Impairment of Intestinal Barrier Function Induced by Early Weaning via Autophagy and Apoptosis Associated With Gut Microbiome and Metabolites

Goat Milk-Derived Extracellular Vesicles Alleviate Colitis Potentially Through Improved Gut Microbiota in Mice

Ulcerative colitis (UC) is characterized clinically by intestinal inflammation and gut microbiota dysbiosis. The consumption of biologics, although effective in inflammation control, may lead to adverse effects and is inconvenient for at-home administration. Goat milk-derived extracellular vesicles (GMEVs) have been proposed as a supplement to prevent intestinal inflammation. However, their therapeutic potential for colitis remains elusive. This study aimed to explore the preventive effect of GMEVs on colitis and its underlying mechanisms through the microbiota-immune axis using a dextran sodium sulfate (DSS)-induced colitis mouse model. We found that a pre-treatment of 20 mg/kg/d GMEVs effectively prevented body weight loss, colon shortening, the depletion of colonic goblet cells, and the disappearance of crypts, while enhancing the intestinal mucosal barrier. Consistent with these phenotypes, GMEV pre-treatment increased levels of IL-22 and IL-10 and decreased levels of IL-1β, TNF-α, IL-6, and iNOS. However, GMEVs themselves had no effect on normal mice. Paralleling the alleviation of intestinal inflammation, GMEV pre-treatment also restored the reduction in unclassified Muribaculaceae, Dubosiella, and Lactobacillus and suppressed the expansion of Alistipes and Proteobacteria following DSS treatment. Additionally, GMEV intake significantly downregulated the expression of proteins in the NF-κB signaling pathway induced by DSS. In summary, GMEVs could prevent colitis by regulating intestinal inflammation, the intestinal mucosal barrier, gut microbiota, organ damage, and the immune microenvironment. This study demonstrated that GMEVs have potential application prospects for UC prevention.

Carvacrol Protects IPEC-J2 Cells from Oxidative Stress by Suppressing Autophagy

Oxidative stress impairs intestinal function and causes poor growth performance in piglets. Carvacrol is a natural essential oil, and its anti-oxidative and anti-inflammatory activities in the intestines of piglets have been reported in many studies. However, the mechanisms underlying these protective effects against oxidative stress remain unclear. This study aimed to investigate the possible pathway of carvacrol in the porcine intestine under oxidative stress using an in vitro model. Porcine intestinal epithelial cells (IPEC-J2) were treated with carvacrol and hydrogen peroxide (H2O2), an oxidative stress inducer, to investigate the protective mechanisms of carvacrol under oxidative stress. We found that carvacrol ameliorated a H2O2-induced loss of cell viability, apoptosis, and reduced intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels. Carvacrol reduced mitochondrial ROS generation and increased citrate synthase activity during oxidative stress. Furthermore, carvacrol attenuated an increase in the autophagy marker LC3II-to-I ratio and reduced the accumulation of lysosomes and autolysosomes induced by H2O2. The increased protein expression of the mitophagy marker PINK1, induced by H2O2, was also reduced by carvacrol treatment. Metformin-activated autophagy diminished the protective effects of carvacrol on cell viability and MDA levels under H2O2 treatment, indicating that autophagy inhibition is necessary for carvacrol-induced protection in IPEC-J2 cells during oxidative stress. In conclusion, this study demonstrated the underlying mechanism that carvacrol exerted its anti-oxidative effects on porcine intestinal epithelial cells by relieving excessive autophagy during weaning stress.

Effect of microbe-derived antioxidants on intestinal oxidative stress, NLRP3 inflammasome, morphologic structure, and growth performance in weanling piglets

Weaning stress induces pigs oxidative stress, which decreases growth performance, causes intestinal damage, and increases diarrhea and death in piglets. Microbe-derived antioxidants (MA) have an antioxidant and immune-modulatory role, but the impacts of MA on growth performance, intestinal oxidative stress, structure and function, and inflammatory response of weaned piglets are unclear. To elucidate whether MA can modulate intestinal oxidative stress, inflammatory response, and barrier function impairment and the possible mechanisms of its modulation, a total of 60 DLY (a crossbreed of Duroc, Landrance, and Yorkshire) piglets were randomly selected from 6 litters, with 10 piglets from each litter. Piglets from the same litter with similar body weight (6.44 ± 0.08 kg) were assigned to two groups: MA group (MA) and control group (Con). Results indicated that MA treatment markedly increased (p < 0.01) the average daily gain and average feed intake while decreasing the F/G (feed conversion ratio) (p < 0.01) at days 21-41. The addition of MA noticeably inhibited the ROS-NLRP3-IL-1β pathway (p < 0.05) and decreased inflammatory factors such as IL-1β and IL-18 in the intestine (p < 0.01). Moreover, MA supplementation significantly reduced the jejunal myosin light-chain kinase content (p < 0.01) while increasing the jejunal ZO-1 and Occludin content (p < 0.05). MA supplementation resulted in a noticeable rise in the colonic CD206+ positive cells (p < 0.01) and mRNA expression of iNOS (p < 0.01), COX2 (p < 0.05), TLR4 (p < 0.01), MyD88 (p < 0.01), and NF-κB (p < 0.01). MA treatment also activated the Nrf2-HO-1 pathway (p < 0.01). These discoveries imply that MA can improve the antioxidant capacity by activating the Nrf2 pathway, alleviate intestinal inflammation by inhibiting the activation of the ROS-NLRP3-IL-1β pathway and regulating the polarization of intestinal macrophages, and ultimately improve the growth performance of weaned piglets.

Lactobacillus reuteri ZJ617 attenuates metabolic syndrome via microbiota-derived spermidine

Metabolic syndrome (MetS) is a difficult-to-manage disease that poses a significant risk to human health. Here, we show that the supplementation of Lactobacillus reuteri ZJ617 ameliorates symptoms of MetS in mice induced by the high-fat diet. L. reuteri ZJ617 modulates host metabolism by interacting with the microbiome, resulting in the production of spermidine synthesized by the microbiota. L. reuteri ZJ617 serves as a source of substrates for the microbiota to synthesize spermidine, hence preventing the decline of bacteria responsible for spermidine production. Spermidine treatment mimics the metabolic effects of L. reuteri ZJ617, whereas pharmacological inhibition of spermidine biosynthesis in mice abolishes these benefits. Our findings reveal the mechanism by which L. reuteri ZJ617 alleviates MetS symptoms and provide support for its potential use as a probiotic for promoting metabolic health.

The oral-gut microbiome axis in health and disease

The human body hosts trillions of microorganisms throughout many diverse habitats with different physico-chemical characteristics. Among them, the oral cavity and the gut harbour some of the most dense and diverse microbial communities. Although these two sites are physiologically distinct, they are directly connected and can influence each other in several ways. For example, oral microorganisms can reach and colonize the gastrointestinal tract, particularly in the context of gut dysbiosis. However, the mechanisms of colonization and the role that the oral microbiome plays in causing or exacerbating diseases in other organs have not yet been fully elucidated. Here, we describe recent advances in our understanding of how the oral and intestinal microbiota interplay in relation to their impact on human health and disease.

Mulberry leaf benefits the intestinal epithelial barrier via direct anti-oxidation and indirect modulation of microbiota in pigs

BACKGROUND

Diarrhea and intestinal dysfunction commonly occur in young mammals, causing malnutrition and growth retardation in both human and livestock. As the traditional Chinese herb, mulberry leaf contains various bioactive compounds and showed several health benefits, such as regulating glucose and lipid metabolism, and modulating gut microbiota. Mulberry leaf exhibits the potential to modulate redox homeostasis and improve gut health, but the function and underlying mechanisms remains elucidative.

PURPOSE

To investigate the benefit of mulberry leaf on intestinal barrier in weanling pigs, illustrate the possible involvement of Keap1-Nrf2 mediated anti-oxidation and gut microbiota.

METHODS

Chemical compositions of mulberry leaf powder (MLP) and mulberry leaf extract (MLE) were determined. The effects of MLP on growth performance, intestinal barrier integrity, anti-oxidative capacity, immune function and gut microbiota were evaluated in weaned pigs. The regulation of redox homeostasis by MLE and the involvement of Keap1-Nrf2 signaling were further determined in H2O2 induced oxidative stress (OS) model in IPEC-J2 cells via determining reactive oxygen species (ROS) production by flow cytometry and related protein abundance by western blot analysis.

RESULTS

In weanling pigs, MLP reduced diarrhea incidence, and increased villus height, intestinal integrity and expression of tight junctions in intestinal mucosa. The improvement of intestinal barrier by MLP was associated with the enhancement in anti-oxidative capacity and the changes in gut microbiota and related short chain fatty acids production. Our study further revealed the direct regulation of MLE on tight junction expressions and ROS production to alleviate H2O2 induced OS in IPEC-J2 cells via the activating Keap1-Nrf2 signaling pathway.

CONCLUSIONS

Mulberry leaf in diet improved epithelial barrier via the direct anti-oxidation through the activation of Keap1-Nrf2 signaling pathway and the indirect modulation of gut microbiota in weaned pigs.

Bacillus spp. as potential probiotics: promoting piglet growth by improving intestinal health

The application of Bacillus spp. as probiotics in the swine industry, particularly for piglet production, has garnered significant attention in recent years. This review aimed to summarized the role and mechanisms of Bacillus spp. in promoting growth and maintaining gut health in piglets. Bacillus spp. can enhance intestinal barrier function by promoting the proliferation and repair of intestinal epithelial cells and increasing mucosal barrier integrity, thereby reducing the risk of pathogenic microbial invasion. Additionally, Bacillus spp. can activate the intestinal immune system of piglets, thereby enhancing the body's resistance to diseases. Moreover, Bacillus spp. can optimize the gut microbial community structure, enhance the activity of beneficial bacteria such as Lactobacillus, and inhibit the growth of harmful bacteria such as Escherichia coli, ultimately promoting piglet growth performance and improving feed efficiency. Bacillus spp. has advantages as well as challenges as an animal probiotic, and safety evaluation should be conducted when using the newly isolated Bacillus spp. This review provides a scientific basis for the application of Bacillus spp. in modern piglet production, highlighting their potential in improving the efficiency of livestock production and animal welfare.

Elucidating the modulatory role of dietary hydroxyproline on the integrity and functional performance of the intestinal barrier in early-weaned piglets: A comprehensive analysis of its interplay with the gut microbiota and metabolites

Piglets receive far less hydroxyproline (Hyp) from a diet after weaning than they obtained from sow's milk prior to weaning, suggesting that Hyp may play a protective role in preserving intestinal mucosal homeostasis. This study aimed to evaluate the effect of Hyp on intestinal barrier function and its associated gut microbiota and metabolites in early-weaned piglets. Eighty weaned piglets were divided into four groups and fed diets containing different Hyp levels (0 %, 0.5 %, 1 %, or 2 %) for 21 days. Samples, including intestinal contents, tissues, and blood, were collected on day 7 for analysis of microbial composition, intestinal barrier function, and metabolites. We demonstrated that dietary supplementation with 2 % Hyp improved the feed conversion ratio and reduced the incidence of diarrhea in early-weaned piglets compared to the control group. Concurrently, Hyp enhanced intestinal barrier function by facilitating tight junction protein (zonula occludens (ZO)-1 and occludin) expression and mucin production in the jejunal, ileal, and colonic mucosas. It also improved mucosal immunity (by increasing the amount of secretory IgA (sIgA) and the ratio of CD4+/CD8+ T lymphocytes and decreasing NF-κB phosphorylation) and increased antioxidant capacity (by raising total antioxidant capacity (T-AOC) and glutathione levels) in the intestinal mucosa. In addition, Hyp supplementation resulted in an increase in the levels of glycine, glutathione, and glycine-conjugated bile acids, while decreasing the concentrations of cortisol and methionine sulfoxide in plasma. Intriguingly, piglets fed diet containing Hyp exhibited a remarkable increase in the abundance of probiotic Enterococcus faecium within their colonic contents. This elevation occurred alongside an attenuation of pro-inflammatory responses and an enhancement in intestinal barrier integrity. Further, these changes were accompanied by a rise in anti-inflammatory metabolites, specifically glycochenodeoxycholic acid and guanosine, along with a suppression of pro-inflammatory lipid peroxidation products, including (12Z)-9,10-dihydroxyoctadec-12-enoic acid (9,10-DHOME) and 13-L-hydroperoxylinoleic acid (13(S)-HPODE). In summary, Hyp holds the capacity to enhance the intestinal barrier function in weaned piglets; this effect is correlated with changes in the gut microbiota and metabolites. Our findings provide novel insights into the role of Hyp in maintaining gut homeostasis, highlighting its potential as a dietary supplement for promoting intestinal health in early-weaned piglets.

Goat milk exosomal microRNAs alleviate LPS-induced intestinal inflammation in mice

Intestinal inflammation is a common digestive system disease. Milk-derived exosomes can participate in intercellular communication and transport a variety of bioactive components, and the microRNAs (miRNAs) they carry play important roles in a variety of biological processes in the body. At present, the preventive effect and mechanism of action of goat milk exosomes and their derived miRNAs on intestinal inflammation are still unclear. In this study, the protective effect of goat milk exosomes on LPS-induced intestinal inflammation was investigated using mouse intestinal inflammation model and IEC-6 cell inflammation model. Small RNA sequencing was used to analyze the miRNA expression profile of goat milk exosomes. In this study, C-Exo and M-Exo alleviated intestinal inflammation by reducing the LPS-induced release of proinflammatory cytokines, inhibiting the increase in the NLRP3 protein and the activation of the TLR4/NFκB signaling pathway. C-Exo has a more significant inhibitory effect on them, and better therapeutic efficacy than M-Exo. Notably, the target genes of miRNAs in C-Exo and M-Exo were significantly enriched in immune-related pathways. Furthermore, their derived miR-26a-5p and miR-30a-5p were found to ameliorate the IEC-6 inflammatory response. These findings suggest that miRNAs in goat milk exosomes have the potential to attenuate LPS-induced intestinal inflammation.

In vitro and in vivo fermentation models to study the function of dietary fiber in pig nutrition

The importance of dietary fiber (DF) in animal diets is increasing with the advancement of nutritional research. DF is fermented by gut microbiota to produce metabolites, which are important in improving intestinal health. This review is a systematic review of DF in pig nutrition using in vitro and in vivo models. The fermentation characteristics of DF and the metabolic mechanisms of its metabolites were summarized in an in vitro model, and it was pointed out that SCFAs and gases are the important metabolites connecting DF, gut microbiota, and intestinal health, and they play a key role in intestinal health. At the same time, some information about host-microbe interactions could have been improved through traditional animal in vivo models, and the most direct feedback on nutrients was generated, confirming the beneficial effects of DF on sow reproductive performance, piglet intestinal health, and growing pork quality. Finally, the advantages and disadvantages of different fermentation models were compared. In future studies, it is necessary to flexibly combine in vivo and in vitro fermentation models to profoundly investigate the mechanism of DF on the organism in order to promote the development of precision nutrition tools and to provide a scientific basis for the in-depth and rational utilization of DF in animal husbandry. KEY POINTS: • The fermentation characteristics of dietary fiber in vitro models were reviewed. • Metabolic pathways of metabolites and their roles in the intestine were reviewed. • The role of dietary fiber in pigs at different stages was reviewed.

Effect of tea polyphenols on intestinal barrier and immune function in weaned lambs

Introduction

The purpose of this study was to explore the effects of tea polyphenols on growth performance, cytokine content, intestinal antioxidant status and intestinal barrier function of lambs, in order to provide reference for intestinal health of ruminants.

Methods

Thirty weaned lambs (average initial weight 9.32 ± 1.72 kg) were randomly divided into five groups with six lambs in each group. The control group did not add anything but the basic diet mainly composed of Pennisetum and Corn, and the other four groups added 2, 4, 6 g/kg tea polyphenols and 50 mg/kg chlortetracycline to the basic diet, respectively. The experiment lasted for 42 days.

Results

Dietary tea polyphenols improved the growth and stress response and reduced intestinal permeability of lambs (p > 0.05), while CTC did not affect the final lamb weight (p > 0.05). Both tea phenols and CTC significantly reduced inflammatory factors and enhanced the immune system (p > 0.05). Dietary tea polyphenols increased villus height, villus height/crypt depth, secretory immunoglobulin A (p > 0.05), and antioxidant enzymes, while decreasing MDA and apoptosis in the intestine (p > 0.05). However, compared with other groups, the content of T-AOC in jejunum did not change significantly (p > 0.05). Tea polyphenols also increased claudin-1 levels in the duodenum, jejunum, and ileum more than CTC (p > 0.05). CTC had a limited effect on the mRNA expression of Occludin and ZO-1, while tea polyphenols increased these in both the duodenum and ileum (p > 0.05).

Conclusion

This study demonstrated that tea polyphenols can effectively improve the intestinal barrier of weaned lambs, and that they have anti-inflammatory and antioxidant effects similar to those of antibiotics. Thus, tea polyphenols could be used to replace antibiotics in ensuring safety of livestock products and in achieving the sustainable development of modern animal husbandry.

The Use of Fruit and Vegetable by-Products as Enhancers of Health Status of Piglets after Weaning: The Role of Bioactive Compounds from Apple and Carrot Industrial Wastes

At weaning, piglets are exposed to a large variety of stressors, from environmental/behavioral factors to nutritional stress. Weaning transition affects the gastrointestinal tract especially, resulting in specific disturbances at the level of intestinal morphology, barrier function and integrity, mucosal immunity and gut microbiota. All these alterations are associated with intestinal inflammation, oxidative stress and perturbation of intracellular signaling pathways. The nutritional management of the weaning period aims to achieve the reinforcement of intestinal integrity and functioning to positively modulate the intestinal immunity and that of the gut microbiota and to enhance the health status of piglets. That is why the current research is focused on the raw materials rich in phytochemicals which could positively modulate animal health. The composition analysis of fruit, vegetable and their by-products showed that identified phytochemicals could act as bioactive compounds, which can be used as modulators of weaning-induced disturbances in piglets. This review describes nutritional studies which investigated the effects of bioactive compounds derived from fruit (apple) and vegetables (carrot) or their by-products on the intestinal architecture and function, inflammatory processes and oxidative stress at the intestinal level. Data on the associated signaling pathways and on the microbiota modulation by bioactive compounds from these by-products are also presented.

Bidirectional Interaction between Tetracyclines and Gut Microbiome

The escalating misuse of antibiotics, particularly broad-spectrum antibiotics, has emerged as a pivotal driver of drug resistance. Among these agents, tetracyclines are widely prescribed for bacterial infections, but their indiscriminate use can profoundly alter the gut microbiome, potentially compromising both their effectiveness and safety. This review delves into the intricate and dynamic interplay between tetracyclines and the gut microbiome, shedding light on their reciprocal influence. By exploring the effects of tetracyclines on the gut microbiome and the impact of gut microbiota on tetracycline therapy, we seek to gain deeper insights into this complex relationship, ultimately guiding strategies for preserving antibiotic efficacy and mitigating resistance development.

Effects of lactic acid bacteria-fermented formula milk supplementation on colonic microbiota and mucosal transcriptome profile of weaned piglets

Supplemental probiotic fermented milk as a gut modulator can improve growth performance for weaned piglets by promoting the development of the small intestine in digestion and immune function. The effect on colon health might also play a considerable part in the favourable role of probiotic fermented milk in the growth performance improvement of weaned piglets; however, it has yet to be reported. This study aimed to investigate the effects of supplementation with lactic acid bacteria-fermented formula milk (LFM) on colonic morphology, microbiota composition, and mucosal transcriptome profile in weaned piglets. A total of 24 male weaned piglets were randomly divided into two groups: a control (CON) treatment or the LFM-supplemented treatment. Each group consisted of six replicates (cages) with two piglets per cage, and each piglet in the LFM group was supplemented with 80 mL LFM three times a day for 21 d, while the CON group was treated with the same amount of drinking water. Results showed that supplementation of LFM reduced the colonic histological damage scores and significantly increased the number of goblet cells per crypt. Furthermore, LFM consumption decreased the levels of pro-inflammation cytokines in the colonic mucosa. LFM downregulated the expression of inflammatory genes (CXCL9 and CXCL10) involving Toll-like receptor signalling pathway, immune response, and response to bacterium, and up-regulated two active genes (S100A8 and S100A9) involving the IL-17 signalling pathway and Toll-like receptor 4 binding. In addition, LFM could increase the potential probiotic genera containing Lachnospira and Anaerorhabdus furcosa group, which were positively related to short-chain fatty acid (SCFA) production. Correspondingly, LFM-fed piglets had higher total bacterial load and total SCFA concentration in the colonic digesta compared with the CON group. These novel findings support the benefits of LFM in enhancing intestinal homoeostasis and ameliorating weaning stress for weaned piglets, which is associated with the modulation of gut microbiota composition and immune-related genes.

Dietary lysozyme improves growth performance and intestinal barrier function of weaned piglets

Lysozyme (LZ) is a purely natural, nonpolluting and nonspecific immune factor, which has beneficial effects on the healthy development of animals. In this study, the influences of LZ on the growth performance and intestinal barrier of weaned piglets were studied. A total of 48 weaned piglets (Landrace × Yorkshire, 22 d old) were randomly divided into a control group (basal diet) and a LZ group (0.1% LZ diet) for 19 d. The results showed that LZ could significantly improve the average daily gain (ADG, P < 0.05) and average daily feed intake (ADFI, P < 0.05). LZ also improved the intestinal morphology and significantly increased the expression of occludin in the jejunum (P < 0.05). In addition, LZ down-regulated the expression of interleukin-1β (IL-1β, P < 0.05) and tumor necrosis factor-α (TNF-α, P < 0.05), and inhibited the expression of the genes in the nuclear factor-k-gene binding (NF-κB, P < 0.05) signaling pathway. More importantly, the analysis of intestinal flora showed LZ increased the abundance of Firmicutes (P < 0.05) and the ratio of Firmicutes to Bacteroidota (P = 0.09) at the phylum level, and increased the abundance of Clostridium_sensu_stricto_1 (P < 0.05) and reduced the abundance of Olsenella and Prevotella (P < 0.05) at the genus level. In short, this study proved that LZ could effectively improve the growth performance, relieve inflammation and improve the intestinal barrier function of weaned piglets. These findings provided an important theoretical basis for the application of LZ in pig production.

Weaning stress and intestinal health of piglets: A review

Weaning is considered to be one of the most critical periods in pig production, which is related to the economic benefits of pig farms. However, in actual production, many piglets are often subjected to weaning stress due to the sudden separation from the sow, the changes in diet and living environment, and other social challenges. Weaning stress often causes changes in the morphology and function of the small intestine of piglets, disrupts digestion and absorption capacity, destroys intestinal barrier function, and ultimately leads to reduced feed intake, increased diarrhea rate, and growth retardation. Therefore, correctly understanding the effects of weaning stress on intestinal health have important guiding significance for nutritional regulation of intestinal injury caused by weaning stress. In this review, we mainly reviewed the effects of weaning stress on the intestinal health of piglets, from the aspects of intestinal development, and intestinal barrier function, thereby providing a theoretical basis for nutritional strategies to alleviate weaning stress in mammals in future studies.

Artificial rearing alters intestinal microbiota and induces inflammatory response in piglets

With the ongoing genetic selection for high prolificacy in sow lines and the improvements in environment and farm management, litter size has increased in recent years. Artificial rearing is becoming widely used to raise the surplus piglets in pig industry. This study aimed to investigate the changes that happened in the morphology, microbiota, mucosal barrier function, and transcriptome caused by artificial rearing in piglet colon. Two hundred and forty newborn piglets were randomly assigned into three treatments, sow rearing until weaning (CON group), artificial rearing from day 21 (AR21 group), and artificial rearing from day 7 (AR7 group). On day 35, the piglets were euthanized to collect colon samples. The results showed that the artificially reared-piglets displayed increased pre-weaning diarrhea incidence and reduced growth performance. Artificial rearing changed the diversity and structure of colonic microbiota and increased relative abundance of harmful bacteria, such as Escherichia-Shigella. In addition, the morphological disruption was observed in AR7 group, which was coincided with decreased tight junction proteins and goblet cell numbers. Moreover, the expression of TNFSF11, TNF-α, IL-1β, TLR2, TLR4, MyD88, NF-κB, COX-2, PTGEs, iNOS, IL-2, IL-6, IL-17A, and IFN-γ was upregulated in the colon of the artificially reared-piglets, while the expression of IL-1Ra and IκBα was downregulated, indicating that artificial rearing induced inflammatory response through the activation of NF-κB pathway. Furthermore, artificial rearing regulated SLC family members, which affected solute transport and destroyed intestinal homeostasis. In conclusion, artificial rearing caused microbiota alteration, morphology disruption, the destruction of mucosal barrier function, and inflammatory response, and thus, led to subsequent increased diarrhea incidence and reduced growth performance.

Landscapes of Enteric Virome Signatures in Early-Weaned Piglets

Diarrhea caused by early-weaning-induced stress can increase mortality rates and reduce growth performance of piglets, seriously harming the livestock industry. To date, studies on the gut microbiome of early-weaned piglets have focused almost exclusively on bacteria, while studies on their gut virome are extremely lacking. Here, we used metagenomic and metatranscriptomic sequencing combined with bioinformatic analysis techniques to preliminarily characterize the intestinal virome of early-weaned piglets at different biological classification levels. The alpha diversity of enteroviruses was generally elevated in early-weaned piglets with diarrhea, compared to healthy piglets, whereas the two groups of piglets showed no significant difference in beta diversity. In addition, the species compositions of the gut virome were similar between healthy piglets and piglets with diarrhea, while their respective dominant species were somewhat different. We also identified 58 differential DNA viruses and 16 differential RNA viruses between the two groups of piglets at all biological taxonomic levels. Of these, 1 (family Dhakavirus) and 6 (phylum Artverviricota, class Revtraviricetes, order Ortervirales, family Retroviridae, genus Gammaretrovirus, and species Kirsten murine sarcoma virus) specific viruses disappeared from the intestines of healthy piglets and piglets with diarrhea, respectively. Moreover, we found that some DNA and RNA viruses formed strong correlations among themselves or between them. IMPORTANCE This study systematically reveals the biological diversity, structure, and composition of intestinal DNA and RNA virus profiles in early-weaned piglets. Furthermore, characteristics of differences in gut viromes between early-weaned healthy piglets and piglets with diarrhea were also elucidated. Importantly, some potential biomarkers for early-weaned piglets with diarrhea were identified. These findings fill a gap for the early-weaned piglet gut virome and lay the foundation for the development of strategies to target enteroviruses for the prevention and treatment of early-weaning-induced piglet diarrhea.

S. boulardii Early Intervention Maintains Gut Microbiome Structure and Promotes Gut Mucosal Barrier Function in Early-Weaned Rats

Early weaning leads to the disorder of the gut microbiome and gut mucosal barrier injury. Early intervention of gut microbiome colonization contributes to the development of the gut microbiome and gut function. The aim of this study was to explore the effects of Saccharomyces boulardii (S. boulardii) early intervention on the gut microbiome structure and gut mucosal barrier function of early-weaned rats. The results showed that S. boulardii early intervention improved growth performance along with a decrease in pathogenic bacteria, an increase in beneficial bacteria, a stable and complex microbiome, and a high level of microbial metabolism. Moreover, S. boulardii upregulated the mucosal barrier function including goblet cells and relative gene expression, tight junction, and sIgA level. Furthermore, S. boulardii suppressed the inflammatory response and promoted the anti-inflammatory response. Our study may provide a possible early intervention strategy for preventing an early weaning-induced disorder of the gut microbiome and loss of gut mucosal barrier function.

Immunomodulation by Gut Microbiome on Gastrointestinal Cancers: Focusing on Colorectal Cancer

Gastrointestinal cancer (GI) is a global health disease with a huge burden on a patient's physical and psychological aspects of life and on health care providers. It is associated with multiple disease related challenges which can alter the patient's quality of life and well-being. GI cancer development is influenced by multiple factors such as diet, infection, environment, and genetics. Although activating immune pathways and components during cancer is critical for the host's survival, cancerous cells can target those pathways to escape and survive. As the gut microbiome influences the development and function of the immune system, research is conducted to investigate the gut microbiome-immune interactions, the underlying mechanisms, and how they reduce the risk of GI cancer. This review addresses and summarizes the current knowledge on the major immune cells and gut microbiome interactions. Additionally, it highlights the underlying mechanisms of immune dysregulation caused by gut microbiota on four major cancerous pathways, inflammation, cellular proliferation, apoptosis, and metastasis. Overall, gut-immune interactions might be a key to understanding GI cancer development, but further research is needed for more detailed clarification.