Intestinal microbiota-derived short-chain fatty acids regulation of immune cell IL-22 production and gut immunity

Sodium butyrate alleviates DSS-induced inflammatory bowel disease by inhibiting ferroptosis and modulating ERK/STAT3 signaling and intestinal flora

BACKGROUND

Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), can seriously impact patients' quality of life. Sodium butyrate (NaB), a product of dietary fiber fermentation, has been shown to alleviate IBD symptoms. Some studies have shown that it is related to ferroptosis. However, the precise mechanism linking NaB, IBD, and ferroptosis is not clear.

OBJECTIVE

This study aimed to demonstrate that NaB suppresses ferroptosis, thereby alleviating inflammatory bowel disease (IBD) through modulation of the extracellular regulated protein kinases/signal transducer and activator of transcription 3 (ERK/STAT3) signaling pathway and intestinal flora.

METHODS

An IBD model was established using 2.5% (w/v) dextran sulfate sodium (DSS). Mice were orally administered low-dose NaB, high-dose NaB , or 5-aminosalicylic acid (5-ASA). Ferroptosis-related molecules were measured using specific kits, and western blotting (WB) and real-time polymerase chain reaction (RT-qPCR) were used to determine the levels of the target molecules.

RESULTS

NaB alleviated symptoms in IBD mice, including reduced weight loss, prolonged colon length, reduced disease activity index (DAI), and reduced spleen index and mRNA expression of inflammatory factors. Additionally, NaB reduced the content of Fe2+ and myeloperoxidase (MPO) and increased the content of GSH and the activity of superoxide dismutase (SOD), which reflected NaB-inhibited ferroptosis. Moreover, western blotting showed that NaB enhanced STAT3 and ERK phosphorylation. In addition, NaB regulates the composition and functions of flora related to IBD.

CONCLUSION

NaB alleviates IBD by inhibiting ferroptosis and modulating ERK/STAT3 signaling and the intestinal flora.

Ketogenic diet and cancer: multidimensional exploration and research

The ketogenic diet (KD) has attracted attention in recent years for its potential anticancer effects. KD is a dietary structure of high fat, moderate protein, and extremely low carbohydrate content. Originally introduced as a treatment for epilepsy, KD has been widely applied in weight loss programs and the management of metabolic diseases. Previous studies have shown that KD can potentially inhibit the growth and spread of cancer by limiting energy supply to tumor cells, thereby inhibiting tumor angiogenesis, reducing oxidative stress in normal cells, and affecting cancer cell signaling and other processes. Moreover, KD has been shown to influence T-cell-mediated immune responses and inflammation by modulating the gut microbiota, enhance the efficacy of standard cancer treatments, and mitigate the complications of chemotherapy. However, controversies and uncertainties remain regarding the specific mechanisms and clinical effects of KD as an adjunctive therapy for cancer. Therefore, this review summarizes the existing research and explores the intricate relationships between KD and cancer treatment.

Bacterial indole-3-propionic acid inhibits macrophage IL-1β production through targeting methionine metabolism

The gut microbiota plays key roles in host health by shaping the host immune responses through their metabolites, like indole derivatives from tryptophan. However, the direct role of these indole derivatives in macrophage fate decision and the underlying mechanism remains unknown. Here, we found that bacterial indole-3-propionic acid (IPA) downregulates interleukin-1beta (IL-1β) production in M1 macrophages through inhibition of nuclear factor-kappa B (NF-κB) signaling. Mechanistically, IPA binds specifically with methionine adenosyl-transferase 2A (MAT2A) to promote S-adenosylmethionine (SAM) synthesis, which facilitates the DNA methylation of ubiquitin-specific peptidase 16 (USP16, a deubiquitinase), and in turn promotes Toll-like receptor 4 (TLR4) ubiquitination and NF-κB inhibition. Furthermore, IPA administration attenuates sepsis in mouse models induced by lipopolysaccharides (LPS), showcasing its potential as a microbial-derived adjunct in alleviating inflammation. Collectively, our findings reveal a newly found microbial metabolite-immune system regulatory pathway mediated by IPA.

Role of the microbiome in regulation of the immune system

Immune health and metabolic functions are intimately connected via diet and the microbiota. Immune cells are continuously exposed to a wide range of microbes and microbial-derived compounds, with important mucosal and systemic ramifications. Microbial fermentation of dietary components in vivo generates thousands of molecules, some of which are integral components of the molecular circuitry that regulates immune and metabolic functions. These in turn protect against aberrant inflammatory or hyper-reactive processes and promote effector immune responses that quickly eliminate pathogens, such as SARS-CoV-2. Potent tolerance mechanisms should ensure that these immune cells do not over-react to non-pathogenic factors (e.g. food proteins), while maintaining the ability to respond to infectious challenges in a robust, effective and well controlled manner. In this review we examine the factors and mechanisms that shape microbiota composition and interactions with the host immune system, their associations with immune mediated disorders and strategies for intervention.

Regulation of innate lymphoid cell by microbial metabolites

Innate lymphoid cells (ILCs) are a unique category of immune cell that lack antigen-specific receptors yet possess the capacity to detect signals from the surrounding tissue. The majority of ILCs reside in the lymphoid and mucosal tissues, maintaining close associations with the microbiota. Beyond the contributions of accessory cells and adaptive immune cells, accumulating studies demonstrate that microbial metabolites serve a crucial role in mediating the relationship between ILCs and the microbiota. In this review, we highlight and summarize the roles of microbial metabolites from different sources in modulating ILC subsets, proposing these metabolites as potential therapeutic mechanisms in ILC-mediated diseases.

Ruminococcus bromii-generated acetate alleviated Clonorchis sinensis-induced liver fibrosis in mice

Introduction

Infection with Clonorchis sinensis (C. sinensis) has the potential to induce liver fibrosis and significantly alter the gut microbiota. However, it remains unclear how these changes in the gut microbiota, through the gut-liver axis, influence the progression of liver fibrosis. Furthermore, it is uncertain whether targeting the gut microbiota, based on the concept of the gut-liver axis, could be a potential therapeutic strategy for alleviating liver fibrosis.

Methods

The gut microbiota alterations in C. sinensis-infected mice at multiple time points were analyzed through 16S rDNA high-throughput sequencing. Ruminococcus bromii (R.bromii) therapeutic effect on C. sinensis infected mice was evaluated. Metabolic changes following produced by R. bromii were analyzed using short-chain fatty acids (SCFAs) metabolomics. Additionally, R. bromii conditioned medium (R.b CM) or its metabolites were co-cultured with two hepatic stellate cell lines (LX2 and JS1) in vitro to assess their anti-fibrotic effects. Finally, RNA sequencing was employed to investigate the specific mechanism by which acetate inhibits hepatic stellate cells (HSCs) activation.

Results

The abundance of R. bromii increased during the inflammatory stage of C. sinensis infection and decreased significantly during the fibrosis stage. Oral gavage of R. bromii significantly inhibited C. sinensis-induced liver fibrosis while restoring the intestinal barrier. The activation of HSCs was significantly inhibited in vitro upon incubation with R.b CM. Acetate was identified as a key metabolite generated from R. bromii in R.b CM, and acetate attenuated C. sinensis-induced liver fibrosis in vitro and in vivo. Mechanistically, acetate inhibited the activation of HSCs by activating the PI3K/AKT signaling pathway to prevent the progression of liver fibrosis in mice infected with C. sinensis.

Discussion

R. bromii exerted a protective effect on hepatic fibrosis by delivering acetate via the gut-liver axis to active the PI3K/AKT signaling pathway in HSCs. Furthermore, R. bromii can be used as a probiotic therapy to alleviate hepatic fibrosis.

Coenzyme Q10 modulates the immunity by enhancing mononuclear macrophage, NK cell activity, and regulating gut microbiota

Introduction

Coenzyme Q10 (CoQ10), an important fat-soluble, bioactive molecule that predominantly found in the inner mitochondrial membrane, is widely used in functional food and health food raw materials, which has garnered considerable attention due to its potential role in immunoregulation. However, the intrinsic mechanism of CoQ10 on immunity, and the relationship to the gut microbiota have not been elucidated.

Methods

Here, we conducted a series of in vivo experiments with the aim of comprehensively exploring the effect of CoQ10 on both cellular and humoral immune functions, and on gut microbiota communities in mice.

Results

CoQ10 showed negligible impact on both mouse body weight fluctuations and tissue indices, but enhanced the mouse body immunity by elevating the carbon clearance ability and natural killer (NK) cellular viability. 16S rRNA gene sequencing revealed that administration of CoQ10 modulated the structure and composition of the gut microbiota in mice, notably by enhancing the abundance of Lactobacillus, Limosilactobacillus, and decreasing the abundance of Paramuribaculum species.

Discussion

This work makes a contribution to the application of CoQ10 as an immunomodulator in the biological, pharmaceutical and health care product industries.

Isobutyrate exerts a protective effect against liver injury in a DSS-induced colitis by inhibiting inflammation and oxidative stress

BACKGROUND

Short-chain fatty acids have been reported to have anti-inflammatory and antioxidant functions; whether isobutyrate, a short-chain fatty acid, is protective against liver injury in a dextran sodium sulfate (DSS)-induced colitis and its molecular mechanism is unknown. In this study, DSS was used to induce a liver injury from a colitis model in piglets, which was expected to prevent and alleviate DSS-induced liver injury by feeding sodium isobutyrate in advance.

RESULTS

The results showed that sodium isobutyrate could restore DSS-induced histopathological changes in the liver, inhibit the activation of the toll-like receptor 4/myeloid differentiation primary response 88/nuclear factor kappa-B signaling pathway, and then reduce the DSS-induced release of pro-inflammatory cytokines tumor necrosis factor-α, interleukin 1β, and interleukin 6, reducing inflammatory response. Moreover, we found that sodium isobutyrate could play an antioxidant and apoptosis-reducing role by maintaining reduced mitochondrial function.

CONCLUSION

In conclusion, sodium isobutyrate has a preventive and protective effect on liver injury in a DSS-induced colitis. There is a potential application prospect for it in treating ulcerative-colitis-induced liver injuries. © 2024 Society of Chemical Industry.

Maternal high-fat diet disrupts intestinal mucus barrier of offspring by regulating gut immune receptor LRRC19

Maternal high fat diet (MHFD) increased colitis susceptibility in adulthood. However, the mechanism remains unclear. We sought to explore whether novel gut immune receptor leucine-rich repeat C19 (LRRC19) contributed to the impaired mucus barrier of offspring exposed to MHFD via gut immune response and microbiota. The results showed that MHFD significantly impaired the intestinal mucus barrier of offspring, and up-regulated the expression of LRRC19. Lrrc19 deletion alleviated the mucus barrier disruption. Mechanistically, metagenome sequencing revealed that the MHFD-induced gut microbiota alteration was partly restored in Lrrc19-/- offspring. Muc2-associated bacteria were decreased in the MHFD group, such as Akkermansia_muciniphila_CAG_154, which increased in the Lrrc19-deficient offspring. Moreover, Lrrc19-/- offspring had a higher rate of indole-3-acetic acid (IAA)-producing bacterium, such as Lactobacillus reuteri. A targeted metabolomics analysis revealed that IAA emerged as the top candidate that might mediate the protective effects. IAA was found to improve the mucus barrier function by increasing the ratio of interleukin-22 (IL-22)+ ILC3 cells in an aryl hydrocarbon receptor (AhR)-dependent manner. These results suggest that MHFD disrupts the intestinal mucus barrier of offspring through regulating gut immune receptor LRRC19 and inducing an imbalance of gut microbiota and microbiota-derived metabolites.

Exploring effects of gut microbiota on tertiary lymphoid structure formation for tumor immunotherapy

Anti-tumor immunity, including innate and adaptive immunity is critical in inhibiting tumorigenesis and development of tumor. The adaptive immunity needs specific lymph organs such as tertiary lymphoid structures (TLSs), which are highly correlated with improved survival outcomes in many cancers. In recent years, with increasing attention on the TLS in tumor microenvironment, TLSs have emerged as a novel target for anti-tumor therapy. Excitingly, studies have shown the contribution of TLSs to the adaptive immune responses. However, it is unclear how TLSs to form and how to more effectively defense against tumor through TLS formation. Recent studies have shown that the inflammation plays a critical role in TLS formation. Interestingly, studies have also found that gut microbiota can regulate the occurrence and development of inflammation. Therefore, we here summarize the potential effects of gut microbiota- mediated inflammation or immunosuppression on the TLS formation in tumor environments. Meanwhile, this review also explores how to manipulate mature TLS formation through regulating gut microbiota/metabolites or gut microbiota associated signal pathways for anti-tumor immunity, which potentially lead to a next-generation cancer immunotherapy.

Multi-Omics Analysis Revealed the Molecular Mechanisms Affecting Average Daily Gain in Cattle

The average daily gain (ADG) is a critical index for evaluating growth rates in cattle and is closely linked to the economic benefits of the cattle industry. Heredity is one of the factors affecting the daily gain of cattle. However, the molecular mechanisms regulating ADG remain incompletely understood. This study aimed to systematically unravel the molecular mechanisms underlying the divergence in ADG between high average daily gain (HADG) and low average daily gain (LADG) Angus cattle through integrated multi-omics analyses (microbiome, metabolome, and transcriptome), hypothesizing that the gut microbiota-host gene-metabolism axis is a key regulatory network driving ADG divergence. Thirty Angus cattle were classified according to their HADG and LADG. Fecal and serum samples were collected for 16S, fecal metabolome, and blood transcriptome analysis. The results showed that compared with the LADG group, the abundance of Firmicutes increased in the HADG group, while the abundance of Bacteroidetes and Proteobacteria decreased. Metabolomics and transcriptomic analysis revealed that KEGG pathways associated with differentially expressed genes (DEGs) and differentially abundant metabolites (DAMs) were enriched in bile acid metabolism. Spearman correlation analysis showed that Oscillospira was positively correlated with ZBTB20 and negatively correlated with RADIL. ZBTB20 was negatively correlated with dgA-11_gut_group. This study analyzed the regulatory mechanism of average daily gain of beef cattle from genetic, metabolic, and microbial levels, providing a theoretical basis for analyzing the mechanism of differential daily gain of beef cattle, and has important significance for improving the production performance of beef cattle. The multi-omics network provides biomarker foundations for machine learning-based ADG prediction models, offering potential applications in precision breeding. While these biomarkers show promise for precision breeding, their causal roles require further validation. The conclusions are derived from a single breed (Angus) and gender (castrated males). Future studies should include females and diverse breeds to assess generalizability.

Total ginsenosides from wild ginseng improve immune regulation in a rat model of spleen qi deficiency by modulating fecal-bacteria-associated short-chain fatty acids and intestinal barrier integrity

For thousands of years, traditional Chinese medicine (TCM) has made extensive use of wild ginseng. It is thought to provide vital energy effects and to boost immunity. This study aimed to clarify the processes by which short-chain fatty acids (SCFAs) metabolites and the intestinal barrier are used by total ginsenosides wild ginseng (TWG) to modulate immunity. In this study, we analyzed and identified ginsenosides in the colon using UPLC-Q-TOF-MSE methods. In the meantime, a rat model of spleen qi deficiency (SQD) was created using reserpine, and the effects of TWG on intestinal barrier function and short-chain fatty acids in the feces of SQD-affected rats were examined. 28 ginsenosides were found in the colon during this experiment, and the main components were measured. TWG considerably increased fecal concentrations of acetic, propionic and 6 others, according to SCFAs analysis. According to serum immunological markers, TWG reduced IL-17 and IL-1β levels, increased IL-10, IL-22, and TGF-β concentrations, balanced Th17/Treg ratios, and reduced toxicants such DAO and LPS in rats with SQD. TWG improved barrier function, reduced permeability, increased tight junction protein expression, and lessened intestinal injury. A favorable correlation between intestinal barrier proteins and fatty acids was shown by correlation studies. The gut barrier and SCFAs perspectives helped to clarify the mechanism by which TWG controls immune activity. This study offers a fresh theoretical framework for TWG's future advancement and application.

Gut Microbiota-Derived Hyocholic Acid Enhances Type 3 Immunity and Protects Against Salmonella enterica Serovar Typhimurium in Neonatal Rats

This study investigates how microbiome colonization influences the development of intestinal type 3 immunity in neonates. The results showed that reduced oxygen levels in the small intestine of neonatal rats induced by Saccharomyces boulardii accelerated microbiome colonization and type 3 immunity development, which protected against Salmonella enterica serovar Typhimurium infection. Microbiome maturation increased the abundance of microbiome-encoded bile salt hydrolase (BSH) genes and hyocholic acid (HCA) levels. Furthermore, reducing oxygen levels in the intestine increased the abundance of Limosilactobacillus reuteri, a bacterium encoding BSH, and promoted intestinal type 3 immunity. However, inhibition of BSH blocked the L. reuteri-induced development of intestinal type 3 immunity. Mechanistically, HCA promoted the development of gamma-delta T cells and type 3 innate lymphoid cells by stabilizing the mRNA expression of RAR-related orphan receptor C via the farnesoid X receptor-WT1-associated protein-N6-methyl-adenosine axis. These results reveal that gut microbiota-derived HCA plays a crucial role in promoting the development of intestinal type 3 immunity in neonates. This discovery introduces potential therapeutic avenues for strengthening intestinal immunity in early life or treating bacterial infections by targeting microbial metabolites.

The link between obesity and the gut microbiota and immune system in early-life

In early-life, the gut microbiota is highly modifiable, being modulated by external factors such as maternal microbiota, mode of delivery, and feeding strategies. The composition of the child's gut microbiota will deeply impact the development and maturation of its immune system, with consequences for future health. As one of the main sources of microorganisms to the child, the mother represents a crucial factor in the establishment of early-life microbiota, impacting the infant's wellbeing. Recent studies have proposed that dysbiotic maternal gut microbiota could be transmitted to the offspring, influencing the development of its immunity, and leading to the development of diseases such as obesity. This paper aims to review recent findings in gut microbiota and immune system interaction in early-life, highlighting the benefits of a balanced gut microbiota in the regulation of the immune system.

Aryl hydrocarbon receptor (AHR) and nuclear factor erythroid-derived 2-like 2 (NRF2): An important crosstalk in the gut-liver axis

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor, mainly involved in detoxification. However, in the intestine, metabolites derived from the diet, which are converted by a wide range of bacteria can also activate the AHR. This intestinal AHR activation plays a key role in maintaining the gut barrier by, for example, upregulating antimicrobial peptides and anti-inflammatory cytokines. Since the gut barrier influences the gut-liver axis by regulating the leaking of metabolites, bacteria, and endotoxins into circulation and particularly into the liver, the AHR is a key factor in the gut-liver axis. Vice versa, certain liver pathologies also influence the gut microbiome, thereby altering bacteria-derived activation of the AHR. Additionally, bile acids can impact the gut via the liver and thereby also affect the AHR. The aryl hydrocarbon receptor (AHR) interacts with several molecular factors, one of which is the nuclear factor erythroid-derived 2-like 2 (NRF2), a transcription factor primarily associated with regulating antioxidant stress responses. The interplay between AHR and NRF2 has been investigated in the context of various diseases; this review highlights the significance of this interaction within the framework of the gut-liver axis.

Gut microbiota derived DCA enhances FOLFOX efficacy via Ugt1a6b mediated enterohepatic circulation in colon cancer

FOLFOX (5-Fluorouracil, Calcium Folinate combined with Oxaliplatin) is a preferred chemotherapy regimen for colon cancer, but its limited efficacy remains a major challenge, significantly impairs patient outcomes. There is an urgent need to identify strategies to improve its therapeutic effectiveness. Our previous studies have suggested that gut microbiota-derived bile acids may be involved in the anticancer effect of FOLFOX in vitro, however, the underlying mechanism remains unclear. In this study, we investigated the role of bile acids in modulating FOLFOX efficacy and the related mechanisms. We first demonstrated that bile acids depletion (cholestyramine treatment) enhanced FOLFOX efficacy in an orthotopic colon cancer mouse model, suggesting that bile acids play a key role in FOLFOX's therapeutic effects. Further, based on the system screen of 15 bile acids on FOLFOX efficacy via MTT, colony formation and flow cytometry assay, Deoxycholic Acid (DCA) and Glycodeoxycholic Acid (GDCA) were annotated as potential modulators of FOLFOX efficacy. Among these, DCA was further validated to significantly enhance FOLFOX's anti-colon cancer effects in vivo. Transcriptomic analysis and subsequent biological experiments revealed that DCA enhanced FOLFOX efficacy via Ugt1a6b. In conclusion, our findings establish that gut microbiota-derived DCA enhances the efficacy of FOLFOX potentially via Ugt1a6b mediated enterohepatic circulation, providing novel insights into a synergistic therapeutic strategy for improving colon cancer treatment.

The role of the gut microbiome in disorders of gut-brain interaction

Disorders of Gut-Brain Interaction (DGBI) are widely prevalent and commonly encountered in gastroenterology practice. While several peripheral and central mechanisms have been implicated in the pathogenesis of DGBI, a recent body of work suggests an important role for the gut microbiome. In this review, we highlight how gut microbiota and their metabolites affect physiologic changes underlying symptoms in DGBI, with a particular focus on their mechanistic influence on GI transit, visceral sensitivity, intestinal barrier function and secretion, and CNS processing. This review emphasizes the complexity of local and distant effects of microbial metabolites on physiological function, influenced by factors such as metabolite concentration, duration of metabolite exposure, receptor location, host genetics, and underlying disease state. Large-scale in vitro work has elucidated interactions between host receptors and the microbial metabolome but there is a need for future research to integrate such preclinical findings with clinical studies. The development of novel, targeted therapeutic strategies for DGBI hinges on a deeper understanding of these metabolite-host interactions, offering exciting possibilities for the future of treatment of DGBI.

Recent insights and advances in gut microbiota's influence on host antiviral immunity

A diverse array of microbial organisms colonizes the human body, collectively known as symbiotic microbial communities. Among the various pathogen infections that hosts encounter, viral infections represent one of the most significant public health challenges worldwide. The gut microbiota is considered an important biological barrier against viral infections and may serve as a promising target for adjuvant antiviral therapy. However, the potential impact of symbiotic microbiota on viral infection remains relatively understudied. In this review, we discuss the specific regulatory mechanisms of gut microbiota in antiviral immunity, highlighting recent advances in how gut microbiota regulate the host immune response, produce immune-related molecules, and enhance the host's defense against viruses. Finally, we also discuss the antiviral potential of oral probiotics.

HDAC inhibitors and IBD: Charting new approaches in disease management

Inflammatory bowel disease (IBD) represents a group of chronic inflammatory disorders of the gastrointestinal tract. Despite substantial advances in our understanding of IBD pathogenesis, the currently available therapeutic options remain limited in their efficacy and often come with significant side effects. Therefore, there is an urgent need to explore novel approaches for the management of IBD. One promising avenue of investigation revolves around the use of histone deacetylase (HDAC) inhibitors, which have garnered considerable attention for their potential in modulating gene expression and curbing inflammatory responses. This review emphasizes the pressing need for innovative drugs in the treatment of IBD, and drawing from a wealth of preclinical studies and clinical trials, we underscore the multifaceted roles and the therapeutic effects of HDAC inhibitors in IBD models and patients. This review aims to contribute significantly to the understanding of HDAC inhibitors' importance and prospects in the management of IBD, ultimately paving the way for improved therapeutic strategies in this challenging clinical landscape.

Chaihuang Qingyi Huoxue granule ameliorates severe acute pancreatitis by modulating gut microbiota and repairing the intestinal mucosal barrier

Background

During severe acute pancreatitis (SAP), damage to the intestinal mucosal barrier and translocation of intestinal pathogenic bacteria are key mechanisms that accelerate the disease progression of SAP. Chaihuang Qingyi Huoxue Granule (CH) is a herbal formula used in the clinical treatment of SAP. This study aims to investigate the role of CH in regulating gut microbiota and intestinal mucosal barrier in SAP rats.

Methods

Sodium taurocholate (3.5%) was retrogradely perfused into the biliopancreatic duct to establish the model of SAP in rats. CH (4.4 g/kg) was administered by gavage. Serum amylase, lipase, and endotoxin levels were measured. Hematoxylin-eosin (HE) staining was used to observe morphological changes in the pancreas and colon. The expression of zona occludens-1 (ZO-1) and occludin in the colon was examined by immunohistochemistry (IHC) and western blot. 16S rDNA gene sequencing was used to analyze the gut microbiota of the rats. The content of short-chain fatty acids (SCFAs) in the intestinal contents of the rats was determined by gas chromatography-mass spectrometry (GC-MS).

Results

CH reduced serum amylase, lipase, and endotoxin levels in SAP rats, alleviated pathological damage in the pancreas and colon, and restored the expression of ZO-1 and occludin. Moreover, CH alleviated gut microbiota dysbiosis in SAP rats, with restored gut microbiota diversity and structure. At the phylum level, the relative abundance of Firmicutes and Bacteroidetes increased, while that of Proteobacteria decreased. At the genus level, the abundance of Ruminococcus 1, Parabacteroides, Prevotellaceae UCG-001, Lachnospiraceae NK4A136 group, and Lactobacillus increased, while that of Escherichia-Shigella, Enterococcus, and Enterobacter decreased. In addition, CH increased the levels of SCFAs in the intestinal contents of SAP rats.

Conclusion

CH ameliorates SAP by maintaining the homeostasis and diversity of the gut microbiota, increasing the levels of SCFAs, and repairing the intestinal mucosal barrier.

Histone deacetylase in inflammatory bowel disease: novel insights

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is characterized by chronic nonspecific intestinal inflammation. Despite considerable efforts, IBD remains a heavy burden on society and human health, with increasing morbidity. Posttranslational modification, especially histone acetylation, is a key process in controlling DNA transcriptional activity. Histone deacetylases (HDACs) play a vital role in the mechanism of IBD pathogenesis through histone and nonhistone protein deacetylation. Herein, we present a summary of different categories of HDACs as well as HDAC inhibitors (HDACis) and analyze the role of HDAC inhibition in alleviating IBD along with its mechanism, as well as clinical potential of HDACis in IBD treatment.

Dietary manipulation of intestinal microbes prolongs survival in a mouse model of Hirschsprung disease

Enterocolitis is a common and potentially deadly manifestation of Hirschsprung disease (HSCR) but disease mechanisms remain poorly defined. Unexpectedly, we discovered that diet can dramatically affect the lifespan of a HSCR mouse model ( Piebald lethal , sl/sl ) where affected animals die from HAEC complications. In the sl/sl model, diet alters gut microbes and metabolites, leading to changes in colon epithelial gene expression and epithelial oxygen levels known to influence colitis severity. Our findings demonstrate unrecognized similarity between HAEC and other types of colitis and suggest dietary manipulation could be a valuable therapeutic strategy for people with HSCR.

Abstract

Hirschsprung disease (HSCR) is a birth defect where enteric nervous system (ENS) is absent from distal bowel. Bowel lacking ENS fails to relax, causing partial obstruction. Affected children often have "Hirschsprung disease associated enterocolitis" (HAEC), which predisposes to sepsis. We discovered survival of Piebald lethal ( sl/sl ) mice, a well-established HSCR model with HAEC, is markedly altered by two distinct standard chow diets. A "Protective" diet increased fecal butyrate/isobutyrate and enhanced production of gut epithelial antimicrobial peptides in proximal colon. In contrast, "Detrimental" diet-fed sl/sl had abnormal appearing distal colon epithelium mitochondria, reduced epithelial mRNA involved in oxidative phosphorylation, and elevated epithelial oxygen that fostered growth of inflammation-associated Enterobacteriaceae . Accordingly, selective depletion of Enterobacteriaceae with sodium tungstate prolonged sl/sl survival. Our results provide the first strong evidence that diet modifies survival in a HSCR mouse model, without altering length of distal colon lacking ENS.

Highlights

Two different standard mouse diets alter survival in the Piebald lethal ( sl/sl ) mouse model of Hirschsprung disease, without impacting extent of distal colon aganglionosis (the region lacking ENS). Piebald lethal mice fed the "Detrimental" diet had many changes in colon epithelial transcriptome including decreased mRNA for antimicrobial peptides and genes involved in oxidative phosphorylation. Detrimental diet fed sl/sl also had aberrant-appearing mitochondria in distal colon epithelium, with elevated epithelial oxygen that drives lethal Enterobacteriaceae overgrowth via aerobic respiration. Elimination of Enterobacteriaceae with antibiotics or sodium tungstate improves survival of Piebald lethal fed the "Detrimental diet".

Graphical abstract

Sea buckthorn berries alleviate ulcerative colitis via regulating gut Faecalibaculum rodentium-mediated butyrate biosynthesis

BACKGROUND

The gut microbiota is firmly associated with the progression of ulcerative colitis (UC). Beneficial microbial metabolites, such as butyrate, exert vital roles in maintaining intestinal homeostasis. The Sea buckthorn berry is a traditional Chinese medicine homologous to food and medicine which is widely applied in the prevention and treatment of UC in clinic practice. Recent studies have exhibited the potential function of Sea buckthorn on regulating the gut microbiota, however, the mechanism underlying its anti-colitis effects and the key gut microbes mediating its efficacy are still unclear.

PURPOSE

This study is intended to explore the pharmacological mechanism of the efficacy of Sea buckthorn berries extract (SBE) in alleviating UC from the perspective of the gut microbial regulation.

METHODS

The effect of SBE on UC was evaluated on dextran sulfate sodium (DSS)-induced murine model by assessing the body weight change, colon length, disease activity index (DAI), histopathological staining and the transcriptional expression of genes associated with inflammation and mucosal integrity. The dependence of the gut microbiota in the therapeutical effects of SBE on UC was confirmed by pseudo-germ-free mice and the co-housing experiment. The differential gut microbes altered by SBE were discovered by 16S rRNA sequencing and qPCR. The levels of short chain fatty acids (SCFAs) in bacterial medium and colonic contents were determined by GC-MS/MS. Bacterial colonization was conducted to estimate the effects of the bacteria on UC and to verify the involvement of the functional bacteria in the efficacy of SBE. A butyrate receptor G protein-coupled receptor (GPR)109A antagonist mepenzolate bromide (MPN) was used to validate the important role of butyrate and GPR109A in the anti-colitis effects of SBE and functional bacteria on UC. Two-way ANOVA was employed for multiple curve comparison and One-way ANOVA and Brown-Forsythe ANOVA test were used for multiple group comparison. Statistical significance was defined as p< 0.05.

RESULTS

SBE treatment significantly alleviated DSS-induced UC and its therapeutical effects was impaired in pseudo-germ-free mice. Moreover, the co-housing experiment exhibited that SBE-altered microbiota could effectively ameliorate UC. Further research demonstrated that Faecalibaculum rodentium was obviously increased by SBE and could be transferable by co-housing. Moreover, butyrate, a product of F. rodentium, dramatically decreased in UC mice while could be recovered by SBE administration. Abolishment of F. rodentium using vancomycin deprived the efficacy of SBE, but this could be reversed by recolonization of F. rodentium. Finally, blockage of the butyrate's receptor GPR109A weakened the effects of F. rodentium, indicating the indispensability of butyrate and GPR109A in the anti-colitis effects of F. rodentium.

CONCLUSION

SBE has potent therapeutical efficacy on UC including relieving inflammation and enhancing intestinal epithelial integrity, which is mediated by the gut F. rodentium-regulated butyrate-GPR109A axis.

Overcoming immunotherapy resistance in gastric cancer: insights into mechanisms and emerging strategies

Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide, with limited treatment options in advanced stages. Immunotherapy, particularly immune checkpoint inhibitors (ICIs) targeting PD1/PD-L1, has emerged as a promising therapeutic approach. However, a significant proportion of patients exhibit primary or acquired resistance, limiting the overall efficacy of immunotherapy. This review provides a comprehensive analysis of the mechanisms underlying immunotherapy resistance in GC, including the role of the tumor immune microenvironment, dynamic PD-L1 expression, compensatory activation of other immune checkpoints, and tumor genomic instability. Furthermore, the review explores GC-specific factors such as molecular subtypes, unique immune evasion mechanisms, and the impact of Helicobacter pylori infection. We also discuss emerging strategies to overcome resistance, including combination therapies, novel immunotherapeutic approaches, and personalized treatment strategies based on tumor genomics and the immune microenvironment. By highlighting these key areas, this review aims to inform future research directions and clinical practice, ultimately improving outcomes for GC patients undergoing immunotherapy.

The role of short-chain fatty acid in metabolic syndrome and its complications: focusing on immunity and inflammation

Metabolic syndrome (Mets) is an important contributor to morbidity and mortality in cardiovascular, liver, neurological, and reproductive diseases. Short-chain fatty acid (SCFA), an organismal energy donor, has recently been demonstrated in an increasing number of studies to be an important molecule in ameliorating immuno-inflammation, an important causative factor of Mets, and to improve lipid distribution, blood glucose, and body weight levels in animal models of Mets. This study reviews recent research advances on SCFA in Mets from an immune-inflammatory perspective, including complications dominated by chronic inflammation, as well as the fact that these findings also contribute to the understanding of the specific mechanisms by which gut flora metabolites contribute to metabolic processes in humans. This review proposes an emerging role for SCFA in the inflammatory Mets, followed by the identification of major ambiguities to further understand the anti-inflammatory potential of this substance in Mets. In addition, this study proposes novel strategies to modulate SCFA for the treatment of Mets that may help to mitigate the prognosis of Mets and its complications.

Exploring Extracellular Vesicles: A Novel Approach in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) represents an increasing public health concern. The underlying pathophysiological mechanisms of NAFLD remains unclear, and as a result, there is currently no specific therapy for this condition. However, recent studies focus on extracellular vesicles (EVs) as a novelty in their role in cellular communication. An imbalance in the gut microbiota composition may contribute to the progression of NAFLD, making the gut-liver axis a promising target for therapeutic strategies. This review aims to provide a comprehensive overview of EVs in NAFLD. Additionally, exosome-like nanovesicles derived from plants (PELNs) and probiotics-derived extracellular vesicles (postbiotics) have demonstrated the potential to re-establish intestinal equilibrium and modulate gut microbiota, thus offering the potential to alleviate NAFLD via the gut-liver axis. Further research is needed using multiple omics approaches to comprehensively characterize the cargo including protein, metabolites, genetic material packaged, and biological activities of extracellular vesicles derived from diverse microbes and plants.

Open Label Vancomycin in Primary Sclerosing Cholangitis-Inflammatory Bowel Disease: Improved Colonic Disease Activity and Associations With Changes in Host-Microbiome-Metabolomic Signatures

BACKGROUND

We conducted a single-arm interventional study, to explore mucosal changes associated with clinical remission under oral vancomycin (OV) treatment, in primary sclerosing cholangitis-associated inflammatory bowel disease (PSC-IBD); NCT05376228.

METHODS

Fifteen patients with PSC and active colitis (median fecal calprotectin 459 µg/g; median total Mayo score 5) were treated with OV (125 mg QID) for 4 weeks and followed-up for a further 4 weeks of treatment withdrawal (8 weeks, end-of-study). Colonic biopsies were obtained at baseline and Week 4. Clinical assessments, and serum and stool samples (metagenomics, metatranscriptomics, and metabolomics) were collected at Weeks 0, 2, 4, and 8. The primary efficacy outcome measure was the induction of clinical remission.

RESULTS

Oral vancomycin resulted in clinical remission in 12/15 patients and significant reductions in fecal calprotectin. Oral vancomycin was associated with reduced abundances of Lachnospiraceae, genera Blautia and Bacteroides; and enrichment of Enterobacteriaceae, and genera Veillonella, Akkermansia, and Escherichia. Oral vancomycin treatment was associated with the downregulation of multiple metatranscriptomic pathways (including short-chain fatty acid [SCFA] metabolism and bile acid [BA] biotransformation), along with host genes and multiple pathways involved in inflammatory responses and antimicrobial defence; and an upregulation of genes associated with extracellular matrix repair. Oral vancomycin use resulted in the loss of specific fecal SCFAs and secondary BAs, including lithocholic acid derivatives. Colitis activity relapsed following OV withdrawal, with host mucosal and microbial changes trending toward baseline.

CONCLUSIONS

Four weeks of OV induces remission in PSC-IBD activity, associated with a reduction in gut bacterial diversity and compositional changes relating to BA and SCFA homeostasis.

Exploring Mechanism of Electroacupuncture in Modulating Neuroinflammation Based on Intestinal Flora and Its Metabolites

Neuroinflammatory responses play an important role in the pathogenesis of various diseases, particularly those affecting the central nervous system. Inhibition of neuroinflammation is a crucial therapeutic strategy for the management of central nervous system disorders. The intestinal microbial-gut-brain axis serves as a key regulatory pathway that modulates neuroinflammatory processes. Intestinal flora metabolites such as short-chain fatty acids, indoles and their derivatives, lipopolysaccharides, trimethylamine oxide, and secondary bile acids exert direct or indirect effects on neuroinflammation. Studies have shown that electroacupuncture (EA) modulates the composition of the intestinal microbiota and its metabolites, while also suppressing neuroinflammation by targeting the TLR4/NF- κ B, NLRP3/caspase-1, and microglial cell M2-type transformation pathways. This review discusses the mechanisms by which EA regulates neuroinflammation via intestinal microbiota and its metabolites, providing information and a foundation for further investigation of the precise therapeutic mechanisms of EA in neurological disorders.

Pathophysiological mechanisms of gut dysbiosis and food allergy and an investigation of probiotics as an intervention for atopic disease

BACKGROUND AND AIMS

Epidemiological studies have associated reduced bacterial diversity and abundance and food allergy. This mechanistic review investigated the link between gut dysbiosis and food allergy with a focus on the role of short-chain fatty acids (SCFAs) in modulating T-cells. T-cell differentiation poses an opportunity to direct the immune cells towards an anergic regulatory T cell (Treg) or allergic T helper 2 (Th2) response. Probiotic intervention to prevent and/or treat atopic disease symptoms through this mechanistic pathway was explored.

METHODOLOGY

A narrative review was conducted following a three-stage systematic literature search of EMBASE and Medline databases. Ninety-six of 571 papers were accepted and critically appraised using ARRIVE and SIGN50 forms. Thematic analysis identified key pathophysiological mechanisms within the narrative of included papers.

RESULTS

Preclinical studies provided compelling evidence for SCFAs' modulation of T-cell differentiation, which may act through G-protein coupled receptors 41, 43 and 109a and histone deacetylase inhibition. Foxp3 transcription factor was implicated in the upregulation of Tregs. Human probiotic intervention studies aimed at increasing SCFAs and Tregs and preventing atopic disease showed inconclusive results. However, evidence for probiotic intervention in children with cow's milk protein allergy (CMPA) was more promising and warrants further investigation.

CONCLUSION

Preclinical evidence suggests that the mechanism of gut dysbiosis and reduced SCFAs may skew T-cell differentiation towards a Th2 response, thus inducing allergy symptoms. Probiotic trials were inconclusive: probiotics were predominantly unsuccessful in the prevention of allergic disease, however, may be able to modulate food allergy symptoms in infants with CMPA.

Tissue-Specific Metabolic Reprogramming in Innate Lymphoid Cells and Its Impact on Disease

Recent advances have highlighted the crucial role of metabolic reprogramming in shaping the functions of innate lymphoid cells (ILCs), which are vital for tissue immunity and homeostasis. As tissue-resident cells, ILCs dynamically respond to local environmental cues, with tissue-derived metabolites such as short-chain fatty acids and amino acids directly modulating their effector functions. The metabolic states of ILC subsets-ILC1, ILC2, and ILC3-are closely linked to their ability to produce cytokines, sustain survival, and drive proliferation. This review provides a comprehensive analysis of how key metabolic pathways, including glycolysis, oxidative phosphorylation, and fatty acid oxidation, influence ILC activation and function. Furthermore, we explore the complex interactions between these metabolic pathways and tissue-specific metabolites, which can shape ILC-mediated immune responses in health and disease. Understanding these interactions reveals new insights into the pathogenesis of conditions such as asthma, inflammatory bowel disease, and cancer. A deeper understanding of these mechanisms may not only advance our knowledge of disease pathogenesis but also lead to the development of novel therapeutic strategies targeting metabolic pathways in ILCs to treat tissue-specific immune disorders.

Berberine Alleviates Kainic Acid-Induced Acute Epileptic Seizures in Mice via Reshaping Gut Microbiota-Associated Lipid Metabolism

BACKGROUND

Berberine (BBR) has been reported to mitigate epileptic seizures. However, the potential mechanism of its anti-seizure effect remains uncharacterized.

AIMS

This study aimed to investigate the protective effect of BBR on acute epileptic seizures induced by kainic acid (KA) in mice and further explore its mechanism of action in the aspect of analysis of gut microbiota.

MATERIALS AND METHODS

The protective effect of BBR against acute epileptic seizures was assessed via Racine score and Nissl training. Alterations of gut microbiota and metabolites in seizure mice after BBR treatment were analyzed through 16S sequencing and lipidomics, respectively.

RESULTS

Our results showed that the BBR remarkably alleviated acute epileptic seizures and hippocampal neuron damage in KA-induced mice. The analysis of gut microbiota indicated that BBR reduced the acute epileptic seizures in KA-induced mice by increasing the abundance of Bacteroidetes and Alloprevotella, regulating short-chain fatty acids (SCFAs). Results of lipidomics also identified 21 candidate metabolites in the colon and hippocampus possibly involved in the protective effect of BBR against acute seizures.

CONCLUSION

These findings suggest that BBR exerts neuroprotection against KA-induced epileptic seizures through remodeling gut microbiota-associated lipid metabolism in the colon and hippocampus. BBR may serve as a valuable candidate drug for curing patients with epilepsy.

Microbial molecules, metabolites, and malignancy

Research elucidating the role of the microbiome in carcinogenesis has grown exponentially over the past decade. Initially isolated to associative studies on colon cancer development, the field has expanded to encompass nearly every solid and liquid malignancy that may afflict the human body. Investigations are rapidly progressing from association to causation and one particular area of causal effect relates to microbial metabolites and how they influence cancer development, progression, and treatment response. These metabolites can be produced de novo from individual members of the microbiome, whether that be bacteria, fungi, archaea, or other microbial organisms, or they can be through metabolic processing of dietary compounds or even host-derived molecules. In this review, contemporary research elucidating mechanisms whereby microbial-derived molecules and metabolites impact carcinogenesis and cancer treatment efficacy will be presented. While many of the examples focus on bacterial metabolites in colon carcinogenesis, this simply illustrates the accelerated nature of these investigations that occurred early in microbiome research but provides an opportunity for growth in other cancer areas. Indeed, research into the interaction of microbiome-derived metabolites in other malignancies is growing as well as investigations that involve non-bacterial metabolites. This review will provide the reader a framework to expand their knowledge regarding this complex and exciting field of cancer research.

Nobiletin restores the intestinal barrier of HFD-induced obese mice by promoting MHC-II expression and lipid metabolism

The incidence of obesity is increasing annually worldwide. A high-fat diet (HFD) causes intestinal barrier damage, but effective interventions are currently unavailable. Our previous work demonstrated the therapeutic effect of nobiletin on obese mice; thus, we hypothesized that nobiletin could reverse HFD-induced damage to the intestinal barrier. Male C57BL/6 J mice were orally administered nobiletin for 14 d. After identification, the obese mice were equally divided into three groups: the HFD group, the low-dose (NOL, 100 mg/kg/d) group and the high-dose nobiletin (NOH, 200 mg/kg/d) group. A normal control group (CON) was also included. Hematoxylin and eosin (HE) staining and immunofluorescence were used to observe the intestinal barrier. RT-qPCR was used to determine the transcriptomic levels of genes involved in intestinal barrier integrity and lipid metabolism. The results revealed that intestinal tight proteins, including ZO-1 and Occludin, were significantly reduced in HFD-fed mice but markedly restored after nobiletin intervention, particularly in NOH mice. Improvements in the intestinal barrier and lipid metabolism associated with major histocompatibility complex class II (MHC-II) and relevant elements were revealed after nobiletin intervention. Enrichment analysis revealed that MHC-II plays an important role in the restoration of the intestinal barrier. Taken together, nobiletin restored intestinal barrier integrity and lipid metabolism by regulating MHC-II expression.

Chemical interplay between gut microbiota and epigenetics: Implications in circadian biology

Circadian rhythms are intrinsic molecular mechanisms that synchronize biological functions with the day/night cycle. The mammalian gut is colonized by a myriad of microbes, collectively named the gut microbiota. The microbiota impacts host physiology via metabolites and structural components. A key mechanism is the modulation of host epigenetic pathways, especially histone modifications. An increasing number of studies indicate the role of the microbiota in regulating host circadian rhythms. However, the mechanisms remain largely unknown. Here, we summarize studies on microbial regulation of host circadian rhythms and epigenetic pathways, highlight recent findings on how the microbiota employs host epigenetic machinery to regulate circadian rhythms, and discuss its impacts on host physiology, particularly immune and metabolic functions. We further describe current challenges and resources that could facilitate research on microbiota-epigenetic-circadian rhythm interactions to advance our knowledge of circadian disorders and possible therapeutic avenues.

Konjac Glucomannan and Its Degradation Products Inhibit Intestinal Lipid Absorption by Regulating Gut Microbiota and the Production of Short-Chain Fatty Acids

The effect of konjac glucomannan (KGM) on lipid absorption is related to the viscosity effect and hepatic lipid synthesis. However, the molecular mechanism of regulation of intestinal lipid absorption by KGM and its correlation with gut microbiota have not been studied. This study explored the effects of KGM and degradation products of KGM (DKGM) on intestinal lipid absorption and output in obese mice and their potential mechanisms. The results showed that KGM significantly reduces blood lipids and intestinal lipid accumulation compared to DKGM in obese mice. Moreover, KGM and DKGM downregulated intestinal HDAC3 and NFLI3 expression to suppress CD36, SREBP1, FABP1, and PPARα expression. Notably, KGM more effectively inhibited fatty acid uptake in extraintestinal tissues than DKGM. Importantly, KGM more effectively enhanced the intestinal barrier, altered microbe abundance associated with lipid absorption, and promoted SCFA production than DKGM. Correlation analysis found that KGM and DKGM inhibited intestinal lipid absorption, which were positively correlated with the abundance of Lactobacillus, Desulfovibrio, Allobaculum etc. In conclusion, KGM more effectively inhibits intestinal lipid absorption and output in high-fat diet mice than DKGM, which is related to viscosity, intestinal HDAC3 activity, and differential remodeling of the microbiome. These findings provide insights into how microbe-dietary fiber interactions regulate the host energy balance.

Microbiota-derived proteins synergize with IL-23 to drive IL22 production in model type 3 innate lymphoid cells

Microbiota-induced production of IL-22 by type 3 innate lymphoid cells (ILC3) plays an important role in maintaining intestinal health. Such IL-22 production is driven, in part, by IL-23 produced by gut myeloid cells that have sensed select microbial-derived mediators. The extent to which ILC3 can directly respond to microbial metabolites via IL-22 production is less clear, in part due to the difficulty of isolating and maintaining sufficient numbers of viable ILC3 ex vivo. Hence, we, herein, examined the response of the ILC3 cell line, MNK-3, to microbial metabolites in vitro. We observed that fecal supernatants (FS), by themselves, elicited modest levels of IL-22 and synergized with IL-23 to drive robust IL-22 production assayed by qRT-PCR and ELISA. The IL-22 synergistic activity of FS was not mimicked by an array of candidate microbial metabolites but could be attributed to bacterial proteins. Examining how MNK3 cells exposed to IL-23, FS, both, or neither via RNA-seq and immunoblotting indicated that FS activated MNK-3 cells in a distinct pattern from IL-23: FS activates p-38 MAPK while IL-23 activates STAT3 signaling pathways. Collectively, these studies indicate ILC3 sensing of microbiota proteins promotes IL-22 production suggesting the possibility of manipulating microbiota to increase IL-22 without risk of IL-23-mediated chronic inflammatory diseases.

Unveiling the Interplay Between the Human Microbiome and Gastric Cancer: A Review of the Complex Relationships and Therapeutic Avenues

The human microbiota plays a crucial role in maintaining overall health and well-being. The gut microbiota has been implicated in developing and progressing various diseases, including cancer. This review highlights the related mechanisms and the compositions that influence cancer pathogenesis with a highlight on gastric cancer. We provide a comprehensive overview of the mechanisms by which the microbiome influences cancer development, progression, and response to treatment, with a focus on identifying potential biomarkers for early detection, prevention strategies, and novel therapeutic interventions that leverage microbiome modulation. This comprehensive review can guide future research and clinical practices in understanding and harnessing the microbiome to optimize gastric cancer therapies.

Nanotherapeutics-mediated restoration of pancreatic homeostasis and intestinal barrier for the treatment of severe acute pancreatitis

Severe acute pancreatitis (SAP) is an inflammatory disease of the pancreas accompanied with intestinal injury, and effective therapeutic modalities are still highly lacking. Herein, a facile and effective nanotherapeutics (pHA@IBNCs) is developed to alleviate pancreatic inflammation and restore intestinal barrier for SAP treatment. Epigallocatechin gallate (EGCG, an anti-oxidant), interleukin-22 (IL-22, an anti-inflammatory and epithelial barrier-protecting cytokine), and bovine serum albumin (a framework protein), are assembled via non-covalent interactions to form nanocomplexes (IBNCs). Then, phenylboronic acid-modified hyaluronic acid (pHA) is synthesized and coated onto IBNCs via formation of the reversible boronate ester bonds to obtain pHA@IBNCs. Upon intravenous injection, pHA@IBNCs could efficiently accumulate at the lesion sites of sodium taurocholate (STC)-induced SAP mice, based on their prolonged blood circulation time and pHA-mediated targeting of activated intestinal epithelial cells and macrophages. Inside the inflammatory microenvironment, over-produced reactive oxygen species (ROS) trigger the shedding of the pHA layer and release of the drug payloads. Thereby, EGCG cooperates with IL-22 to attenuate pancreatitis and restore the intestinal barrier by scavenging ROS, suppressing pro-inflammatory cytokines secretion, and promoting the repair of intestinal epithelia. Such a nano-therapeutic approach targeting multiple pathological events may serve as a promising paradigm for the effective management of SAP.

Neohesperidin Mitigates High-Fat-Diet-Induced Colitis In Vivo by Modulating Gut Microbiota and Enhancing SCFAs Synthesis

Previous research has consistently shown that high-fat diet (HFD) consumption can lead to the development of colonic inflammation. Neohesperidin (NHP), a naturally occurring flavanone glycoside in citrus fruits, has anti-inflammatory properties. However, the efficacy and mechanism of NHP in countering prolonged HFD-induced inflammation remains unclear. In this study, rats on HFD were intragastrically administered (i.g.) with NHP for 12 consecutive weeks. Results indicate that this natural compound is effective in reducing colorectal inflammation at doses of 40-80 mg/kg body weight (BW) by i.g. administration, with significant decreases in inflammation markers such as TNF-α and IL-1β levels. It also improved intestinal mucosal tissue integrity and reduced HFD-stimulated colorectal inflammation via the JAK2/STAT3 pathway. Furthermore, intestinal microbiota sequencing results show that NHP intervention significantly downregulated the Firmicutes/Bacteroidetes ratio. This ratio is closely related to the preventive role in the context of glycolipid metabolism disorder. Compared with fecal cultures of rats from the HFD group, after 48 h in vitro fermentation, those from the NHP group had distinct microbiota composition and notably higher concentrations of SCFAs. Collectively, these observations suggest that 80 mg/kg BW NHP possesses biological activities in downregulating HFD-induced colorectal inflammation by regulating intestinal flora and promoting SCFAs formation.

The ultimate microbial composition for correcting Th17/Treg cell imbalance and lipid metabolism disorders in osteoporosis

Osteoporosis is a systemic bone disease characterised by decreased bone mass and a deteriorated bone microstructure, leading to increased bone fragility and fracture risk. Disorders of the intestinal microbiota may be key inducers of osteoporosis. Furthermore, such disorders may contribute to osteoporosis by influencing immune function and lipid metabolism. Therefore, in this review, we aimed to summarise the molecular mechanisms through which the intestinal microbiota affect the onset and development of osteoporosis by regulating Th17/Treg imbalance and lipid metabolism disorders. We also discussed the regulatory mechanisms underlying the effect of intestinal microbiota-related modulators on Th17/Treg imbalance and lipid metabolism disorders in osteoporosis, to explore new molecular targets for its treatment and provide a theoretical basis for clinical management.

Intestinal Epithelial Tight Junction Barrier Regulation by Novel Pathways

Intestinal epithelial tight junctions (TJs), a dynamically regulated barrier structure composed of occludin and claudin family of proteins, mediate the interaction between the host and the external environment by allowing selective paracellular permeability between the luminal and serosal compartments of the intestine. TJs are highly dynamic structures and can undergo constant architectural remodeling in response to various external stimuli. This is mediated by an array of intracellular signaling pathways that alters TJ protein expression and localization. Dysfunctional regulation of TJ components compromising the barrier homeostasis is an important pathogenic factor for pathological conditions including inflammatory bowel disease (IBD). Previous studies have elucidated the significance of TJ barrier integrity and key regulatory mechanisms through various in vitro and in vivo models. In recent years, considerable efforts have been made to understand the crosstalk between various signaling pathways that regulate formation and disassembly of TJs. This review provides a comprehensive view on the novel mechanisms that regulate the TJ barrier and permeability. We discuss the latest evidence on how ion transport, cytoskeleton and extracellular matrix proteins, signaling pathways, and cell survival mechanism of autophagy regulate intestinal TJ barrier function. We also provide a perspective on the context-specific outcomes of the TJ barrier modulation. The knowledge on the diverse TJ barrier regulatory mechanisms will provide further insights on the relevance of the TJ barrier defects and potential target molecules/pathways for IBD.

Advancing therapeutic strategies for graft-versus-host disease by targeting gut microbiome dynamics in allogeneic hematopoietic stem cell transplantation: current evidence and future directions

Hematopoietic stem cell transplantation (HSCT) is a highly effective therapy for malignant blood illnesses that pose a high risk, as well as diseases that are at risk due to other variables, such as genetics. However, the prevalence of graft-versus-host disease (GVHD) has impeded its widespread use. Ensuring the stability of microbial varieties and associated metabolites is crucial for supporting metabolic processes, preventing pathogen intrusion, and modulating the immune system. Consequently, it significantly affects the overall well-being and susceptibility of the host to disease. Patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) may experience a disruption in the balance between the immune system and gut bacteria when treated with medicines and foreign cells. This can lead to secondary intestinal inflammation and GVHD. Thus, GM is both a reliable indicator of post-transplant mortality and a means of enhancing GVHD prevention and treatment after allo-HSCT. This can be achieved through various strategies, including nutritional support, probiotics, selective use of antibiotics, and fecal microbiota transplantation (FMT) to target gut microbes. This review examines research advancements and the practical use of intestinal bacteria in GVHD following allo-HSCT. These findings may offer novel insights into the prevention and treatment of GVHD after allo-HSCT.

Oral administration of Bifidobacterium longum and Bifidobacterium infantis ameliorates cefcapene pivoxil-induced attenuation of anti-programmed cell death protein-1 antibody action in mice

Gut bacteria play pivotal roles in the antitumor effects of immune checkpoint inhibitors (ICIs). However, antimicrobial therapy, often necessary for infections in cancer patients, can reduce the efficacy of ICIs. The potential of probiotics to restore ICI efficacy remains uncertain. This study evaluated the effects of Bifidobacterium longum and Bifidobacterium infantis (BLBI) in a CT-26 subcutaneous tumor mouse model treated with anti-programmed cell death protein 1 antibody (αPD-1) and cefcapene pivoxil (CFPN-PI). BALB/c mice received daily oral gavage of CFPN-PI for 5 days before tumor inoculation, followed by weekly αPD-1 administration and tumor growth monitoring. BLBI was administered via ad libitum feeding, mixed in powdered feed. Gut microbiota composition and fecal short-chain fatty acid concentrations were assessed, along with gene expression and immune cell populations in the tumor microenvironment, using quantitative RT-PCR and flow cytometry, respectively. CFPN-PI alone increased tumor growth and attenuated the antitumor effect of αPD-1. In contrast, BLBI inhibited CFPN-PI-induced tumor growth and improved the efficacy of αPD-1. Probiotic treatment increased the stool propionic acid concentration and the number of tumor-infiltrating conventional type 1 dendritic cells. Relative decreases in Bacteroides and Lachnospiraceae _NK4A136_group species and relative increases in Muribaculaceae and Unclassified_f_Oscillospiraceae species correlated with an improved αPD-1 response. These results suggest that probiotic administration may be a new therapeutic strategy to rescue the attenuated efficacy of ICIs in patients with cancer who require antimicrobial therapy.

Sishen Pill & Tongxieyaofang ameliorated ulcerative colitis through the activation of HIF-1α acetylation by gut microbiota-derived propionate and butyrate

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory bowel disease closely related to gut microbiota dysbiosis and intestinal homeostasis imbalance. Sishen Pill&Tongxieyaofang (SSP-TXYF) has a long history of application in traditional Chinese medicine and is widely used in UC clinics. However, its mechanism of action is still unclear.

PURPOSE

This study aimed to explore the potential regulatory role of SSP-TXYF in protecting against UC through metabolites produced by the intestinal microbiota, and elucidate its underlying molecular mechanism.

STUDY DESIGN AND METHODS

16S rRNA and UPLC-QE-Orbitrap-MS were used to assess the microbiota and short-chain fatty acids (SCFAs). A rat model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced gut microbiota dysbiosis was used to study the effects of SSP-TXYF on UC in vivo. Intestinal epithelial cells-6 (IEC-6) were treated with lipopolysaccharide (LPS). The intestinal mucosal barrier (IMB) functions were investigated by alcian blue staining and western blot analysis. The mechanism of SSP-TXYF influenced the HIF-1α acetylation pathway was examined by real-time fluorescence quantitative PCR (qPCR), Western blotting, and Co-immunoprecipitation.

RESULTS

Using 16S rRNA gene-based microbiota analysis, we found that SSP-TXYF ameliorated TNBS-induced gut microbiota dysbiosis. We found that SSP-TXYF significantly inhibited the decreased abundance of Firmicutes in UC rats, in addition, the abundance of Actinobacteria was also improved. The mechanism of SSP-TXYF-treated TNBS-induced UC resulted from improved IMB functions via the activation of hypoxia-inducible factor-1 (HIF-1α) acetylation. Notably, SSP-TXYF Enriched microbiota-derived metabolites propionate and butyrate, which could activate HIF-1α acetylation in IEC. Furthermore, exogenous treatment of propionate and butyrate reproduced similar protective effects as SSP-TXYF to UC through improving HIF-1α-dependent IMB functions.

CONCLUSIONS

Overall, our findings suggest that the gut microbiota-propionate/butyrate-HIF-1α-IMB axis plays an important role in SSP-TXYF-maintaining intestinal homeostasis, which may represent a novel approach for UC prevention via the intervention of any link in this axis.

Triple probiotics attenuate colitis via inhibiting macrophage glycolysis dependent pro-inflammatory response

Probiotics, a class of live microorganisms, play an important role in anti-inflammation, regulating immunity and optimizing intestinal microecological environment. In this study, we constructed a combination of three strains - Lactobacillus acidophilus, Bacillus bulgaricus, and Bacillus subtilis - to ferment triple probiotics Bornlisy. Our findings indicate that Bornlisy has a significant therapeutic effect in alleviating colitis in mice, further proofing its ability to suppress inflammation in colon, enhance intestinal barrier function and restore imbalanced intestinal microbiome. Then we found Bornlisy could modulate immune response by inhibiting macrophage glycolysis and ultimately attenuated the progression of colitis in mice. Our investigation into the therapeutic efficacy of Bornlisy in colitis revealed that triple probiotics offer a promising approach for the management of intestinal inflammation.

Gut Microbiota as Emerging Players in the Development of Alcohol-Related Liver Disease

The global incidence and mortality rates of alcohol-related liver disease are on the rise, reflecting a growing health concern worldwide. Alcohol-related liver disease develops due to a complex interplay of multiple reasons, including oxidative stress generated during the metabolism of ethanol, immune response activated by immunogenic substances, and subsequent inflammatory processes. Recent research highlights the gut microbiota's significant role in the progression of alcohol-related liver disease. In patients with alcohol-related liver disease, the relative abundance of pathogenic bacteria, including Enterococcus faecalis, increases and is positively correlated with the level of severity exhibited by alcohol-related liver disease. Supplement probiotics like Lactobacillus, as well as Bifidobacterium, have been found to alleviate alcohol-related liver disease. The gut microbiota is speculated to trigger specific signaling pathways, influence metabolite profiles, and modulate immune responses in the gut and liver. This research aimed to investigate the role of gut microorganisms in the onset and advancement of alcohol-related liver disease, as well as to uncover the underlying mechanisms by which the gut microbiota may contribute to its development. This review outlines current treatments for reversing gut dysbiosis, including probiotics, fecal microbiota transplantation, and targeted phage therapy. Particularly, targeted therapy will be a vital aspect of future alcohol-related liver disease treatment. It is to be hoped that this article will prove beneficial for the treatment of alcohol-related liver disease.

Colon-targeted engineered postbiotics nanoparticles alleviate osteoporosis through the gut-bone axis

The potential for mitigating intestinal inflammation through the gut-bone axis in the treatment of osteoporosis is significant. While various gut-derived postbiotics or bacterial metabolites have been created as dietary supplements to prevent or reverse bone loss, their efficacy and safety still need improvement. Herein, a colon-targeted drug delivery system is developed using surface engineering of polyvinyl butyrate nanoparticles by shellac resin to achieve sustained release of postbiotics butyric acid at the colorectal site. These engineered postbiotics nanoparticles can effectively suppress macrophage inflammatory activation, modulate the redox balance, and regulate the composition of the gut microbiota, thereby restoring epithelial barriers, inhibiting bacterial invasion, and down-regulating pro-inflammatory responses. As a result, the remission of systemic inflammation is accompanied by a rebalancing of osteoblast and osteoclast activity, alleviating inflammatory bowel disease-related and post-menopausal bone loss. Specifically, the treatment of engineered postbiotics nanoparticles can also improve the quality and quantity of bone with restoration of deteriorative mechanical properties, which indicating a therapeutic potential on fracture prevention. This study provides valuable insights into the gut-bone axis and establishes a promising and safe therapeutic strategy for osteoporosis.

Key Interleukins in Inflammatory Bowel Disease-A Review of Recent Studies

Inflammatory bowel disease (IBD) is an immune disorder of the gastrointestinal tract with a complex aetiopathogenesis, whose development is influenced by many factors. The prevalence of IBD is increasing worldwide, in both industrialized and developing countries, making IBD a global health problem that seriously affects quality of life. In 2019, there were approximately 4.9 million cases of IBD worldwide. Such a large number of patients entails significant healthcare costs. In the treatment of patients with IBD, the current therapeutic target is mucosal healing, as intestinal inflammation often persists despite resolution of abdominal symptoms. Treatment strategies include amino salicylates, corticosteroids, immunosuppressants, and biologic therapies that focus on reducing intestinal mucosal inflammation, inducing and prolonging disease remission, and treating complications. The American College of Gastroenterology (ACG) guidelines also indicate that nutritional therapies may be considered in addition to other therapies. However, current therapeutic approaches are not fully effective and are associated with various limitations, such as drug resistance, variable efficacy, and side effects. As the chronic inflammation that accompanies IBD is characterized by infiltration of a variety of immune cells and increased expression of a number of pro-inflammatory cytokines, including IL-6, TNF-α, IL-12, IL-23 and IFN-γ, new therapeutic approaches are mainly targeting immune pathways. Interleukins are one of the molecular targets in IBD therapy. Interleukins and related cytokines serve as a means of communication for innate and adaptive immune cells, as well as nonimmune cells and tissues. These cytokines play an important role in the pathogenesis and course of IBD, making them promising targets for current and future therapies. In our work, we review scientific studies published between January 2022 and November 2024 describing the most important interleukins involved in the pathogenesis of IBD. Some of the papers present new data on the precise role that individual interleukins play in IBD. New clinical data have also been provided, particularly on blocking interleukin 23 and interleukin 1beta. In addition, several new approaches to the use of different interleukins in the treatment of IBD have been described in recent years.

Butyrate attenuates intestinal inflammation in Crohn's disease by suppressing pyroptosis of intestinal epithelial cells via the cGSA-STING-NLRP3 axis

Butyrate can strengthen the intestinal epithelial barrier. However, the mechanisms by which butyrate affects intestinal epithelial cells (IECs) pyroptosis in Crohn's disease (CD) remain unclear. In this study, we collected colonic biopsy samples from CD patients and healthy controls to assess pyroptosis levels. Our findings indicated elevated expression of pyroptosis markers in CD patients, alongside distinct morphological evidence of pyroptosis in IECs. We further investigated the effects of tributyrin on pyroptosis and the cGAS-STING pathway in a trinitrobenzene sulfonic acid-induced colitis rat model. Tributyrin significantly mitigated intestinal inflammation, reduced pathological progression, and inhibited pyroptosis and cGAS-STING pathway activation in the colitis rat model. Similarly, in an in vitro model of IECs pyroptosis, sodium butyrate inhibited pyroptosis and cGAS-STING pathway activation in HT-29 cells. Co-treatment with a cGAS-STING pathway activator and butyrate demonstrated that the activator reversed the inhibitory effects of butyrate on pyroptosis and cGAS-STING pathway activation in both the colitis rat model and HT-29 cells. Mechanistically, the cGAS-STING pathway was found to interact with NLRP3. Taken together, butyrate may mitigate intestinal inflammation in CD by suppressing cGAS-STING-NLRP3 axis-mediated IECs pyroptosis. These findings offer new insights into potential therapeutic strategies for managing CD.

Broccoli, Artichoke, Carob and Apple By-Products as a Source of Soluble Fiber: How It Can Be Affected by Enzymatic Treatment with Pectinex® Ultra SP-L, Viscozyme® L and Celluclast® 1.5 L

Dietary fiber (DF), and especially soluble dietary fiber (SDF), is a nutrient of particular interest today because of its anti-inflammatory role and its ability to reduce cardiovascular risk. Therefore, the enhancement of SDF in foods using different techniques has become a promising field of research. In order to prove the possibility of increasing this SDF content, the effects of different commercial enzymes (Pectinex® Ultra SP-L, Viscozyme® L and Celluclast® 1.5 L) were tested on a variety of carob (CE), artichoke (ARE), apple (APE) and broccoli (BE) by-product extracts. Enzymatic treatment significantly affected SDF content in all by-products, showing the greatest increases for CE, ARE and APE using Celluclast® 1.5 L, while Viscozyme® L obtained the best results after application in BE. On the other hand, positive results were reported in the solubility, WHC and FAC of the by-products due to the enzymatic treatment, being increased in all extracts analyzed. Moreover, a general increase in antioxidant capacity (FRAP, ABTS and DPPH) was observed after enzymatic treatment. Finally, high yields were obtained after the application of the enzymatic processes, reaching values of 80-85% for each food by-product. These results evidenced a potential revalorization of carob, artichoke, apple and broccoli by-products after enzymatic treatment, improving its nutritional and physicochemical properties, revealing a possible application as a higher value-added ingredient.