Gut microbiota mediates the effects of inulin on enhancing sulfomucin production and mucosal barrier function in a pig model

Developmental Dynamics of the Gut Virome in Tibetan Pigs at High Altitude: A Metagenomic Perspective across Age Groups

Tibetan pig is a geographically isolated pig breed that inhabits high-altitude areas of the Qinghai-Tibetan plateau. At present, there is limited research on viral diseases in Tibetan pigs. This study provides a novel metagenomic exploration of the gut virome in Tibetan pigs (altitude ≈ 3000 m) across three critical developmental stages, including lactation, nursery, and fattening. The composition of viral communities in the Tibetan pig intestine, with a dominant presence of Microviridae phages observed across all stages of development, in combination with the previous literature, suggest that it may be associated with geographical locations with high altitude. Functional annotation of viral operational taxonomic units (vOTUs) highlights that, among the constantly increasing vOTUs groups, the adaptability of viruses to environmental stressors such as salt and heat indicates an evolutionary response to high-altitude conditions. It shows that the lactation group has more abundant viral auxiliary metabolic genes (vAMGs) than the nursery and fattening groups. During the nursery and fattening stages, this leaves only DNMT1 at a high level. which may be a contributing factor in promoting gut health. The study found that viruses preferentially adopt lytic lifestyles at all three developmental stages. These findings not only elucidate the dynamic interplay between the gut virome and host development, offering novel insights into the virome ecology of Tibetan pigs and their adaptation to high-altitude environments, but also provide a theoretical basis for further studies on pig production and epidemic prevention under extreme environmental conditions.

Cordyceps militaris Extract and Cordycepin Alleviate Oxidative Stress, Modulate Gut Microbiota and Ameliorate Intestinal Damage in LPS-Induced Piglets

Cordycepin is considered a major bioactive component in Cordyceps militaris extract. This study was performed to evaluate the ameliorative effect of Cordyceps militaris extract (CME) and cordycepin (CPN) supplementation on intestinal damage in LPS-challenged piglets. The results showed that CPN or CME supplementation significantly increased the villus height (p < 0.01) and villus height/crypt depth ratio (p < 0.05) in the jejunum and ileum of piglets with LPS-induced intestinal inflammation. Meanwhile, CPN or CME supplementation alleviated oxidative stress and inflammatory responses by reducing the levels of MDA (p < 0.05) and pro-inflammatory cytokines in the serum. Additionally, supplementation with CPN or CME modulated the structure of the intestinal microbiota by enriching short-chain fatty acid-producing bacteria, and increased the level of butyrate (p < 0.05). The RNA-seq results demonstrated that CME or CPN altered the complement and coagulation-cascade-related genes (p < 0.05), including upregulating gene KLKB1 while downregulating the genes CFD, F2RL2, CFB, C4BPA, F7, C4BPB, CFH, C3 and PROS1, which regulate the complement activation involved in inflammatory and immune responses. Correlation analysis further demonstrated the potential relation between the gut microbiota and intestinal inflammation, oxidative stress, and butyrate in piglets. In conclusion, CPN or CME supplementation might inhibit LPS-induced inflammation and oxidative stress by modulating the intestinal microbiota and its metabolite butyrate in piglets.

Panax notoginseng stems and leaves affect microbial community and function in cecum of duzang pigs

Panax notoginseng is a Chinese medicine with a long history in which stems and leaves are the wastes of processing Panax notoginseng and have not been effectively utilized. The effects of diets containing Panax notoginseng stems and leaves on the cecal short-chain fatty acid (SCFA) concentration and microbiome of independent pigs were studied. Diets containing Panax notoginseng stems and leaves did not affect the concentration of SCFA in the cecal contents of Duzang pigs but affected the microbial composition and diversity. Firmicutes, Proteobacteria, and Bacteroidetes dominate in the cecal of Duzang pigs. Feeding Duzang pigs with a 10% Panax notoginseng stems and leaves diet increases the abundance of Lactobacillus, Christensenellaceae R-7 group, and Akkermansia in the cecal. We found 14 genera positively associated with acetate, and they were Lactobacillus, Ruminococcaceae UCG 005, Ruminiclostridium 6; Escherichia Shigella and Family XIII AD3011 group showed negative correlations. Solobacterium, Desulfovibrio, and Erysipelatoclostridium were positively associated with propionate. Campylobacter, Clostridium sensu stricto 11, and Angelakisella were positively associated with butyrate. In conclusion, Panax notoginseng stems and leaves could affect the cecal microbial community and functional composition of Duzang pigs. Panax notoginseng stems and leaves reduce the enrichment of lipopolysaccharide biosynthetic pathway of the cecal microbiome, which may have a positive effect on intestinal health. The higher abundance of GH25 family in Duzang pig's cecal microbiome of fed Panax notoginseng stems and leaves diet. This increase may be the reason for the microbial diversity decrease.

An inulin-type fructan isolated from Serratula chinensis alleviated the dextran sulfate sodium-induced colitis in mice through regulation of intestinal barrier and gut microbiota

Herein, we aimed to explore the polysaccharide material basis of Serratula chinensis and establish its beneficial effects against colitis. A neutral polysaccharide (SCP) was extracted from S. chinensis in high yield using hot water. The molecular weights were calculated by HPSEC as Mw = 2928 Da, Mn = 2634 Da, and Mw/Mn = 1.11. FT-IR and 1D/2D-NMR spectroscopic analyses confirmed that SCP was an inulin-type fructan with α-D-Glcp-(1 → [1)-β-D-Fruf-(2]17) linkages. Treatment with SCP (200 or 400 mg/kg) alleviated dextran sulfate sodium (DSS)-induced mouse colitis symptoms, including the loss of body weight, increase of disease activity index score, and shortening of colon length. Histopathological and immunofluorescence assessments revealed that SCP could reduce pathological damage to the colon, restore the number of goblet cells, increase the content of glycoproteins in goblet cells and mucins in crypts, and enhance the expression of tight junction proteins ZO-1 and occludin. In addition, metagenomic sequencing revealed that SCP could improve the dysbiosis of gut microbiomes and act on multiple microbial functions. Moreover, SCP treatment increased the content of colonic acetic acid and butanoic acid. Collectively, these results indicated that SCP could alleviate the DSS-induced colitis in mice through regulation of intestinal barrier and gut microbiota.

Diversity and potential function of pig gut DNA viruses

Viruses are ubiquitous in the gut of animals and play an important role in the ecology of the gut microbiome. The potential effects of these substances on the growth and development of the body are not fully known. Little is known about the effects of breeding environment on pig gut virome. Here, there are 3584 viral operational taxonomic units (vOTUs) longer than 5 kb identified by virus-enriched metagenome sequencing from 25 pig fecal samples. Only a small minority of vOTUs (11.16%) can be classified at the family level, and ∼50% of the genes could be annotated, supporting the concept of pig gut as reservoirs of substantial undescribed viral genetic diversity. The composition of pig gut virome in the six regions may be related to geography. There are only 20 viral clusters (VCs) shared among pig gut virome in six regions of Shanxi Province. These viruses rarely carry antibiotic resistance genes (ARGs). At the same time, they possess abundant auxiliary metabolic genes (AMGs) potentially involved in carbon, sulfur metabolism and cofactor biosynthesis, etc. This study has revealed the unique characteristics and potential function of pig gut DNA virome and established a foundation for the recognition of the viral roles in gut environment.

Pectin supplement alleviates gut injury potentially through improving gut microbiota community in piglets

As pectin is widely used as a food and feed additive due to its tremendous prebiotic potentials for gut health. Yet, the underlying mechanisms associated with its protective effect remain unclear. Twenty-four piglets (Yorkshire × Landrace, 6.77 ± 0.92 kg) were randomly divided into three groups with eight replicates per treatment: (1) Control group (CON), (2) Lipopolysaccharide-challenged group (LPS), (3) Pectin-LPS group (PECL). Piglets were administrated with LPS or saline on d14 and 21 of the experiment. Piglets in each group were fed with corn-soybean meal diets containing 5% citrus pectin or 5% microcrystalline cellulose. Our result showed that pectin alleviated the morphological damage features by restoring the goblet numbers which the pig induced by LPS in the cecum. Besides, compared with the LPS group, pectin supplementation elevated the mRNA expression of tight junction protein [Claudin-1, Claudin-4, and zonula occludens-1 (ZO-1)], mucin (Muc-2), and anti-inflammatory cytokines [interleukin 10 (IL-10), and IL-22]. Whereas pectin downregulated the expression of proinflammatory cytokines (IL-1β, IL-6, IL-18), tumor necrosis factor-&alpha (TNF-α), and NF-κB. What is more, pectin supplementation also significantly increased the abundance of beneficial bacteria (Lactobacillus, Clostridium_sensu_stricto_1, Blautia, and Subdoligranulum), and significantly reduced the abundance of harmful bacteria, such as Streptococcus. Additionally, pectin restored the amount of short-chain fatty acids (SCFAs) after being decreased by LPS (mainly Acetic acid, Propionic acid, and Butyric acid) to alleviate gut injury and improve gut immunity via activating relative receptors (GPR43, GPR109, AhR). Mantel test and correlation analysis also revealed associations between intestinal microbiota and intestinal morphology, and intestinal inflammation in piglets. Taken together, dietary pectin supplementation enhances the gut barrier and improves immunity to ameliorate LPS-induced injury by optimizing gut microbiota and their metabolites.

Mucin O-glycan-microbiota axis orchestrates gut homeostasis in a diarrheal pig model

BACKGROUND

Post-weaning diarrhea in piglets reduces growth performance and increases mortality, thereby causing serious economic losses. The intestinal epithelial cells and microbiota reciprocally regulate each other in order to maintain intestinal homeostasis and control inflammation. However, a relative paucity of research has been focused on the host-derived regulatory network that controls mucin O-glycans and thereby changes gut microbiota during diarrhea in infancy. At the development stage just after birth, the ontogeny of intestinal epithelium, immune system, and gut microbiota appear similar in piglets and human infants. Here, we investigated the changes of mucin O-glycans associated with gut microbiota using a diarrheal post-weaned piglet model.

RESULTS

We found that diarrhea disrupted the colonic mucus layer and caused aberrant mucin O-glycans, including reduced acidic glycans and truncated glycans, leading to an impaired gut microenvironment. Subsequently, the onset of diarrhea, changes in microbiota and bacterial translocation, resulting in compromised epithelial barrier integrity, enhanced susceptibility to inflammation, and mild growth faltering. Furthermore, we found the activation of NLRP3 inflammasome complexes in the diarrheal piglets when compared to the healthy counterparts, triggered the release of proinflammatory cytokines IL-1β and IL-18, and diminished autophagosome formation, specifically the defective conversion of LC3A/B I into LC3A/B II and the accumulation of p62. Additionally, selective blocking of the autophagy pathway by 3-MA led to the reduction in goblet cell-specific gene transcript levels in vitro.

CONCLUSIONS

We observed that diarrheal piglets exhibited colonic microbiota dysbiosis and mucosal barrier dysfunction. Our data demonstrated that diarrhea resulted in the activation of inflammasomes and autophagy restriction along with aberrant mucin O-glycans including reduced acidic glycans and truncated glycans. The results suggested the mucin O-glycans-microbiota axis is likely associated with diarrheal pathogenesis. Our study provides novel insights into the pathophysiology of early-weaning-induced diarrheal disease in piglets and potentially understanding of disease mechanisms of diarrhea for human infants. Understanding the molecular pathology and pathogenesis of diarrhea is a prerequisite for the development of novel and effective therapies. Our data suggest that facilitating O-glycan elongation, modifying the microbiota, and developing specific inhibitors to some key inflammasomes could be the options for therapy of diarrhea including human infants. Video abstract.

Transcriptomic Analysis of the Porcine Gut in Response to Heat Stress and Dietary Soluble Fiber from Beet Pulp

This study aimed to investigate the impact of heat stress (HS) and the effects of dietary soluble fiber from beet pulp (BP) on gene expression (differentially expressed genes, DEGs) of the porcine jejunum. Out of the 82 DEGs, 47 genes were up-regulated, and 35 genes were downregulated between treatments. The gene ontology (GO) enrichment analysis showed that the DEGs were related mainly to the actin cytoskeleton organization and muscle structure development in biological processes, cytoplasm, stress fibers, Z disc, cytoskeleton, and the extracellular regions in cellular composition, and actin binding, calcium ion binding, actin filament binding, and pyridoxal phosphate binding in the molecular function. The KEGG pathway analysis showed that the DEGs were involved in hypertrophic cardiomyopathy, dilated cardiomyopathy, vascular smooth muscle contraction, regulation of actin cytoskeleton, mucin type O-glycan biosynthesis, and African trypanosomiasis. Several of the genes (HSPB6, HSP70, TPM1, TAGLN, CCL4) in the HS group were involved in cellular oxidative stress, immune responses, and cellular differentiation. In contrast, the DEGs in the dietary BP group were related to intestinal epithelium integrity and immune response to pathogens, including S100A2, GCNT3, LYZ, SCGB1A1, SAA3, and ST3GAL1. These findings might help understand the HS response and the effect of dietary fiber (DF) regarding HS and be a valuable reference for future studies.

The Role of Gut Microbiota in the Skeletal Muscle Development and Fat Deposition in Pigs

Pork quality is a factor increasingly considered in consumer preferences for pork. The formation mechanisms determining meat quality are complicated, including endogenous and exogenous factors. Despite a lot of research on meat quality, unexpected variation in meat quality is still a major problem in the meat industry. Currently, gut microbiota and their metabolites have attracted increased attention in the animal breeding industry, and recent research demonstrated their significance in muscle fiber development and fat deposition. The purpose of this paper is to summarize the research on the effects of gut microbiota on pig muscle and fat deposition. The factors affecting gut microbiota composition will also be discussed, including host genetics, dietary composition, antibiotics, prebiotics, and probiotics. We provide an overall understanding of the relationship between gut microbiota and meat quality in pigs, and how manipulation of gut microbiota may contribute to increasing pork quality for human consumption.

Inulin Improves Diet-Induced Hepatic Steatosis and Increases Intestinal Akkermansia Genus Level

Hepatic steatosis is characterized by triglyceride accumulation within hepatocytes in response to a high calorie intake, and it may be related to intestinal microbiota disturbances. The prebiotic inulin is a naturally occurring polysaccharide with a high dietary fiber content. Here, we evaluate the effect of inulin on the intestinal microbiota in a non-alcoholic fatty liver disease model. Mice exposed to a standard rodent diet or a fat-enriched diet, were supplemented or not, with inulin. Liver histology was evaluated with oil red O and H&E staining and the intestinal microbiota was determined in mice fecal samples by 16S rRNA sequencing. Inulin treatment effectively prevents liver steatosis in the fat-enriched diet group. We also observed that inulin re-shaped the intestinal microbiota at the phylum level, were Verrucomicrobia genus significantly increased in the fat-diet group; specifically, we observed that Akkermansia&nbsp;muciniphila increased by 5-fold with inulin supplementation. The family Prevotellaceae was also significantly increased in the fat-diet group. Overall, we propose that inulin supplementation in liver steatosis-affected animals, promotes a remodeling in the intestinal microbiota composition, which might regulate lipid metabolism, thus contributing to tackling liver steatosis.