thus, investigated the beneficial effects of dietary probiotic supplementation in weaning pigs. Ninety weaning piglets (Landrace × large white, 45 males and 45 females, 25 days of age) were randomized into three dietary treatments (30 piglets/treatment, divided into five replicates/treatment, i.e., six piglets/replicate) in this 28-day trial: control (C group, basal diet); probiotic [lactic acid bacteria (LAB) group, basal diet plus Lactiplantibacillus plantarum P-8]; and antibiotic (A group; basal diet plus chlortetracycline). The piglets' growth performance [average daily gain, average daily feed intake (ADFI), and feed conversion ratio (FCR)], immune and antioxidant markers, ileal mucosal morphology, and ileal and colonic microbiomes were compared among treatment groups. Compared to the C and A groups, probiotic supplementation significantly decreased the ADFI, FCR, and ileal mucosal crypt depth while increasing the villus height-to-crypt depth ratio, hepatic glutathione peroxidase and catalase activities, and serum levels of interleukin-2. Both probiotic and antibiotic treatments modulated the piglets' gut microbiomes, with more L. plantarum in the LAB group and more Eubacterium rectale and Limosilactobacillus reuteri in the A group. Probiotic supplementation significantly increased the relative abundance of genes encoding the acetylene, galactose, and stachyose degradation pathways, potentially enhancing nutrient absorption, energy acquisition, and growth performance. Probiotics are effective alternatives to antibiotics for promoting the health of piglets, possibly via gut microbiome modulation.IMPORTANCEWeaning impacts piglet health, performance, and mortality. Antibiotic treatment during weaning can mitigate the negative effects on growth. However, antibiotic use in livestock production contributes to the emergence of antibiotic resistance, which is a threat to global public health. This comprehensive study describes the gut microbial composition and growth performance of weaned piglets after dietary supplementation with Lactiplantibacillus plantarum P-8 or antibiotics. L. plantarum P-8 ameliorated stress and improved antioxidant capacity and growth performance in weaned piglets, accompanied by gut microbiota improvement. L. plantarum P-8 is an effective substitute for antibiotics to promote the health of weaned piglets while avoiding the global concern of drug resistance.

Effects of Lactobacillus rhamnosus Supplementation on Growth Performance, Immune Function, and Antioxidant Capacity of Newborn Foals

This study aimed to explore the effects of Lactobacillus rhamnosus GG (LGG) supplementation on the growth performance, immune function, and antioxidant capacity of foals. Fifteen newborn foals with similar birth weight (51.67 ± 6.07 kg) and good health were randomly assigned to three groups: control group and test groups I and II, which were supplemented with 5.0 × 109 CFU/day and 1.0 × 1010 CFU/day LGG, respectively, for 150 days. LGG intake increased the daily body height (P < .01) and weight (P < .01) gain of foals aged 120 to 150 days. The foals' IgA (P < .05) and IgG (P < .01) plasma levels increased at 30 and 150 days, respectively, and IL-6 plasma level increased at 90 days (P < .01). Plasma total antioxidant capacity level was significantly higher in test group I than in the control and test group II at 30 days (P < .01), whereas glutathione peroxidase level was significantly higher in test group II than in the control and test group I at 30 days (P < .01). Both test groups had significantly higher superoxide dismutase level than the control group (P < .01) and significantly decreased malondialdehyde plasma level at 90 and 150 days (P < .05). Overall, our findings indicate that dietary supplementation of LGG can improve the growth performance, immune function, and antioxidant capacity of newborn foals.

Exploring the Benefits of Probiotics in Gut Inflammation and Diarrhea-From an Antioxidant Perspective

Inflammatory bowel disease (IBD), characterized by an abnormal immune response, includes two distinct types: Crohn's disease (CD) and ulcerative colitis (UC). Extensive research has revealed that the pathogeny of IBD encompasses genetic factors, environmental factors, immune dysfunction, dysbiosis, and lifestyle choices. Furthermore, patients with IBD exhibit both local and systemic oxidative damage caused by the excessive presence of reactive oxygen species. This oxidative damage exacerbates immune response imbalances, intestinal mucosal damage, and dysbiosis in IBD patients. Meanwhile, the weaning period represents a crucial phase for pigs, during which they experience pronounced intestinal immune and inflammatory responses, leading to severe diarrhea and increased mortality rates. Pigs are highly similar to humans in terms of physiology and anatomy, making them a potential choice for simulating human IBD. Although the exact mechanism behind IBD and post-weaning diarrhea remains unclear, the oxidative damage, in its progression and pathogenesis, is well acknowledged. Besides conventional anti-inflammatory drugs, certain probiotics, particularly Lactobacillus and Bifidobacteria strains, have been found to possess antioxidant properties. These include the scavenging of reactive oxygen species, chelating metal ions to inhibit the Fenton reaction, and the regulation of host antioxidant enzymes. Consequently, numerous studies in the last two decades have committed to exploring the role of probiotics in alleviating IBD. Here, we sequentially discuss the oxidative damage in IBD and post-weaning diarrhea pathogenesis, the negative consequences of oxidative stress on IBD, the effectiveness of probiotics in IBD treatment, the application of probiotics in weaned piglets, and the potential antioxidant mechanisms of probiotics.

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.

Antiviral effects of Pediococcus acidilactici isolated from Tibetan mushroom and comparative genomic analysis

Rotavirus is one of the main pathogens that cause diarrhoea in young animals, and countless animals have died of rotavirus infection worldwide. Three strains of lactic acid bacteria isolated from Tibetan mushrooms were used to study the inhibition of rotavirus in vitro and in vivo. One part was to identify and study the biochemical and probiotic characteristics of three isolated lactic acid bacteria, and the other part was to evaluate the inhibitory effect on rotavirus via in vivo and in vitro experiments. The whole genome of the lactic acid bacteria with the best antiviral effect was sequenced, and the differences between them and the standard strains were analyzed by comparative genomic analysis, so as to provide a theoretical basis for exploring the antiviral effect of lactic acid bacteria.The three strains were identified as Pediococcus acidilactici, Lactobacillus casei and Lactobacillus paracasei. Pediococcus acidilactici showed good acid tolerance, bile salt tolerance, survival in artificial intestinal fluid, survival in gastric fluid and bacteriostasis. In in vitro experiments, pig intestinal epithelial cells cocultured with Pediococcus acidilactici exhibited reduced viral infection. In the in vivo experiment, the duodenum of mice fed Pediococcus acidilactici had extremely low numbers of virus particles. The total genome size was 2,026,809 bp, the total number of genes was 1988, and the total length of genes was 1,767,273 bp. The proportion of glycoside hydrolases and glycoside transferases in CAZy was 50.6 and 29.6%, respectively. The Metabolism function in KEEG had the highest number of Global and overview maps. Among the comparative genomes, Pediococcus acidilactici had the highest homology with GCF 000146325.1, and had a good collinearity with GCF 013127755.1, without numerous gene rearrangement events such as insertion, deletion, inversion and translocation. In conclusion, Pediococcus acidilactici was a good candidate strain for antiviral probiotics.

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.

Bifidobacterium longum, Lactobacillus plantarum and Pediococcus acidilactici Reversed ETEC-Inducing Intestinal Inflammation in Mice

Microecological preparation could relieve Enterotoxigenic Escherichia coli (ETEC) K88-induced diarrhea in piglets, but which bacteria play a key role and the mitigation mechanism have not been fully clarified. In this study, 36 male mice were randomly divided into six groups (CON, K88, BK (Bifidobacterium longum + K88), LK (Lactobacillus plantarum + K88), PK (Pediococcus acidilactici + K88), and MK (mixed strains + K88)) to explore the prevention mechanisms. Three probiotic strains and their mixtures (TPSM) significantly relieved the weight loss and restored the ratio of villus height to crypt depth in the jejunum. Except for Bifidobacterium longum, other strains significantly decreased interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in mice serum. The TPSM treatment significantly downregulated the mRNA expression of the inflammatory cytokines and the Toll-like receptor and downstream gene (TLR4, MyD88, NF-κB) in jejunum induced by ETEC. Furthermore, the TPSM could restore dysbiosis of the intestinal microbiota caused by ETEC. The intestinal microbiota analysis demonstrated that Bifidobacterium longum enriched the Bifidobacterium genus (p < 0.05), Lactobacillus plantarum enriched the Lactobacillus genus (p < 0.05), Pediococcus acidilactici enriched the Coriobacteriaceae_UCG-002 and Christensenellaceae_R-7_group genus (p < 0.05), mixed bacteria enriched the Akkermansia genus (p < 0.05), but ETEC enriched the Desulfovibrio genus (p < 0.05). Meanwhile, the starch and sucrose metabolism, galactose and fructose metabolism, mannose metabolism and ABC transporters were increased with probiotics pre-treatment (p < 0.05). To sum up, the microecological preparation alleviated ETEC-induced diarrhea by regulating the immune response, rebalancing intestinal microbiota and improving carbohydrate metabolism.

Lactic Acid Bacteria as Mucosal Immunity Enhancers and Antivirals through Oral Delivery

Mucosal vaccination offer an advantage over systemic inoculation from the immunological viewpoint. The development of an efficient vaccine is now a priority for emerging diseases such as COVID-19, that was declared a pandemic in 2020 and caused millions of deaths globally. Lactic acid bacteria (LAB) especially Lactobacillus are the vital microbiota of the gut, which is observed as having valuable effects on animals’ and human health. LAB produce lactic acid as the major by-product of carbohydrate degradation and play a significant role in innate immunity enhancement. LAB have significant characteristics to mimic pathogen infections and intrinsically possess adjuvant properties to enhance mucosal immunity. Increasing demand and deliberations are being substantially focused on probiotic organisms that can enhance mucosal immunity against viral diseases. LAB can also strengthen their host’s antiviral defense system by producing antiviral peptides, and releasing metabolites that prevent viral infections and adhesion to mucosal surfaces. From the perspectives of “one health” and the use of probiotics, conventional belief has opened up a new horizon on the use of LAB as antivirals. The major interest of this review is to depict the beneficial use of LAB as antivirals and mucosal immunity enhancers against viral diseases.

Effect of Dietary Lactose Supplementation on Growth Performance and Intestinal Epithelium Functions in Weaned Pigs Challenged by Rotavirus

The purpose of this study was to investigate whether dietary lactose supplementation relieves rotavirus (RV)-induced diarrhea and gut dysfunction. Thirty-six crossbred weaned piglets were randomly allocated into three groups and fed diets containing 0, 4%, and 6% lactose for 20 days. On Day 15, half of the piglets in each group were orally infused with RV. RV infection impaired growth performance; induced severe diarrhea; decreased serum D-xylose concentration and morphology and sIgA level of jejunal mucosa; downregulated MUC1, MUC2, occludin, Bcl-2, IL-4, pBD3, pBD2, and pBD1 mRNA expression of jejunal mucosa and/or mesenteric lymph nodes; upregulated Bax, caspase-3, IL-2, IFN-γ, and IFN-β mRNA expression of jejunal mucosa and/or mesenteric lymph nodes; and damaged microbiota and metabolites of cecal digesta in weaned piglets (p < 0.05). Dietary lactose supplementation improved nutrient digestibility and growth performance and relieved the negative influence of RV challenge on intestinal barrier function, mRNA expression of cytokines, and host defense peptides of jejunal mucosa and/or mesenteric lymph nodes in weaned piglets (p < 0.05). Dietary administration of 6% lactose tended to relieve diarrhea (p = 0.07). These results suggest that lactose in feed increases growth performance and has a tendency to alleviate RV-induced diarrhea, derived from the improvement of nutrient utilization, gut barrier function, and immunity.

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.

Dietary Supplementation of Limosilactobacillus mucosae LM1 Enhances Immune Functions and Modulates Gut Microbiota Without Affecting the Growth Performance of Growing Pigs

Limosilactobacillus mucosae LM1 (LM1) is previously isolated from the intestine of piglets, but its potential as a probiotic supplement has not yet been assessed in growing pigs. In this study, we analyzed the probiotic effect of LM1 on the growth performance, apparent total tract digestibility (ATTD) of nutrients, immune properties, intestinal morphology, and gut microbiota and their metabolites in growing pigs. The experiment included 145 Duroc × (Landrace × Yorkshire) pigs (average body weight: 21.21 ± 1.14 kg) distributed into five treatment groups. The pigs were fed either a control diet (CON), or the control diet supplemented with incremental doses of LM1, namely low-dose LM1 (LL, 8.3 × 108 CFU/kg), moderate-low dose LM1 (ML, 4.2 × 109 CFU/kg), moderate-high dose LM1 (MH, 8.3 × 109 CFU/kg), and high-dose LM1 (HH, 2.1 × 1010 CFU/kg) for 42 d. On d 42, 12 pigs from each of the CON and MH groups were slaughtered. The results indicated that the ATTD of nitrogen (N, P = 0.038) was improved with MH supplementation. In addition, increasing dose of LM1 improved the immune response in pigs by reducing serum pro-inflammatory cytokines (interleukin-1β and tumor necrosis factor-alpha) and increasing anti-inflammatory cytokines (interleukin-10). Pigs fed with MH LM1 also had higher jejunal villus height and ileal villus height: crypt depth ratio, demonstrating improved intestinal morphology. Moreover, moderate-high LM1 supplementation enriched SCFA-producing taxa such as Lactobacillus, Holdemanella, Peptococcus, Bifidobacterium, Eubacterium_hallii_group, and Lachnospiraceae_AC2044_group, which correlated positively with increased fecal levels of butyrate and iso-valerate. These results strongly suggest the probiotic potential of LM1 on growing pigs. Overall, the current study provides insights on the use of L. mucosae LM1 as a novel livestock probiotic to improve pig gut health.

Lactobacilli Attenuate the Effect of Aggregatibacter actinomycetemcomitans Infection in Gingival Epithelial Cells

Probiotics may be considered as an additional strategy to achieve a balanced microbiome in periodontitis. However, the mechanisms underlying the use of probiotics in the prevention or control of periodontitis are still not fully elucidated. This in vitro study aimed to evaluate the effect of two commercially available strains of lactobacilli on gingival epithelial cells (GECs) challenged by Aggregatibacter actinomycetemcomitans. OBA-9 GECs were infected with A. actinomycetemcomitans strain JP2 at an MOI of 1:100 and/or co-infected with Lactobacillus acidophilus La5 (La5) or Lacticaseibacillus rhamnosus Lr32 (Lr32) at an MOI of 1:10 for 2 and 24 h. The number of adherent/internalized bacteria to GECs was determined by qPCR. Production of inflammatory mediators (CXCL-8, IL-1β, GM-CSF, and IL-10) by GECs was determined by ELISA, and the expression of genes encoding cell receptors and involved in apoptosis was determined by RT-qPCR. Apoptosis was also analyzed by Annexin V staining. There was a slight loss in OBA-9 cell viability after infection with A. actinomycetemcomitans or the tested probiotics after 2 h, which was magnified after 24-h co-infection. Adherence of A. actinomycetemcomitans to GECs was 1.8 × 107 (± 1.2 × 106) cells/well in the mono-infection but reduced to 1.2 × 107 (± 1.5 × 106) in the co-infection with Lr32 and to 6 × 106 (± 1 × 106) in the co-infection with La5 (p < 0.05). GECs mono-infected with A. actinomycetemcomitans produced CXCL-8, GM-CSF, and IL-1β, and the co-infection with both probiotic strains altered this profile. While the co-infection of A. actinomycetemcomitans with La5 resulted in reduced levels of all mediators, the co-infection with Lr32 promoted reduced levels of CXCL-8 and GM-CSF but increased the production of IL-1β. The probiotics upregulated the expression of TLR2 and downregulated TLR4 in cells co-infected with A. actinomycetemcomitans. A. actinomycetemcomitans-induced the upregulation of NRLP3 was attenuated by La5 but increased by Lr32. Furthermore, the transcription of the anti-apoptotic gene BCL-2 was upregulated, whereas the pro-apoptotic BAX was downregulated in cells co-infected with A. actinomycetemcomitans and the probiotics. Infection with A. actinomycetemcomitans induced apoptosis in GECs, whereas the co-infection with lactobacilli attenuated the apoptotic phenotype. Both tested lactobacilli may interfere in A. actinomycetemcomitans colonization of the oral cavity by reducing its ability to interact with gingival epithelial cells and modulating cells response. However, L. acidophilus La5 properties suggest that this strain has a higher potential to control A. actinomycetemcomitans-associated periodontitis than L. rhamnosus Lr32.

Could the COVID-19-Driven Increased Use of Ivermectin Lead to Incidents of Imbalanced Gut Microbiota and Dysbiosis?

The microfilaricidal anthelmintic drug ivermectin (IVM) has been used since 1988 for treatment of parasitic infections in animals and humans. The discovery of IVM’s ability to inactivate the eukaryotic importin α/β1 heterodimer (IMPα/β1), used by some viruses to enter the nucleus of susceptible hosts, led to the suggestion of using the drug to combat SARS-CoV-2 infection. Since IVM has antibacterial properties, prolonged use may affect commensal gut microbiota. In this review, we investigate the antimicrobial properties of IVM, possible mode of activity, and the concern that treatment of individuals diagnosed with COVID-19 may lead to dysbiosis.

Parasite-Probiotic Interactions in the Gut: Bacillus sp. and Enterococcus faecium Regulate Type-2 Inflammatory Responses and Modify the Gut Microbiota of Pigs During Helminth Infection

Dietary probiotics may enhance gut health by directly competing with pathogenic agents and through immunostimulatory effects. These properties are recognized in the context of bacterial and viral pathogens, but less is known about interactions with eukaryotic pathogens such as parasitic worms (helminths). In this study we investigated whether two probiotic mixtures (comprised of Bacillus amyloliquefaciens, B. subtilis, and Enterococcus faecium [BBE], or Lactobacillus rhamnosus LGG and Bifidobacterium animalis subspecies Lactis Bb12 [LB]) could modulate helminth infection kinetics as well as the gut microbiome and intestinal immune responses in pigs infected with the nodular worm Oesophagostomum dentatum. We observed that neither probiotic mixture influenced helminth infection levels. BBE, and to a lesser extent LB, changed the alpha- and beta-diversity indices of the colon and fecal microbiota, notably including an enrichment of fecal Bifidobacterium spp. by BBE. However, these effects were muted by concurrent O. dentatum infection. BBE (but not LB) significantly attenuated the O. dentatum-induced upregulation of genes involved in type-2 inflammation and restored normal lymphocyte ratios in the ileo-caecal lymph nodes that were altered by infection. Moreover, inflammatory cytokine release from blood mononuclear cells and intestinal lymphocytes was diminished by BBE. Collectively, our data suggest that selected probiotic mixtures can play a role in maintaining immune homeostasis during type 2-biased inflammation. In addition, potentially beneficial changes in the microbiome induced by dietary probiotics may be counteracted by helminths, highlighting the complex inter-relationships that potentially exist between probiotic bacteria and intestinal parasites.

Active or Autoclaved Akkermansia muciniphila Relieves TNF-α-Induced Inflammation in Intestinal Epithelial Cells Through Distinct Pathways

Intestinal inflammation is a major threat to the health and growth of young animals such as piglets. As a next-generation probiotics, limited studies have shown that Akkermansia muciniphila could alleviate inflammation of intestinal epithelial cells (IECs). In this study, a TNF-α-induced inflammatory model of IPEC-J2 cells, the intestinal porcine enterocytes, was built to evaluate the effects of active or inactive A. muciniphila on the inflammation of IECs. The viability of IPEC-J2 cells was the highest when treated with active (10⁸ copies/mL) or inactive (10⁹ copies/mL) A. muciniphila for 7.5 h (P < 0.01). Treated with 20 ng/mL of TNF-α and followed by a treatment of A. muciniphila, the mRNA level of proinflammatory cytokines (IL-8, IL-1β, IL-6 and TNF-α) was remarkably reduced (P < 0.05) along with the increased mRNA level of tight junction proteins (ZO-1 and Occludin, P < 0.05). Flow cytometry analysis showed that active or inactive A. muciniphila significantly suppressed the rate of the early and total apoptotic of the inflammatory IPEC-J2 cells (P < 0.05). According to results of transcriptome sequencing, active and inactive A. muciniphila may decline cell apoptosis by down-regulating the expression of key genes in calcium signaling pathway, or up-regulating the expression of key genes in cell cycle signaling pathway. And the bacterium may alleviate the inflammation of IECs by down-regulating the expression of PI3K upstream receptor genes. Our results indicate that A. muciniphila may be a promising NGP targeting intestinal inflammation.

Apple polyphenols improve intestinal barrier function by enhancing antioxidant capacity and suppressing inflammation in weaning piglets

This study aimed to examine the effects of apple polyphenols (APPs) on antioxidant capacity, immune and inflammatory response, and barrier function in weaning piglets. Results showed that APPs improved jejunal barrier function by increasing the villus height, villus height/crypt depth, the mRNA levels of occludin, mucin-1, and mucin-4 and up-regulating the protein expression of occluding (P < 0.05). As for antioxidant capacity, APPs increased the activities of total superoxide dismutase and glutathione peroxidase and total antioxidant capacity level in jejunum (P < 0.05). Besides, APPs up-regulated the protein expressions of NAD(P)H quinone dehydrogenase 1 (NQO1), heme oxygenase-1 (HO-1), and nuclear-related factor 2 (NRF2) and down-regulated the protein expression of kelch-like ECH-associated protein 1 (Keap1). As regard to immune and inflammatory response, APPs increased the immunoglobulin A content in serum and decreased the mRNA levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB), and IL-8 in jejunum (P < 0.05). Overall, dietary APPs supplementation improves the jejunal barrier function by enhancing antioxidant capacity and suppressing the mRNA expression related to inflammation, which may be related to the NRF2 signal and TLR4/NF-κB signal.

Protective Effects of Bacillus amyloliquefaciens 40 Against Clostridium perfringens Infection in Mice

This study aimed to investigate the protective effects of Bacillus amyloliquefaciens (BA40) against Clostridium perfringens (C. perfringens) infection in mice. Bacillus subtilis PB6 was utilized as a positive control to compare the protective effects of BA40. In general, a total of 24 5-week-old male C57BL/6 mice were randomly divided into four groups, with six mice each. The BA40 and PB6 groups were orally dosed with resuspension bacteria (1 × 10⁹ CFU/ml) once a day, from day 1 to 13, respectively. In the control and infected groups, the mice were orally pre-treated with phosphate-buffered saline (PBS) (200 μl/day). The mice in the infected groups, PB6 + infected group and BA40 + infected group, were orally challenged with C. perfringens type A (1 × 10⁹ CFU/ml) on day 11, whereas the control group was orally dosed with PBS (200 μl/day). The results showed that the BA40 group ameliorated intestinal structure damage caused by the C. perfringens infection. Furthermore, the inflammatory responses detected in the infected groups which include the concentrations of IL-1β, TNF-α, IL-6, and immunoglobulin G (IgG) in the serum and secretory immunoglobulin (SigA) in the colon, and nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) activity in the jejunum, were also alleviated (P < 0.05) by BA40 treatment. Similarly, cytokines were also detected by quantitative PCR (qPCR) in the messenger RNA (mRNA) levels, and the results were consistent with the enzyme-linked immunosorbent assay (ELISA) kits. Additionally, in the infected group, the mRNA expression of Bax and p53 was increasing and the Bcl-2 expression was decreasing, which was reversed by BA40 and PB6 treatment (P < 0.05). Moreover, the intestinal microbiota imbalance induced by the C. perfringens infection was restored by the BA40 pre-treatment, especially by improving the relative abundance of Verrucomicrobiota (P < 0.05) and decreasing the relative abundance of Bacteroidetes (P < 0.05) in the phyla level, and the infected group increased the relative abundance of some pathogens, such as Bacteroides and Staphylococcus (P < 0.05) in the genus level. The gut microbiota alterations in the BA40 group also influenced the metabolic pathways, and the results were also compared. The purine metabolism, 2-oxocarboxylic acid metabolism, and starch and sucrose metabolism were significantly changed (P < 0.05). In conclusion, our results demonstrated that BA40 can effectively protect mice from C. perfringens infection.

Research progress on diarrhoea and its mechanism in weaned piglets fed a high-protein diet

In order to pursue faster growth and development of weaned piglets, increased dietary protein (CP) levels were favoured by the pig industry and the feed industry. The digestive organs of piglets were not fully developed at weaning, and the digestive absorption capacity of protein was limited. High-protein diets can cause allergic reactions in piglets, destroy intestinal structural integrity, reduce immunity, and cause intestinal flora imbalance. Undigested proteins were prone to produce toxic substances, such as ammonia and biogenic amines, after fermentation in the hindgut, which negatively affects the health of the intestine and eventually causes reduced growth performance and diarrhoea in piglets. This review revealed the mechanism of diarrhoea caused by high-protein diets in weaned piglets and provided ideas for preventing diarrhoea in weaned piglets.

Double-Barrel Shotgun: Probiotic Lactic Acid Bacteria with Antiviral Properties Modified to Serve as Vaccines

Contrary to the general belief that the sole function of probiotics is to keep intestinal microbiota in a balanced state and stimulate the host’s immune response, several studies have shown that certain strains of lactic acid bacteria (LAB) have direct and/or indirect antiviral properties. LAB can stimulate the innate antiviral immune defence system in their host, produce antiviral peptides, and release metabolites that prevent either viral replication or adhesion to cell surfaces. The SARS-CoV (COVID-19) pandemic shifted the world’s interest towards the development of vaccines against viral infections. It is hypothesised that the adherence of SARS-CoV spike proteins to the surface of Bifidobacterium breve could elicit an immune response in its host and trigger the production of antibodies. The question now remains as to whether probiotic LAB could be genetically modified to synthesize viral antigens and serve as vaccines—this concept and the role that LAB play in viral infection are explored in this review.

Potential Probiotic Lactobacillus rhamnosus (MTCC-5897) Inhibits Escherichia coli Impaired Intestinal Barrier Function by Modulating the Host Tight Junction Gene Response

Probiotic as a preventive medicine is emerging as an indispensable tool in addressing the foodborne infections or gastrointestinal disorders. The present study was sought to determine the in vitro prophylactic potential of probiotic Lactobacillus rhamnosus (LR: MTCC-5897) against Escherichia coli (ATCC 14948) induced impairment in intestinal barrier function using Caco-2 cells. Intestinal cells exposed to E. coli demonstrated significantly higher phenol red flux (p < 0.05) and concomitantly decreased TEER (0.69 ± 0.01) in contrast to control or L. rhamnosus (10⁹ cfu/mL)-treated cells. However, E. coli-induced barrier hyperpermeability was restored to significant extents (p < 0.01) when E. coli were excluded, competed or displaced by probiotic LR. Similarly, exposure of Caco-2 cells to E. coli reduced the mRNA expression of key tight junction genes, viz. Zo-1, Claudin-1, Occludin and Cingulin which however were restored significantly (p < 0.05) with L. rhamnosus treatment during exclusion or competition than displacement assays. The protective behaviour of probiotic LR against E. coli can also be observed in immunofluorescent and electron micrograph where intact cellular morphology along with preserved distribution and localisation of key integrity proteins can be found in LR-treated cells in contrast to distorted and disorganised distribution observed with E. coli exposure. In conclusion, L. rhamnosus inhibited and re-established E. coli-impaired intestinal barrier function by improving the expression and distribution of key junction protein and hence could serve an essential food additive to address the various health complications especially those associated with gastrointestinal tract.

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.

Exopolysaccharides as Antimicrobial Agents: Mechanism and Spectrum of Activity

Exopolysaccharides (EPSs) are metabolites synthesized and excreted by a variety of microorganisms, including lactic acid bacteria (LAB). EPS serve several biological functions such as interactions between bacteria and their environments, protection against hostile conditions including dehydration, the alleviation of the action of toxic compounds (bile salts, hydrolyzing enzymes, lysozyme, gastric, and pancreatic enzymes, metal ions, antibiotics), and stresses (changing pH, osmolarity), and evasion of the immune response and phage attack. Bacterial EPSs are considered valuable by the food, pharmaceutical, and nutraceutical industries, owing to their health-promoting benefits and rheological impacts. Numerous studies have reported the unusual antimicrobial activities of various EPS against a wide variety of pathogenic microbes (bacteria, virus, and fungi). This review aims to provide a comprehensive examination of the in vitro and in vivo antimicrobial activities of different EPSs, mainly against foodborne bacterial, fungal, and viral pathogens. The mechanism of EPS action against these pathogens as well as the methods used to measure antimicrobial activities are critically reviewed.

Lentinan administration alleviates diarrhea of rotavirus-infected weaned pigs via regulating intestinal immunity

BACKGROUND

Lentinan (LNT) may regulate many important physiological functions of human and animals. This study aimed to verify whether LNT administration could relieve diarrhea via improving gut immunity in rotavirus (RV)-challenged weaned pigs.

METHODS

Twenty-eight weaned pigs were randomly fed 2 diets containing 0 or 84 mg/kg LNT product for 19 d (n = 14). RV infection was executed on d 15. After extracting polysaccharides from LNT product, its major monosaccharides were analyzed. Then, LNT polysaccharide was used to administrate RV-infected IPEC-J2 cells.

RESULTS

Dietary LNT supplementation supported normal function of piglets even when infected with RV, as reflected by reduced growth performance loss and diarrhea prevalence, and maintained gut immunity (P < 0.05). The polysaccharide was isolated from LNT product, which molecular weight was 5303 Da, and major monosaccharides included glucose, arabinose and galactose. In RV-infected IPEC-J2 cells, this polysaccharide significantly increased cell viability (P < 0.05), and significantly increased anti-virus immunity via regulating pattern recognition receptors and host defense peptides (P < 0.05).

CONCLUSION

Those results suggest that LNT administration increases the piglets' resistance to RV-induced stress, likely by supporting intestinal immunity.

Infusion of short chain fatty acids in the ileum improves the carcass traits, meat quality and lipid metabolism of growing pigs

Short chain fatty acids (SCFA) are the main products of indigestible carbohydrates undergoing bacterial fermentation in the hindgut, which are related to some physiological functions. This study was designed to investigate the effects of SCFA infusion by ileum on the carcass traits, meat quality and lipid metabolism of growing pigs. In a 28-day study, 24 growing barrows fitted with a T-cannula in distal ileum were divided into 4 treatments: 1) Control, 2) antibiotics (AB), 3) AB + 300 mL of SCFA1 solution (ABS1), 4) AB + 300 mL of SCFA2 solution (ABS2). The concentrations of acetate, propionate and butyrate in SCFA1 solution were respectively 61.84, 18.62 and 12.55 mmol/L, and in SCFA2 were respectively 40.08, 15.41 and 9.78 mmol/L. The results showed that the SCFA infusion increased the average daily feed intake and average daily gain of pigs (P < 0.05). Meanwhile, the SCFA treatments increased longissimus dorsi area (P < 0.05) and carcass weight (P = 0.058), decreased the drip loss of longissimus dorsi (P = 0.059), and reduced serum concentrations of triglyceride, total cholesterol and urea nitrogen (P < 0.05). Besides, the SCFA administration inhibited the mRNA expressions of fatty acid synthase (FAS) and acetyl-CoA carboxylase in longissimus dorsi (P < 0.05), the mRNA expression of FAS in the liver (P < 0.05), and the mRNA expression of hormone-sensitive lipase in abdominal fat (P < 0.05). Short chain fatty acid infusion also enhanced the mRNA expression of carnitine palmitoyltransferase-1α in the liver (P < 0.05), the mRNA expressions of peroxisome proliferator activated receptor gamma and lipoprotein lipase in abdominal fat (P < 0.05), and the mRNA expressions of free fatty acid receptor 2, glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1 in the colon (P < 0.05). These results suggested that SCFA administration in the ileum could improve the carcass traits and meat quality of growing pigs, which was possibly due to the fact that SCFA modulated lipid metabolism.

Sodium acetate, propionate, and butyrate reduce fat accumulation in mice via modulating appetite and relevant genes

OBJECTIVES

Acetate, propionate, and butyrate, three of the most common short-chain fatty acids (SCFAs), can be produced when some non-digestible carbohydrates enter the large intestine and undergo bacterial fermentation. The aim of this study was to investigate the effects of these three SCFAs on appetite regulation and lipid metabolism and to determine the extent that appetite contributes to the beneficial influences of SCFAs.

METHODS

In a 35-d study, 48 C57BL/6J male mice were randomly allocated to six groups: control; 5% sodium acetate; 5% sodium propionate; 5% sodium butyrate; pair fed 1; and pair fed 2.

RESULTS

The study showed that dietary supplementation of sodium acetate reduced serum triacylglycerol, free fatty acids, glucose, and interleukin (IL)-6 levels (P < 0.05), increased serum glucagon-like peptide 1, and leptin levels (P < 0.05), downregulated the mRNA expressions of fatty acid synthase, peroxisome proliferator-activated receptor, and lipoprotein lipase (P < 0.05), and upregulated the mRNA expressions of fasting-induced adipose factor, nuclear respiratory factor 1, mitochondrial transcription factor A, tumor necrosis factor receptor superfamily member 9, cytochrome-C oxidase IV and free fatty acid receptor 2 (P < 0.05). Sodium propionate also reduced serum IL-1β level (P < 0.05), increased serum peptide YY level (P < 0.05), downregulated the mRNA expressions of acetyl-coenzyme A carboxylase and sterol regulatory element-binding protein 1c (P < 0.05), and upregulated the mRNA expression of transmembrane protein 26 (P < 0.05). Additionally, sodium butyrate decreased average daily feed intake (P < 0.05) downregulated the mRNA expression of myosin heavy-chain (MyHc) Ⅱb (P < 0.05), and upregulated the mRNA expressions of lipase hormone-sensitive, MyHC Ⅱa and carnitine palmitoyltransferase-1α (P < 0.05). Moreover, the metabolic benefits of SCFAs were partly attributed to the reduction of feed intake.

CONCLUSION

Taken together, SCFAs could reduce appetite and fat accumulation via modulating relevant genes and hormones, which might further illustrate the potential mechanisms that underlay the effects of SCFAs on lipid homeostasis and control of body weight.

Harnessing the potential of Lactobacillus species for therapeutic delivery at the lumenal-mucosal interface

Lactobacillus species have been studied for over 30 years in their role as commensal organisms in the human gut. Recently there has been a surge of interest in their abilities to natively and recombinantly stimulate immune activities, and studies have identified strains and novel molecules that convey particular advantages for applications as both immune adjuvants and immunomodulators. In this review, we discuss the recent advances in Lactobacillus-related activity at the gut/microbiota interface, the efforts to probe the boundaries of the direct and indirect therapeutic potential of these bacteria, and highlight the continued interest in harnessing the native capacity for the production of biogenic compounds shown to influence nervous system activity. Taken together, these aspects underscore Lactobacillus species as versatile therapeutic delivery vehicles capable of effector production at the lumenal-mucosal interface, and further establish a foundation of efficacy upon which future engineered strains can expand.

Combined use of lactic-acid-producing bacteria as probiotics and rotavirus vaccine candidates expressing virus-specific proteins

Due to the lower efficacy of currently approved live attenuated rotavirus (RV) vaccines in developing countries, a new approach to the development of safe mucosally administered live bacterial vectors is being considered, using probiotic bacteria as an efficient delivery platform for heterologous RV antigens. Lactic acid bacteria (LAB), which are considered food-grade bacteria and normal microbiota, have been utilized throughout history as probiotics and developed since the 1990s as a delivery system for recombinant heterologous proteins. Over the last decade, LAB have frequently been used as a platform for the delivery of various RV antigens to the mucosa. Given the appropriate safety profile for neonates and providing the benefits of probiotics, recombinant LAB-based vaccines could potentially address the need for a subunit RV vaccine. The present review focuses mainly on different recombinant LAB vaccine constructs for RV and their potential as an alternative recombinant vaccine against RV disease.

Pediococcus pentosaceus ZJUAF-4 relieves oxidative stress and restores the gut microbiota in diquat-induced intestinal injury

Lactic acid bacteria (LAB) play a key role in promoting health and preventing diseases because of their beneficial effects, such as antimicrobial activities, modulating immune responses, maintaining the gut epithelial barrier and antioxidant capacity. However, the mechanisms with which LAB relieve oxidative stress and intestinal injury induced by diquat in vivo are poorly understood. In the present study, Pediococcus pentosaceus ZJUAF-4 (LAB, ZJUAF-4), a selected probiotics strain with strong antioxidant capacities, was appointed to evaluate the efficiency against oxidative stress in diquat-induced intestinal injury of mice. Alanine transaminase (ALT) and aspartate aminotransferase (AST) were analyzed to estimate the liver injury. The intestinal permeability was evaluated by 4 kDa fluorescein isothiocyanate (FITC)-dextran (FD4), D-lactate (DLA), and diamine oxidase (DAO) levels. Jejunum reactive oxygen species (ROS) production was examined by dihydroethidium (DHE) staining. Western blotting was used to detect the expression of nuclear factor (erythroid-derived-2)-like 2 (Nrf2) and its downstream genes in jejunum. The gut microbiota was analyzed by high-throughput sequencing method based on the 16S rRNA genes. The results showed that ZJUAF-4 pretreatment was found to protect the intestinal barrier function and maintain intestinal redox homeostasis under diquat stimulation. Moreover, oral administration of ZJUAF-4 increased the expression of Nrf2 and its downstream genes. High-throughput sequencing analysis indicated that ZJUAF-4 contributed to restoring the gut microbiota influenced by diquat. Our results suggested that ZJUAF-4 protected the intestinal barrier from oxidative stress-induced damage by modulating the Nrf2 pathway and gut microbiota, indicating that ZJUAF-4 may have potential applications in preventing and treating oxidative stress-related intestinal diseases. KEY POINTS: • ZJUAF-4 exerted protective effects against diquat-induced intestinal injury. • Activation of Nrf2 and its downstream targets towards oxidative stress. • ZJUAF-4 administration restoring gut microbiota.

Overview of the Development, Impacts, and Challenges of Live-Attenuated Oral Rotavirus Vaccines

Safety, efficacy, and cost-effectiveness are paramount to vaccine development. Following the isolation of rotavirus particles in 1969 and its evidence as an aetiology of severe dehydrating diarrhoea in infants and young children worldwide, the quest to find not only an acceptable and reliable but cost-effective vaccine has continued until now. Four live-attenuated oral rotavirus vaccines (LAORoVs) (Rotarix^®, RotaTeq^®, Rotavac^®, and RotaSIIL^®) have been developed and licensed to be used against all forms of rotavirus-associated infection. The efficacy of these vaccines is more obvious in the high-income countries (HIC) compared with the low- to middle-income countries (LMICs); however, the impact is far exceeding in the low-income countries (LICs). Despite the rotavirus vaccine efficacy and effectiveness, more than 90 countries (mostly Asia, America, and Europe) are yet to implement any of these vaccines. Implementation of these vaccines has continued to suffer a setback in these countries due to the vaccine cost, policy, discharging of strategic preventive measures, and infrastructures. This review reappraises the impacts and effectiveness of the current live-attenuated oral rotavirus vaccines from many representative countries of the globe. It examines the problems associated with the low efficacy of these vaccines and the way forward. Lastly, forefront efforts put forward to develop initial procedures for oral rotavirus vaccines were examined and re-connected to today vaccines.

Dynamic alterations in early intestinal development, microbiota and metabolome induced by in ovo feeding of L-arginine in a layer chick model

Background

Prenatal nutrition is crucial for embryonic development and neonatal growth, and has the potential to be a main determinant of life-long health. In the present study, we used a layer chick model to investigate the effects of in ovo feeding (IOF) of L-arginine (Arg) on growth, intestinal development, intestinal microbiota and metabolism. The treatments included the non-injected control, saline-injected control, and saline containing 2, 6, or 10 mg Arg groups.

Results

IOF Arg increased early intestinal index and villus height, and enhanced uptake of residual yolk lipid, contributing to subsequent improvement in the early growth performance of chicks. Prenatal Arg supplementation also increased the early microbial α-diversity, the relative abundance of Lactobacillales and Clostridiales, and decreased the relative abundance of Proteobacteria of cecum in chicks. Furthermore, the shift of cecal microbiota composition and the colonization of potential probiotics were accelerated by IOF of Arg. Simultaneously, metabolomics showed that metabolisms of galactose, taurine-conjugated bile acids and lipids were modulated to direct more energy and nutrients towards rapid growth of intestine at the beginning of post-hatch when embryos received IOF of Arg.

Conclusions

Prenatal Arg supplementation showed beneficial effects on the early intestinal development, cecal microbiota and host metabolism of layer chicks, contributing to subsequent improvement in the early growth performance. These findings provide new insight into the role of IOF of Arg in the establishment of the gut microbiota of newly-hatched layer chicks, and can expand our fundamental knowledge about prenatal nutrition, early bacterial colonization and intestinal development in neonate.

Dietary pectic oligosaccharide supplementation improves rat reproductive performance via regulating intestinal volatile fatty acids during middle gestation

As a kind of green additive, pectic oligosaccharide (POS) may regulate some physiological functions of animals, such as gut health, antioxidant capacity, immunity and lipid metabolism. This study aimed to identify whether POS administration can improve maternal reproduction, and to determine the possible metabolism. A total of 48 pregnant Wistar rats randomly allotted into 2 groups, and each group was fed a diet supplemented with 0 or 800 mg/kg of POS. Pectic oligosaccharide administration increased rat born number (P < 0.05), did not affect rat embryo number on d 7 of gestation, but increased rat fetus number on d 14 of gestation (P < 0.05). On d 14 of gestation, POS treatment improved Lactobacillus and Bifidobacterium populations and volatile fatty acid concentrations of cecal digesta (P < 0.05), hormone (progesterone and nitric oxide) and cytokine (interleukin 2) concentrations of serum (P < 0.05), and antioxidant capacity of serum (increased total antioxidant capacity and decreased malondialdehyde) and placenta (increased total superoxide dismutase, decreased malondialdehyde) (P < 0.05) in pregnant rats. These results suggest that POS administration improved rat reproduction via decreasing fetus loss in middle gestation. This was due to the increased volatile fatty acid concentrations in rat gut improving hormone and inflammatory-cytokine productions, and antioxidant capacity.

Prophylactic effect of Lactobacillus plantarum KSFY06 on HCl/ethanol-induced gastric injury in mice

The present study was conducted to determine the prophylactic effect of Lactobacillus plantarum KSFY06 (LP-KSFY06) on HCl/ethanol-induced gastric injury in Kunming mice.

Short chain fatty acids could prevent fat deposition in pigs via regulating related hormones and genes

Short chain fatty acids (SCFAs) are produced when indigestible carbohydrates, such as fiber and resistant starch, undergo fermentation by specific microbiota in the hindgut.

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

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

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

Effect of a Synbiotic Mix on Intestinal Structural Changes, and Salmonella Typhimurium and Clostridium Perfringens Colonization in Broiler Chickens

Synbiotics can prevent gastrointestinal infections in broilers. This work studies the effect of a Synbiotic on broilers. One-day-old male broilers were divided into groups: Control; Synbiotic; Synbiotic + S. Typhimurium; Synbiotic + C. perfringens; Synbiotic + S. Typhimurium + C. perfringens; S. Typhimurium; C. perfringens; and S. Typhimurium + C. perfringens. Histopathological analysis revealed that the Synbiotic promoted longer villi, less deep crypts, and better villi-crypt ratio. Broilers treated with the Synbiotic, infected with pathogens or not, had healthier mucosa. In groups infected with pathogens, the frequency and intensity of histopathologic lesions were lessened often in groups treated with the Synbiotic. The Synbiotic group had higher lactic acid bacteria counts than the Control group on day 39, and the isolation frequency of S. Typhimurium was lower (p < 0.05) in the Synbiotic-treated groups. On day 18, mucosa, villi, villi-crypt ratio, crypt, and feed intake were influenced by Enterobacteriaceae. However, on day 39 (end of the trial), those parameters were influenced by lactic acid bacteria. The Synbiotic influenced morphological modifications in the duodenal mucosa, which in turn gave the broilers the ability to resist infections caused by S. Typhimurium and C. perfringens, by inhibiting their growth and decreasing the intensity and frequency of histopathological injuries.

Lentinan administration relieves gut barrier dysfunction induced by rotavirus in a weaned piglet model

Rotavirus (RV) is a pathogen that induces severe diarrhea in infants and young animals. Shiitake mushroom is a traditional food, which can improve physiological function, including gut health. Lentinan (LNT) is the main functional component of Shiitake mushroom. This study aimed to verify whether LNT administration could improve intestinal barrier function, thereby decreasing RV-induced diarrhea in a porcine model. According to initial weight and origin, a total of 28 weaned piglets were randomly fed 2 diets containing 0 or 84 mg kg-1 LNT for 19 d (n = 14). On day 15, RV was orally infused to half of the pigs in each group. RV-induced diarrhea (P < 0.05), the positive rate of RV non-structural protein 4 (NSP4), impaired intestinal morphology, antioxidant capacity and microbiota (P < 0.05), and increased apoptosis of jejunal epithelial cells (P < 0.05) were assessed in the piglets. Dietary LNT supplementation was found to improve intestinal morphology, permeability, antioxidant capacity and microbiota (P < 0.05). Supplementation also further alleviated the effects of RV infection on diarrhea, intestinal morphology, permeability, antioxidant capacity, microbiota and apoptosis of jejunal epithelial cells in piglets (P < 0.05). Thus, these results suggest that LNT administration relieved RV-induced diarrhea in piglets, which could be due to the increase in antioxidant capacity, reduction in apoptosis and improvement of the microbiota-increased gut barrier.

Oral administration of Lactobacillus rhamnosus GG to newborn piglets augments gut barrier function in pre-weaning piglets

To understand the effects of Lactobacillus rhamnosus GG (ATCC 53103) on intestinal barrier function in pre-weaning piglets under normal conditions, twenty-four newborn littermate piglets were randomly divided into two groups. Piglets in the control group were orally administered with 2 mL 0.1 g/mL sterilized skim milk while the treatment group was administered the same volume of sterilized skim milk with the addition of viable L. rhamnosus at the 1st, 3rd, and 5th days after birth. The feeding trial was conducted for 25 d. Results showed that piglets in the L. rhamnosus group exhibited increased weaning weight and average daily weight gain, whereas diarrhea incidence was decreased. The bacterial abundance and composition of cecal contents, especially Firmicutes, Bacteroidetes, and Fusobacteria, were altered by probiotic treatment. In addition, L. rhamnosus increased the jejunal permeability and promoted the immunologic barrier through regulating antimicrobial peptides, cytokines, and chemokines via Toll-like receptors. Our findings indicate that oral administration of L. rhamnosus GG to newborn piglets is beneficial for intestinal health of pre-weaning piglets by improving the biological, physical, and immunologic barriers of intestinal mucosa.

Experiences with rotavirus vaccines: can we improve rotavirus vaccine impact in developing countries?

Rotavirus vaccines have been introduced into over 95 countries globally and demonstrate substantial impact in reducing diarrheal mortality and diarrheal hospitalizations in young children. The vaccines are also considered by WHO as "very cost effective" interventions for young children, particularly in countries with high diarrheal disease burden. Yet the full potential impact of rotavirus immunization is yet to be realized. Large countries with big birth cohorts and where disease burden is high in Africa and Asia have not yet implemented rotavirus vaccines at all or at scale. Significant advances have been made demonstrating the impact of the vaccines in low- and lower-middle income countries, yet the modest effectiveness of the vaccines in these settings is challenging. Current research highlights these challenges and considers alternative strategies to overcome them, including alternative immunization schedules and host factors that may inform us of new opportunities.

Effects of dietary supplementation with Lactobacillus acidophilus on the performance, intestinal physical barrier function, and the expression of NOD-like receptors in weaned piglets

Lactobacillus supplementation is beneficial to the barrier function of the intestinal physical barrier in piglets. However, the mechanisms underlying this beneficial function remain largely unknown. Here, we investigated the effects of dietary supplementation with Lactobacillus acidophilus on the performance, intestinal physical barrier functioning, and NOD-like receptors (NLRs) expression in weaned piglets. Sixteen weaned piglets were randomly allocated to two groups. The control group received a corn-soybean basal diet, while the treatment group received the same diet adding 0.1% L. acidophilus, for 14 days. As a result, dietary L. acidophilus supplementation was found to increase the average daily gain (ADG) (P < 0.05), reduced serum diamine oxidase (DAO) activity (P < 0.05), increased the mRNA expression and protein abundance of occludin in the jejunum and ileum (P < 0.01), reduced the mRNA levels of NOD1 (P < 0.01), receptor interacting serine/threonine kinase 2 (RIPK2) (P < 0.05), nuclear factor κB (NF-κB) (P < 0.01), NLR family pyrin domain containing 3 (NLRP3) (P < 0.01), caspase-1 (P < 0.01), interleukin 1β (IL-1β) (P < 0.05) and IL-18 (P < 0.01) in the jejunum tissues of the weaned pigs. The expression of NLRP3 (P < 0.05), caspase-1 (P < 0.01), IL-1β (P < 0.05) and IL-18 (P < 0.05) was also reduced in the ileum tissues of the weaned pigs. These results showed that L. acidophilus supplementation improves the growth performance, enhances the intestinal physical barrier function, and inhibits the expression of NOD1 and NLRP3 signaling-pathway-related genes in jejunum and ileum tissues. They also suggest that L. acidophilus enhances the intestinal physical barrier functioning by inhibiting IL-1β and IL-18 pro-inflammatory cytokines via the NOD1/NLRP3 signaling pathway in weaned piglets.

Effects of Newly Developed Synbiotic and Commercial Probiotic Products on The Haematological Indices, Serum Cytokines, Acute Phase Proteins Concentration, and Serum Immunoglobulins Amount in Sows and Growing Pigs - A Pilot Study

Introduction

The aim of the study was to determine the effects of supplementation of sows' and growing pigs' diets with three newly developed synbiotic and two extant commercial probiotic products on selected immune parameters under field conditions.

Material and Methods

The study was performed on 30 sows and 48 piglets of the Danbred breed. Immune parameters such as concentration and proportion of white blood cells and their subpopulations, immunoglobulins amount in serum, and serum concentration of cytokines and acute phase proteins were recorded with the use of a haematology analyser and ELISA kits.

Results

No significant differences between treatment groups and controls were found with regard to the immune parameters evaluated except for serum immunoglobulin concentration, which was significantly increased by synbiotic products B and C and probiotic product D.

Conclusion

The results of the study indicate that the synbiotic products B and C and probiotic product D are worthy of further investigation as promising candidates to improve the immune status of healthy sows and their offspring.

Probiotics-fermented Massa Medicata Fermentata ameliorates weaning stress in piglets related to improving intestinal homeostasis

Weaning stress has serious negative effects on piglets' health and the swine industry. Probiotics-fermented Chinese herbal medicines are potential feed additives to ameliorate weaning stress. In this study, the effects of probiotics-fermented Massa Medicata Fermentata (MMFP) on intestinal homeostasis were evaluated in weaning piglets. Dietary supplementation with MMFP promoted the development of the intestinal structure and elevated the concentrations of lactic acid and short-chain fatty acids (SCFAs) in the intestinal contents and antioxidant capacities in serum. MMFP reduced the levels of inflammatory factors in the intestinal mucosa. Microbial community analysis demonstrated that MMFP led to the selective and progressive enrichment of lactic acid- and SCFA-producing bacteria along the gastrointestinal tract, in particular, OTUs corresponding to Lactobacillus, Streptococcus, Acetitomaculum, Roseburia, and Eubacterium xylanophilum group, while MMFP reduced the relative abundance of pathogenic bacteria. On the contrary, antibiotics had negative effects on intestinal histology and increased the relative abundance of pro-inflammatory bacterium, such as Marvinbryantia, Peptococcus, Turicibacter, and Blautia. Correlation analysis reflected that the bacteria enriched in MMFP group were positively correlated with enhanced intestinal homeostasis, which suggested that dietary supplementation with MMFP enhanced host intestinal homeostasis by modulating the composition of gut microbiota and the levels of beneficial SCFAs, thus ameliorating weaning stress in piglets.

Effects of an oral synbiotic on the gastrointestinal immune system and microbiota in patients with diarrhea-predominant irritable bowel syndrome

Purpose

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a common functional gastrointestinal disorder. Probiotics and synbiotics have been shown to improve symptoms of IBS, although mechanisms of action are currently not understood.

Methods

We investigated the effects of a 4-week oral synbiotic treatment (OMNi-BiOTiC^® Stress Repair) in ten IBS-D patients on gastrointestinal mucosal and fecal microbiota, mucosa-associated immune cells, and fecal short-chain fatty acids. The upper and lower gastrointestinal tracts were compared before and after a 4-week synbiotic treatment using endoscopic evaluation to collect mucosal specimens for FACS analysis and mucosal 16S rRNA gene analysis. In stool samples, analysis for fecal SCFAs using GC–MS, fecal zonulin using ELISA, and fecal 16S rRNA gene analysis was performed.

Results

Synbiotics led to an increased microbial diversity in gastric (p = 0.008) and duodenal (p = 0.025) mucosal specimens. FACS analysis of mucosal immune cells showed a treatment-induced reduction of CD4⁺ T cells (60 vs. 55%, p = 0.042) in the ascending colon. Short-chain fatty acids (acetate 101 vs. 202 µmol/g; p = 0.007) and butyrate (27 vs. 40 µmol/g; p = 0.037) were elevated in fecal samples after treatment. Furthermore, treatment was accompanied by a reduction of fecal zonulin concentration (67 vs. 36 ng/ml; p = 0.035) and disease severity measured by IBS-SSS (237 vs. 54; p = 0.002).

Conclusions

Our findings indicate that a short-course oral synbiotic trial may influence the human gastrointestinal tract in IBS-D patients on different levels which are region specific.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1826-7) contains supplementary material, which is available to authorized users.

Probiotics interaction with foodborne pathogens: a potential alternative to antibiotics and future challenges

Antibiotics are a key tool used nowadays in health care industry to fight against bacterial infections; however, repeated antibiotic use or misuses, have led to bacterial resistance, causing significant threats for many people with common bacterial infections. The use of probiotics to enhance gastrointestinal health has been proposed for many years. In recent years, there has been an increasing interest in the use of probiotic bacteria as alternatives for antibiotics for preventing or treating various intestinal infections. Several important underlying mechanisms responsible for the antagonistic effects of probiotics on different microorganisms include: (1) competitive exclusion for adhesion sites and nutritional sources; (2) secretion of antimicrobial substances; (3) enhancement of intestinal barrier function; and (4) immunomodulation. However, their mode of action is not very well understood and therefore a clearer understanding of these mechanisms is necessitated. This will enable appropriate probiotic strains to be selected for particular applications and may reveal new probiotic functions. The goal of this review was to highlight some studies from literature describing the probiotic interaction with several major foodborne pathogens, as well as explore the mechanisms for such probiotic-pathogen interaction. The review will conclude by presenting future perspective and challenges of probiotic application in food products.

Dietary supplementation with Clostridium butyricum helps to improve the intestinal barrier function of weaned piglets challenged with enterotoxigenic Escherichia coli K88

AIMS

The objective of this study was twofold: (i) to examine the effect of Clostridium butyricum on intestinal barrier function and (ii) to elucidate the mechanisms involved in enhanced intestinal barrier function.

METHODS AND RESULTS

Forty-eight weaned piglets were assigned randomly to either a basal diet or a C. butyricum-supplemented diet. On day 15, all pigs were orally challenged with enterotoxigenic Escherichia coli (ETEC) K88 or saline. Clostridium butyricum decreased serum diamine oxidase activity and d-lactic acid concentration, as well as increased intestinal tight junction proteins (ZO-1, claudin-3 and occludin) expression in ETEC K88-infected pigs. Moreover, C. butyricum decreased IL-1β and IL-18 levels in serum and gut, whereas it increased IL-10 levels. Furthermore, C. butyricum downregulated NLRP3 and caspase-1 expression in ETEC K88-challenged pig gut, but did not affect apoptosis-associated speck-like protein expression.

CONCLUSIONS

Clostridium butyricum enhanced intestinal barrier function and inhibited apoptosis-associated speck-like protein-independent NLRP3 inflammasome signalling pathway in weaned piglets after ETEC K88 challenge.

SIGNIFICANCE AND IMPACT OF THE STUDY

The novelty of this study lies in the beneficial effects of C. butyricum on intestinal health, likely by improving intestinal barrier function and alleviating inflammatory reactions.