The role of goblet cells and mucus in intestinal homeostasis

Yeast β-glucan attenuates dextran sulfate sodium-induced colitis: Involvement of gut microbiota and short-chain fatty acids

Yeast β-glucan intervention offers a promising strategy for managing colitis; however, the mechanisms remain unknown. In the present work, the protective effects of yeast β-glucan on DSS-induced colitis in mice was evaluated, focusing on its interaction with gut microbiota. The result showed yeast β-glucan significantly alleviated colitis symptoms, evidenced by reduced weight loss, lower disease activity index (DAI) scores, and minimized intestinal damage. It enhanced intestinal barrier integrity via upregulation of tight junction proteins, suppressed lipopolysaccharide (LPS) release, and decreased pro-inflammatory cytokines production. Additionally, yeast β-glucan boosted short-chain fatty acids (SCFAs) production, and activated their receptors, increased the relative abundances of beneficial microbes like Lactobacillus and Lachnospiraceae_UCG-006. Transcriptomic analyses suggest that yeast β-glucan mitigates inflammation by downregulating gene expression related to IL-17 pathway. Our findings highlight potential of yeast β-glucan as a therapeutic agent for colitis through modulation of gut microbiota and inflammatory responses.

The Microbiota of the Outer Gut Mucus Layer of the Migrating Northeast Arctic Cod (Gadus morhua) as Determined by Shotgun DNA Sequencing

Animals form functional units with their microbial communities, termed metaorganisms. Despite extensive research on some model animals, microbial diversity in many species remains unexplored. Here, we describe the taxonomic profile of the microbes from the outer gut mucus layer from the Northeast Arctic cod using a shotgun DNA sequencing approach. We focused on the mucus to determine if its microbial composition differs from that of the fecal microbiota, which could reveal unique microbial interactions and functions. Metagenomes from six individuals were analyzed, revealing three different taxonomic profiles: Type I is dominated in numbers by Pseudomonadaceae (44%) and Xanthomonadaceae (13%), Type II by Vibrionaceae (65%), and Type III by Enterobacteriaceae (76%). This stands in sharp contrast to the bacterial diversity of the transient gut content (i.e., feces). Additionally, binning of assembled reads followed by phylogenomic analyses place a high-completeness bin of Type I within the Pseudomonas fluorescens group, Type II within the Photobacterium phosphoreum clade, and Type III within the Escherichia/Shigella group. In conclusion, we describe the adherent bacterial diversity in the Northeast Arctic cod's intestine using shotgun sequencing, revealing different taxonomic profiles compared to the more homogenous transient microbiota. This suggests that the intestine contains two separate and distinct microbial populations.

Impaired activation of succinate-induced type 2 immunity and secretory cell production in the small intestines of Ptk6-/- male mice

Protein tyrosine kinase 6 (PTK6) is an intracellular tyrosine kinase that is distantly related to the SRC family of tyrosine kinases. It is expressed in epithelial linings and regulates regeneration and repair of the intestinal epithelium. Analysis of publicly available datasets showed Ptk6 is upregulated in tuft cells upon activation of type 2 immunity. We found that disruption of Ptk6 influences gene expression involved in intestinal immune responses. Administration of succinate, which mimics infection and activates tuft cells, revealed PTK6-dependent activation of innate immune responses in male but not female mice. In contrast to all wild type and Ptk6-/- female mice, Ptk6-/- male mice do not activate innate immunity or upregulate differentiation of the tuft and goblet secretory cell lineages following succinate treatment. Mechanistically, we found that PTK6 regulates Il25 and Irag2, genes that are required for tuft cell effector functions and activation of type 2 innate immunity, in organoids derived from intestines of male but not female mice. In patients with Crohn's disease, PTK6 is upregulated in tuft cells in noninflamed regions of intestine. These data highlight roles for PTK6 in contributing to sex differences in intestinal innate immunity and provide new insights into the regulation of IL-25.

IGF2 contributes to the immunomodulatory effects of exosomes from endometrial regenerative cells on experimental colitis

BACKGROUND

Exosomes derived from endometrial regenerative cells (ERC-Exos) can inherit the immunomodulatory function from ERCs, however, whether ERC-Exos exhibit such effect on inflammatory bowel diseases with mucosal immune dysregulation has not been explored. Insulin-like growth factor-Ⅱ (IGF2) is considered to possess the potential to induce an anti-inflammatory phenotype in immune cells. In this study, the contribution of IGF2 in mediating the protective efficacy of ERC-Exos on colitis was investigated.

METHODS

Lentiviral transfection was employed to obtain IGF2-specific knockout ERC-Exos (IGF2-/--ERC-Exos). Experimental colitis mice induced by dextran sulfate sodium (DSS) were divided into the phosphate-buffered saline (untreated), ERC-Exos-treated and IGF2-/--ERC-Exos-treated groups. Colonic histopathological analysis and intestinal barrier function were explored. The infiltration of CD4+ T cells and dendritic cells (DCs) were analyzed by immunofluorescence staining and flow cytometry. The maturation and function of bone marrow-derived dendritic cells (BMDCs) in different exosome administrations were evaluated by flow cytometry, ELISA and the coculture system, respectively.

RESULTS

Compared with the untreated group, ERC-Exos treatment significantly attenuated DSS-induced weight loss, bloody stools, shortened colon length, pathological damage, as well as repaired the weakened intestinal mucosal barrier, including promoting the goblet cells retention, restoring the intestinal barrier integrity and enhancing the expression of tight junction proteins, while the protective effect of exosomes was impaired with the knockout of IGF2 in ERC-Exos. Additionally, IGF2-expressing ERC-Exos decreased the proportions of Th1 and Th17, increased the proportions of Treg, as well as attenuated DC infiltration and maturation in mesenteric lymph nodes and lamina propria of the colitis mice. ERC-Exos were also observed to be phagocytosed by BMDCs and IGF2 is responsible for the modulating effect of ERC-Exos on BMDCs in vitro.

CONCLUSIONS

Exosomes derived from ERCs can exert a therapeutic effect on experimental colitis with remarkable alleviation of the intestinal barrier damage and the abnormal mucosal immune responses. We emphasized that IGF2 plays a critical role for ERC-Exos mediated immunomodulatory function and protection against colitis.

Host-pathobiont interactions in Crohn's disease

The mammalian intestine is colonized by trillions of microorganisms that are collectively referred to as the gut microbiota. The majority of symbionts have co-evolved with their host in a mutualistic relationship that benefits both. Under certain conditions, such as in Crohn's disease, a subtype of inflammatory bowel disease, some symbionts bloom to cause disease in genetically susceptible hosts. Although the identity and function of disease-causing microorganisms or pathobionts in Crohn's disease remain largely unknown, mounting evidence from animal models suggests that pathobionts triggering Crohn's disease-like colitis inhabit certain niches and penetrate the intestinal tissue to trigger inflammation. In this Review, we discuss the distinct niches occupied by intestinal symbionts and the evidence that pathobionts triggering Crohn's disease live in the mucus layer or near the intestinal epithelium. We also discuss how Crohn's disease-associated mutations in the host disrupt intestinal homeostasis by promoting the penetration and accumulation of pathobionts in the intestinal tissue. Finally, we discuss the potential role of microbiome-based interventions in precision therapeutic strategies for the treatment of Crohn's disease.

Gut Microbiota-Derived Metabolites and Their Role in the Pathogenesis of Necrotizing Enterocolitis in Preterm Infants: A Narrative Review

Background: Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease that occurs predominantly in premature infants and is characterized by the inflammation and necrosis of the intestine, showing high morbidity and mortality rates. Despite decades of research efforts, a specific treatment is currently lacking, and preventive strategies are the mainstays of care. This review aims to help understand the complex interplay between gut microbiota and their metabolites in NEC pathogenesis. In particular, we focused on how these factors can influence gut health, immune responses, and intestinal barrier integrity. Discussion: Current research has increasingly focused on the role of the gut microbiota and their metabolites in NEC pathogenesis, thanks to their involvement in modulating gut health, immune responses, and intestinal barrier integrity. Conclusions: A deeper understanding of the interplay between gut microbiota and their metabolites is essential for developing personalized strategies to prevent NEC. By targeting these microbial interactions, new therapeutic approaches may emerge that offer improved outcomes for preterm infants at a high risk of NEC.

Goat Milk Exosomes Ameliorate Ulcerative Colitis in Mice through Modulation of the Intestinal Barrier, Gut Microbiota, and Metabolites

Goat milk is rich in a variety of nutrients that are important for intestinal health and disease prevention. However, the role of exosomes in goat milk remains to be elucidated. This study investigated for the first time the therapeutic efficacy and molecular underlying mechanisms of mature milk exosomes (M-exo) and goat colostrum exosomes (C-exo) on dextran sodium sulfate-induced ulcerative colitis (UC) in mice. The findings demonstrate that M-exo and C-exo significantly improved physiological indices, suppressed the secretion of proinflammatory cytokines, and diminished oxidative stress and apoptosis in UC mice. Moreover, C-exo and M-exo restored the intestinal barrier function, remodeled the gut microbiota, and improved metabolite composition in the feces of colitis mice. In conclusion, goat milk exosomes ameliorate UC in mice, which provides a basis for the development of functional food applications for the prevention and treatment of inflammatory bowel disease.

A comprehensive update on the immunoregulatory mechanisms of Akkermansia muciniphila: insights into active ingredients, metabolites, and nutrient-driven modulation

Akkermansia muciniphila (A. muciniphila) has gained recognition as a pioneering probiotic, exhibiting considerable potential to enhance immune conditions across both humans and animals. The health benefits of A. muciniphila are attributed to its various components, including outer membrane proteins (PilQ and Amuc_1100), secreted proteins (P9 and AmTARS), extracellular vesicles, and metabolites such as SCFAs, ornithine lipids, γ-aminobutyric acid, cobalamin, and inosine. The dynamic control of the mucus layer by A. muciniphila plays a crucial role in regulating intestinal mucosal immunity. Furthermore, A. muciniphila modulates immune function by interacting with macrophages, dendritic cells, T lymphocytes, and Paneth cells. Increasing the abundance of A. muciniphila in the gut through nutritional strategies represents a safe and effective means to augment immune function. Various polyphenols, oligosaccharides, and polysaccharides have been shown to elevate the levels of this bacterium, thereby contributing to favorable immunoregulatory outcomes. This paper delves into the latest research advancements related to the probiotic mechanisms of A. muciniphila and provides an overview of the current understanding of how its abundance responds to nutrients. These insights offer a theoretical foundation for the utilization of A. muciniphila in immunoregulation.

The comparative effects of probiotics on growth, antioxidant indices and intestinal histomorphology of broilers under heat stress condition

Heat stress adversely affects both the productivity and well-being of chickens. Probiotics offer beneficial impacts on the health and growth performance of broilers. The current study investigates the influence of administering of Bacillus (including B. subtilis, B. licheniformis, B. coagulans, and B. indicus) and Lactobacillus (consisting of L. acidophilus, L. plantarum, L. buchneri, and L. rhamnosus) probiotics via drinking water, either singular or combined, on various aspects including growth performance, oxidative stress markers, carcass characteristics, fecal microbial composition, intestinal structure, and intestinal pH in broilers exposed to chronic heat stress. A total of 150 one-day-old broiler chicks were divided into 5 groups: (1) NC, negative control; (2) HS, birds exposed to chronic heat stress; (3) HSpBacil, exposed to chronic heat stress and received Bacillus probiotic; (4) HSpLAB, subjected to chronic heat stress and provided with Lactobacillus probiotic; (5) HSpMix, subjected to chronic heat stress and administered a combined probiotic from Bacillus and Lactobacillus. The HS group exhibited significantly reduced levels of growth performance, carcass traits, and notably affected oxidative stress indices, as well as intestinal pH and histomorphology in the birds. Additionally, the administered probiotics led to increased weight of lymphoid organs, enhanced body weight gain, and improved intestinal histomorphology. Furthermore, the probiotics decreased malondialdehyde and increased total antioxidant capacity in broilers. In conclusion, Bacillus and Lactobacillus probiotics, as single or multi-species, particularly Lactobacillus and combined probiotic, demonstrated potential in alleviating the adverse effects of heat stress in broiler chickens. They could serve as beneficial feed additives and growth enhancers.

Effects and mechanisms of Helicobacter pylori infection on the occurrence of extra-gastric tumors

Helicobacter pylori (H. pylori) colonizes the human stomach and many studies have discussed the mechanisms of H. pylori infection leading to gastric diseases, including gastric cancer. Additionally, increasing data have shown that the infection of H. pylori may contribute to the development of extra-gastric diseases and tumors. Inflammation, systemic immune responses, microbiome disorders, and hypergastrinemia caused by H. pylori infection are associated with many extra-gastric malignancies. This review highlights recent discoveries; discusses the relationship between H. pylori and various extra-gastric tumors, such as colorectal cancer, lung cancer, cholangiocarcinoma, and gallbladder carcinoma; and explores the mechanisms of extra-gastric carcinogenesis by H. pylori. Overall, these findings refine our understanding of the pathogenic processes of H. pylori, provide guidance for the clinical treatment and management of H. pylori-related extra-gastric tumors, and help improve prognosis.

What defines a healthy gut microbiome?

The understanding that changes in microbiome composition can influence chronic human diseases and the efficiency of therapies has driven efforts to develop microbiota-centred therapies such as first and next generation probiotics, prebiotics and postbiotics, microbiota editing and faecal microbiota transplantation. Central to microbiome research is understanding how disease impacts microbiome composition and vice versa, yet there is a problematic issue with the term 'dysbiosis', which broadly links microbial imbalances to various chronic illnesses without precision or definition. Another significant issue in microbiome discussions is defining 'healthy individuals' to ascertain what characterises a healthy microbiome. This involves questioning who represents the healthiest segment of our population-whether it is those free from illnesses, athletes at peak performance, individuals living healthily through regular exercise and good nutrition or even elderly adults or centenarians who have been tested by time and achieved remarkable healthy longevity.This review advocates for delineating 'what defines a healthy microbiome?' by considering a broader range of factors related to human health and environmental influences on the microbiota. A healthy microbiome is undoubtedly linked to gut health. Nevertheless, it is very difficult to pinpoint a universally accepted definition of 'gut health' due to the complexities of measuring gut functionality besides the microbiota composition. We must take into account individual variabilities, the influence of diet, lifestyle, host and environmental factors. Moreover, the challenge in distinguishing causation from correlation between gut microbiome and overall health is presented.The review also highlights the resource-heavy nature of comprehensive gut health assessments, which hinders their practicality and broad application. Finally, we call for continued research and a nuanced approach to better understand the intricate and evolving concept of gut health, emphasising the need for more precise and inclusive definitions and methodologies in studying the microbiome.

Teleost Muc2 and Muc5ac: Key guardians of mucosal immunity in flounder (Paralichthys olivaceus)

Mucins secreted by mucous cells constitute a core part of the defense line against the invasion of pathogens. However, mucins' structure and immunological functions remain largely unknown in teleost fish. In this study, two typical mucins, Muc2 and Muc5ac of flounder (Paralichthys olivaceus), were cloned and their physicochemical properties, structure and conservation were analyzed. Notably, specific antibodies against flounder Muc2 and Muc5ac were developed. It was verified at the gene and protein level that Muc2 was expressed in the hindgut and gills but not in the skin, while Muc5ac was expressed in the skin and gills but not in the hindgut. After flounders were immunized by immersion with inactivated Edwardsiella tarda, Muc2 and Muc5ac were significantly upregulated at both the gene expression and protein levels, and Muc2+/Muc5ac+ mucous cells proliferated and increased secretion of Muc2 and Muc5ac. Moreover, Muc2 and Muc5ac exerted retention and clearance effects on E. tarda in a short period (within 1 dpi). These results revealed the characterization of fish mucins Muc2 and Muc5ac at the protein level and clarified the role of mucins as key guardians to maintain the mucus barrier, which advanced our understanding of teleost mucosal barrier.

Cellular and molecular basis of proximal small intestine disorders

The proximal part of the small intestine, including duodenum and jejunum, is not only dedicated to nutrient digestion and absorption but is also a highly regulated immune site exposed to environmental factors. Host-protective responses against pathogens and tolerance to food antigens are essential functions in the small intestine. The cellular ecology and molecular pathways to maintain those functions are complex. Maladaptation is highlighted by common immune-mediated diseases such as coeliac disease, environmental enteric dysfunction or duodenal Crohn's disease. An expanding spectrum of more than 100 rare monogenic disorders inform on causative molecular mechanisms of nutrient absorption, epithelial homeostasis and barrier function, as well as inflammatory immune responses and immune regulation. Here, after summarizing the architectural and cellular traits that underlie the functions of the proximal intestine, we discuss how the integration of tissue immunopathology and molecular mechanisms can contribute towards our understanding of disease and guide diagnosis. We propose an integrated mechanism-based taxonomy and discuss the latest experimental approaches to gain new mechanistic insight into these disorders with large disease burden worldwide as well as implications for therapeutic interventions.

Polysaccharide from Areca catechu L. inflorescence enhances the intestinal mucosal immunity to maintain immune homeostasis

Being the first line of defense, intestinal mucosal immunity serves as in maintaining immune homeostasis among organisms. This study investigated the impact of the areca inflorescence polysaccharide (AFP) on intestinal mucosal immunity and elucidated the mechanisms responsible for the immunomodulatory effects of AFP. The immunosuppression mouse model was established using the cyclophosphamide. The intestinal mucosal status was evaluated based on the intestinal integrity, chemical and mucosal immune barriers, and intestinal flora. According to the findings, AFP enhances intestinal integrity by up-regulating the expression of tight junction proteins and reinforcing the chemical barrier through increased mucin-2, β-defensins, and SIgA expression and secretion. Furthermore, AFP restores the mucosal immune barrier by regulating immune cells within Peyer's patches and lamina propria. AFP also reverses the intestinal flora balance and regulates its metabolism. Additionally, AFP effectively modulates the immune response in the spleen and peripheral blood. Together, these results indicated that AFP repairs mucosal damage and restores mucosal immunity, thereby preserving the immune homeostasis of organisms.

Melinjo (Gnetum gnemon L) Extract Attenuates Colonic Inflammation in a Mouse Colitis Model by Regulating the AMPK/NFκB/Sirt1 Pathway

Ulcerative colitis (UC) is a subtype of inflammatory bowel disease affecting the colon with idiopathic origin. Melinjo endosperm extract (MeE) contains polyphenolic compounds that have antioxidative and anticancer properties. We examined the effect of MeE on inflammation and mucin expression in the colons of UC of mice treated with dextran sulfate sodium (DSS). C57BL/6J male mice were assigned into four categories: control, DSS + 0% MeE, DSS + 0.1% MeE, and DSS + 0.5% MeE. The control group was provided distilled water and a standard chow diet for 4 weeks. In DSS + 0% MeE, DSS + 0.1% MeE, and DSS + 0.5% MeE groups, the mice were treated with MeE for 3 weeks followed by MeE diets and drinking water containing 3% DSS for a week. Macrophage count, the mucus area stained by Alcian blue (AB), the levels of adenosine monophosphate-activated protein kinase (AMPK), nuclear factor-κB (NFκB) p65, and silent information regulator (Sirt) 1 protein expression, as well as proinflammatory mediators and Mucin 2 mRNA expression were assessed. In the DSS + 0% MeE group, the AB-stained areas and Mucin 2 mRNA expression levels were observed to be lower than those of controls. However, the levels in the +0.5% MeE group were significantly increased. Compared with the control group, the macrophage number, the expression of IL-1β mRNA, and NFκB p65 protein in the DSS + 0% MeE group showed a significant increase. Conversely, these levels were significantly decreased in the +0.5% MeE group. The phosphorylated AMPK and Sirt1 protein levels were upregulated in the +0.5% MeE group. In conclusion, MeE may alleviate UC injury by reducing macrophage infiltration and regulating the AMPK/NFκB/Sirt1 pathway.

Toll-like receptor 4 damages the intestinal epithelial cells by activating endoplasmic reticulum stress in septic rats

Background

The severity of acute gastrointestinal injury (AGI) is a critical determinant of survival in sepsis. However, there is no specifically interventional management for gastrointestinal dysfunction. Toll-like Receptor 4 (TLR4) is an important contributor to sepsis-induced multiple organ dysfunction syndrome. So, we investigated the effect of TLR4 on leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) + cells and goblet cells and its potential mechanism.

Methods

A cecal ligation and puncture (CLP) model reflecting the development of clinical sepsis was developed. Tak-242, a TLR4 inhibitor, was administered to septic rats at a dose of 3 mg/kg via intraperitoneal injection. Immunohistochemistry was performed to detect TLR4 and Lgr5+ cells. AB-PAS staining was performed to detect goblet cells. MUC1 and MUC2 secreted by goblet cells, biomarkers of endoplasmic reticulum (ER) stress and inflammatory cytokines in the intestine were detected by western blotting and real-time PCR.

Results

We found that the upregulation of the TLR4/NF-κB signaling pathway activated intestinal inflammatory response in sepsis. Meanwhile, the structure of intestinal mucosa was destroyed, Lgr5+ cells and goblet cells count were significantly reduced, and the secretory function of goblet cells also decreased. Further studies have found that TLR4 increased the levels of activating transcription factor-6 (ATF6), XBP1, ER chaperone (Bip) and CHOP, but did not activate the protein kinase RNA (PKR)-like ER kinase (P-PERK).

Conclusion

We concluded that the inhibition of TLR4/NF-κB signaling pathway can reduce intestinal inflammatory response, protect intestinal mucosa, protect Lgr5+ cells, goblet cells and relieve ER stress. Our findings suggest that Tak-242 protects Lgr5+ cells and goblet cells after sepsis, partly may be through the suppression of ER stress. Thus, inhibition of TLR4-mediated ER stress may be a promising therapy of septic AGI.

Regulation of intestinal epithelial homeostasis by mesenchymal cells

The gastrointestinal tract harbors diverse microorganisms in the lumen. Epithelial cells segregate the luminal microorganisms from immune cells in the lamina propria by constructing chemical and physical barriers through the production of various factors to prevent excessive immune responses against microbes. Therefore, perturbations of epithelial integrity are linked to the development of gastrointestinal disorders. Several mesenchymal stromal cell populations, including fibroblasts, myofibroblasts, pericytes, and myocytes, contribute to the establishment and maintenance of epithelial homeostasis in the gut through regulation of the self-renewal, proliferation, and differentiation of intestinal stem cells. Recent studies have revealed alterations in the composition of intestinal mesenchymal stromal cells in patients with inflammatory bowel disease and colorectal cancer. A better understanding of the interplay between mesenchymal stromal cells and epithelial cells associated with intestinal health and diseases will facilitate identification of novel biomarkers and therapeutic targets for gastrointestinal disorders. This review summarizes the key findings obtained to date on the mechanisms by which functionally distinct mesenchymal stromal cells regulate epithelial integrity in intestinal health and diseases at different developmental stages.

A Ctnnb1 enhancer transcriptionally regulates Wnt signaling dosage to balance homeostasis and tumorigenesis of intestinal epithelia

The β-catenin-dependent canonical Wnt signaling is pivotal in organ development, tissue homeostasis, and cancer. Here, we identified an upstream enhancer of Ctnnb1 - the coding gene for β-catenin, named ieCtnnb1 (intestinal enhancer of Ctnnb1), which is crucial for intestinal homeostasis. ieCtnnb1 is predominantly active in the base of small intestinal crypts and throughout the epithelia of large intestine. Knockout of ieCtnnb1 led to a reduction in Ctnnb1 transcription, compromising the canonical Wnt signaling in intestinal crypts. Single-cell sequencing revealed that ieCtnnb1 knockout altered epithelial compositions and potentially compromised functions of small intestinal crypts. While deletion of ieCtnnb1 hampered epithelial turnovers in physiologic conditions, it prevented occurrence and progression of Wnt/β-catenin-driven colorectal cancers. Human ieCTNNB1 drove reporter gene expression in a pattern highly similar to mouse ieCtnnb1. ieCTNNB1 contains a single-nucleotide polymorphism associated with CTNNB1 expression levels in human gastrointestinal epithelia. The enhancer activity of ieCTNNB1 in colorectal cancer tissues was stronger than that in adjacent normal tissues. HNF4α and phosphorylated CREB1 were identified as key trans-factors binding to ieCTNNB1 and regulating CTNNB1 transcription. Together, these findings unveil an enhancer-dependent mechanism controlling the dosage of Wnt signaling and homeostasis in intestinal epithelia.

Baicalin ameliorates heat stress-induced hepatic injury and intestinal microecology dysbiosis in late gestational mice

Heat stress (HS) disrupts intestinal microbiota, glycolipid metabolism, and hepatic mitochondrial function in late gestational mice. Baicalin (BAI), a Chinese herbal medicine known for its heat-clearing and anti-inflammatory properties, has shown promise in modulating intestinal microecology and mitigating inflammation in various organs. This study investigates whether baicalin attenuates HS-induced intestinal microbial dysbiosis and liver damage in pregnant mice during late gestation. Twenty-four pregnant mice were randomly assigned to four groups, including thermoneutral (TN) (24 ± 1 ℃), HS (35 ± 1 ℃), HS+BAI200 (oral gavaged with 200 mg/kg BW of BAI), and HS+BAI400 (oral gavaged with 400 mg/kg BW of BAI). 400 mg/kg BAI treatment markedly decreased the rectal temperature and increased fetal weight in HS pregnant mice. Furthermore, 400 mg/kg BAI administration effectively ameliorated HS-induced hepatic damage and lipid disorders, reducing HSP70, AST, and ALT levels while increasing TG concentration. Notably, it activated a network of genes involved in lipid synthesis, including fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and oxidation, such as peroxisome proliferator-activated receptor alpha (PPARα), carnitine palmityl transferase 1 beta (CPT1β). Moreover, BAI intervention restored the intestinal morphology and barrier function, evidenced by increased intestinal villus height, the ratio of villus height to crypt depth, and colonic goblet cells numbers. 400 mg/kg of BAI treatment up-regulated the expression of tight junction proteins, such as claudin-1 and Zonula Occludens-1 (ZO-1), in the jejunum and ileum, counteracting HS-induced downregulation. High-throughput sequencing showed that BAI treatment altered cecal microbial composition, increasing the relative abundance of beneficial Bacteroidota and decreasing Deferribacterota, Turicibacter, and Akkermansia. Spearman's correlation analysis highlighted significant correlations between differential cecal microbiota and physiological indexes. In conclusion, BAI administration alleviated adverse impacts in heat-exposed mice during late gestation, improving maternal physiological parameters, and ameliorating hepatic damage with altered cecal microbial composition. The findings suggest that BAI may regulate the gut-liver axis by modulating intestinal morphology, microecology, and hepatic function.

Standardization and quality assessment for human intestinal organoids

To enhance the practical application of intestinal organoids, it is imperative to establish standardized guidelines. This proposed standardization outlines a comprehensive framework to ensure consistency and reliability in the development, characterization, and application of intestinal organoids. The recommended guidelines encompass crucial parameters, including culture conditions, critical quality attributes, quality control measures, and functional assessments, aimed at fostering a standardized approach across diverse research initiatives. The implementation of these guidelines is anticipated to significantly contribute to the reproducibility and comparability of results in the burgeoning field of intestinal organoid research.

Protection against DSS-induced colitis in mice through FcεRIα deficiency: the role of altered Lactobacillus

The role of mast cells (MCs) in ulcerative colitis (UC) development is controversial. FcεRI, the IgE high-affinity receptor, is known to activate MCs. However, its role in UC remains unclear. In our study, Anti-FcεRI showed highly diagnostic value for UC. FcεRIα knockout in mice ameliorated DSS-induced colitis in a gut microbiota-dependent manner. Increased Lactobacillus abundance in FcεRIα deficient mice showed strongly correlation with the remission of colitis. RNA sequencing indicated activation of the NLRP6 inflammasome pathway in FcεRIα knockout mice. Additionally, Lactobacillus plantarum supplementation protected against inflammatory injury and goblet cell loss, with activation of the NLRP6 inflammasome during colitis. Notably, this effect was absent when the strain is unable to produce lactic acid. In summary, colitis was mitigated in FcεRIα deficient mice, which may be attributed to the increased abundance of Lactobacillus. These findings contribute to a better understanding of the relationship between allergic reactions, microbiota, and colitis.

Advancements in Inflammatory Bowel Disease Management: From Traditional Treatments to Monoclonal Antibodies and Future Drug Delivery Systems

Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammatory disorder with two main subtypes: ulcerative colitis (UC) and Crohn's disease (CD). The pathogenesis involves genetic predisposition, dysbiosis, and immune dysregulation. Complications include perianal lesions, strictures, fistulas, perforations, and an increased risk of colon cancer. Clinical classification ranges from mild to fulminant and recurrent disease, with common symptoms such as abdominal discomfort, rectal bleeding, diarrhea, and weight loss. Extraintestinal manifestations include arthritis, erythema nodosum, pyoderma gangrenosum, and uveitis. Conventional treatments using aminosalicylates, corticosteroids, and immunomodulators have limitations. Biologics, introduced in the 1990s, offer improved efficacy and specificity, targeting factors like TNF-α, integrins, and cytokines. Monoclonal antibodies play a crucial role in IBD management, aiming to reduce relapses, hospitalizations, and surgeries. In conclusion, this review is aimed at summarizing the latest knowledge, advantages, and drawbacks of IBD therapies, such as small molecules, biologics, and monoclonal antibodies, to provide a basis for further research in the IBD field.

The Pax transcription factor EGL-38 links EGFR signaling to assembly of a cell-type specific apical extracellular matrix in the Caenorhabditis elegans vulva

The surface of epithelial tissues is covered by an apical extracellular matrix (aECM). The aECMs of different tissues have distinct compositions to serve distinct functions, yet how a particular cell type assembles the proper aECM is not well understood. We used the cell-type specific matrix of the C. elegans vulva to investigate the connection between cell identity and matrix assembly. The vulva is an epithelial tube composed of seven cell types descending from EGFR/Ras-dependent (1°) and Notch-dependent (2°) lineages. Vulva aECM contains multiple Zona Pellucida domain (ZP) proteins, which are a common component of aECMs across life. ZP proteins LET-653 and CUTL-18 assemble on 1° cell surfaces, while NOAH-1 assembles on a subset of 2° surfaces. All three ZP genes are broadly transcribed, indicating that cell-type specific ZP assembly must be determined by features of the destination cell surface. The paired box (Pax) transcription factor EGL-38 promotes assembly of 1° matrix and prevents inappropriate assembly of 2° matrix, suggesting that EGL-38 promotes expression of one or more ZP matrix organizers. Our results connect the known signaling pathways and various downstream effectors to EGL-38/Pax expression and the ZP matrix component of vulva cell fate execution. We propose that dedicated transcriptional networks may contribute to cell-appropriate assembly of aECM in many epithelial organs.

Gut mechanoimmunology: Shaping immune response through physical cues

The gut immune system embodies a complex interplay between the gut mucosal barrier, the host's immune cells, and gut microbiota. These components exist within a dynamic environment characterized by a variety of physical cues, e.g., compression, tension, shear stress, stiffness, and viscoelasticity. The physical cues can be modified under specific pathological conditions. Given their dynamic nature, comprehending the specific effects of these physical cues on the gut immune system is critical for pathological and therapeutic studies of intestinal immune-related diseases. This review aims to discuss how physical cues influence gut immunology by affecting the gut mucosal barrier, host immune cells, and gut microbiota, defining this concept as gut mechanoimmunology. This review seeks to highlight that an enhanced understanding of gut mechanoimmunology carries therapeutic implications, not only for intestinal diseases but also for extraintestinal diseases.

From vacant to vivid: The nutritional landscape drives infant gut microbiota establishment

From the moment of birth, the newborn gastrointestinal tract is infiltrated by various bacteria originating from both maternal and environmental sources. These colonizing bacteria form a complex microbiota community that undergoes continuous changes until adulthood and plays an important role in infant health. The maturation of the infant gut microbiota is driven by many factors and follows a distinct patterned trajectory, with specific bacterial taxa establish in the intestine in accordance with developmental milestones as the infant grows. In this review, we highlight how elements such as diet and host physiology select for specific microbial functions and shape the composition of the bacterial community in the large intestine.

Phosphatidylserine improves aging sepsis survival, modulates gut microbiome, and prevents sepsis-associated encephalopathy

Aged adults are prone to both short- and long-term complications following sepsis due to ineffective therapy. Phosphatidylserine (PS) is a membrane nutrient supplement known to enhance cognition and brain function, but its potential effects in treating sepsis are not well-documented. Our study aimed to explore the potential of PS in improving outcomes in sepsis and sepsis-associated encephalopathy (SAE). Middle-aged mice were administered PS for two months following induction of sepsis by lipopolysaccharides. The results indicated a significant increase in the survival rate of mice treated with PS after sepsis. Surviving mice underwent open field and shuttle box tests 45 days post-sepsis, revealing potential alleviation of neurobehavioral impairments due to PS pretreatment. Analysis at 60 days post-sepsis euthanasia showed reduced cleaved-caspase 3 in neurons and glial cell markers in the PS-treated group compared to the untreated sepsis group. Furthermore, PS administration effectively reduced proinflammatory cytokine gene expression in the hippocampus of mice with SAE, potentially inhibiting the TBK1/NLRP3/ASC signaling pathway. In the gut, PS pretreatment modulated β-diversity while maintaining jejunal morphology and colon ZO-1 expression, without significantly affecting α-diversity indices. Our findings suggest that PS administration improves survival rates, modulates the gut microbiome, preserves gut integrity, and ameliorates brain pathology in survived mice after sepsis. Importantly, these findings have significant implications for sepsis treatment and cognitive function preservation in aging individuals, providing new insights and sparking further interest and investigation into the potential of PS in sepsis treatment.

Cy3-Based Nanoviscosity Determination of Mucus: Effect of Mucus Collection Methods and Antibiotics Treatment

The integrity of the protective mucus layer as a primary defense against pathogen invasion and microbial leakage into the intestinal epithelium can be compromised by the effects of antibiotics on the commensal microbiome. Changes in mucus integrity directly affect the solvent viscosity in the immediate vicinity of the mucin network, that is, the nanoviscosity, which in turn affects both biochemical reactions and selective transport. To assess mucus nanoviscosity, a reliable readout via the viscosity-dependent fluorescence lifetime of the molecular rotor dye cyanine 3 is established and nanoviscosities from porcine and murine ex vivo mucus are determined. To account for different mucin concentrations due to the removal of digestive residues during mucus collection, the power law dependence of mucin concentration on viscosity is used. The impact of antibiotics combinations (meropenem/vancomycin, gentamycin/ampicillin) on ex vivo intestinal mucus nanoviscosity is presented. The significant increase in viscosity of murine intestinal mucus after treatment suggests an effect of antibiotics on the microbiota that affects mucus integrity. This method will be a useful tool to assess how drugs, directly or indirectly, affect mucus integrity. Additionally, the method can be utilized to analyze the role of mucus nanoviscosity in health and disease, as well as in drug development.

A Comprehensive Review of the Triangular Relationship among Diet-Gut Microbiota-Inflammation

The human gastrointestinal tract hosts a complex and dynamic community of microorganisms known as the gut microbiota, which play a pivotal role in numerous physiological processes, including digestion, metabolism, and immune function. Recent research has highlighted the significant impact of diet on the gut microbiota composition and functionality, and the consequential effects on host health. Concurrently, there is growing evidence linking the gut microbiota to inflammation, a key factor in many chronic diseases such as inflammatory bowel disease (IBD), obesity, diabetes, and cardiovascular diseases (CVDs). This review explores how dietary components influence the gut microbiota composition, how these microbial changes affect inflammatory pathways, and the therapeutic implications of modulating this axis for chronic inflammatory disease prevention and management. Beneficial dietary patterns, such as the Mediterranean diet (MD) and plant-based diets, promote a diverse and balanced gut microbiota composition, supporting anti-inflammatory pathways. Conversely, the Western diet (WD), high in saturated fats and refined sugars, is associated with dysbiosis and increased inflammation. With all the links between the three variables considered, this review attempts to offer a thorough examination of the triangle formed by inflammation, the gut microbiota, and food.

A comprehensive immunobiology review of IBD: With a specific glance to Th22 lymphocytes development, biology, function, and role in IBD

The two primary forms of inflammatory disorders of the small intestine andcolon that make up inflammatory bowel disease (IBD) are ulcerative colitis (UC) and Crohn's disease (CD). While ulcerative colitis primarily affects the colon and the rectum, CD affects the small and large intestines, as well as the esophagus,mouth, anus, andstomach. Although the etiology of IBD is not completely clear, and there are many unknowns about it, the development, progression, and recurrence of IBD are significantly influenced by the activity of immune system cells, particularly lymphocytes, given that the disease is primarily caused by the immune system stimulation and activation against gastrointestinal (GI) tract components due to the inflammation caused by environmental factors such as viral or bacterial infections, etc. in genetically predisposed individuals. Maintaining homeostasis and the integrity of the mucosal barrier are critical in stopping the development of IBD. Specific immune system cells and the quantity of secretory mucus and microbiome are vital in maintaining this stability. Th22 cells are helper T lymphocyte subtypes that are particularly important for maintaining the integrity and equilibrium of the mucosal barrier. This review discusses the most recent research on these cells' biology, function, and evolution and their involvement in IBD.

Importance of diet and intestinal microbiota in the prevention of colorectal cancer - colonoscopy early screening diagnosis

Colorectal cancer is a term used to describe colon and rectal cancer, which is the third most common type of cancer. A MEDLINE and PubMed search resulted in the inclusion of manuscripts written in the last 10 years, using keywords relevant to the topic of the manuscript. By analyzing the aim of the searched studies and manuscripts, adequate articles were included that described the stated problem. The frequency of colorectal cancer varies with climate, nutrition, and many other factors, primarily endogenous, hereditary, intestinal microbiome, as well as external factors, such as exposure of the individual to stress, and bad eating habits. Colon cancer and rectal cancer or colorectal cancer in general in the early stages of the disease, may not show symptoms or are barely noticeable. Colorectal cancer symptoms will most often not develop until the disease has progressed to stage 2 or beyond. Regular screening tests for colon or rectal cancer, especially colonoscopy, are recommended as part of a regular checkup for people aged 50 years or younger who are at high risk due to a family history of the disease or other cancers. Diet and colonoscopy as an early screening method play an important role in the prevention of colorectal cancer.

Restore Intestinal Barrier Integrity: An Approach for Inflammatory Bowel Disease Therapy

The intestinal barrier maintained by various types of columnar epithelial cells, plays a crucial role in regulating the interactions between the intestinal contents (such as the intestinal microbiota), the immune system, and other components. Dysfunction of the intestinal mucosa is a significant pathophysiological mechanism and clinical manifestation of inflammatory bowel disease (IBD). However, current therapies for IBD primarily focus on suppressing inflammation, and no disease-modifying treatments specifically target the epithelial barrier. Given the side effects associated with chronic immunotherapy, effective alternative therapies that promote mucosal healing are highly attractive. In this review, we examined the function of intestinal epithelial barrier function and the mechanisms of behind its disruption in IBD. We illustrated the complex process of intestinal mucosal healing and proposed therapeutic approaches to promote mucosal healing strategies in IBD. These included the application of stem cell transplantation and organ-like tissue engineering approaches to generate new intestinal tissue. Finally, we discussed potential strategies to restore the function of the intestinal barrier as a treatment for IBD.

Astragalus polysaccharides-induced gut microbiota play a predominant role in enhancing of intestinal barrier function of broiler chickens

BACKGROUND

The intestinal barrier is the first line of defense against intestinal invasion by pathogens and foreign antigens and is closely associated with the gut microbiota. Astragalus polysaccharides (APS) have a long history of use in traditional Chinese medicine owing to its protective properties against intestinal barrier function. The mechanism of APS-induced gut microbiota enhancing intestinal barrier function is urgently needed.

RESULTS

Dietary polysaccharide deprivation induced intestinal barrier dysfunction, decreased growth performance, altered microbial composition (Faecalibacterium, Dorea, and Coprobacillus), and reduced isobutyrate concentration. The results showed that APS facilitates intestinal barrier function in broiler chickens, including a thicker mucus layer, reduced crypt depth, and the growth of tight junction proteins. We studied the landscape of APS-induced gut microbiota and found that APS selectively promoted the growth of Parabacteroides, a commensal bacterium that plays a predominant role in enhancing intestinal barrier function. An in vitro growth assay further verified that APS selectively increased the abundance of Parabacteroides distasonis and Bacteroides uniformis. Dietary APS supplementation increased the concentrations of isobutyrate and bile acid (mainly chenodeoxycholic acid and deoxycholate acid) and activated signaling pathways related to intestinal barrier function (such as protein processing in the endoplasmic reticulum, tight junctions, and adherens junction signaling pathways).

CONCLUSIONS

APS intervention restored the dietary polysaccharide-induced dysfunction of the intestinal barrier by selectively promoting the abundance of Parabacteroides distasonis, and increasing the concentrations of isobutyrate and bile acids (mainly CDCA and DCA). These findings suggest that APS-induced gut microbiota and metabolic niches are promising strategies for enhancing intestinal barrier function.

Establishment and Evaluation of a Mouse Model of Experimental Ulcerative Colitis Induced by the Gavage Administration of Dextran Sulfate Sodium

Given the critical role of dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mouse models in the appraisal of associated therapeutic drugs, the optimization of the administration method and dosages is of paramount importance. Therefore, UC was induced in mice through the gavage administration of a DSS solution instead of free drinking water. The effects of varying daily dosages (2, 4, 6, and 8 g/kg) and frequencies (once or twice) of administration on the body weight and survival rate of the model mice were evaluated. Concurrently, the inflammatory indicators and tissue sections of the model mice were thoroughly evaluated. The results revealed that when the daily dosage reached 8 g/kg, the dosage exhibited a high level of toxicity, resulting in a high mortality rate among the mice. The DSS administration of 6 g/kg*2 not only elicited conspicuous symptoms, significant weight loss, substantial shortening of the colon, and significant changes in various inflammatory indicators, such as myeloperoxidase (MPO), nitric oxide (NO), reactive oxygen species (ROS), and glutathione (GSH), but it also maintained a high survival rate in the UC mice. The findings from this experiment lay a solid experimental foundation for future research on drugs intended for the treatment of UC.

Advances in single-cell transcriptomics in animal research

Understanding biological mechanisms is fundamental for improving animal production and health to meet the growing demand for high-quality protein. As an emerging biotechnology, single-cell transcriptomics has been gradually applied in diverse aspects of animal research, offering an effective method to study the gene expression of high-throughput single cells of different tissues/organs in animals. In an unprecedented manner, researchers have identified cell types/subtypes and their marker genes, inferred cellular fate trajectories, and revealed cell‒cell interactions in animals using single-cell transcriptomics. In this paper, we introduce the development of single-cell technology and review the processes, advancements, and applications of single-cell transcriptomics in animal research. We summarize recent efforts using single-cell transcriptomics to obtain a more profound understanding of animal nutrition and health, reproductive performance, genetics, and disease models in different livestock species. Moreover, the practical experience accumulated based on a large number of cases is highlighted to provide a reference for determining key factors (e.g., sample size, cell clustering, and cell type annotation) in single-cell transcriptomics analysis. We also discuss the limitations and outlook of single-cell transcriptomics in the current stage. This paper describes the comprehensive progress of single-cell transcriptomics in animal research, offering novel insights and sustainable advancements in agricultural productivity and animal health.

A novel function of benzoic acid to enhance intestinal barrier defense against PEDV infection in Piglets

The intestinal barrier of newborn piglets is vulnerable and underdeveloped, making them susceptible to enteric virus infections. Benzoic acid (BA), employed as a growth promoter, exhibits the potential to enhance the gut health of piglets by modulating intestinal morphometry and tight junction dynamics. However, the extent to which BA regulates the intestinal mucus barrier through its impact on stem cells remains inadequately elucidated. Therefore, this study was conducted to investigate the effects of BA on the intestinal barrier and the differentiation of intestinal stem cells, employing in vivo piglet and in vitro intestinal organoid models. Our investigation revealed a significant increase in the number of goblet cells within the small intestine, as well as the strengthening of the mucus barrier in vivo following oral treatment with BA, providing partial protection against PEDV infection in piglets. Additionally, in vitro cultivation of enteroids with BA led to a notable increase in the number of MUC2+ GCs, indicating the promotion of GC differentiation by BA. Furthermore, transcriptome analysis revealed an upregulation of the number of GCs and the expression of cell vesicle transport-related genes during BA stimulation, accompanied by the downregulation of the Wnt and Notch signaling pathways. Mechanistically, MCT1 facilitated the transport of BA, subsequently activating the MAPK pathway to mediate GC differentiation. Overall, this study highlights a novel function for BA as a feed additive in enhancing the intestinal mucus barrier by promoting intestinal GC differentiation, and further prevents viral infection in piglets.

Design strategies, advances and future perspectives of colon-targeted delivery systems for the treatment of inflammatory bowel disease

Inflammatory bowel diseases (IBD) significantly contribute to high mortality globally and negatively affect patients' qualifications of life. The gastrointestinal tract has unique anatomical characteristics and physiological environment limitations. Moreover, certain natural or synthetic anti-inflammatory drugs are associated with poor targeting, low drug accumulation at the lesion site, and other side effects, hindering them from exerting their therapeutic effects. Colon-targeted drug delivery systems represent attractive alternatives as novel carriers for IBD treatment. This review mainly discusses the treatment status of IBD, obstacles to drug delivery, design strategies of colon-targeted delivery systems, and perspectives on the existing complementary therapies. Moreover, based on recent reports, we summarized the therapeutic mechanism of colon-targeted drug delivery. Finally, we addressed the challenges and future directions to facilitate the exploitation of advanced nanomedicine for IBD therapy.

The Role of Viruses in the Pathogenesis of Immune-Mediated Gastro-Intestinal Diseases

Immune-mediated gastrointestinal (GI) diseases, including achalasia, celiac disease, and inflammatory bowel diseases, pose significant challenges in diagnosis and management due to their complex etiology and diverse clinical manifestations. While genetic predispositions and environmental factors have been extensively studied in the context of these conditions, the role of viral infections and virome dysbiosis remains a subject of growing interest. This review aims to elucidate the involvement of viral infections in the pathogenesis of immune-mediated GI diseases, focusing on achalasia and celiac disease, as well as the virome dysbiosis in IBD. Recent evidence suggests that viral pathogens, ranging from common respiratory viruses to enteroviruses and herpesviruses, may trigger or exacerbate achalasia and celiac disease by disrupting immune homeostasis in the GI tract. Furthermore, alterations in the microbiota and, specifically, in the virome composition and viral-host interactions have been implicated in perpetuating chronic intestinal inflammation in IBD. By synthesizing current knowledge on viral contributions to immune-mediated GI diseases, this review aims to provide insights into the complex interplay between viral infections, host genetics, and virome dysbiosis, shedding light on novel therapeutic strategies aimed at mitigating the burden of these debilitating conditions on patients' health and quality of life.

Dietary Triple-Strain Bacillus-Based Probiotic Supplementation Improves Performance, Immune Function, Intestinal Morphology, and Microbial Community in Weaned Pigs

Probiotics provide health benefits and are used as feed supplements as an alternative prophylactic strategy to antibiotics. However, the effects of Bacillus-based probiotics containing more than two strains when supplemented to pigs are rarely elucidated. SOLVENS (SLV) is a triple-strain Bacillus-based probiotic. In this study, we investigate the effects of SLV on performance, immunity, intestinal morphology, and microbial community in piglets. A total of 480 weaned pigs [initial body weight (BW) of 8.13 ± 0.08 kg and 28 days of age] were assigned to three treatments in a randomized complete block design: P0: basal diet (CON); P200: CON + 200 mg SLV per kg feed (6.5 × 108 CFU/kg feed); and P400: CON + 400 mg SLV per kg feed (1.3 × 109 CFU/kg feed). Each treatment had 20 replicated pens with eight pigs (four male/four female) per pen. During the 31 d feeding period (Phase 1 = wean to d 14, Phase 2 = d 15 to 31 after weaning), all pigs were housed in a temperature-controlled nursery room (23 to 25 °C). Feed and water were available ad libitum. The results showed that the pigs in the P400 group increased (p < 0.05) average daily gain (ADG) in phase 2 and tended (p = 0.10) to increase ADG overall. The pigs in the P200 and P400 groups tended (p = 0.10) to show improved feed conversion ratios overall in comparison with control pigs. The pigs in the P200 and P400 groups increased (p < 0.05) serum immunoglobulin A, immunoglobulin G, and haptoglobin on d 14, and serum C-reactive protein on d 31. The pigs in the P200 group showed an increased (p < 0.01) villus height at the jejunum, decreased (p < 0.05) crypt depth at the ileum compared with other treatments, and tended (p = 0.09) to have an increased villus-crypt ratio at the jejunum compared with control pigs. The pigs in the P200 and P400 groups showed increased (p < 0.05) goblet cells in the small intestine. Moreover, the pigs in the P400 group showed down-regulated (p < 0.05) interleukin-4 and tumor necrosis factor-α gene expressions, whereas the pigs in the P400 group showed up-regulated occludin gene expression in the ileum. These findings suggest that SLV alleviates immunological reactions, improves intestinal microbiota balance, and reduces weaning stress in piglets. Therefore, SOLVENS has the potential to improve health and performance for piglets.

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.

Alginate Oligosaccharides Enhance Antioxidant Status and Intestinal Health by Modulating the Gut Microbiota in Weaned Piglets

Alginate oligosaccharides (AOSs), which are an attractive feed additive for animal production, exhibit pleiotropic bioactivities. In the present study, we investigated graded doses of AOS-mediated alterations in the physiological responses of piglets by determining the intestinal architecture, barrier function, and microbiota. A total of 144 weaned piglets were allocated into four dietary treatments in a completely random design, which included a control diet (CON) and three treated diets formulated with 250 mg/kg (AOS250), 500 mg/kg (AOS500), and 1000 mg/kg AOS (AOS1000), respectively. The trial was carried out for 28 days. Our results showed that AOS treatment reinforced the intestinal barrier function by increasing the ileal villus height, density, and fold, as well as the expression of tight junction proteins, especially at the dose of 500 mg/kg AOS. Meanwhile, supplementations with AOSs showed positive effects on enhancing antioxidant capacity and alleviating intestinal inflammation by elevating the levels of antioxidant enzymes and inhibiting excessive inflammatory cytokines. The DESeq2 analysis showed that AOS supplementation inhibited the growth of harmful bacteria Helicobacter and Escherichia_Shigella and enhanced the relative abundance of Faecalibacterium and Veillonella. Collectively, these findings suggested that AOSs have beneficial effects on growth performance, antioxidant capacity, and gut health in piglets.

Forces Bless You: Mechanosensitive Piezo Channels in Gastrointestinal Physiology and Pathology

The gastrointestinal (GI) tract is an organ actively involved in mechanical processes, where it detects forces via a mechanosensation mechanism. Mechanosensation relies on specialized cells termed mechanoreceptors, which convert mechanical forces into electrochemical signals via mechanosensors. The mechanosensitive Piezo1 and Piezo2 are widely expressed in various mechanosensitive cells that respond to GI mechanical forces by altering transmembrane ionic currents, such as epithelial cells, enterochromaffin cells, and intrinsic and extrinsic enteric neurons. This review highlights recent research advances on mechanosensitive Piezo channels in GI physiology and pathology. Specifically, the latest insights on the role of Piezo channels in the intestinal barrier, GI motility, and intestinal mechanosensation are summarized. Additionally, an overview of Piezo channels in the pathogenesis of GI disorders, including irritable bowel syndrome, inflammatory bowel disease, and GI cancers, is provided. Overall, the presence of mechanosensitive Piezo channels offers a promising new perspective for the treatment of various GI disorders.

Lacticaseibacillus casei IB1 Alleviates DSS-Induced Inflammatory Bowel Disease by Regulating the Microbiota and Restoring the Intestinal Epithelial Barrier

Inflammatory bowel disease (IBD) is becoming an increasingly serious health problem in humans and animals. Probiotics can inhibit the development of IBD. Due to the specificity of the strains, the function and mechanism of action of different strains are still unclear. Here, a DSS-induced colitis mouse model was utilized to investigate the ability and mechanism by which Lacticaseibacillus casei IB1 alleviates colitis. Treatment with L. casei IB1 improved DSS-induced colitis in mice, as indicated by increased body weight, colon length, and goblet cell numbers and decreased disease activity index (DAI), proinflammatory factor (TNF-α, IL-1β, and IL-6) levels, and histopathological scores after intake of IB1. IB1 supplementation also improved the expression of tight junction proteins and inhibited the activation of the MAPK and NF-κB signaling pathways to alleviate intestinal inflammation. In addition, IB1 rebalanced the intestinal microbial composition of colitis mice by increasing the abundance of Faecalibaculum and Alistipes and decreasing the abundance of Bacteroides and Escherichia_Shigella. In summary, L. casei IB1 showed great potential for relieving colitis by regulating the microbiota and restoring the epithelial barrier. It can be used as a potential probiotic for the prevention and treatment of UC in the future.

Neonatal microbiota colonization drives maturation of primary and secondary goblet cell mediated protection in the pre-weaning colon

In the distal colon, mucus secreting goblet cells primarily confer protection from luminal microorganisms via generation of a sterile inner mucus layer barrier structure. Bacteria-sensing sentinel goblet cells provide a secondary defensive mechanism that orchestrates mucus secretion in response to microbes that breach the mucus barrier. Previous reports have identified mucus barrier deficiencies in adult germ-free mice, thus implicating a fundamental role for the microbiota in programming mucus barrier generation. In this study, we have investigated the natural neonatal development of the mucus barrier and sentinel goblet cell-dependent secretory responses upon postnatal colonization. Combined in vivo and ex vivo analyses of pre- and post-weaning colonic mucus barrier and sentinel goblet cell maturation demonstrated a sequential microbiota-dependent development of these primary and secondary goblet cell-intrinsic protective functions, with dynamic changes in mucus processing dependent on innate immune signalling via MyD88, and development of functional sentinel goblet cells dependent on the NADPH/Dual oxidase family member Duox2. Our findings therefore identify new mechanisms of microbiota-goblet cell regulatory interaction and highlight the critical importance of the pre-weaning period for the normal development of colonic barrier function.

Gut microbiota and D-ribose mediate the anti-colitic effect of punicalagin in DSS-treated mice

Background: Inflammatory bowel disease (IBD) is an increasing health burden worldwide. Punicalagin, a bioactive component rich in pomegranate rind, has been shown to attenuate chemical or bacteria-induced experimental colitis in mice, but whether punicalagin exerts its function through modulating gut microbiota and metabolites remains unexplored. Results: Punicalagin (100 mg per kg per day) administered orally to mice alleviated dextran-sodium sulfate (DSS)-induced colitis. Gut microbiota analyzed by 16S rRNA sequencing showed that punicalagin altered gut microbiota by increasing the Lachnospiraceae_NK4A136_group and Bifidobacterium abundance. To evaluate the effect of punicalagin-modulated microbiota and its metabolites in colitis mice, we transplanted fecal microbiota and sterile fecal filtrate (SFF) to mice treated with oral antibiotics. The results of fecal microbiota transplantation (FMT) demonstrated that punicalagin's anti-colitic effect is transferable by transplanting punicalagin-modulated gut microbiota and its metabolites. Additionally, we discovered that punicalagin-modulated sterile fecal filtrate also exhibits anti-colitis effects, as evidenced by improved intestinal barrier integrity and decreased inflammation. Subsequently, fecal metabolites were analyzed using liquid chromatography-mass spectrometry (LC-MS). The analysis revealed that punicalagin significantly increased the level of D-ribose. In vitro experiments showed that D-ribose has both anti-inflammatory and antioxidant properties. Furthermore, D-ribose significantly mitigated DSS-induced colitis symptoms in mice. Conclusions: Overall, this study demonstrated that gut microbiota and its metabolites partly mediate the protective effect of punicalagin against DSS-induced colitis in mice. D-ribose is a key metabolite that contributes to the anti-colitic effect of punicalagin in mice.

PIM1-HDAC2 axis modulates intestinal homeostasis through epigenetic modification

The mucosal barrier is crucial for intestinal homeostasis, and goblet cells are essential for maintaining the mucosal barrier integrity. The proviral integration site for Moloney murine leukemia virus-1 (PIM1) kinase regulates multiple cellular functions, but its role in intestinal homeostasis during colitis is unknown. Here, we demonstrate that PIM1 is prominently elevated in the colonic epithelia of both ulcerative colitis patients and murine models, in the presence of intestinal microbiota. Epithelial PIM1 leads to decreased goblet cells, thus impairing resistance to colitis and colitis-associated colorectal cancer (CAC) in mice. Mechanistically, PIM1 modulates goblet cell differentiation through the Wnt and Notch signaling pathways. Interestingly, PIM1 interacts with histone deacetylase 2 (HDAC2) and downregulates its level via phosphorylation, thereby altering the epigenetic profiles of Wnt signaling pathway genes. Collectively, these findings investigate the unknown function of the PIM1-HDAC2 axis in goblet cell differentiation and ulcerative colitis/CAC pathogenesis, which points to the potential for PIM1-targeted therapies of ulcerative colitis and CAC.

Imaging assessment of conjunctival goblet cells in dry eye disease

Dry eye disease (DED) is a widespread, multifactorial, and chronic disorder of the ocular surface with disruption of tear film homeostasis as its core trait. Conjunctival goblet cells (CGCs) are specialised secretory cells found in the conjunctival epithelium that participate in tear film formation by secreting mucin. Changes in both the structure and function of CGCs are hallmarks of DED, and imaging assessment of CGCs is important for the diagnosis, classification, and severity evaluation of DED. Existing imaging methods include conjunctival biopsy, conjunctival impression cytology and in vivo confocal microscopy, which can be used to assess the morphology, distribution, and density of the CGCs. Recently, moxifloxacin-based fluorescence microscopy has emerged as a novel technique that enables efficient, non-invasive and in vivo imaging of CGCs. This article presents a comprehensive overview of both the structure and function of CGCs and their alterations in the context of DED, as well as current methods of CGCs imaging assessment. Additionally, potential directions for the visual evaluation of CGCs are discussed.

Multichiral Mesoporous Silica Screws with Chiral Differential Mucus Penetration and Mucosal Adhesion for Oral Drug Delivery

In the harsh gastrointestinal tract, helical bacteria with hierarchical chiral architectures possess strong abilities. Taking inspirations from nature, we developed a multichiral mesoporous silica nanoscrew (L/D-MCNS) as an efficient oral drug delivery platform by modifying the structural chiral silica nanoscrew (CNS) with L/D-alanine (L/D-Ala) enantiomers via the sequential application of a chiral template and postmodification strategies. We demonstrated that L-MCNS showed differential biological behaviors and superior advantages in oral adsorption compared to those of CNS, D-MCNS, and DL-MCNS. During the delivery, helical L/D-MCNS presenting distinctive topological structures, including small section area, large rough external surface, and a screw-like body, displayed multiple superiorities in mucus diffusion and mucosal adhesion. Meanwhile, the grafted chiral enantiomers enabled positive or negative chiral recognition with the biosystems. Once racemic flurbiprofen (FP) was encapsulated into the nanopores of L/D-MCNS (FP@L/D-MCNS), L/D-MCNS providing highly cross-linked and mesoscopic chiral nanochannels was beneficial for controlling the drug loading/release kinetics with chiral microenvironment sensitivity. Particularly, we noticed enantioselective absorption of FP in vivo, which could be attributed to the differential biological behaviors of L/D-MCNS. By simple design and regulation of the multilevel chirality of nanocarriers, L/D-MCNS can be employed for efficient oral drug delivery from the perspectives of material science, pharmacy, and bionics.

Fucoxanthin alleviates lipopolysaccharide-induced intestinal barrier injury in mice

The aim of this study was to evaluate the preventive role and underlying mechanisms of fucoxanthin (Fx) on lipopolysaccharide (LPS)-induced intestinal barrier injury in mice. Our results demonstrated that the oral administration of Fx (50 and 200 mg per kg body weight per day) for consecutive 7 days significantly alleviated the severity of LPS-induced intestinal barrier injury in mice, as evidenced by attenuating body weight loss, improving intestinal permeability, and ameliorating intestinal morphological damage such as reduction in the ratio of the villus length to the crypt depth (V/C), intestinal epithelium distortion, goblet cell depletion, and low mucin 2 (MUC2) expression. Fx also significantly mitigated LPS-induced excessive apoptosis of intestinal epithelial cells (IECs) and curbed the decrease of tight junction proteins including claudin-1, occludin, and zonula occludens-1 in the ileum and colon. Additionally, Fx effectively alleviated LPS-induced extensive infiltration of macrophages and neutrophils into the intestinal mucosa, the overproduction of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 1beta (IL-1β) and IL-6, and gasdermin D (GSDMD)-mediated pyroptosis of IECs. The underlying mechanisms might be associated with inhibiting the activation of nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs) and nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling pathways. Moreover, Fx also notably restrained intestinal reactive oxygen species (ROS), malondialdehyde and protein carbonylation levels in LPS-treated mice, and it might be mediated by activating the nuclear factor-erythroid 2 related factor 2 (Nrf2) signaling pathway. Overall, these findings indicated that Fx might be developed as a potential effective dietary supplement to prevent intestinal barrier injury.

Intestinal Taste Receptor Expression and Its Implications for Health: An Integrative Analysis in Female Rats after Chronic Insect Supplementation

Taste receptors are found in the gastrointestinal tract, where they are susceptible to dietary modulation, a key point that is crucial for diet-related responses. Insects are sustainable and good-quality protein sources. This study analyzed the impact of insect consumption on the modulation of taste receptor expression across various segments of the rat intestine under healthy or inflammatory conditions. Female Wistar rats were supplemented with Tenebrio molitor (T) or Alphitobius diaperinus (B), alongside a control group (C), over 21 days under healthy or LPS-induced inflammation. The present study reveals, for the first time, that insect consumption modulates taste receptor gene expression, mainly in the ascending colon. This modulation was not found under inflammation. Integrative analysis revealed colonic Tas1r1 as a key discriminator for insect consumption (C = 1.04 ± 0.32, T = 1.78 ± 0.72, B = 1.99 ± 0.82, p-value <0.05 and 0.01, respectively). Additionally, correlation analysis showed the interplay between intestinal taste receptors and metabolic and inflammatory responses. These findings underscore how insect consumption modulates taste receptors, influencing intestinal function and broader physiological mechanisms.