Phlorizin Mitigates Dextran Sulfate Sodium-Induced Colitis in Mice by Modulating Gut Microbiota and Inhibiting Ferroptosis

A novel transgenic miniature pig model of human PSGL-1 reveals critical roles in thrombosis, inflammation, and immune perturbation

Dysregulated inflammation, thrombosis, and immunity are fundamental pathological mechanisms underlying a wide range of human diseases. Limitations inherent in existing animal models for studying these complex processes and evaluating therapeutic interventions necessitate the development of more physiologically relevant systems. Here, we report the establishment and characterization of a humanized PSGL-1 transgenic (hPSGL-1 TG) Bama miniature pig model. Beginning at two months postnatally postnatally, hPSGL-1 TG pigs exhibited overt inflammatory signs, including rhinorrhea and diarrhea. Progressive cardiac dysfunction, marked by significantly reduced ejection fraction, developed prior to humane endpoints, resulting in a median survival of 110.5 days. Postmortem analysis revealed extensive fibrinous thrombi occluding cardiac and pulmonary vasculature, indicative of severe, systemic thrombosis. Consistent with this thromboembolic phenotype, coagulation profiling demonstrated a profound hypercoagulable state. Histological examination further revealed widespread inflammatory cell infiltration within thrombotic lesions, ventricular myocardium, lung, and colon. Circulating levels of key inflammatory cytokines, including IL-4, IL-6, and TGF-β1, were significantly elevated. Conversely, analysis of peripheral blood immune cell populations showed depletion of monocytes and CD8β + T cells. In conclusion, this is the first report to generated a hPSGL-1 TG miniature pig model and underscores the critical role of hPSGL-1 in severe thrombosis, inflammation, and complex alterations in peripheral immune cell populations. This novel model serves as a valuable tool for investigating the mechanistic contributions of hPSGL-1 to these pathological processes and provides a compelling preclinical platform for the development and evaluation of hPSGL-1-targeted therapies.

NUDT1 aggravates intestinal epithelial barrier injury through oxidative stress in ulcerative colitis

BACKGROUND

Nudix hydrolase 1 (NUDT1) plays a crucial role in tumours, where it helps limit cellular damage caused by reactive oxygen species. However, the exact function of NUDT1 in ulcerative colitis (UC) is not well understood.

METHODS

NUDT1 expression in the intestinal mucosal tissues of patients with UC was analysed using quantitative reverse transcription polymerase chain reaction. A public database was used to analyse the expression of selected signature genes of interest in patients with UC with different NUDT1 expression levels. TH588, a potent NUDT1 inhibitor, was used to treat intestinal epithelial cells (IECs) in mice. The functions of the IECs were assessed using quantitative reverse transcription polymerase chain reaction, flow cytometry, western blotting, and fluorescence microscopy. A mouse model of dextran sodium sulphate-induced colitis was established.

RESULTS

We examined NUDT1 expression and found that it was significantly elevated in the colon tissues of patients with UC. A colitis model was established in wild-type mice treated with TH588, which significantly reduced intestinal mucosal inflammation and induced notable alterations in faecal microbiota composition. Moreover, TH588 helped preserve intestinal mucosal barrier function. Inhibition of NUDT1 expression in IECs enhanced antioxidant activity by increasing Nrf2 expression and reducing ERK phosphorylation, which, in turn, stabilised tight junctions in IECs exposed to oxidative stress.

CONCLUSIONS

Our research emphasises the role of NUDT1 in modulating the intestinal microbiota and intestinal mucosal barrier in UC, indicating that targeting NUDT1 during intestinal mucosal inflammation could serve as a promising therapeutic strategy for UC.

The metabolites of gut microbiota: their role in ferroptosis in inflammatory bowel disease

Inflammatory bowel disease (IBD) includes chronic inflammatory conditions, such as Crohn's disease and ulcerative colitis, characterized by impaired function of the intestinal mucosal epithelial barrier. In recent years, ferroptosis, a novel form of cell death, has been confirmed to be involved in the pathological process of IBD and is related to various pathological changes, such as oxidative stress and inflammation. Recent studies have further revealed the complex interactions between the microbiome and ferroptosis, indicating that ferroptosis is an important target for the regulation of IBD by the gut microbiota and its metabolites. This article reviews the significant roles of gut microbial metabolites, such as short-chain fatty acids, tryptophan, and bile acids, in ferroptosis in IBD. These metabolites participate in the regulation of ferroptosis by influencing the intestinal microenvironment, modulating immune responses, and altering oxidative stress levels, thereby exerting an impact on the pathological development of IBD. Treatments based on the gut microbiota for IBD are gradually becoming a research hotspot. Finally, we discuss the potential of current therapeutic approaches, including antibiotics, probiotics, prebiotics, and fecal microbiota transplantation, in modulating the gut microbiota, affecting ferroptosis, and improving IBD symptoms. With a deeper understanding of the interaction mechanisms between the gut microbiota and ferroptosis, it is expected that more precise and effective treatment strategies for IBD will be developed in the future.

Fructosyl-mangiferin ameliorates dextran sulfate sodium-induced colitis in mice via the STAT3/M1/Th17 axis

BACKGROUND

Inflammatory bowel disease (IBD), a chronic inflammatory condition categorized into ulcerative colitis (UC) and Crohn's disease (CD), affects a growing global patient population. Despite the prevalence, clinically there is a scarcity of effective therapeutic agents.

PURPOSE

This study investigated the therapeutic effects of fructosyl mangiferin (FM) on UC and elucidated its underlying mechanisms through in vivo and in vitro experiments.

METHODS

In vivo, a UC model of C57BL/6J mice was established via dextran sulfate sodium (DSS) induction, and the therapeutic effects were assessed through intragastric administration. In vitro, the murine macrophage cell line RAW264.7 was stimulated with lipopolysaccharide (LPS) to establish an M1 polarization model and introduced to explore the role of FM in immune cells. Molecular docking was further employed to investigate the specific molecular mechanisms of FM.

RESULTS

In vivo experimental findings indicate that FM, like mangiferin (M), preserves mucin secretion and the expression of occludin protein, and both significantly impede the progression of fibrosis associated with colitis. Additionally, FM effectively suppresses M1 macrophage polarization and exerts a pronounced inhibitory effect on the adaptive immune response, outperforming M in mitigating UC. In vitro results corroborate FM's inhibitory action on M1 polarization. Molecular docking studies identified FM as a potential signal transducer and activator of transcription 3 (STAT3) inhibitor, aligning with western blot analyses from both in vivo and in vitro experiments.

CONCLUSION

In conclusion, following fructosylation, FM exhibits remarkable anti-inflammatory and colonic protective effects. FM's ability to control the progression of UC offers a novel strategy for its potential treatment, warranting further investigation into its clinical application.

Thymol Alleviates Colitis by Modulating Intestinal Barrier Damage, Gut Microbiota, and Amino Acid Metabolic Pathways

Thymol (THY) is a phenolic monoterpene compound that has garnered attention due to its various biological properties, including antioxidant, anti-inflammatory, and immune-regulatory effects. The purpose of this study was to determine the therapeutic and protective effects of THY in colitic mice, with a particular focus on the mechanisms involving gut microbiota. The results showed that early intervention with THY (40 and 80 mg/kg) not only alleviated the clinical symptoms and colonic damage in mice with dextran sodium sulfate (DSS)-induced colitis but also suppressed the colonic production of inflammatory cytokines (IL-1β, IL-6, and IL-18) and enhanced the expression of mucins (MUC1 and MUC2) and trefoil factor family 3 (TFF3), thereby improving the integrity of the intestinal epithelial barrier. In addition, THY altered the composition of the gut microbiota in colitis mice by increasing the abundance of Bacteroides and reducing the abundance of Proteobacteria. Fecal microbial transplantation (FMT) results demonstrated that FM from THY donor mice significantly improved symptoms of inflammatory bowel disease (IBD), confirming the crucial role of the gut microbiota. Metagenomic and untargeted metabolomic studies found that the characteristic microbiota of THY is Prevotellaceae, and THY significantly upregulated the amino acid metabolic pathways related to arginine and proline metabolism, arginine biosynthesis, and glycerophospholipid metabolism. In summary, THY holds significant potential as a functional additive to enhance host intestinal activity.

Cecropin AD ameliorates pneumonia and intestinal injury in mice with mycoplasma pneumoniae by mediating gut microbiota

Animals infected with mycoplasma pneumoniae not only develop respiratory diseases, but also cause digestive diseases through the lung-gut axis mediated by the intestinal flora, and vice versa. Antimicrobial peptides are characterized by their bactericidal, anti-inflammatory, and intestinal flora-regulating properties. However, the effect of cecropin AD (CAD) against mycoplasma pneumonia remains unclear. To investigate the anti-inflammatory effect of CAD on mycoplasma pneumonia and the associated mechanism, mice were infected with Mycoplasma capricolum subsp. Capripneumoniae(Mccp) to elicit lung inflammation, followed by oral administration of CAD via gavage. The findings showed that mice receiving twice injections of 2.08 × 108 copies of Mccp suffered significant pathological damage to their lungs and colons. Additionally, there was a notable upsurge in inflammatory factors within the affected tissues. 16 S rDNA sequencing revealed alterations in the colonic microbiota, including a decrease in the abundance of beneficial bacteria such as Corynebacterium_glutamicum and Candidatus_Saccharimonas, and an increase in the abundance of potential pathogens like Lachnospiraceae_NK4A136_group and Escherichia-Shigella. As a result, there were abnormal rises in lipopolysaccharide (LPS) levels in both colonic content and blood. Moreover, CAD treatment reversed the microbial dysbiosis and decreased the LPS levels induced by Mccp, thereby suppressing the activation of the TLR-4/NF-κB pathway and the Fas/FasL-caspase-8/-3 pathway. Consequently, this significantly mitigated the morphological and functional damage to the lungs and colons caused by Mccp. The findings offer novel insights and approaches for the clinical management of Mccp infections.

Apple polyphenols prevent patulin-induced intestinal damage by modulating the gut microbiota and metabolism of the gut-liver axis

Patulin (PAT), a foodborne toxin, causes severe intestinal damage. To mitigate this health threat, mice were pretreated with apple polyphenols (AP) in their drinking water (0.01 % and 0.05 %) for eight weeks, followed by exposure to PAT during the last two weeks. Subsequently, histopathological and biochemical evaluations of intestinal tissues were conducted, alongside assessments of alterations in gut microbiota, colonic content metabolome, and hepatic metabolome. Consequently, AP alleviated PAT-induced villus and crypt injury, mucus depletion, GSH level decline, GSH-Px and SOD activity reduction, and MPO activity elevation. Notably, AP counteracted PAT-mediated microbiota disruptions and promoted the abundance of beneficial bacteria (Dubosiella, Akkermansia, Lachnospiraceae, and Lactobacillus). Furthermore, AP counteracted PAT-induced metabolic disorders in the colonic contents and liver. Ultimately, AP prevented intestinal injury by regulating the gut microbiota and amino acid, purine, butanoate, and glycerophospholipid metabolism in the gut-liver axis. These results underscore the potential of AP to prevent foodborne toxin-induced intestinal damage.

Phlorizin ameliorates cognitive and behavioral impairments via the microbiota-gut-brain axis in high-fat and high-fructose diet-induced obese male mice

The long-term high-fat, high-sugar diet exacerbates type 2 diabetes mellitus (T2DM)-related cognitive impairments. Phlorizin, a well-studied natural compound found in apples and other plants, is recognized for its bioactive properties, including modulation of glucose and lipid metabolism. Despite its established role in mitigating metabolic disorders, the neuroprotective effects of phlorizin, particularly against diabetes-related cognitive dysfunction, have not been fully elucidated. Therefore, the present study aimed to investigate the effect of dietary supplementation of phlorizin on high-fat and high-fructose diet (HFFD)-induced cognitive dysfunction and evaluate the crucial role of the microbiota-gut-brain axis. We found that dietary supplementation of phlorizin for 14 weeks effectively prevented glucolipid metabolism disorder, spatial learning impairment, and memory impairment in HFFD mice. In addition, phlorizin improved the HFFD-induced decrease in synaptic plasticity, neuroinflammation, and excessive activation of microglia in the hippocampus. Transcriptomics analysis shows that the protective effect of phlorizin on cognitive impairment was associated with increased expression of neurotransmitters and synapse-related genes in the hippocampus. Phlorizin treatment alleviated colon microbiota disturbance, mainly manifested by an increase in gut microbiota diversity and the abundance of short-chain fatty acid (SCFA)-producing bacteria. The level of microbial metabolites, including SCFA, inosine 5'-monophosphate (IMP), and D (-)-beta-hydroxybutyric acid (BHB) were also significantly increased after phlorizin treatment. Integrating multiomics analysis observed tight connections between phlorizin-regulated genes, microbiota, and metabolites. Furthermore, removal of the gut microbiota via antibiotics treatment diminished the protective effect of phlorizin against HFFD-induced cognitive impairment, underscoring the critical role of the gut microbiota in mediating cognitive behavior. Importantly, supplementation with SCFA and BHB alone mimicked the regulatory effects of phlorizin on cognitive function. Therefore, phlorizin shows promise as a potential nutritional therapy for addressing cognitive impairment associated with metabolic disorders. Further research is needed to explore its effectiveness in preventing and alleviating neurodegenerative diseases.

Gut microbiota in health and disease: advances and future prospects

The gut microbiota plays a critical role in maintaining human health, influencing a wide range of physiological processes, including immune regulation, metabolism, and neurological function. Recent studies have shown that imbalances in gut microbiota composition can contribute to the onset and progression of various diseases, such as metabolic disorders (e.g., obesity and diabetes) and neurodegenerative conditions (e.g., Alzheimer's and Parkinson's). These conditions are often accompanied by chronic inflammation and dysregulated immune responses, which are closely linked to specific forms of cell death, including pyroptosis and ferroptosis. Pathogenic bacteria in the gut can trigger these cell death pathways through toxin release, while probiotics have been found to mitigate these effects by modulating immune responses. Despite these insights, the precise mechanisms through which the gut microbiota influences these diseases remain insufficiently understood. This review consolidates recent findings on the impact of gut microbiota in these immune-mediated and inflammation-associated conditions. It also identifies gaps in current research and explores the potential of advanced technologies, such as organ-on-chip models and the microbiome-gut-organ axis, for deepening our understanding. Emerging tools, including single-bacterium omics and spatial metabolomics, are discussed for their promise in elucidating the microbiota's role in disease development.

Antioxidant Therapy in Inflammatory Bowel Diseases: How Far Have We Come and How Close Are We?

Inflammatory bowel diseases (IBD) pose a growing public health challenge with unclear etiology and limited efficacy of traditional pharmacological treatments. Alternative therapies, particularly antioxidants, have gained scientific interest. This systematic review analyzed studies from MEDLINE, Cochrane, Web of Science, EMBASE, and Scopus using keywords like "Inflammatory Bowel Diseases" and "Antioxidants." Initially, 925 publications were identified, and after applying inclusion/exclusion criteria-covering studies from July 2015 to June 2024 using murine models or clinical trials in humans and evaluating natural or synthetic substances affecting oxidative stress markers-368 articles were included. This comprised 344 animal studies and 24 human studies. The most investigated antioxidants were polyphenols and active compounds from medicinal plants (n = 242; 70.3%). The review found a strong link between oxidative stress and inflammation in IBD, especially in studies on nuclear factor kappa B and nuclear factor erythroid 2-related factor 2 pathways. However, it remains unclear whether inflammation or oxidative stress occurs first in IBD. Lipid peroxidation was the most studied oxidative damage, followed by DNA damage. Protein damage was rarely investigated. The relationship between antioxidants and the gut microbiota was examined in 103 animal studies. Human studies evaluating oxidative stress markers were scarce, reflecting a major research gap in IBD treatment. PROSPERO registration: CDR42022335357 and CRD42022304540.

Effects of chitosan guanidine on blood glucose regulation and gut microbiota in T2DM

Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycemia. Type 2 diabetes mellitus (T2DM) represents approximately 90 % of all DM cases and is primarily caused by an imbalance in blood glucose homeostasis due to inadequate insulin secretion or insulin resistance. This study explores the potential therapeutic effects of chitosan guanidine (CSG) on a T2DM mouse model. The findings reveal that CSG significantly enhances oral glucose tolerance (OGTT) and insulin sensitivity (ITT), reduces fasting blood glucose (FBG) levels, and suppresses the expression of proinflammatory cytokines in T2DM mice. These changes improve insulin resistance and diminish inflammation. Additionally, CSG markedly ameliorates lipid metabolism disorders, lowers total cholesterol (TC) and triglyceride (TG) levels, and inhibits hepatic fat accumulation. 16S rRNA and Spearman correlation analyses indicate that CSG promotes the relative abundance of probiotic genera such as Bacteroidota, Patescibacteria, Actinobacteria, and Cyanobacteria. These bacteria are positively correlated with short-chain fatty acids (SCFAs) and high-density lipoprotein cholesterol (HDLC) levels. Conversely, CSG reduces the relative abundance of pathogenic bacteria, including Proteobacteria and Ralstonia, leading to an improved intestinal microbial community composition in T2DM mice and alleviating T2DM symptoms. These results suggest that CSG holds significant potential as a non-insulin therapeutic agent for diabetes management.

Hydrolyzed protein formula improves the nutritional tolerance by increasing intestinal development and altering cecal microbiota in low-birth-weight piglets

Background

Prematurity or low birth weight (LBW), poses a significant challenge in global health. Exploring appropriate and effective nutritional interventions is crucial for the growth and development of LBW infants. Hydrolyzed protein formula has been suggested as a potential solution to prevent intestinal dysfunction and improve digestion and absorption in infants.

Objectives

This study aimed to investigate the benefits of hydrolyzed protein formula on feeding intolerance, intestinal morphological development, and microbiota in a LBW piglet model.

Methods

A total of 24 male piglets (3 d of age, 0.95-1.25 kg average BW) were assigned (8 pens/diet; 1 pigs/pen) into three dietary treatments and fed with a basic formula (BF), standard premature infant formula (SF) and hydrolyzed protein formula (HF) respectively, for 7 d. After the piglets sacrifice, growth performance, amino acid metabolism and intestinal morphology were assessed. 16S rRNA sequencing and microbial metabolic phenotypes analyzed the effects of different formula treatments on intestinal flora structure of LBW piglets.

Results

The HF diet reduced the rates of diarrhea and milk vomiting were reduced by 20.44% (p > 0.05) and 58.44% (p > 0.05), and decreased the crypt depth in the ileum while increasing the ratio of villus height/crypt depth and the mRNA expressions of y+LAT1 and b0,+AT in the ileum (p < 0.05). HF increased the final body weight, serum Thr and essential amino acid contents, and CAT2 and b0,+AT mRNA expressions in ileal mucosa compared with the SF diet (p < 0.05). Microbiota sequencing results showed that the colonic microbial richness indices (Chao1, ACE, and observed species), the diversity indices (Shannon and Simpson), and the phyla Actinobacteriota, unidentified_Bacteria, Acidobacteriota and Actinobacteria, the genus Rubrobacter and RB41 were reduced (p < 0.05) in SF and HF groups. Microbial metabolic phenotypes analysis showed a reduction in the richness of biofilm-forming bacteria (p < 0.05).

Conclusion

In summary, hydrolyzed protein formula had better nutrition and tolerance in LBW suckling piglets by improving amino acid transport and intestinal development, and regulating gut microbial communities.

Morin alleviates DSS-induced ulcerative colitis in mice via inhibition of inflammation and modulation of intestinal microbiota

Ulcerative colitis (UC) is a chronic inflammatory condition with recurrent and challenging symptoms. Effective treatments are lacking, making UC management a critical research area. Morin (MO), a flavonoid from the Moraceae family, shows potential as an anti-UC agent, but its mechanisms are not fully understood. Using a dextran sulfate sodium (DSS)-induced UC mouse model, we employed network pharmacology to predict MO's therapeutic effects. Assessments included changes in body weight, disease activity index (DAI), and colon length. Immunofluorescence, hematoxylin and eosin (H&E), and PAS staining evaluated colon damage. ELISA and western blot analyzed inflammatory factors, tight junction (TJ)-associated proteins (Claudin-3, Occludin, ZO-1), and Mitogen-Activated Protein Kinase (MAPK)/ Nuclear Factor kappa B (NF-κB) pathways. 16S rRNA sequencing assessed gut microbiota diversity, confirmed by MO's modulation via Fecal Microbial Transplantation (FMT). Early MO intervention reduced UC severity by improving weight, DAI scores, and colon length, increasing goblet cells, enhancing barrier function, and inhibiting MAPK/NF-κB pathways. MO enriched gut microbiota, favoring beneficial bacteria like Muribaculaceae and Erysipelotrichaceae while reducing harmful Erysipelotrichaceae and Muribaculaceae. This study highlights MO's potential in UC management through inflammation control, mucosal integrity maintenance, and gut flora modulation.

Anthocyanins-rich cranberry extract attenuates DSS-induced IBD in an intestinal flora independent manner

Cranberry is abundantly rich in anthocyanins, a type of flavonoid with potent antioxidant properties and the resistance against certain diseases. In this study, anthocyanin-rich cranberry extract was extracted, purified, and its components were analyzed. 92.18 % of anthocyanins was obtained and the total content of anthocyanins was 302.62 mg/g after AB-8 resin purification. Quantification analysis showed that the extract mainly contained cyanidin-3-galactoside, procyanidin B2 and procyanidin B4. Then we explored its effects on dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD) in mice. The supplementation of cranberry extract resulted in an alleviation of IBD symptoms, evidenced by improvements in the disease activity index (DAI), restoration of colon length and colonic morphology. Cranberry extract reversed the elevated iron and malondialdehyde (MDA) levels and restored glutathione (GSH) levels in IBD mice. Further analysis revealed that cranberry modulated ferroptosis-associated genes and reduced expression of pro-inflammatory cytokines. Although cranberry influenced the intestinal flora balance by reducing Proteobacteria and Escherichia-Shigella, and increasing Lactobacillus, as well as enhancing SCFAs content, these effects were not entirely dependent on intestinal flora modulation, as indicated by antibiotic intervention and fecal microbiota transplantation (FMT) experiments. In conclusion, our findings suggest that the beneficial impact of cranberry extract on IBD may primarily involve the regulation of colonic ferroptosis, independent of significant alterations in intestinal flora.

Advances in research on immunocyte iron metabolism, ferroptosis, and their regulatory roles in autoimmune and autoinflammatory diseases

Autoimmune diseases commonly affect various systems, but their etiology and pathogenesis remain unclear. Currently, increasing research has highlighted the role of ferroptosis in immune regulation, with immune cells being a crucial component of the body's immune system. This review provides an overview and discusses the relationship between ferroptosis, programmed cell death in immune cells, and autoimmune diseases. Additionally, it summarizes the role of various key targets of ferroptosis, such as GPX4 and TFR, in immune cell immune responses. Furthermore, the release of multiple molecules, including damage-associated molecular patterns (DAMPs), following cell death by ferroptosis, is examined, as these molecules further influence the differentiation and function of immune cells, thereby affecting the occurrence and progression of autoimmune diseases. Moreover, immune cells secrete immune factors or their metabolites, which also impact the occurrence of ferroptosis in target organs and tissues involved in autoimmune diseases. Iron chelators, chloroquine and its derivatives, antioxidants, chloroquine derivatives, and calreticulin have been demonstrated to be effective in animal studies for certain autoimmune diseases, exerting anti-inflammatory and immunomodulatory effects. Finally, a brief summary and future perspectives on the research of autoimmune diseases are provided, aiming to guide disease treatment strategies.

Ferroptosis in ulcerative colitis: Potential mechanisms and promising therapeutic targets

Ulcerative colitis (UC) is a complex immune-mediated chronic inflammatory bowel disease. It is mainly characterized by diffuse inflammation of the colonic and rectal mucosa with barrier function impairment. Identifying new biomarkers for the development of more effective UC therapies remains a pressing task for current research. Ferroptosis is a newly identified form of regulated cell death characterized by iron-dependent lipid peroxidation. As research deepens, ferroptosis has been demonstrated to be involved in the pathological processes of numerous diseases. A growing body of evidence suggests that the pathogenesis of UC is associated with ferroptosis, and the regulation of ferroptosis provides new opportunities for UC treatment. However, the specific mechanisms by which ferroptosis participates in the development of UC remain to be more fully and thoroughly investigated. Therefore, in this review, we focus on the research advances in the mechanism of ferroptosis in recent years and describe the potential role of ferroptosis in the pathogenesis of UC. In addition, we explore the underlying role of the crosslinked pathway between ferroptosis and other mechanisms such as macrophages, neutrophils, autophagy, endoplasmic reticulum stress, and gut microbiota in UC. Finally, we also summarize the potential compounds that may act as ferroptosis inhibitors in UC in the future.

Oyster Peptides Ameliorate Dextran Sulfate Sodium-Induced Ulcerative Colitis via Modulating the Gut Microbiota and Inhibiting the TLR4/NF-κB Pathway

Ulcerative colitis (UC) is an inflammatory bowel disease with an increasing prevalence year over year, and the medications used to treat patients with UC clinically have severe side effects. Oyster peptides (OPs) have anti-inflammatory and antioxidant properties as functional foods that can alleviate a wide range of inflammatory conditions. However, the application of oyster peptides in ulcerative colitis is not well studied. In this work, an animal model of acute colitis was established using 3% dextran sulfate sodium (DSS), and the impact of OP therapy on colitis in mice was examined. Supplementing with OPs prevented DSS-induced colitis from worsening, reduced the expression of oxidative stress and inflammatory markers, and restored the intestinal barrier damage caused by DSS-induced colitis in mice. The 16S rDNA results showed that the OP treatment improved the gut microbiota structure of the UC mice, including increasing microbial diversity, increasing beneficial bacteria, and decreasing harmful bacteria. In the UC mice, the OP therapy decreased the relative abundance of Family_XIII_AD3011_group and Prevotella_9 and increased the relative abundance of Alistipes. In conclusion, OP treatment can inhibit the TLR4/NF-κB pathway and improve the intestinal microbiota in UC mice, which in turn alleviates DSS-induced colitis, providing a reference for the treatment of clinical UC patients.

Phlorizin Limits Bovine Viral Diarrhea Virus Infection in Mice via Regulating Gut Microbiota Composition

Phlorizin (PHZ) is one of the main pharmacologically active ingredients in Lithocarpus polystachyus. We have previously shown that PHZ inhibits the replication of bovine viral diarrhea virus (BVDV), but the exact antiviral mechanism, especially in vivo, is still unknown. Here, we further confirm that PHZ has good protective effects in BVDV-infected mice. We analyzed BVDV-induced CD3+, CD4+, and CD8+ T cells among peripheral blood lymphocytes and found that PHZ significantly restored their percentage. Metagenomic analyses revealed that PHZ markedly improved the richness and diversity of intestinal microbiota and increased the abundance of potentially health-related microbes (families Lachnosipiraceae, Ruminococcaceae, and Oscillospiraceae). Specifically, the relative abundance of short chain fatty acid (SCFA)-producing bacteria, including Lachnospiraceae_UCG-006, unclassified_f_Ruminococcaceae, Oscillibacter, Intestinimonas, Blautia, and Lachnoclostridium increased significantly after PHZ treatment. Interestingly, BVDV-infected mice that received fecal microbiota from PHZ-treated mice (PHZ-FMT) had a significantly lower viral load in the duodenum and jejunum than untreated mice. Pathological lesions of duodenum and jejunum were also greatly reduced in the PHZ-FMT group, confirming a significant antiviral effect. These findings show that gut microbiota play an important role in PHZ's antiviral activity and suggest that their targeted intervention might be a promising endogenous strategy to prevent and control BVDV.

Sea Cucumber Peptides Ameliorate DSS-Induced Ulcerative Colitis: The Role of the Gut Microbiota, the Intestinal Barrier, and Macrophage Polarization

The incidence of ulcerative colitis (UC) is increasing annually. There are few treatments for UC patients, and some drugs have serious side effects. Sea cucumber peptide (SCP) has anti-inflammatory, antioxidant and other biological activities, and various sea cucumber species are in pharmaceutical development. However, relevant studies on the effects of SCP on UC progression are still lacking. In this study, a mouse model of acute colitis was induced by 3% dextran sulfate (DSS), and the effect of 500 mg/kg SCP on colitis was investigated. The results showed that SCP can alleviate DSS-induced colon damage and intestinal barrier damage. SCP significantly inhibited the expression of inflammatory factors and oxidative stress in UC mice. SCP reversed the intestinal microbiota dysregulation induced by DSS, inhibited the growth of Sutterella, Prevotella_9 and Escherichia-Shigella harmful bacteria, and increased the abundance of Lachnospiraceae_NK4A136_group. At the same time, SCP treatment significantly inhibited the LPS-induced polarization of M1 macrophages, which may be mediated by two monopeptides, IPGAPGVP and TGPIGPPGSP, via FPR2. In conclusion, SCP can protect against colitis by modulating the intestinal microbiota composition and the intestinal barrier and inhibiting the polarization of M1 macrophages.