Stigmasterol Restores the Balance of Treg/Th17 Cells by Activating the Butyrate-PPARγ Axis in Colitis

Targeting gut microbiota for immunotherapy of diseases

With advances in next-generation sequencing technology, there is growing evidence that the gut microbiome plays a key role in the host's innate and adaptive immune system. Gut microbes and their metabolites directly or indirectly regulate host immune cells. Crucially, dysregulation of the gut microbiota is often associated with many immune system diseases. In turn, microbes modulate disease immunotherapy. Data from preclinical to clinical studies suggest that the gut microbiota may influence the effectiveness of tumor immunotherapy, particularly immune checkpoint inhibitors (ICIs). In addition, the most critical issue now is a COVID-19 vaccine that generates strong and durable immunity. A growing number of clinical studies confirm the potential of gut microbes to enhance the efficacy of COVID-19 vaccines. However, it is still unclear how gut bacteria interact with immune cells and what treatments are based on gut microbes. Here, we outline recent advances in the effects and mechanisms of the gut microbiota and its metabolites (tryptophan metabolites, bile acids, short-chain fatty acids, and inosine) on different immune cells (dendritic cells, CD4+T cells, and macrophages). It also highlights innovative intervention strategies and clinical trials of microbiota-based checkpoint blocking therapies for tumor immunity, and ongoing efforts to maintain the long-term immunogenicity of COVID-19 vaccines. Finally, the challenges to be overcome in this area are discussed. These provide an important basis for further research and clinical translation of gut microbiota.

A novel Bacillus aerolatus CX253 attenuates inflammation induced by Streptococcus pneumoniae in childhood and pregnant rats by regulating gut microbiome

Streptococcus pneumoniae (Spn) is the predominant pathogen responsible for community-acquired pneumonia (CAP) in children under five years old, and it can induce over 17% of pregnant women. However, no more effective measures exist to prevent infection induced by Spn in these two special populations. The beneficial microbes can antagonize Spn and provide new targets for preventing pneumococcal infections. This study used 16S rRNA gene sequencing and targeted metabolomics to evaluate the role of the Bacillus aerolatus CX253 (CX253) in alleviating Spn infection. Additionally, the colonization of CX253 was observed in nose, trachea, and lung by using confocal laser scanning microscopy and fluorescent labeling techniques. Compared with the model group, the expression level of interleukin-1β was dropped 1.81-fold and 2.22-fold, and interleukin-6 was decreased 2.39-fold and 1.84-fold. The express of tumor necrosis factor-α was down 2.30-fold and 3.84-fold in prevention group of childhood and pregnant rats, respectively. The 16S rRNA sequencing results showed that CX253 administration alone significantly increased the abundance of Lactobacillus, Limosilactobacillus, and Prevotella in the gut of childhood and pregnant rats. Furthermore, the CX253 increased propionate in the gut of childhood rats and increased propionate and butyrate in the gut of pregnant rats to inhibit pulmonary inflammation. In summary, CX253 attenuated Spn-induced inflammation by regulating the gut microbiota and SCFAs. The research provides valuable information for the prevention of pneumonia.

Stigmasterol Activates the mTOR Signaling Pathway by Inhibiting ORP5 Ubiquitination to Promote Milk Synthesis in Bovine Mammary Epithelial Cells

Stigmasterol (ST), a phytosterol found in food, has various biological activities. However, the effect of ST on milk synthesis in dairy cows remains unclear. Therefore, bovine primary mammary epithelial cells (BMECs) were isolated, cultured, and treated with ST to determine the effect of ST on milk synthesis. The study revealed that 10 μM ST significantly increased milk synthesis in BMECs by activating the mammalian target of rapamycin (mTOR) signaling pathway. Further investigation revealed that this activation depends on the regulatory role of oxysterol binding protein 5 (ORP5). ST induces the translocation of ORP5 from the cytoplasm to the lysosome, interacts with the mTOR, recruits mTOR to target the lysosomal surface, and promotes the activation of the mTOR signaling pathway. Moreover, ST was found to increase ORP5 protein levels by inhibiting its degradation via the ubiquitin-proteasome pathway. Specifically, the E3 ubiquitin ligase membrane-associated cycle-CH-type finger 4 (MARCH4) promotes the ubiquitination and subsequent degradation of ORP5. ST mitigates the interaction between MARCH4 and ORP5, thereby enhancing the structural stability of ORP5 and reducing its ubiquitination. In summary, ST stabilizes ORP5 by inhibiting the interaction between MARCH4 and ORP5, thereby activating mTOR signaling pathway and enhancing milk synthesis.

Mesenteric lymph nodes: a critical site for the up-regulatory effect of hUC-MSCs on Treg cells by producing TGF-β1 in colitis treatment

BACKGROUND

Mesenchymal stem cells (MSCs) demonstrate a wide range of therapeutic capabilities in the treatment of inflammatory bowel disease (IBD). The intraperitoneal injection of MSCs has exhibited superior therapeutic efficacy on IBD than intravenous injection. Nevertheless, the precise in vivo distribution of MSCs and their biological consequences following intraperitoneal injection remain inadequately understood. Additional studies are required to explore the correlation between MSCs distribution and their biological effects.

METHODS

First, the distribution of human umbilical cord MSCs (hUC-MSCs) and the numbers of Treg and Th17 cells in mesenteric lymph nodes (MLNs) were analyzed after intraperitoneal injection of hUC-MSCs. Subsequently, the investigation focused on the levels of transforming growth factor beta1 (TGF-β1), a key cytokine to the biology of both Treg and Th17 cells, in tissues of mice with colitis, particularly in MLNs. The study also delved into the impact of hUC-MSCs therapy on Treg cell counts in MLNs, as well as the consequence of TGFB1 knockdown hUC-MSCs on the differentiation of Treg cells and the treatment of IBD.

RESULTS

The therapeutic effectiveness of intraperitoneally administered hUC-MSCs in the treatment of colitis was found to be significant, which was closely related to their quick migration to MLNs and secretion of TGF-β1. The abundance of hUC-MSCs in MLNs of colitis mice is much higher than that in other organs even the inflamed sites of colon. Intraperitoneal injection of hUC-MSCs led to a significant increase in the number of Treg cells and a decrease in Th17 cells especially in MLNs. Furthermore, the concentration of TGF-β1, the key cytokine for Treg differentiation, were also found to be significantly elevated in MLNs after hUC-MSCs treatment. Knockdown of TGFB1 in hUC-MSCs resulted in a noticeable reduction of Treg cells in MLNs and the eventually failure of hUC-MSCs therapy in colitis.

CONCLUSIONS

MLNs may be a critical site for the regulatory effect of hUC-MSCs on Treg/Th17 cells and the therapeutic effect on colitis. TGF-β1 derived from hUC-MSCs promotes local Treg differentiation in MLNs. This study will provide new ideas for the development of MSC-based therapeutic strategies in IBD patients.

Stigmasterol: Remodeling gut microbiota and suppressing tumor growth through Treg and CD8+ T cells in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC), the most primary malignant liver tumor and is ranked as the fifth most common malignancy worldwide. Despite various therapeutic approaches being used in clinical practice, the overall effectiveness remains insufficient. Stigmasterol, a compound known for its anti-tumor properties and ability to induce apoptosis in tumor cells, has been found to influenced the composition of the intestinal microbiota. However, the mechanism through which stigmasterol influences the intestinal microbial-host crosstalk in HCC remains elusive.

PURPOSE

This study was to investigate whether stigmasterol can remodel gut microbiota, and suppress tumor volume by regulating Treg and IFN-γ+ CD8+ cell in the host with HCC.

METHOD

Stigmasterol (at dosages of 0, 50, 100, or 200 mg/kg) was orally administered to Balb/c mice with subcutaneous tumor once every 2 days for 3 weeks.

RESULTS

We first found that tumors volume in the group treated with 100 mg/kg stigmasterol were significantly decreased compared with those in the control group (P < 0.05), which exhibited a similar effect as the sorafenib treatment in mice with HCC. This resulted in a significant upregulation of Caspase3, Bax, and P53 expressions, as well as a decrease in Cyclin D1 expression, ultimately leading to a reduction in tumor volume. Additionally, stigmasterol can alter the α and β diversity of the intestinal flora and significantly increase the abundance of Lactobacillus_johnsonii, Lactobacillus_murinus, and Lactobacillus_reuteri (P<0.05), which can lead to a decrease in the ratio of regulatory T cells (Tregs) to CD8+ T cells in the intestinal tract and tumor tissue, and consequently enhance immune response in the tumor microenvironment (TME) in the host with HCC.

CONCLUSION

In this study, we initially utilized different dosages of stigmasterol to intervene in mice with HCC and confirmed its inhibitory effects on tumor growth in vivo, and discovered that stigmasterol affected Lactobacillus johnsonii, Lactobacillus murinus, and Lactobacillus reuteri, resulting in an increased proportion of IFN-γ+ CD8+ T cells and Treg cells in both the intestinal mucosa and tumor tissues, and ultimately leading to increased levels of apoptotic proteins and the subsequent death of tumor cells, which shed light on the effect of stigmasterol on host intestinal tissue and intratumoral immune cells by reshaping the intestinal microbiota, and provide a theoretical foundation for the potential clinical application of stigmasterol in the treatment of HCC.

Stachyose Exerts Anticolitis Efficacy by Re-balancing Treg/Th17 and Activating the Butyrate-Derived PPARγ Signaling Pathway

Ulcerative colitis (UC) is a complex chronic inflammatory disease closely associated with gut homeostasis dysfunction. The previous studies have shown that stachyose, a functional food additive, has the potential to enhance gut health and alleviate UC symptoms. However, the underlying mechanism of its effects remains unknown. In this study, our findings showed that dietary supplements of stachyose had a significant dose-dependent protective effect on colitis symptoms, regulation of gut microbiota, and restoration of the Treg/Th17 cell balance in dextran sulfate sodium (DSS) induced colitis mice. To further validate these findings, we conducted fecal microbiota transplantation (FMT) to treat DSS-induced colitis in mice. The results showed that microbiota from stachyose-treated mice exhibited a superior therapeutic effect against colitis and effectively regulated the Treg/Th17 cell balance in comparison to the control group. Moreover, both stachyose supplementation and FMT resulted in an increase in butyrate production and the activation of PPARγ. However, this effect was partially attenuated by PPARγ antagonist GW9662. These results suggested that stachyose alleviates UC symptoms by modulating gut microbiota and activating PPARγ. In conclusion, our work offers new insights into the benefical effects of stachyose on UC and its potential role in modulating gut microbiota.

Lipid metabolism in tumor-infiltrating regulatory T cells: perspective to precision immunotherapy

Regulatory T cells (Tregs) are essential to the negative regulation of the immune system, as they avoid excessive inflammation and mediate tumor development. The abundance of Tregs in tumor tissues suggests that Tregs may be eliminated or functionally inhibited to stimulate antitumor immunity. However, immunotherapy targeting Tregs has been severely hampered by autoimmune diseases due to the systemic elimination of Tregs. Recently, emerging studies have shown that metabolic regulation can specifically target tumor-infiltrating immune cells, and lipid accumulation in TME is associated with immunosuppression. Nevertheless, how Tregs actively regulate metabolic reprogramming to outcompete effector T cells (Teffs), and how lipid metabolic reprogramming contributes to the immunomodulatory capacity of Tregs have not been fully discussed. This review will discuss the physiological processes by which lipid accumulation confers a metabolic advantage to tumor-infiltrating Tregs (TI-Tregs) and amplifies their immunosuppressive functions. Furthermore, we will provide a summary of the driving effects of various metabolic regulators on the metabolic reprogramming of Tregs. Finally, we propose that targeting the lipid metabolism of TI-Tregs could be efficacious either alone or in conjunction with immune checkpoint therapy.

Assessing causal relationships between gut microbiota and psoriasis: evidence from two sample Mendelian randomization analysis

Mounting data hints that the gut microbiota's role may be pivotal in understanding the emergence of psoriasis. However, discerning a direct causal link is yet elusive. In this exploration, we adopted a Mendelian randomization (MR) strategy to probe the prospective causal interplay between the gut's microbial landscape and the predisposition to psoriasis. Genetic markers acting as instrumental variables for gut microbiota were extrapolated from a genome-wide association study (GWAS) encompassing 18,340 individuals. A separate GWAS yielded summary data for psoriasis, which covered 337,159 patients and 433,201 control subjects. The primary analysis hinged on inverse variance weighting (IVW). Additional methods like the weighted median approach and MR-Egger regression were employed to validate the integrity of our findings. Intriguing correlations emerged between psoriasis risk and eight specific bacterial traits. To illustrate: Mollicutes presented an odds ratio (OR) of 1.003 with a 95% confidence interval (CI) spanning 1.001-1.005 (p = 0.016), while the family. Victivallaceae revealed an OR of 0.998 with CI values between 0.997 and 0.999 (p = 0.023). Eubacterium (coprostanoligenes group) revealed an OR of 0.997 with CI values between 0.994 and 0.999 (p = 0.027). Eubacterium (fissicatena group) revealed an OR of 0.997 with CI values between 0.996 and 0.999 (p = 0.005). Holdemania revealed an OR of 1.001 with CI values 1-1.003 (p = 0.034). Lachnospiraceae (NK4A136 group) revealed an OR of 0.997 with CI values between 0.995 and 0.999 (p = 0.046). Lactococcus revealed an OR of 0.998 with CI values between 0.996 and 0.999 (p = 0.008). Tenericutes revealed an OR of 1.003 with CI values between 1.001 and 1.006 (p = 0.016). Sensitivity analysis for these bacterial features yielded congruent outcomes, reinforcing statistically significant ties between the eight bacterial entities and psoriasis. This comprehensive probe underscores emerging evidence pointing towards a plausible causal nexus between diverse gut microbiota and the onset of psoriasis. It beckons further research to unravel the intricacies of how the gut's microbial constituents might sway psoriasis's pathogenesis.

Intestinal Fibrogenesis in Inflammatory Bowel Diseases: Exploring the Potential Role of Gut Microbiota Metabolites as Modulators

Fibrosis, sustained by the transformation of intestinal epithelial cells into fibroblasts (epithelial-to-mesenchymal transition, EMT), has been extensively studied in recent decades, with the molecular basis well-documented in various diseases, including inflammatory bowel diseases (IBDs). However, the factors influencing these pathways remain unclear. In recent years, the role of the gut microbiota in health and disease has garnered significant attention. Evidence suggests that an imbalanced or dysregulated microbiota, along with environmental and genetic factors, may contribute to the development of IBDs. Notably, microbes produce various metabolites that interact with host receptors and associated signaling pathways, influencing physiological and pathological changes. This review aims to present recent evidence highlighting the emerging role of the most studied metabolites as potential modulators of molecular pathways implicated in intestinal fibrosis and EMT in IBDs. These studies provide a deeper understanding of intestinal inflammation and fibrosis, elucidating the molecular basis of the microbiota role in IBDs, paving the way for future treatments.

Crosstalk between hypoxia-inducible factor-1α and short-chain fatty acids in inflammatory bowel disease: key clues toward unraveling the mystery

The human intestinal tract constitutes a complex ecosystem, made up of countless gut microbiota, metabolites, and immune cells, with hypoxia being a fundamental environmental characteristic of this ecology. Under normal physiological conditions, a delicate balance exists among these complex "residents", with disruptions potentially leading to inflammatory bowel disease (IBD). The core pathology of IBD features a disrupted intestinal epithelial barrier, alongside evident immune and microecological disturbances. Central to these interconnected networks is hypoxia-inducible factor-1α (HIF-1α), which is a key regulator in gut cells for adapting to hypoxic conditions and maintaining gut homeostasis. Short-chain fatty acids (SCFAs), as pivotal gut metabolites, serve as vital mediators between the host and microbiota, and significantly influence intestinal ecosystem. Recent years have seen a surge in research on the roles and therapeutic potential of HIF-1α and SCFAs in IBD independently, yet reviews on HIF-1α-mediated SCFAs regulation of IBD under hypoxic conditions are scarce. This article summarizes evidence of the interplay and regulatory relationship between SCFAs and HIF-1α in IBD, pivotal for elucidating the disease's pathogenesis and offering promising therapeutic strategies.

Effects of dietary N-carbamylglutamate supplementation on the modulation of microbiota and Th17/Treg balance-related immune signaling after lipopolysaccharide challenge

BACKGROUND

This study aimed to evaluate the effects of N-carbamylglutamate (NCG) on piglets' growth performance and immune response, and to unravel the mechanisms of such effects. In a 2 × 2 factorial design including diet (with or without NCG) and immunological challenge (saline or lipopolysaccharide (LPS)), 24 piglets were randomly distributed into four groups. After being fed a basic diet or a NCG-supplemented diet for 21 days, piglets were administered LPS or saline intraperitoneally.

RESULTS

The results showed that NCG increased the average daily gain and average daily feed intake, and the feed conversion ratio of piglets, and alleviated the adverse effects of LPS stimulation on intestinal morphology. At the phylum level, NCG reversed the increase in the abundance of Firmicutes and the reduction in that of Actinomycete caused by LPS stimulation. At the genus level, NCG increased the abundance of Lactobacillus, Blautia, norank_Butyricicoccaceae, Subdoligranulum, and Ruminococcus_gauvreauii_group, and LPS decreased the abundance of Escherichia-Shigella and Ruminococcus_gauvreauii_group. The short-chain fatty acid content was increased by NCG, but LPS reduced its content. N-Carbamylglutamate also inhibited significantly the LPS-induced increase in the relative expression of signal transducer and activator of transcription (STAT) 3, related orphan receptor (RAR) c, and pro-inflammatory cytokines, and the decrease in the relative expression of STAT5, forkhead box P3, IL-10 and transforming growth factor beta 1 mRNA. A significant correlation was found between intestinal microbiota and inflammatory cytokines and short-chain fatty acids.

CONCLUSION

N-Carbamylglutamate can improve piglets' growth performance. It can also attenuate LPS-induced intestinal inflammation by modulating microbiota and Th17/Treg balance-related immune signaling pathways. © 2023 Society of Chemical Industry.

The role of microbial metabolites in endocrine tumorigenesis: From the mechanistic insights to potential therapeutic biomarkers

Microbial metabolites have been indicated to communicate with the host's endocrine system, regulating hormone production, immune-endocrine communications, and interactions along the gut-brain axis, eventually affecting the occurrence of endocrine cancer. Furthermore, microbiota metabolites such as short-chain fatty acids (SCFAs) have been found to affect the tumor microenvironment and boost immunity against tumors. SCFAs, including butyrate and acetate, have been demonstrated to exert anti-proliferative and anti-protective activity on pancreatic cancer cells. The employing of microbial metabolic products in conjunction with radiation and chemotherapy has shown promising outcomes in terms of reducing treatment side effects and boosting effectiveness. Certain metabolites, such as valerate and butyrate, have been made known to improve the efficiency of CAR T-cell treatment, whilst others, such as indole-derived tryptophan metabolites, have been shown to inhibit tumor immunity. This review explores the intricate interplay between microbial metabolites and endocrine tumorigenesis, spanning mechanistic insights to the discovery of potential therapeutic biomarkers.

FFAR2 expressing myeloid-derived suppressor cells drive cancer immunoevasion

BACKGROUND

Emerging evidences suggest that aberrant metabolites contributes to the immunosuppressive microenvironment that leads to cancer immune evasion. Among tumor immunosuppressive cells, myeloid-derived suppressor cells (MDSCs) are pathologically activated and extremely immunosuppressive, which are closely associated with poor clinical outcomes of cancer patients. However, the correlation between MDSCs mediated immunosuppression and particular cancer metabolism remained elusive.

METHODS

Spontaneous lung adenocarcinoma and subcutaneous mouse tumor models, gas chromatography-mass spectrometry (GC-MS) and immunofluorescence assay of patient-derived lung adenocarcinoma tissues, and flow cytometry, RNA sequencing and Western blotting of immune cells, were utilized.

RESULTS

Metabolite profiling revealed a significant accumulation of acetic acids in tumor tissues from both patients and mouse model, which contribute to immune suppression and cancer progression significantly through free fatty acid receptor 2 (FFAR2). Furthermore, FFAR2 is highly expressed in the myeloid-derived suppressor cells (MDSCs) from the tumor of lung adenocarcinoma (LUAD) patients which is greatly associated with poor prognosis. Surprisingly, whole or myeloid Ffar2 gene deletion markedly inhibited urethane-induced lung carcinogenesis and syngeneic tumor growth with reduced MDSCs and increased CD8+ T cell infiltration. Mechanistically, FFAR2 deficiency in MDSCs significantly reduced the expression of Arg1 through Gαq/Calcium/PPAR-γ axis, which eliminated T cell dysfunction through relieving L-Arginine consumption in tumor microenvironment. Therefore, replenishment of L-Arginine or inhibition to PPAR-γ restored acetic acids/FFAR2 mediated suppression to T cells significantly. Finally, FFAR2 inhibition overcame resistance to immune checkpoint blockade through enhancing the recruitment and cytotoxicity of tumor-infiltrating T cells.

CONCLUSION

Altogether, our results demonstrate that the acetic acids/FFAR2 axis enhances MDSCs mediated immunosuppression through Gαq/calcium/PPAR-γ/Arg1 signaling pathway, thus contributing to cancer progression. Therefore, FFAR2 may serve as a potential new target to eliminate pathologically activated MDSCs and reverse immunosuppressive tumor microenvironment, which has great potential in improving clinical outcomes of cancer immunotherapy.

Gut-brain communication mediates the impact of dietary lipids on cognitive capacity

Cognitive impairment, as a prevalent symptom of nervous system disorders, poses one of the most challenging aspects in the management of brain diseases. Lipids present in the cell membranes of all neurons within the brain and dietary lipids can regulate the cognition and memory function. In recent years, the advancements in gut microbiome research have enabled the exploration of dietary lipids targeting the gut-brain axis as a strategy for regulating cognition. This present review provides an in-depth overview of how lipids modulate cognition via the gut-brain axis depending on metabolic, immune, neural and endocrine pathways. It also comprehensively analyzes the effects of diverse lipids on the gut microbiota and intestinal barrier function, thereby affecting the central nervous system and cognitive capacity. Moreover, comparative analysis of the positive and negative effects is presented between beneficial and detrimental lipids. The former encompass monounsaturated fatty acids, short-chain fatty acids, omega-3 polyunsaturated fatty acids, phospholipids, phytosterols, fungal sterols and bioactive lipid-soluble vitamins, as well as lipid-derived gut metabolites, whereas the latter (detrimental lipids) include medium- or long-chain fatty acids, excessive proportions of n-6 polyunsaturated fatty acids, industrial trans fatty acids, and zoosterols. To sum up, the focus of this review is on how gut-brain communication mediates the impact of dietary lipids on cognitive capacity, providing a novel theoretical foundation for promoting brain cognitive health and scientific lipid consumption patterns.

Roles of PPAR activation in cancer therapeutic resistance: Implications for combination therapy and drug development

Therapeutic resistance is a major obstacle to successful treatment or effective containment of cancer. Peroxisome proliferator-activated receptors (PPARs) play an essential role in regulating energy homeostasis and determining cell fate. Despite of the pleiotropic roles of PPARs in cancer, numerous studies have suggested their intricate relationship with therapeutic resistance in cancer. In this review, we provided an overview of the roles of excessively activated PPARs in promoting resistance to modern anti-cancer treatments, including chemotherapy, radiotherapy, targeted therapy, and immunotherapy. The mechanisms through which activated PPARs contribute to therapeutic resistance in most cases include metabolic reprogramming, anti-oxidant defense, anti-apoptosis signaling, proliferation-promoting pathways, and induction of an immunosuppressive tumor microenvironment. In addition, we discussed the mechanisms through which activated PPARs lead to multidrug resistance in cancer, including drug efflux, epithelial-to-mesenchymal transition, and acquisition and maintenance of the cancer stem cell phenotype. Preliminary studies investigating the effect of combination therapies with PPAR antagonists have suggested the potential of these antagonists in reversing resistance and facilitating sustained cancer management. These findings will provide a valuable reference for further research on and clinical translation of PPAR-targeting treatment strategies.

Peptidase inhibitor 16 promotes inflammatory arthritis by suppressing Foxp3 expression via regulating K48-linked ubiquitin degradation Bmi-1 in regulatory T cells

Abnormalities of regulatory T cells (Tregs) has been suggested in rheumatoid arthritis (RA), and Forkhead box P3 (Foxp3) is the key transcriptional factor of Tregs expression. However, the underlying molecular mechanism remains unclear. Here, we demonstrated peptidase inhibitor 16 (PI16) was significantly increased in the peripheral blood, synovial fluid, and synovial tissue from RA patients. PI16 transgenic mice (PI16Tg) aggravated arthritis severity partly through suppressing Foxp3 expression. Mechanistically, PI16 could interact with and stabilize Bmi-1 in Tregs via inhibiting K48-linked polyubiquitin of Bmi-1, which promotes the enrichment of repressive histone mark in Foxp3 promoter. Furthermore, Bmi-1 specific inhibitor PTC209 could restore Foxp3 expression and alleviate arthritis progression in PI16Tg mice, accompanied by increased recruitment of active histone mark in the promoter of Tregs. Our results suggest that PI16-Bmi-1 axis plays an important role in RA and other autoimmune diseases by suppressing Foxp3 expression in Tregs via Bmi-1-mediated histone modification.

Kuijie decoction ameliorates ulcerative colitis by affecting intestinal barrier functions, gut microbiota, metabolic pathways and Treg/Th17 balance in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Currently, the clinical treatment is limited and difficult to achieve satisfactory results for ulcerative colitis (UC). The role of traditional Chinese medicine (TCM) in the treatment of UC is very complex. Kuijie decoction (KJD) as a classic TCM, is widely used in the clinical treatment of UC, but the mechanism of its action is still unclear.

AIM OF THE STUDY

This study is to investigate the protective effects of KJD on UC and the underlying mechanisms.

MATERIALS AND METHODS

The experimental model of UC was induced by DSS, and KJD was introduced into the model at the same time. Clinical symptoms, including the body weight, colon length and colon histopathological, were used to measure the severity of colitis. The expression of inflammatory cytokines and tight junction proteins was quantified. The effect of KJD on intestinal flora and intestinal metabolism was determined by 16S rRNA and untargeted metabolomics analysis, respectively. The proportion of Th17 cells and Tregs in the spleen was examined by flow cytometry.

RESULTS

Mice treated with KJD showed significantly alleviated clinical symptoms and histological damage, such as more body weight gain, lower disease activity index (DAI) score, and longer colon length. The administration of KJD also led to the down-regulation of inflammatory mediators, upregulation of the expression of ZO-1, occludin and decreased claudin-2, as well as altered microbiota composition against DSS challenges (especially an increase of Lachnospiraceae). KJD enhanced the percentage of Treg cells but decreased the proportion of Th17 cells to maintain intestinal homeostasis by improving gut microbiota metabolism.

CONCLUSIONS

In summary, KJD maintained intestinal epithelial homeostasis by regulating epithelial barrier function, intestinal flora, and restoring Th17/Treg balance. KJD has the potential to be a Chinese medicine treatment for UC.

Integrated bioinformatics and network pharmacology identifying the mechanisms and molecular targets of Guipi Decoction for treatment of comorbidity with depression and gastrointestinal disorders

BACKGROUND

Guipi decoction (GPD) not only improves gastrointestinal (GI) function, but also depressive mood. The bioinformatics study aimed to reveal potential crosstalk genes and related pathways between depression and GI disorders. A network pharmacology approach was used to explore the molecular mechanisms and potential targets of GPD for the simultaneous treatment of depression comorbid GI disorders.

METHODS

Differentially expressed genes (DEGs) of major depressive disorder (MDD) were identified based on GSE98793 and GSE19738, and GI disorders-related genes were screened from the GeneCards database. Overlapping genes between MDD and GI disorders were obtained to identify potential crosstalk genes. Protein-protein interaction (PPI) network was constructed to screen for hub genes, signature genes were identified by LASSO regression analysis, and single sample gene set enrichment analysis (ssGSEA) was performed to analyze immune cell infiltration. In addition, based on the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, we screened the active ingredients and targets of GPD and identified the intersection targets of GPD with MDD and GI disorder-related genes, respectively. A "component-target" network was constructed using Cytoscape, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed.

RESULTS

The MDD-corrected dataset contained 2619 DEGs, and a total of 109 crosstalk genes were obtained. 14 hub genes were screened, namely SOX2, CRP, ACE, LEP, SHH, CDH2, CD34, TNF, EGF, BDNF, FN1, IL10, PPARG, and KIT. These genes were identified by LASSO regression analysis for 3 signature genes, including TNF, EGF, and IL10. Gamma.delta.T.cell was significantly positively correlated with all three signature genes, while Central.memory.CD4.T.cell and Central.memory.CD8.T.cell were significantly negatively correlated with EGF and TNF. GPD contained 134 active ingredients and 248 targets, with 41 and 87 relevant targets for the treatment of depression and GI disorders, respectively. EGF, PPARG, IL10 and CRP overlap with the hub genes of the disease.

CONCLUSION

We found that GPD may regulate inflammatory and oxidative stress responses through EGF, PPARG, IL10 and CRP targets, and then be involved in the treatment of both depression and GI disorders.

Implication of Oxysterols and Phytosterols in Aging and Human Diseases

Cholesterol is easily oxidized and can be transformed into numerous oxidation products, among which oxysterols. Phytosterols are plant sterols related to cholesterol. Both oxysterols and phytosterols can have an impact on human health and diseases.Cholesterol is a member of the sterol family that plays essential roles in biological processes, including cell membrane stability and myelin formation. Cholesterol can be metabolized into several molecules including bile acids, hormones, and oxysterols. On the other hand, phytosterols are plant-derived compounds structurally related to cholesterol, which can also have an impact on human health. Here, we review the current knowledge about the role of oxysterols and phytosterols on human health and focus on the impact of their pathways on diseases of the central nervous system (CNS), autoimmune diseases, including inflammatory bowel diseases (IBD), vascular diseases, and cancer in both experimental models and human studies. We will first discuss the implications of oxysterols and then of phytosterols in different human diseases.

Antimicrobial Potential of Different Isolates of Chaetomium globosum Combined with Liquid Chromatography Tandem Mass Spectrometry Chemical Profiling

The antimicrobial resistance of pathogenic microorganisms against commercial drugs has become a major problem worldwide. This study is the first of its kind to be carried out in Egypt to produce antimicrobial pharmaceuticals from isolated native taxa of the fungal Chaetomium, followed by a chemical investigation of the existing bioactive metabolites. Here, of the 155 clinical specimens in total, 100 pathogenic microbial isolates were found to be multi-drug resistant (MDR) bacteria. The Chaetomium isolates were recovered from different soil samples, and wild host plants collected from Egypt showed strong inhibitory activity against MDR isolates. Chaetomium isolates displayed broad-spectrum antimicrobial activity against C. albicans, Gram-positive, and Gram-negative bacteria, with inhibition zones of 11.3 to 25.6 mm, 10.4 to 26.0 mm, and 10.5 to 26.5 mm, respectively. As a consecutive result, the minimum inhibitory concentration (MIC) values of Chaetomium isolates ranged from 3.9 to 62.5 µg/mL. Liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) analysis was performed for selected Chaetomium isolates with the most promising antimicrobial potential against MDR bacteria. The LC-MS/MS analysis of Chaetomium species isolated from cultivated soil at Assuit Governate, Upper Egypt (3), and the host plant Zygophyllum album grown in Wadi El-Arbaein, Saint Katherine, South Sinai (5), revealed the presence of alkaloids as the predominant bioactive metabolites. Most detected bioactive metabolites previously displayed antimicrobial activity, confirming the antibacterial potential of selected isolates. Therefore, the Chaetomium isolates recovered from harsh habitats in Egypt are rich sources of antimicrobial metabolites, which will be a possible solution to the multi-drug resistant bacteria tragedy.

The Role of Long Noncoding RNAs in Intestinal Health and Diseases: A Focus on the Intestinal Barrier

The gut is the body's largest immune organ, and the intestinal barrier prevents harmful substances such as bacteria and toxins from passing through the gastrointestinal mucosa. Intestinal barrier dysfunction is closely associated with various diseases. However, there are currently no FDA-approved therapies targeting the intestinal epithelial barriers. Long noncoding RNAs (lncRNAs), a class of RNA transcripts with a length of more than 200 nucleotides and no coding capacity, are essential for the development and regulation of a variety of biological processes and diseases. lncRNAs are involved in the intestinal barrier function and homeostasis maintenance. This article reviews the emerging role of lncRNAs in the intestinal barrier and highlights the potential applications of lncRNAs in the treatment of various intestinal diseases by reviewing the literature on cells, animal models, and clinical patients. The aim is to explore potential lncRNAs involved in the intestinal barrier and provide new ideas for the diagnosis and treatment of intestinal barrier damage-associated diseases in the clinical setting.

Advances in psoriasis and gut microorganisms with co-metabolites

This review summarizes the potential role of gut microbes and their metabolites as novel mediators of psoriasis, including their composition and function in disease pathogenesis, progression, and management. Gut microbiota network analysis, colony construction, and in vivo large-scale interaction experiments showed that different degrees of damage and repair in psoriasis, both in animals and humans, involve cross-border homeostasis of the microbial community. Which gut microbiota interactions are present in psoriasis and how they collaborate with immune cells and influence psoriasis development via the gut-skin axis remain incompletely elucidated. In this article, we review the latest information on the unique patterns of gut microbiota and co-metabolites involved in the pathogenesis of psoriasis and attempt to explore microbial-based therapeutic targets derived from mono-and polymicrobial probiotics, fecal microbiota transplantation, pharmacomicrobiomics, and dietary interventions as diagnostic or therapeutic approaches promising to provide new options and long-term management for psoriasis.

Sodium butyrate alleviates R97-116 peptide-induced myasthenia gravis in mice by improving the gut microbiota and modulating immune response

Fermented butyrate exhibits an anti-inflammatory response to maintain immune homeostasis within the gut. However, the effect and underlying mechanism of butyrate on myasthenia gravis (MG) remain unclear. The changes in the gut microbiota and fecal contents of SCFAs in MG patients were examined. R97-116 peptide was used to induce the experimental autoimmune myasthenia gravis (EAMG) mice and sodium butyrate (NaB) was gavaged to the EAMG mice. Gut microbiota, the frequency of Th1, Th17, Treg, Tfh, and B cells, the levels of IFN-γ, IL-17 A, IL-10, IL-21, and anti-R97-116 IgG, RNA-seq of total B cells in the spleen were explored by metagenomics, flow cytometry, ELISA, and transcriptomics. A significant reduction in SCFA-producing bacteria including Butyricimonas synergistica and functional modules including butyrate synthesis/production II was observed in MG patients and fecal SCFAs detection confirmed the increase. The EAMG mice were successfully constructed and NaB supplementation has changed the composition and function of the gut microbiota. The numbers of Th1, Th17, Tfh, and B cells were significantly increased while that of Treg cells was obviously decreased in EAMG mice compared with controls. Interestingly, NaB treatment has reduced the amounts of Th17, Tfh, and B cells but increased that of Treg cells. Accordingly, the levels of IL-17 A, IL-21, and IgG were increased while IL-10 was decreased in EAMG mice. However, NaB treatment reduced IL-17 A and IL-21 but increased that of IL-10. RNA-seq of B cells has revealed 4577 deferentially expressed genes (DEGs), in which 1218 DEGs were up-regulated while 3359 DEGs were down-regulated in NaB-treated EAMG mice. GO enrichment and KEGG pathway analysis unveiled that the function of these DEGs was mainly focused on immunoglobulin production, mitochondrial respiratory chain complex, ribosome, oxidative phosphorylation, and CNS diseases including amyotrophic lateral sclerosis. We have found that butyrate was significantly reduced in MG patients and NaB gavage could evidently improve MG symptoms in EAMG mice by changing the gut microbiota, regulating the immune response, and altering the gene expression and function of B cells, suggesting NaB might be a potential immunomodulatory supplement for MG drugs.

Liquiritin apioside alleviates colonic inflammation and accompanying depression-like symptoms in colitis by gut metabolites and the balance of Th17/Treg

BACKGROUND

Inflammatory bowel disease (IBD) is a significant global health concern that can lead to depression in affected patients. Liquiritin apioside (LA) possesses anti-oxidative and anti-inflammatory properties. However, its anti-inflammatory mechanism in IBD has not been extensively studied.

PURPOSE

This study elucidates the pivotal role of LA in alleviating inflammation by regulating gut metabiota-derived metabolites and evaluating its regulative effects on promoting a balance of Th17/Treg cells in colitis mice.

METHODS

To evaluate the effect of LA on IBD,16S rRNA gene sequencing and UPLC-QTOF-MS analysis were used to identify the changes of intestinal bacteria and their metabolites. Cytokines levels were determined by ELISA and qPCR, while immune cell ratios were evaluated via flow cytometry.

RESULTS

Our findings revealed that LA treatment ameliorated general states of DSS-induced colitis mice and their accompanying depressive behaviors. Moreover, LA restricted the expression of pro-inflammatory cytokines and revised the imbalanced Treg/Th17 differentiation, while promoting SCFAs production in inflamed colon tissues. Fecal microbiota transplantation from LA-fed mice also corrected the imbalanced Treg/Th17 differentiation, indicating that LA-mediated restoration of the colonic Treg/Th17 balance mainly depends on the changes in gut metabolites.

CONCLUSION

These results provide scientific evidence explaining the apparent paradox of low bioavailability and high bioactivity in polyphenols, and suggesting that LA could be used as a potential dietary supplement for the prevention and improvement of IBD.

Short-chain fatty acid - A critical interfering factor for allergic diseases

Allergy is a growing global public health problem with a high socio-economic impact. The incidence of allergic diseases is increasing year by year, which has attracted more and more attention. In recent years, a number of epidemiological investigations and gut microbiota studies have shown that gut microbiota dysbiosis is associated with an increased prevalence of various allergic diseases, such as food allergy, asthma, allergic rhinitis, and atopic dermatitis. However, the underlying mechanisms are complex and have not been fully clarified. Metabolites are one of the main ways in which the gut microbiota functions. Short-chain fatty acids (SCFAs) are the main metabolites of intestinal flora fermentation and are beneficial to human health. Studies have shown that SCFAs play an important role in maintaining intestinal homeostasis and regulating immune responses by recognizing receptors and inhibiting histone deacetylases, and are key molecules involved in the occurrence and development of allergic diseases. In addition, research on the regulation of gut microbiota and the application of SCFAs in the treatment of allergic diseases is also emerging. This article reviews the clinical and experimental evidence on the correlation between SCFAs and allergic diseases and the potential mechanisms by which SCFAs regulate allergic diseases. Furthermore, SCFAs as therapeutic targets for allergic diseases are also summarized and prospected.

Exploration of molecular mechanism of Huanglian-Muxiang-Roudoukou formula in treating ulcerative colitis based on gene expression omnibus chip data mining combined with network pharmacology and molecular docking

BACKGROUND

Huanglian-Muxiang-Roudoukou (HMR) formula was recorded in the book of "Pediatric Medicine Prescription". It can improve the clinical symptoms of ulcerative colitis (UC). Using network pharmacology and other methods to study its biological mechanism is helpful to better explore the resources of traditional Chinese medicine and promote the modern development and application of traditional Chinese medicine in the prevention and treatment of UC.

AIM

To explore the potential molecular mechanism of HMR in the treatment of UC based on gene expression omnibus (GEO) chip data mining, network pharmacology, and molecular docking technology.

METHODS

The GEO database was used to obtain UC gene expression data. Then, differentially expressed genes were identified using R software. The active components of Myristicae Semen (Roudoukou), Aucklandiae Radix (Muxiang), and Coptidis Rhizoma (Huanglian) were searched by using the traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP) database, and the corresponding targets were identified. The intersections of HMR and ulcerative colitis disease targets were obtained. The "drug-active ingredients-disease-target" network and protein-protein interaction (PPI) network were constructed to screen out the core components and targets using Cytoscape 3.9.1 software. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses were performed for the intersection targets by Metascapes database. Molecular docking between main active components and core targets was performed using AutoDock vina software.

RESULTS

A total of 967 differential genes were identified, and there were 29 active components and 163 active targets in UC. There were 24 active components in the "drug-active ingredients-disease-target" network, including quercetin, stigmasterol, berberine, beta-sitosterol, palmatine, and so on. There were 26 proteins in the PPI network, including interleukin-1β (IL-1β), interleukin-6 (IL-6), C-C motif chemokine 2 (CCL2), tumor necrosis factor (TNF), matrix metallopeptidase 9 (MMP9), and so on. GO enrichment analysis demonstrated that the intersection targets were mainly concentrated in biological processes such as lipopolysaccharide response, in cellular components such as external side of plasma membrane, and in molecular functions such as cytokine activity. KEGG analysis demonstrated that the intersection targets mainly involved the TNF signal pathway, nuclear factor kappa-B (NF-κB) pathway, Toll-like receptor (TLR) signal pathway, and so on. The results of molecular docking showed that the top five main active components had strong binding ability with the core targets IL-1β, IL-6, CCL2, TNF, and MMP9.

CONCLUSION

HMR may act on the expression of IL-1β, IL-6, CCL2, and other proteins through quercetin, stigmasterol, berberine, and other active components, regulate the TNF signaling pathway, and play a role in the treatment of UC via many mechanisms such as anti-inflammatory and intestinal immunity regulation.

Changes in Gut Microbiota and Metabolites in Papillary Thyroid Carcinoma Patients Following Radioactive Iodine Therapy

Purpose

Radioactive iodine therapy is administered through oral route, which is accumulated and absorbed in the intestine. However, its effects on the intestine remain unclear. In this study, we investigated the changes in the gut microbiota and metabolites following radioactive iodine therapy.

Patients and Methods

A total of 76 stool samples from the same 38 patients were collected at the start of radioactive iodine therapy and three days following the therapy. Stool microbiota and metabolites were detected using 16S rRNA gene sequencing and liquid chromatography-mass spectrometry.

Results

Enterobacteriales, Enterobacteriaceae and Escherichia-Shigella were elevated in most patients (27/38) following the therapy. The levels of 2-hydroxyundec-7-enoylcarnitine were significantly lower, whereas those of 5-dehydroavenasterol, butylisopropylamine, and salsoline-1-carboxylate were higher following the therapy. The relative abundance of Escherichia-Shigella was negatively correlated with 2-hydroxyundec-7-enoylcarnitine level (r2 = -0.661, P = 0.009). Functional pathways were predicted to be involved in amino acid and lipid metabolism following the therapy. Particularly, phenylalanine, linoleic acid, sphingolipid, purine, and alpha-linolenic acid metabolism were the main metabolic pathways.

Conclusion

Gut microbiota was disturbed following radioactive iodine therapy, with increased Escherichia-Shigella. Processes associated with energy production seems to be impacted following the therapy, with significantly decreased 2-hydroxyundec-7-enoylcarnitine level. Meanwhile, some metabolites and functional pathways may have a positive effect on intestinal homeostasis, and may be related to the repair and promotion of gut recovery following the therapy. This study provides a basic foundation to explore how radioactive iodine affects gut microbiota and metabolites, and how gut function is regulated in response to radioactive iodine therapy.

Cell membrane nanomaterials composed of phospholipids and glycoproteins for drug delivery in inflammatory bowel disease: A review

Inflammatory bowel disease (IBD) is a serious chronic intestinal disorder with an increasing global incidence. However, current treatment strategies, such as anti-inflammatory drugs and probiotics, have limitations in terms of safety, stability, and effectiveness. The emergence of targeted nanoparticles has revolutionized IBD treatment by enhancing the biological properties of drugs and promoting efficiency and safety. Unlike synthetic nanoparticles, cell membrane nanomaterials (CMNs) consist primarily of biological macromolecules, including phospholipids, proteins, and sugars. CMNs include red blood cell membranes, macrophage membranes, and leukocyte membranes, which possess abundant glycoprotein receptors and ligands on their surfaces, allowing for the formation of cell-to-cell connections with other biological macromolecules. Consequently, they exhibit superior cell affinity, evade immune responses, and target inflammation effectively, making them ideal material for targeted delivery of IBD therapies. This review explores various CMNs delivery systems for IBD treatment. However, due to the complexity and harsh nature of the intestinal microenvironment, the lack of flexibility or loss of selectivity poses challenges in designing single CMNs delivery strategies. Therefore, we propose a hierarchically programmed delivery modality that combines CMNs with pH, charge, ROS and ligand-modified responsive nanoparticles. This approach significantly improves delivery efficiency and points the way for future research in this area.

Fecal Concentrations of Long-Chain Fatty Acids, Sterols, and Unconjugated Bile Acids in Cats with Chronic Enteropathy

Chronic enteropathy (CE) in cats encompasses food-responsive enteropathy, chronic inflammatory enteropathy (or inflammatory bowel disease), and low-grade intestinal T-cell lymphoma. While alterations in the gut metabolome have been extensively studied in humans and dogs with gastrointestinal disorders, little is known about the specific metabolic profile of cats with CE. As lipids take part in energy storage, inflammation, and cellular structure, investigating the lipid profile in cats with CE is crucial. This study aimed to measure fecal concentrations of various fatty acids, sterols, and bile acids. Fecal samples from 56 cats with CE and 77 healthy control cats were analyzed using gas chromatography-mass spectrometry, targeting 12 fatty acids, 10 sterols, and 5 unconjugated bile acids. Fecal concentrations of nine targeted fatty acids and animal-derived sterols were significantly increased in cats with CE. However, fecal concentrations of plant-derived sterols were significantly decreased in cats with CE. Additionally, an increased percentage of primary bile acids was observed in a subset of cats with CE. These findings suggest the presence of lipid maldigestion, malabsorption, and inflammation in the gastrointestinal tract of cats with CE. Understanding the lipid alterations in cats with CE can provide insights into the disease mechanisms and potential future therapeutic strategies.

Lactobacillus reuteri in digestive system diseases: focus on clinical trials and mechanisms

Objectives

Digestive system diseases have evolved into a growing global burden without sufficient therapeutic measures. Lactobacillus reuteri (L. reuteri) is considered as a new potential economical therapy for its probiotic effects in the gastrointestinal system. We have provided an overview of the researches supporting various L. reuteri strains' application in treating common digestive system diseases, including infantile colic, diarrhea, constipation, functional abdominal pain, Helicobacter pylori infection, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases.

Methods

The summarized literature in this review was derived from databases including PubMed, Web of Science, and Google Scholar.

Results

The therapeutic effects of L. reuteri in digestive system diseases may depend on various direct and indirect mechanisms, including metabolite production as well as modulation of the intestinal microbiome, preservation of the gut barrier function, and regulation of the host immune system. These actions are largely strain-specific and depend on the activation or inhibition of various certain signal pathways. It is well evidenced that L. reuteri can be effective both as a prophylactic measure and as a preferred therapy for infantile colic, and it can also be recommended as an adjuvant strategy to diarrhea, constipation, Helicobacter pylori infection in therapeutic settings. While preclinical studies have shown the probiotic potential of L. reuteri in the management of functional abdominal pain, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases, its application in these disease settings still needs further study.

Conclusion

This review focuses on the probiotic effects of L. reuteri on gut homeostasis via certain signaling pathways, and emphasizes the importance of these probiotics as a prospective treatment against several digestive system diseases.

Protection of Inonotus hispidus (Bull.) P. Karst. against Chronic Alcohol-Induced Liver Injury in Mice via Its Relieving Inflammation Response

Alcoholic liver disease (ALD) can be induced by excessive alcohol consumption, and has a worldwide age-standardized incidence rate (ASIR) of approximately 5.243%. Inonotus hispidus (Bull.) P. Karst. (IH) is a mushroom with pharmacological effects. In ALD mice, the hepatoprotective effects of IH were investigated. IH strongly ameliorated alcohol-induced pathological changes in the liver, including liver structures and its function-related indices. Intestinal microbiota and serum metabolomics analysis showed that IH altered the associated anti-inflammatory microbiota and metabolites. According to results obtained from Western blot, immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA), IH downregulated the levels of pro-inflammation factors interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), enhanced the expressions of peroxisome proliferator-activated receptor alpha (PPARα) and 15-hydroxprostaglandin dehydrogenase (15-PGDH), and inhibited the phosphorylated activation of Janus kinase (JAK) 1 and signal transducer and activator of transcription (STAT) 3, confirming the hepatoprotection of IH against alcohol damage via anti-inflammation. This study provides the experimental evidence for the hepatoprotective effects of IH in chronic ALD.

Total glucosides of Rhizoma Smilacis Glabrae: a therapeutic approach for psoriasis by regulating Th17/Treg balance

Total glucosides of Rhizoma Smilacis Glabrae (RSG) are selective immunosuppressants that exhibit primary efficacy in the treatment of rheumatoid arthritis through targeted inhibition of activated T cells. In this study, we aimed to investigate the potential application of RSG in the treatment of psoriasis and elucidate its mechanism of action and material basis. Our findings revealed significant improvements upon administration of RSG in an imiquimod (IMQ)-induced psoriasis model. These improvements were characterized by a remarkable increase in the number of tail scales in mice and a substantial amelioration of skin erythema, ulceration, and flaking. By transcriptome sequencing and T-cell flow sorting assay, we identified notable effects of RSG on the modulation of various cellular processes. Specifically, RSG prominently down-regulated the Th17/Treg ratio in damaged skin tissues and reduced the proportion of G2 phase cells. Furthermore, RSG exhibited a stimulatory effect on the proliferation and differentiation of epithelial cells. Of particular interest, we discovered that β-sitosterol, sitostenone, stigmasterol, smiglanin, and cinchonain Ib displayed potent inhibitory effects on the IL-17-mediated inflammatory response in HaCaT cells. In summary, our study highlights the therapeutic potential of RSG in the treatment of psoriasis, attributed to its ability to regulate the Th17/Treg balance. These findings contribute to the development of new indications for RSG and provide a solid theoretical foundation for further exploration in this field.

Lactobacillus acidophilus and propionate attenuate Sjögren's syndrome by modulating the STIM1-STING signaling pathway

BACKGROUND

Sjögren's syndrome (SS) is an autoimmune disease characterized by inflammation of the exocrine gland. An imbalance of gut microbiota has been linked to SS. However, the molecular mechanism is unclear. We investigated the effects of Lactobacillus acidophilus (L. acidophilus) and propionate on the development and progression of SS in mouse model.

METHODS

We compared the gut microbiomes of young and old mice. We administered L. acidophilus and propionate up to 24 weeks. The saliva flow rate and the histopathology of the salivary glands were investigated, and the effects of propionate on the STIM1-STING signaling pathway were evaluated in vitro.

RESULTS

Lactobacillaceae and Lactobacillus were decreased in aged mice. SS symptoms were ameliorated by L. acidophilus. The abundance of propionate-producing bacterial was increased by L. acidophilus. Propionate ameliorated the development and progression of SS by inhibiting the STIM1-STING signaling pathway.

CONCLUSIONS

The findings suggest that Lactobacillus acidophilus and propionate have therapeutic potential for SS. Video Abstract.

Paris polyphylla extract attenuates colitis in mice by regulating PPAR-γ mediated Treg/Th17 balance

ETHNOPHARMACOLOGICAL RELEVANCE

Paris polyphylla Sm. (P.P), is a widely-used traditional Chinese medicine (TCM) in the treatment of wound, throat sores and snakebites. Furthermore, P.P was recorded as an anti-inflammatory drug by the Chinese Pharmacopoeia.

AIM OF THE STUDY

We sought to decipher the anti-inflammatory effect of P.P on ulcerative colitis (UC); specifically, to explore whether P.P attenuates colitis by restoring the regulatory T cells (Tregs) and T helper 17 (Th17) cells balance and its mechanism.

MATERIAL AND METHODS

We treated experimental colitis mice with extracts of Paris polyphylla (EPP). The percentage of Tregs and Th17 cells were measured using flow cytometry, and their secreted cytokines levels were evaluated employing ELISA. The expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) in colon tissues was detected using immunofluorescence. Furthermore, GW9662, a PPAR-γ antagonist, was used to validate the mechanism of EPP in restoring the Treg/Th17 balance.

RESULTS

The EPP effectively alleviated the clinical symptoms and inflammatory cytokine levels in mice with colitis. EPP treatment also restored the impaired Treg/Th17 balance in mice. Furthermore, EPP treatment promoted PPAR-γ expression and reduced HIF-1α and p-STAT3 expression in colon tissues, whereas PPAR-γ inhibition blocked the effects of EPP in mice models.

CONCLUSION

Our study indicates that EPP exhibit excellent anti-inflammatory properties via restoring PPAR-γ/STAT3/HIF-1α axis-mediated Treg/Th17 balance in colitis mice. Hence, P. polyphylla is a promising medicinal plant-based alternative for managing colitis that requires further clinical validation.

A Comprehensive Update on Phytochemistry, Analytical Aspects, Medicinal Attributes, Specifications and Stability of Stigmasterol

Phytosterols are bioactive substances naturally found in plant cell membranes, and their chemical structure is comparable to cholesterol found in mammalian cells. They are widely distributed in plant foods like olive oil, nuts, seeds, and legumes. Amongst the variety of phytosterols, stigmasterol is the vital compound found abundantly in plants. Numerous hormones, including estrogen, progesterone, corticoids and androgen, are synthesized by stigmasterol. Multiple in-vitro and in-vivo investigations have shown that stigmasterol has various biological effects, including antioxidant, anticancer, antidiabetic, respiratory diseases, and lipid-lowering effects. Experimental research on stigmasterol provides indisputable proof that this phytosterol has the potential to be employed in supplements used to treat the illnesses mentioned above. This substance has a high potential, making it a noteworthy medication in the future. Although several researchers have investigated this phytosterol to assess its prospective qualities, it has not yet attained therapeutic levels, necessitating additional clinical studies. This review offers a comprehensive update on stigmasterol, including chemical framework, biosynthesis, synthetic derivatives, extraction and isolation, analytical aspects, pharmacological profile, patent status, clinical trials, stability and specifications as per regulatory bodies.

Gut-Microbiota-Derived Metabolites Maintain Gut and Systemic Immune Homeostasis

The gut microbiota, including bacteria, archaea, fungi, viruses and phages, inhabits the gastrointestinal tract. This commensal microbiota can contribute to the regulation of host immune response and homeostasis. Alterations of the gut microbiota have been found in many immune-related diseases. The metabolites generated by specific microorganisms in the gut microbiota, such as short-chain fatty acids (SCFAs), tryptophan (Trp) and bile acid (BA) metabolites, not only affect genetic and epigenetic regulation but also impact metabolism in the immune cells, including immunosuppressive and inflammatory cells. The immunosuppressive cells (such as tolerogenic macrophages (tMacs), tolerogenic dendritic cells (tDCs), myeloid-derived suppressive cells (MDSCs), regulatory T cells (Tregs), regulatory B cells (Breg) and innate lymphocytes (ILCs)) and inflammatory cells (such as inflammatory Macs (iMacs), DCs, CD4 T helper (Th)1, CD4Th2, Th17, natural killer (NK) T cells, NK cells and neutrophils) can express different receptors for SCFAs, Trp and BA metabolites from different microorganisms. Activation of these receptors not only promotes the differentiation and function of immunosuppressive cells but also inhibits inflammatory cells, causing the reprogramming of the local and systemic immune system to maintain the homeostasis of the individuals. We here will summarize the recent advances in understanding the metabolism of SCFAs, Trp and BA in the gut microbiota and the effects of SCFAs, Trp and BA metabolites on gut and systemic immune homeostasis, especially on the differentiation and functions of the immune cells.

Two Argan Oil Phytosterols, Schottenol and Spinasterol, Attenuate Oxidative Stress and Restore LPS-Dysregulated Peroxisomal Functions in Acox1-/- and Wild-Type BV-2 Microglial Cells

Oxidative stress and inflammation are the key players in neuroinflammation, in which microglia dysfunction plays a central role. Previous studies suggest that argan oil attenuates oxidative stress, inflammation, and peroxisome dysfunction in mouse brains. In this study, we explored the effects of two major argan oil (AO) phytosterols, Schottenol (Schot) and Spinasterol (Spina), on oxidative stress, inflammation, and peroxisomal dysfunction in two murine microglial BV-2 cell lines, wild-ype (Wt) and Acyl-CoA oxidase 1 (Acox1)-deficient cells challenged with LPS treatment. Herein, we used an MTT test to reveal no cytotoxicity for both phytosterols with concentrations up to 5 µM. In the LPS-activated microglial cells, cotreatment with each of these phytosterols caused a significant decrease in intracellular ROS production and the NO level released in the culture medium. Additionally, Schot and Spina were able to attenuate the LPS-dependent strong induction of Il-1β and Tnf-α mRNA levels, as well as the iNos gene and protein expression in both Wt and Acox1-/- microglial cells. On the other hand, LPS treatment impacted both the peroxisomal antioxidant capacity and the fatty acid oxidation pathway. However, both Schot and Spina treatments enhanced ACOX1 activity in the Wt BV-2 cells and normalized the catalase activity in both Wt and Acox1-/- microglial cells. These data suggest that Schot and Spina can protect cells from oxidative stress and inflammation and their harmful consequences for peroxisomal functions and the homeostasis of microglial cells. Collectively, our work provides a compelling argument for the protective mechanisms of two major argan oil phytosterols against LPS-induced brain neuroinflammation.

The role of Th17 cells in inflammatory bowel disease and the research progress

Th17 cells play an important role in the abnormal immune response in inflammatory bowel disease (IBD) and are involved in the development and progression of inflammation and fibrosis. An increasing amount of data has shown that gut microbes are important parts of intestinal immunity and regulators of Th17 cellular immunity. Th17 cell differentiation is regulated by intestinal bacteria and cytokines, and Th17 cells regulate the intestinal mucosal immune microenvironment by secreting cytokines, such as IL-17, IL-21, and IL-26. Solid evidence showed that, regarding the treatment of IBD by targeting Th17 cells, the therapeutic effect of different biological agents varies greatly. Fecal bacteria transplantation (FMT) in the treatment of IBD has been a popular research topic in recent years and is safe and effective with few side effects. To further understand the role of Th17 cells in the progression of IBD and associated therapeutic prospects, this review will discuss the progress of related research on Th17 cells in IBD by focusing on the interaction and immune regulation between Th17 cells and gut microbiota.

Biometabolites of Citrus unshiu Peel Enhance Intestinal Permeability and Alter Gut Commensal Bacteria

Flavanones in Citrus unshiu peel (CUP) have been used as therapeutic agents to reduce intestinal inflammation; however, the anti-inflammatory effects of their biometabolites remain ambiguous. Here, we identified aglycone-type flavanones, such as hesperetin and naringenin, which were more abundant in the bioconversion of the CUP than in the ethanol extracts of the CUP. We found that the bioconversion of the CUP induced the canonical nuclear factor-κB pathway via degradation of IκB in Caco-2 cells. To check the immune suppressive capacity of the aglycones of the CUP in vivo, we orally administered the bioconversion of the CUP (500 mg/kg) to mice for two weeks prior to the 3% dextran sulfate sodium treatment. The CUP-pretreated group showed improved body weight loss, colon length shortage, and intestinal inflammation than the control mice. We also found a significant decrease in the population of lamina propria Th17 cells in the CUP-pretreated group following dextran sodium sulfate (DSS) treatment and an increase in mRNA levels of occludin in CUP-treated Caco-2 cells. Pyrosequencing analysis revealed a decreased abundance of Alistipes putredinis and an increased abundance of Muribaculum intestinale in the feces of the CUP-pretreated mice compared to those of the control mice. Overall, these findings suggest that the pre-administration of CUP biometabolites may inhibit the development of murine colitis by modulating intestinal permeability and the gut microbiome.

Maternal prebiotic supplementation impacts colitis development in offspring mice

Background and aims

Maternal diet plays a key role in preventing or contributing to the development of chronic diseases, such as obesity, allergy, and brain disorders. Supplementation of maternal diet with prebiotics has been shown to reduce the risk of food allergies and affect the intestinal permeability in offspring later in life. However, its role in modulating the development of other intestinal disorders, such as colitis, remains unknown. Therefore, we investigated the effects of prebiotic supplementation in pregnant mice on the occurrence of colitis in their offspring.

Materials and methods

Offspring from mothers, who were administered prebiotic galacto-oligosaccharides and inulin during gestation or fed a control diet, were subjected to three cycles of dextran sulphate sodium (DSS) treatment to induce chronic colitis, and their intestinal function and disease activity were evaluated. Colonic remodelling, gut microbiota composition, and lipidomic and transcriptomic profiles were also assessed.

Results

DSS-treated offspring from prebiotic-fed mothers presented a higher disease score, increased weight loss, and increased faecal humidity than those from standard diet-fed mothers. DSS-treated offspring from prebiotic-fed mothers also showed increased number of colonic mucosal lymphocytes and macrophages than the control group, associated with the increased colonic concentrations of resolvin D5, protectin DX, and 14-hydroxydocosahexaenoic acid, and modulation of colonic gene expression. In addition, maternal prebiotic supplementation induced an overabundance of eight bacterial families and a decrease in the butyrate caecal concentration in DSS-treated offspring.

Conclusion

Maternal prebiotic exposure modified the microbiota composition and function, lipid content, and transcriptome of the colon of the offspring. These modifications did not protect against colitis, but rather sensitised the mice to colitis development.

The gut microbiota-artery axis: A bridge between dietary lipids and atherosclerosis?

Atherosclerotic cardiovascular disease is one of the major leading global causes of death. Growing evidence has demonstrated that gut microbiota (GM) and its metabolites play a pivotal role in the onset and progression of atherosclerosis (AS), now known as GM-artery axis. There are interactions between dietary lipids and GM, which ultimately affect GM and its metabolites. Given these two aspects, the GM-artery axis may play a mediating role between dietary lipids and AS. Diets rich in saturated fatty acids (SFAs), omega-6 polyunsaturated fatty acids (n-6 PUFAs), industrial trans fatty acids (TFAs), and cholesterol can increase the levels of atherogenic microbes and metabolites, whereas monounsaturated fatty acids (MUFAs), ruminant TFAs, and phytosterols (PS) can increase the levels of antiatherogenic microbes and metabolites. Actually, dietary phosphatidylcholine (PC), sphingomyelin (SM), and omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been demonstrated to affect AS via the GM-artery axis. Therefore, that GM-artery axis acts as a communication bridge between dietary lipids and AS. Herein, we will describe the molecular mechanism of GM-artery axis in AS and discuss the complex interactions between dietary lipids and GM. In particular, we will highlight the evidence and potential mechanisms of dietary lipids affecting AS via GM-artery axis.

Revisiting the "starved gut" hypothesis in inflammatory bowel disease

Active episodes of inflammatory bowel disease (IBD), which include ulcerative colitis and Crohn's disease, coincide with profound shifts in the composition of the microbiota and host metabolic energy demand. Intestinal epithelial cells (IEC) that line the small intestine and colon serve as an initial point for contact for the microbiota and play a central role in innate immunity. In the 1980s, Roediger et al proposed the hypothesis that IBD represented a disease of diminished mucosal nutrition and energy deficiency ("starved gut") that strongly coincided with the degree of inflammation. These studies informed the scientific community about the important contribution of microbial-derived metabolites, particularly short-chain fatty acids (SCFA) such as butyrate, to overall energy homeostasis. Decades later, it is appreciated that disease-associated shifts in the microbiota, termed dysbiosis, places inordinate demands on energy acquisition within the mucosa, particularly during active inflammation. Here, we review the topic of tissue energetics in mucosal health and disease from the original perspective of that proposed by the starved gut hypothesis.

Causal effects between gut microbiota and IgA nephropathy: a bidirectional Mendelian randomization study

Background

Therapeutic approaches that target the gut microbiota (GM) may be helpful in the potential prevention and treatment of IgA nephropathy (IgAN). Meanwhile, relevant studies demonstrated a correlation between GM and IgAN, however, these confounding evidence cannot prove a causal relationship between GM and IgAN.

Methods

Based on the data from the GM genome-wide association study (GWAS) of MiBioGen and the IgAN GWAS data from the FinnGen research. A bi-directional Mendelian randomization (MR) study was performed to explore the causal relationship between GM and IgAN. We used inverse variance weighted (IVW) method as the primary method to determine the causal relationship between exposure and outcome in our MR study. Besides, we used additional analysis (MR-Egger, weighted median) and sensitivity analysis (Cochrane's Q test, MR-Egger and MR-PRESSO) to select significant results, followed by Bayesian model averaging (MR-BMA) to test the results of MR study. Finally, a reverse MR analysis was conducted to estimate the probability of reverse causality.

Results

At the locus-wide significance level, the results of IVW method and additional analysis showed that Genus Enterorhabdus was a protective factor for IgAN [OR: 0.456, 95% CI: 0.238-0.875, p=0.023], while Genus butyricicoccus was a risk factor for IgAN [OR: 3.471, 95% CI: 1.671-7.209, p=0.0008]. In the sensitivity analysis, no significant pleiotropy or heterogeneity of the results was found.

Conclusion

Our study revealed the causal relationship between GM and IgAN, and expanded the variety of bacterial taxa causally related to IgAN. These bacterial taxa could become novel biomarkers to facilitate the development of targeted therapies for IgAN, developing our understanding of the "gut-kidney axis".

MiRNA-374b-5p and miRNA-106a-5p are related to inflammatory bowel disease via regulating IL-10 and STAT3 signaling pathways

Background

Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is one of the most frequent gastrointestinal disorders worldwide. Although the actual etiology of IBD remains unclear, growing evidence suggests that CD4+ T cells-associated cytokines, including interferon (IFN)-γ, interleukin (IL)-10 and IL-17A, are crucial for the occurrence of IBD. It has been reported that there is a positive association between miRNAs and IBD development. In this study, we investigated the roles of hsa-miRNA-374b-5p(miRNA-374b-5p) and hsa-miRNA-106a-5p(miRNA-106a-5p) in regulating IBD development.

Methods

Serum was obtained from vein blood of IBD patients and healthy controls, qRT-PCR was performed to study the expression of miRNA-374b-5p and miRNA-106a-5p. Furthermore, we investigate the effects of overexpression or inhibition of miRNA-374b-5p on naïve CD4 + T cell subsets differentiation from vein blood of healthy controls by RT-qPCR, flow cytometry and western blot. And more the prediction and confirmation of the targeting genes of miRNA-374b-5p and miRNA-106a-5p were performed by bioinformatics softwares and dual-luciferase reporter assay.

Results

The results showed that miRNA-106a-5p and miRNA-374b-5p were significantly overexpressed in IBD patients. MiRNA-374b-5p could enhance Th1/Th17 cell differentiation and was related to IBD pathogenesis. MiRNA-374b-5p overexpression induced the mRNA expression of IL-17A and IFN-γ, and suppressed that of IL-10 in T cells. MiRNA-374b-5p inhibition decreased the mRNA expression of IL-17A and IFN-γ, while upregulated that of IL-10 in T cells. These qPCR data were further verified at protein level by western blotting and flow cytometry. In addition, dual-luciferase reporter (DLR) assay indicated that miRNA-374b-5p was directly targeted by IL-10, a key anti-inflammatory cytokine for preventing the occurrence of IBD. Meanwhile, STAT3 was identified as a target gene of miRNA-106a-5p by DLR assays. Further analysis revealed that miRNA-374b-5p regulated JAK1 and STAT3 pathways in CD4+ T cells via IL-10/STAT3 axis. MiRNA-374b-5p overexpression remarkably decreased the mRNA expression and phosphorylated (ser-727) protein levels of STAT3, while miRNA-374b-5p inhibition had the opposite effects.

Conclusion

MiRNA-374b-5p and miRNA-106a-5p may contribute to IBD development by regulating IL-10/STAT3 signal transduction.

Health Benefits and Pharmacological Properties of Stigmasterol

Stigmasterol is an unsaturated phytosterol belonging to the class of tetracyclic triterpenes. It is one of the most common plant sterols, found in a variety of natural sources, including vegetable fats or oils from many plants. Currently, stigmasterol has been examined via in vitro and in vivo assays and molecular docking for its various biological activities on different metabolic disorders. The findings indicate potent pharmacological effects such as anticancer, anti-osteoarthritis, anti-inflammatory, anti-diabetic, immunomodulatory, antiparasitic, antifungal, antibacterial, antioxidant, and neuroprotective properties. Indeed, stigmasterol from plants and algae is a promising molecule in the development of drugs for cancer therapy by triggering intracellular signaling pathways in numerous cancers. It acts on the Akt/mTOR and JAK/STAT pathways in ovarian and gastric cancers. In addition, stigmasterol markedly disrupted angiogenesis in human cholangiocarcinoma by tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor receptor-2 (VEGFR-2) signaling down-regulation. The association of stigmasterol and sorafenib promoted caspase-3 activity and down-regulated levels of the anti-apoptotic protein Bcl-2 in breast cancer. Antioxidant activities ensuring lipid peroxidation and DNA damage lowering conferred to stigmasterol chemoprotective activities in skin cancer. Reactive oxygen species (ROS) regulation also contributes to the neuroprotective effects of stigmasterol, as well as dopamine depletion and acetylcholinesterase inhibition. The anti-inflammatory properties of phytosterols involve the production of anti-inflammatory cytokines, the decrease in inflammatory mediator release, and the inhibition of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Stigmasterol exerts anti-diabetic effects by reducing fasting glucose, serum insulin levels, and oral glucose tolerance. Other findings showed the antiparasitic activities of this molecule against certain strains of parasites such as Trypanosoma congolense (in vivo) and on promastigotes and amastigotes of the Leishmania major (in vitro). Some stigmasterol-rich plants were able to inhibit Candida albicans, virusei, and tropicalis at low doses. Accordingly, this review outlines key insights into the pharmacological abilities of stigmasterol and the specific mechanisms of action underlying some of these effects. Additionally, further investigation regarding pharmacodynamics, pharmacokinetics, and toxicology is recommended.

Stigmasterol attenuates hepatic steatosis in rats by strengthening the intestinal barrier and improving bile acid metabolism

Stigmasterol (ST) has been shown to improve both lipid and bile acid (BA) metabolism. However, the mechanism(s) by which ST prevents dyslipidemia via BA metabolism, and the potential involvement of other regulatory mechanisms, remains unclear. Here, we found that ST treatment effectively alleviates lipid metabolism disorder induced by a high-fat diet (HFD). Moreover, we also show that fecal microbiota transplantation from ST-treated rats displays similar protective effects in rats fed on an HFD. Our data confirm that the gut microbiota plays a key role in attenuating HFD-induced fat deposition and metabolic disorders. In particular, ST reverses HFD-induced gut microbiota dysbiosis in rats by reducing the relative abundance of Erysipelotrichaceae and Allobaculum bacteria in the gut. In addition, ST treatment also modifies the serum and fecal BA metabolome profiles in rats, especially in CYP7A1 mediated BA metabolic pathways. Furthermore, chenodeoxycholic acid combined with ST improves the therapeutic effects in HFD-induced dyslipidemia and hepatic steatosis. In addition, this treatment strategy also alters BA metabolism profiles via the CYP7A1 pathway and gut microbiota. Taken together, ST exerts beneficial effects against HFD-induced hyperlipidemia and obesity with the underlying mechanism being partially related to both the reprogramming of the intestinal microbiota and metabolism of BAs in enterohepatic circulation. This study provides a theoretical basis for further study of the anti-obesity effects of ST and consideration of the gut microbiota as a potential target for the treatment of HFD-induced dyslipidemia.

Isomaltulose alleviates acute colitis via modulating gut microbiota and the Treg/Th17 balance in mice

Food-grade isomaltulose exhibits significant modulation of gut microbiota and its metabolites in healthy populations. This study further explored the preventive therapeutic effect and anti-colitis potential of isomaltulose on dextran sulfate sodium-induced colitis in mice. Our results suggested that isomaltulose played a significant role in preventing colon shortening, reducing intestinal epithelial destruction and inhibiting inflammatory cell infiltration. Meanwhile, the isomaltulose supplement greatly reduced the production of pro-inflammatory cytokines and restored the balance between T helper type 17 (Th17) cells and regulatory T (Treg) cells. Pathway enrichment analysis for differentially expressed genes (DEGs) also indicated that the anti-inflammatory effect of isomaltulose was closely related to intestinal immunity. Moreover, the disturbed gut microbiota in ulcerative colitis (UC) was partially restored after treatment with isomaltulose. These results suggest that isomaltulose is a promising therapeutic agent for the prevention and adjunctive treatment of UC by maintaining intestinal immune homeostasis and remodeling the gut microbiota.

Different Dose of Sucrose Consumption Divergently Influences Gut Microbiota and PPAR-γ/MAPK/NF-κB Pathway in DSS-Induced Colitis Mice

Sugar reduction and sugar control are advocated and gaining popularity around the world. Sucrose, as the widely consumed ingredient in our daily diet, has been reported a relation to gastrointestinal diseases. However, the role of sucrose in inflammatory bowel disease remains controversial. Hence, our study aimed to elucidate the potential role of three doses of sucrose on DSS-induced colitis in C57BL/6 mice and the underlying mechanisms. The results showed that low-dose sucrose intervention alleviated colitis in mice, reducing the expression of inflammatory cytokines and repairing mucosal damages. In contrast, high-dose sucrose intervention exacerbated colitis. Furthermore, three doses of sucrose administration markedly altered gut microbiota composition. Notably, the low-dose sucrose restored microbial dysfunction and enhanced the production of short chain fatty acids (SCFAs). Specifically, the abundance of SCFAs-producing bacteria Faecalibaculum, Bacteroides, and Romboutsia were increased significantly in the LOW group. Consistently, PPAR-γ, activated by SCFAs, was elevated in the LOW group, thereby inhibiting the MAPK/NF-κB pathway. Together, our study demonstrates the differential effects of sucrose on colitis at different doses, providing a scientific basis for measuring and modifying the safe intake level of sugar and providing favorable evidence for implementing sugar reduction policies.

Swimming Impedes Intestinal Microbiota and Lipid Metabolites of Tumorigenesis in Colitis-Associated Cancer

Background

Accumulating data support that regular physical activity potentially inhibits chronic colitis, a risk factor for colitis-associated cancer (CAC). However, possible effects of physical activity on CAC and the underlying mechanisms remain poorly understood.

Methods

A pretreatment of swimming on azoxymethane/dextran sodium sulfate (AOM/DSS)-induced CAC mice was implemented to determine its protective effect. Inflammation and tumorigenesis were assessed using colorectums from C57BL/6 mice. In order to determine how swimming alters colonic lipid metabolism and gene expression, a comparative analysis was conducted. Meanwhile, alterations in intestinal microbiota and short-chain fatty acids (SCFAs) were detected and analyzed. Finally, an integration analysis of colonic lipid metabolism with gene expression and intestinal microbiota was performed respectively.

Result

Swimming pretreatment relieved bowel inflammation and minimized tumor formation. We demonstrated that prostaglandin E2 (PGE2)/PGE2 receptor 2 subtype (EP2) signaling as a potential regulatory target for swimming induces colonic lipid metabolites. Swimming-induced genera, Erysipelatoclostridium, Parabacteroides, Bacteroides, and Rikenellaceae_RC9_gut_group, induced intestinal SCFAs and affected the function of colonic lipid metabolites enriched in glycerophospholipid metabolism and choline metabolism in cancer.

Conclusion

According to our experiments, swimming pretreatment can protect mice from CAC by intervention in the possible link between colonic lipid metabolites and PGE2/EP2 signaling. Further, swimming-induced genera and probiotics promoted glycerophospholipid metabolism and choline metabolism in cancer, the major constituents of colonic lipid metabolites, and increased SCFAs, which were also important mechanisms for the anti-inflammatory and anti-tumorigenic effects of swimming.