The interplay between the gut microbiota and NLRP3 activation affects the severity of acute pancreatitis in mice

Inhibition of Pck1 in intestinal epithelial cells alleviates acute pancreatitis via modulating intestinal homeostasis

Intestinal barrier dysfunction usually occurred in acute pancreatitis (AP) but the mechanism remains unclear. In this study, RNA sequencing of ileum in L-arginine-induced AP mice demonstrated that phosphoenolpyruvate kinase 1 (Pck1) was significantly up-regulated. Increased Pck1 expression in intestinal epithelial cells (IECs) was further validated in ileum of AP mice and duodenum of AP patients. In AP mice, level of Pck1 was positively correlated with pancreatic and ileal histopathological scores, serum amylase activity, and intestinal permeability (serum diamine oxidase (DAO), D-lactate, and endotoxin). In AP patients, level of Pck1 had a positive correlation with Ranson scores, white blood cell count and C-reactive protein. Inhibition of Pck1 by 3-Mercaptopicolinic acid hydrochloride (3-MPA) alleviated pancreatic and ileal injuries in AP mice. AP + 3-MPA mice showed improved intestinal permeability, including less epithelial apoptosis, increased tight junction proteins (TJPs) expression, decreased serum DAO, D-lactate, endotoxin, and FITC-Dextran levels, and reduced bacteria translocation. Lysozyme secreted by Paneth cells and mucin2 (MUC2) secretion in goblet cells were also partly restored in AP + 3-MPA mice. Meanwhile, inhibition of Pck1 improved intestinal immune response during AP, including elevation of M2/M1 macrophages ratio and secretory immunoglobulin A (sIgA) and reduction in neutrophils infiltration. In vitro, administration of 3-MPA dramatically ameliorated inflammation and injuries of epithelial cells in enteroids treated by LPS. In conclusion, inhibition of Pck1 in IECs might alleviate AP via modulating intestinal homeostasis.

Intestinal Mucosal Immune Barrier: A Powerful Firewall Against Severe Acute Pancreatitis-Associated Acute Lung Injury via the Gut-Lung Axis

The pathogenesis of severe acute pancreatitis-associated acute lung injury (SAP-ALI), which is the leading cause of mortality among hospitalized patients in the intensive care unit, remains incompletely elucidated. The intestinal mucosal immune barrier is a crucial component of the intestinal epithelial barrier, and its aberrant activation contributes to the induction of sustained pro-inflammatory immune responses, paradoxical intercellular communication, and bacterial translocation. In this review, we firstly provide a comprehensive overview of the composition of the intestinal mucosal immune barrier and its pivotal roles in the pathogenesis of SAP-ALI. Secondly, the mechanisms of its crosstalk with gut microbiota, which is called gut-lung axis, and its effect on SAP-ALI were summarized. Finally, a number of drugs that could enhance the intestinal mucosal immune barrier and exhibit potential anti-SAP-ALI activities were presented, including probiotics, glutamine, enteral nutrition, and traditional Chinese medicine (TCM). The aim is to offer a theoretical framework based on the perspective of the intestinal mucosal immune barrier to protect against SAP-ALI.

Aflatoxin B1 exposure causes splenic pyroptosis by disturbing the gut microbiota-immune axis

Aflatoxin B1 (AFB1) causes serious immunotoxicity and has attracted considerable attention owing to its high sensitivity and common chemical-viral interactions in living organisms. However, the sensitivity of different species to AFB1 widely varies, which cannot be explained by the different metabolism in species. The gut microbiota plays a crucial role in the immune system, but the interaction of the microbiota with AFB1-induced immunotoxicity still needs to be determined. Our results indicated that AFB1 exposure disrupted the structure of the gut microbiota and damaged the gut barrier, which caused translocation of microbiota metabolites, lipopolysaccharides, to the spleen. Subsequently, pyroptosis of the spleen was activated. Interestingly, AFB1 exposure had little effect on the splenic pyroptosis of pseudo-germfree mice (antibiotic mixtures eliminated their gut microbiota, ABX). Then, fecal microbiota transplant (FMT) and sterile fecal filtrate (SFF) were employed to validate the function of the gut microbiota and its metabolites in AFB1-induced splenic pyroptosis. The AFB1-disrupted microbiota and its metabolites significantly promoted splenic pyroptosis, which was worse than that in control mice. Overall, AFB1-induced splenic pyroptosis is associated with the gut microbiota and its metabolites, which was further demonstrated by FMT and SFF. The mechanism of AFB1-induced splenic pyroptosis was explored for the first time, which paves a new way for preventing and treating the immunotoxicity from mycotoxins by regulating the gut microbiota.

Berberine alleviates concanavalin A-induced autoimmune hepatitis in mice by modulating the gut microbiota

BACKGROUND

Autoimmune hepatitis (AIH) is an immune-mediated liver disease of unknown etiology accompanied by intestinal dysbiosis and a damaged intestinal barrier. Berberine (BBR) is a traditional antibacterial medicine that has a variety of pharmacological properties. It has been reported that BBR alleviates AIH, but relevant mechanisms remain to be fully explored.

METHODS

BBR was orally administered at doses of 100 mg⋅kg-1⋅d-1 for 7 days to mice before concanavalin A-induced AIH model establishment. Histopathological, immunohistochemical, immunofluorescence, western blotting, ELISA, 16S rRNA analysis, flow cytometry, real-time quantitative PCR, and fecal microbiota transplantation studies were performed to ascertain BBR effects and mechanisms in AIH mice.

RESULTS

We found that liver necrosis and apoptosis were decreased upon BBR administration; the levels of serum transaminase, serum lipopolysaccharide, liver proinflammatory factors TNF-α, interferon-γ, IL-1β, and IL-17A, and the proportion of Th17 cells in spleen cells were all reduced, while the anti-inflammatory factor IL-10 and regulatory T cell proportions were increased. Moreover, BBR treatment increased beneficial and reduced harmful bacteria in the gut. BBR also strengthened ileal barrier function by increasing the expression of the tight junction proteins zonula occludens-1 and occludin, thereby blocking lipopolysaccharide translocation, preventing lipopolysaccharide/toll-like receptor 4 (TLR4)/ NF-κB pathway activation, and inhibiting inflammatory factor production in the liver. Fecal microbiota transplantation from BBR to model mice also showed that BBR potentially alleviated AIH by altering the gut microbiota.

CONCLUSIONS

BBR alleviated concanavalin A-induced AIH by modulating the gut microbiota and related immune regulation. These results shed more light on potential BBR therapeutic strategies for AIH.

Effect of chronic cold stress on gut microbial diversity, intestinal inflammation and pyroptosis in mice

Hypothermia is an essential environmental factor in gastrointestinal diseases, but the main molecular mechanisms of pathogenesis remain unclear. The current study sought to better understand how chronic cold stress affects gut damage and its underlying mechanisms. In this work, to establish chronic cold stress (CS)-induced intestinal injury model, mice were subjected to continuous cold exposure (4 °C) for 3 h per day for 3 weeks. Our results indicated that CS led to gut injury via inducing changes of heat shock proteins 70 (HSP70) and apoptosis-related (caspases-3, Bax and Bcl-2) proteins; enhancing expression of intestinal tight-related (ZO-1 and occludin) proteins; promoting releases of inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), high mobility group box 1 (HMGB1), interleukin1β (IL-1β), IL-18 and IL-6 inflammatory mediators in the ileum; and altering gut microbial diversity. Furthermore, persistent cold exposure resulted in the cleavage of pyroptosis-related Gasdermin D (GSDMD) protein by regulating the NLRP3/ASC/caspase-1 and caspase-11 pathway, and activation of toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)-mediated nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, which are strongly associated with changes in gut microbiota diversity. Taken together, these investigations provide new insights into the increased risk of intestinal disorders at extremely low temperatures and establish a theoretical foundation for the advancement of novel pharmaceutical interventions targeting cold-related ailments.

Acute pancreatitis is associated with gut dysbiosis in children

BACKGROUND

Pediatric acute pancreatitis (AP) is associated with significant morbidity. Therefore, improved understanding of children who will develop severe AP is critical. Adult studies have reported AP associated gut dysbiosis, but pediatric studies are lacking.

AIMS

Assess stool microbial taxonomic and functional profiles of children with first attack of AP compared to those of healthy controls (HC), and between mild and severe AP METHODS: Children under 21 years hospitalized at a tertiary center (n = 30) with first AP attack were recruited including HC (n = 34) from same region. Shotgun metagenomic sequencing was performed on extracted DNA.

RESULTS

Demographics were similar between AP and HC. Alpha diversity (-0.68 ± 0.13, p-value < 0.001), and beta-diversity (R2=0.13, p-value < 0.001) differed, in children with AP compared to HC. Species including R.gnavus, V.parvula, E.faecalis, C.innocuum were enriched in AP. MetaCyc pathways involved in amino acid metabolism and fatty acid beta-oxidation were enriched in AP. Beta-diversity (R2=0.06, p-value = 0.02) differed for severe AP compared to mild AP with enrichment in E.faecalis and C.citroniae.

CONCLUSIONS

Gut dysbiosis occurs in pediatric AP and is associated with AP severity. A multicenter study confirming these findings could pave way for interventional trials manipulating the gut microbiome to mitigate AP severity.

The Role of the Gut Microbiome in the Development of Acute Pancreatitis

With the explosion research on the gut microbiome in the recent years, much insight has been accumulated in comprehending the crosstalk between the gut microbiota community and host health. Acute pancreatitis (AP) is one of the gastrointestinal diseases associated with significant morbidity and subsequent mortality. Studies have elucidated that gut microbiota are engaged in the pathological process of AP. Herein, we summarize the major roles of the gut microbiome in the development of AP. We then portray the association between dysbiosis of the gut microbiota and the severity of AP. Finally, we illustrate the promises and challenges that arise when seeking to incorporate the microbiome in acute pancreatitis treatment.

Bibliometric analysis of pancreatic diseases and gut microbiota research from 2002 to 2022

Background

An increasing number of studies have indicated that pancreatic diseases are associated with the structure of the gut microbiota. We aimed to assess the research hotspots and trends in this field through a quantitative method.

Materials and methods

Articles related to pancreatic diseases and the gut microbiota published from 2002 to 2022 were retrieved from the Web of Science database. We visualized the countries/regions, institutions, authors, journals, and keywords using VOSviewer and CiteSpace software. The interplay between pancreatic diseases and the gut microbiota was also analysed.

Results

A total of 129 publications were finally identified. The number of papers increased gradually, and China held the dominant position with respect to publication output. Shanghai Jiao Tong University was the most influential institution. Zeng Yue ranked highest in the number of papers, and Scientific Reports was the most productive journal. The keywords "gut", "bacterial translocation", and "acute pancreatitis" appeared early for the first time, and "gut microbiota", "community", and "diversity" have been increasingly focused on. The predominant pancreatic disease correlated with the gut microbiota was pancreatic inflammatory disease (50.39%). Pancreatic diseases are associated with alterations in the gut microbiota, characterized by a decrease in beneficial bacteria and an increase in harmful bacteria.

Conclusion

This is the first comprehensive bibliometric analysis of all pancreatic diseases and the gut microbiota. The research on the relationship between them is still in the preliminary stage, and the trend is toward a gradual deepening of the research and precise treatment development. The interaction between the gut microbiota and pancreatic diseases will be of increasing concern in the future.

Bone Marrow Mesenchymal Stem Cells Alleviate Acute Severe Pancreatitis and Promote Lung Repair via Inhibiting NLRP3 Inflammasome in Rat

BACKGROUND

Acute severe pancreatitis (SAP) is a severe acute abdominal disease, which can lead to pancreatic infection and necrosis as well as distant organ damage. Bone marrow mesenchymal stem cells (BMSCs) can exert anti-inflammatory effect on SAP, while NLRP3 inflammasomes play an important role in the inflammatory response. This study aimed to investigate whether BMSCs exert anti-inflammatory effect on SAP by inhibiting NLRP3 inflammasome.

METHODS

The rat SAP model was established. Serum amylase, lipase and inflammatory factor levels were measured by ELISA, and the level of tissue injury was assessed by HE staining. The expression of NLRP3 inflammasome was detected by PCR, Western Blot and immunohistochemistry. ML385 was used to block Nrf2 pathway, aiming to investigate whether Nrf2 pathway was involved in the therapeutic effect of BMSCs on SAP by regulating NLRP3 inflammasome expression.

RESULTS

In SAP rats, NLRP3 inflammasome was activated, which became more evident over time. After transplantation of BMSCs, the NLRP3 inflammasome expression decreased at both mRNA and protein levels, the serum levels of amylase, lipase and inflammatory factors decreased, and the pathological scores of the pancreas and lung were both improved. After blocking the Nrf2 pathway, the NLRP3 inflammasome expression increased in the injured pancreas and lung, and the inflammation deteriorated, which inhibited the therapeutic effects of BMSCs on SAP.

CONCLUSION

The therapeutic effect of BMSC on SAP is at least partially ascribed to the inhibition of NLRP3 inflammasome, and Nrf2 pathway mediates the therapeutic effect of BMSC on SAP by inhibiting NLRP3 inflammasome.

Priming of microglia with dysfunctional gut microbiota impairs hippocampal neurogenesis and fosters stress vulnerability of mice

BACKGROUND

Mental disorders may be involved in neuroinflammatory processes that are triggered by gut microbiota. How gut microbiota influence microglia-mediated sensitivity to stress remains unclear. Here we explored in an animal model of depression whether disruption of the gut microbiome primes hippocampal microglia, thereby impairing neurogenesis and sensitizing to stress.

METHODS

Male C57BL/6J mice were exposed to chronic unpredictable mild stress (CUMS) for 4 weeks, and effects on gut microbiota were assessed using 16S rRNA sequencing. Fecal microbiota was transplanted from control or CUMS mice into naïve animals. The depression-like behaviors of recipients were evaluated in a forced swimming test and sucrose preference test. The morphology and phenotype of microglia in the hippocampus of recipients were examined using immunohistochemistry, quantitative PCR, and enzyme-linked immunosorbent assays. The recipients were treated with lipopolysaccharide or chronic stress exposure, and effects were evaluated on behavior, microglial responses and hippocampal neurogenesis. Finally, we explored the ability of minocycline to reverse the effects of CUMS on hippocampal neurogenesis and stress sensitivity in recipients.

RESULTS

CUMS altered the gut microbiome, leading to higher relative abundance of some bacteria (Helicobacter, Bacteroides, and Desulfovibrio) and lower relative abundance of some bacteria (Lactobacillus, Bifidobacterium, and Akkermansia). Fecal microbiota transplantation from CUMS mice to naïve animals induced microglial priming in the dentate gyrus of recipients. This microglia showed hyper-ramified morphology, and became more sensitive to LPS challenge or chronic stress, which characterized by more significant morphological changes and inflammatory responses, as well as impaired hippocampal neurogenesis and increased depressive-like behaviors. Giving minocycline to recipients reversed these effects of fecal transplantation.

CONCLUSIONS

These findings suggest that gut microbiota from stressed animals can induce microglial priming in the dentate gyrus, which is associated with a hyper-immune response to stress and impaired hippocampal neurogenesis. Remodeling the gut microbiome or inhibiting microglial priming may be strategies to reduce sensitivity to stress.

Decreased survival in patients with pancreatic cancer may be associated with an increase in histopathological expression of inflammasome marker NLRP3

Pancreatic cancer is a malignant neoplasm that, despite its low frequency, has a 5-year survival rate of less than 10%. The study of different histopathological markers has allowed a better understanding of the onset and development of this type of tumor as well as facilitating an approach to clinical variables based on their diagnostic, prognostic, and predictive value. In this sense, the NLRP3 protein of the inflammasome has been shown to be a component of great relevance in the initiation and progression of pancreatic cancer, although the value of this biomarker in patients has not yet been clarified. In this study, we selected 41 patients with pancreatic cancer and followed them for 60 months (5 years), evaluating their NLRP3 expression using immunohistochemical techniques. Furthermore, by performing Kaplan-Meier curves, we evaluated the survival of these patients in relation to their NLRP3 expression. Our results show that a significant percentage of our cohort had high expression of this component (90.74%) and that there is an inverse relationship between the expression of NLRP3 and patient survival. High levels of NLRP3 expression are related to lower survival and worse prognosis in these patients, possibly due to an ineffective immune system response and increased tumor-promoted inflammation. Future studies should be aimed at confirming these results in larger groups and evaluating various clinical strategies based on this knowledge.

The Interaction of Microbiome and Pancreas in Acute Pancreatitis

Acute pancreatitis (AP) is a common acute abdomen disease characterized by the pathological activation of digestive enzymes and the self-digestion of pancreatic acinar cells. Secondary infection and sepsis are independent prognosticators for AP progression and increased mortality. Accumulating anatomical and epidemiological evidence suggests that the dysbiosis of gut microbiota affects the etiology and severity of AP through intestinal barrier disruption, local or systemic inflammatory response, bacterial translocation, and the regulatory role of microbial metabolites in AP patients and animal models. Recent studies discussing the interactions between gut microbiota and the pancreas have opened new scopes for AP, and new therapeutic interventions that target the bacteria community have received substantial attention. This review concentrates on the alterations of gut microbiota and its roles in modulating gut-pancreas axis in AP. The potential therapies of targeting microbes as well as the major challenges of applying those interventions are explored. We expect to understand the roles of microbes in AP diagnosis and treatment.

Food-derived peptides as novel therapeutic strategies for NLRP3 inflammasome-related diseases: a systematic review

NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3), a member of the nucleotide-binding domain (NOD) and leucine-rich repeat sequence (LRR) protein (NLR) family, plays an essential role in the inflammation initiation and inflammatory mediator secretion, and thus is also associated with many disease progressions. Food-derived bioactive peptides (FDBP) exhibit excellent anti-inflammatory activity in both in vivo and in vitro models. They are encrypted in plant, meat, and milk proteins and can be released under enzymatic hydrolysis or fermentation conditions, thereby hindering the progression of hyperuricemia, inflammatory bowel disease, chronic liver disease, neurological disorders, lung injury and periodontitis by inactivating the NLRP3. However, there is a lack of systematic review around FDBP, NLRP3, and NLRP3-related diseases. Therefore, this review summarized FDBP that exert inhibiting effects on NLRP3 inflammasome from different protein sources and detailed their preparation and purification methods. Additionally, this paper also compiled the possible inhibitory mechanisms of FDBP on NLRP3 inflammasomes and its regulatory role in NLRP3 inflammasome-related diseases. Finally, the progress of cutting-edge technologies, including nanoparticle, computer-aided screening strategy and recombinant DNA technology, in the acquisition or encapsulation of NLRP3 inhibitory FDBP was discussed. This review provides a scientific basis for understanding the anti-inflammatory mechanism of FDBP through the regulation of the NLRP3 inflammasome and also provides guidance for the development of therapeutic adjuvants or functional foods enriched with these FDBP.

Co-Housing and Fecal Microbiota Transplantation: Technical Support for TCM Herbal Treatment of Extra-Intestinal Diseases Based on Gut Microbial Ecosystem Remodeling

Dysregulation of the gut microbial ecosystem (GME) (eg, alterations in the gut microbiota, gut-derived metabolites, and gut barrier) may contribute to the onset and progression of extra-intestinal diseases. Previous studies have found that Traditional Chinese Medicine herbs (TCMs) play an important role in manipulating the GME, but a prominent obstacle in current TCM research is the causal relationship between GME and disease amelioration. Encouragingly, co-housing and fecal microbiota transplantation (FMT) provide evidence-based support for TCMs to treat extra-intestinal diseases by targeting GME. In this review, we documented the principles, operational procedures, applications and limitations of the key technologies (ie, co-housing and FMT); furthermore, we provided evidence that TCM works through the GME, especially the gut microbiota (eg, SCFA- and BSH-producing bacteria), the gut-derived metabolites (eg, IS, pCS, and SCFAs), and intestinal barrier to alleviate extra-intestinal diseases. This will be beneficial in constructing microecological pathways for TCM treatment of extra-intestinal diseases in the future.

Berberine Mediates the Production of Butyrate to Ameliorate Cerebral Ischemia via the Gut Microbiota in Mice

Ischemic stroke (IS) is a vascular disease group concomitant with high morbidity and mortality. Berberine is a bioactive substance and it has been known to improve stroke, but its mechanism is yet to be proven. Mice were fed with BBR for 14 days. Then, the mice were made into MCAO/R models. Neurological score, infarct volume, neuronal damage and markers associated with inflammation were detected. We tested the changes in intestinal flora in model mice after BBR administration using 16SrRNA sequencing. Chromatography-mass spectrometry was used to detect butyrate chemically. Tissue immunofluorescence was used to detect the changes in the microglia and astroglia in the mice brains. Our findings suggest that berberine improves stroke outcomes by modulating the gut microbiota. Specifically, after MCAO/R mice were given berberine, the beneficial bacteria producing butyric acid increased significantly, and the mice also had significantly higher levels of butyric acid. The administration of butyric acid and an inhibitor of butyric acid synthesis, heptanoyl-CoA, showed that butyric acid improved the stroke outcomes in the model mice. In addition, butyric acid could inhibit the activation of the microglia and astrocytes in the brains of model mice, thereby inhibiting the generation of pro-inflammatory factors IL-6, IL-1β and TNF-α as well as improving stroke outcomes. Our results suggest that berberine may improve stroke outcomes by modulating the gut flora to increase the abundance of butyric acid. These findings elucidate the mechanisms by which berberine improves stroke outcomes and provide some basis for clinical treatment.

Gut liver brain axis in diseases: the implications for therapeutic interventions

Gut-liver-brain axis is a three-way highway of information interaction system among the gastrointestinal tract, liver, and nervous systems. In the past few decades, breakthrough progress has been made in the gut liver brain axis, mainly through understanding its formation mechanism and increasing treatment strategies. In this review, we discuss various complex networks including barrier permeability, gut hormones, gut microbial metabolites, vagus nerve, neurotransmitters, immunity, brain toxic metabolites, β-amyloid (Aβ) metabolism, and epigenetic regulation in the gut-liver-brain axis. Some therapies containing antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), polyphenols, low FODMAP diet and nanotechnology application regulate the gut liver brain axis. Besides, some special treatments targeting gut-liver axis include farnesoid X receptor (FXR) agonists, takeda G protein-coupled receptor 5 (TGR5) agonists, glucagon-like peptide-1 (GLP-1) receptor antagonists and fibroblast growth factor 19 (FGF19) analogs. Targeting gut-brain axis embraces cognitive behavioral therapy (CBT), antidepressants and tryptophan metabolism-related therapies. Targeting liver-brain axis contains epigenetic regulation and Aβ metabolism-related therapies. In the future, a better understanding of gut-liver-brain axis interactions will promote the development of novel preventative strategies and the discovery of precise therapeutic targets in multiple diseases.

A dynamics association study of gut barrier and microbiota in hyperuricemia

Introduction

The intricate interplay between gut microbiota and hyperuricemia remains a subject of growing interest. However, existing studies only provided snapshots of the gut microbiome at single time points, the temporal dynamics of gut microbiota alterations during hyperuricemia progression and the intricate interplay between the gut barrier and microbiota remain underexplored. Our investigation revealed compelling insights into the dynamic changes in both gut microbiota and intestinal barrier function throughout the course of hyperuricemia.

Methods

The hyperuricemia mice (HY) were given intragastric administration of adenine and potassium oxalate. Gut microbiota was analyzed by 16S rRNA sequencing at 3, 7, 14, and 21 days after the start of the modeling process. Intestinal permeability as well as LPS, TNF-α, and IL-1β levels were measured at 3, 7, 14, and 21 days.

Results

We discovered that shifts in microbial community composition occur prior to the onset of hyperuricemia, key bacterial Bacteroidaceae, Bacteroides, and Blautia exhibited reduced levels, potentially fueling microbial dysbiosis as the disease progresses. During the course of hyperuricemia, the dynamic fluctuations in both uric acid levels and intestinal barrier function was accompanied with the depletion of key beneficial bacteria, including Prevotellaceae, Muribaculum, Parabacteroides, Akkermansia, and Bacteroides, and coincided with an increase in pathogenic bacteria such as Oscillibacter and Ruminiclostridium. This microbial community shift likely contributed to elevated lipopolysaccharide (LPS) and pro-inflammatory cytokine levels, ultimately promoting metabolic inflammation. The decline of Burkholderiaceae and Parasutterella was inversely related to uric acid levels, Conversely, key families Ruminococcaceae, Family_XIII, genera Anaeroplasma exhibited positive correlations with uric acid levels. Akkermansiaceae and Bacteroidaceae demonstrating negative correlations, while LPS-containing microbiota such as Desulfovibrio and Enterorhabdus exhibited positive correlations with intestinal permeability.

Conclusion

In summary, this study offers a dynamic perspective on the complex interplay between gut microbiota, uric acid levels, and intestinal barrier function during hyperuricemia progression. Our study suggested that Ruminiclostridium, Bacteroides, Akkermansiaceae, Bilophila, Burkholderiaceae and Parasutterella were the key bacteria that play vital rols in the progress of hyperuricemia and compromised intestinal barrier, which provide a potential avenue for therapeutic interventions in hyperuricemia.

Long non-coding RNA MM2P suppresses M1-polarized macrophages-mediated excessive inflammation to prevent sodium taurocholate-induced acute pancreatitis by blocking SHP2-mediated STAT3 dephosphorylation

M1 macrophage-mediated excessive inflammatory response plays a key role in the onset and progression of acute pancreatitis (AP), and this study aimed to investigate the role and underlying mechanisms by which the macrophage polarization-related long noncoding RNA (lncRNA) MM2P participated in the regulation of AP progression. By performing quantitative reverse-transcription PCR (qRT-PCR) assay, lncRNA MM2P was found to be downregulated in both sodium taurocholate-induced AP model mice tissues and lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and gain-of-function experiments confirmed that overexpression of lncRNA MM2P counteracted inflammatory responses, reduced macrophage infiltration and facilitated M1-to-M2 transformation of macrophages to ameliorate AP development in vitro and in vivo. Further mechanical experiments revealed that lncRNA MM2P inhibited Src homology 2 containing protein tyrosine phosphatase 2 (SHP2)-mediated signal transducer and activator of transcription 3 (STAT3) dephosphorylation to activate the STAT3 signaling, and silencing of SHP2 suppressed M1 type skewing in LPS-induced RAW264.7 cells. Interestingly, our rescuing experiments verified that lncRNA MM2P-induced suppressing effects on M1-polarization of LPS-treated RAW264.7 cells were abrogated by co-treating cells with STAT3 inhibitor stattic. Collectively, our data for the first time revealed that lncRNA MM2P suppressed M1-polarized macrophages to attenuate the progression of sodium taurocholate-induced AP, and lncRNA MM2P might be an ideal biomarker for AP diagnosis and treatment.

The 'speck'-tacular oversight of the NLRP3-pyroptosis pathway on gastrointestinal inflammatory diseases and tumorigenesis

The NLRP3 inflammasome is an intracellular sensor and an essential component of the innate immune system involved in danger recognition. An important hallmark of inflammasome activation is the formation of a single supramolecular punctum, known as a speck, per cell, which is the site where the pro-inflammatory cytokines IL-1β and IL-18 are converted into their bioactive form. Speck also provides the platform for gasdermin D protein activation, whose N-terminus domain perforates the plasma membrane, allowing the release of mature cytokines alongside with a highly inflammatory form of cell death, namely pyroptosis. Although controlled NLRP3 inflammasome-pyroptosis pathway activation preserves mucosal immunity homeostasis and contributes to host defense, a prolonged trigger is deleterious and could lead, in genetically predisposed subjects, to the onset of inflammatory bowel disease, including Crohn's disease and ulcerative colitis, as well as to gastrointestinal cancer. Experimental evidence shows that the NLRP3 inflammasome has both protective and pathogenic abilities. In this review we highlight the impact of the NLRP3-pyroptosis axis on the pathophysiology of the gastrointestinal tract at molecular level, focusing on newly discovered features bearing pro- and anti-inflammatory and neoplastic activity, and on targeted therapies tested in preclinical and clinical trials.

Maternal Diet Determines Milk Microbiome Composition and Offspring Gut Colonization in Wistar Rats

Mother's milk contains a unique microbiome that plays a relevant role in offspring health. We hypothesize that maternal malnutrition during lactation might impact the microbial composition of milk and affect adequate offspring gut colonization, increasing the risk for later onset diseases. Then, Wistar rats were fed ad libitum (Control, C) food restriction (Undernourished, U) during gestation and lactation. After birth, offspring feces and milk stomach content were collected at lactating day (L)4, L14 and L18. The V3-V4 region of the bacterial 16S rRNA gene was sequenced to characterize bacterial communities. An analysis of beta diversity revealed significant disparities in microbial composition between groups of diet at L4 and L18 in both milk, and fecal samples. In total, 24 phyla were identified in milk and 18 were identified in feces, with Firmicutes, Proteobacteria, Actinobacteroidota and Bacteroidota collectively representing 96.1% and 97.4% of those identified, respectively. A higher abundance of Pasteurellaceae and Porphyromonas at L4, and of Gemella and Enterococcus at L18 were registered in milk samples from the U group. Lactobacillus was also significantly more abundant in fecal samples of the U group at L4. These microbial changes compromised the number and variety of milk-feces or feces-feces bacterial correlations. Moreover, increased offspring gut permeability and an altered expression of goblet cell markers TFF3 and KLF3 were observed in U pups. Our results suggest that altered microbial communication between mother and offspring through breastfeeding may explain, in part, the detrimental consequences of maternal malnutrition on offspring programming.

Gut microbiota interacts with inflammatory responses in acute pancreatitis

Acute pancreatitis (AP) is one of the most common acute abdominal conditions, and its incidence has been increasing for years. Approximately 15-20% of patients develop severe AP (SAP), which is complicated by critical inflammatory injury and intestinal dysfunction. AP-associated inflammation can lead to the gut barrier and function damage, causing dysbacteriosis and facilitating intestinal microbiota migration. Pancreatic exocrine deficiency and decreased levels of antimicrobial peptides in AP can also lead to abnormal growth of intestinal bacteria. Meanwhile, intestinal microbiota migration influences the pancreatic microenvironment and affects the severity of AP, which, in turn, exacerbates the systemic inflammatory response. Thus, the interaction between the gut microbiota (GM) and the inflammatory response may be a key pathogenic feature of SAP. Treating either of these factors or breaking their interaction may offer some benefits for SAP treatment. In this review, we discuss the mechanisms of interaction of the GM and inflammation in AP and factors that can deteriorate or even cure both, including some traditional Chinese medicine treatments, to provide new methods for studying AP pathogenesis and developing therapies.

Gut microbiota aggravates neutrophil extracellular traps-induced pancreatic injury in hypertriglyceridemic pancreatitis

Hypertriglyceridemic pancreatitis (HTGP) is featured by higher incidence of complications and poor clinical outcomes. Gut microbiota dysbiosis is associated with pancreatic injury in HTGP and the mechanism remains unclear. Here, we observe lower diversity of gut microbiota and absence of beneficial bacteria in HTGP patients. In a fecal microbiota transplantation mouse model, the colonization of gut microbiota from HTGP patients recruits neutrophils and increases neutrophil extracellular traps (NETs) formation that exacerbates pancreatic injury and systemic inflammation. We find that decreased abundance of Bacteroides uniformis in gut microbiota impairs taurine production and increases IL-17 release in colon that triggers NETs formation. Moreover, Bacteroides uniformis or taurine inhibits the activation of NF-κB and IL-17 signaling pathways in neutrophils which harness NETs and alleviate pancreatic injury. Our findings establish roles of endogenous Bacteroides uniformis-derived metabolic and inflammatory products on suppressing NETs release, which provides potential insights of ameliorating HTGP through gut microbiota modulation.

Tryptophan metabolite norharman secreted by cultivated Lactobacillus attenuates acute pancreatitis as an antagonist of histone deacetylases

BACKGROUND

Patients with acute pancreatitis (AP) exhibit specific phenotypes of gut microbiota associated with severity. Gut microbiota and host interact primarily through metabolites; regrettably, little is known about their roles in AP biological networks. This study examines how enterobacterial metabolites modulate the innate immune system in AP aggravation.

METHODS

In AP, alterations in gut microbiota were detected via microbiomics, and the Lactobacillus metabolites of tryptophan were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). By culturing Lactobacillus with tryptophan, differential metabolites were detected by LC-MS/MS. Lipopolysaccharide (LPS)-stimulated RAW264.7 cells and mice with cerulein plus LPS-induced AP were used to evaluate the biological effect of norharman on M1 macrophages activation in AP development. Further, RNA sequencing and lipid metabolomics were used for screening the therapeutic targets and pathways of norharman. Confocal microscopy assay was used to detect the structure of lipid rafts. Molecular docking was applied to predict the interaction between norharman and HDACs. Luciferase reporter assays and chromatin immunoprecipitation (ChIP) were used to explore the direct mechanism of norharman promoting Rftn1 expression. In addition, myeloid-specific Rftn1 knockout mice were used to verify the role of Rftn1 and the reversed effect of norharman.

RESULTS

AP induced the dysfunction of gut microbiota and their metabolites, resulting in the suppression of Lactobacillus-mediated tryptophan metabolism pathway. The Lactobacillus metabolites of tryptophan, norharman, inhibited the release of inflammatory factor in vitro and in vivo, as a result of its optimal inhibitory action on M1 macrophages. Moreover, norharman blocked multiple inflammatory responses in AP exacerbation due to its ability to maintain the integrity of lipid rafts and restore the dysfunction of lipid metabolism. The mechanism of norharman's activity involved inhibiting the enzyme activity of histone deacetylase (HDACs) to increase histone H3 at lysine 9/14 (H3K9/14) acetylation, which increased the transcription level of Rftn1 (Raftlin 1) to inhibit M1 macrophages' activation.

CONCLUSIONS

The enterobacterial metabolite norharman can decrease HDACs activity to increase H3K9/14 acetylation of Rftn1, which inhibits M1 macrophage activation and restores the balance of lipid metabolism to relieve multiple inflammatory responses. Therefore, norharman may be a promising prodrug to block AP aggravation.

Mechanisms of Qingyi Decoction in Severe Acute Pancreatitis-Associated Acute Lung Injury via Gut Microbiota: Targeting the Short-Chain Fatty Acids-Mediated AMPK/NF-κB/NLRP3 Pathway

The pivotal roles of gut microbiota in severe acute pancreatitis-associated acute lung injury (SAP-ALI) are increasingly revealed, and recent discoveries in the gut-lung axis have provided potential approaches for treating SAP-ALI. Qingyi decoction (QYD), a traditional Chinese medicine (TCM), is commonly used in clinical to treat SAP-ALI. However, the underlying mechanisms remain to be fully elucidated. Herein, by using a caerulein plus lipopolysaccharide (LPS)-induced SAP-ALI mice model and antibiotics (Abx) cocktail-induced pseudogermfree mice model, we tried to uncover the roles of the gut microbiota by administration of QYD and explored its possible mechanisms. Immunohistochemical results showed that the severity of SAP-ALI and intestinal barrier functions could be affected by the relative depletion of intestinal bacteria. The composition of gut microbiota was partially recovered after QYD treatment with decreased Firmicutes/Bacteroidetes ratio and increased relative abundance in short-chain fatty acids (SCFAs)-producing bacteria. Correspondingly increased levels of SCFAs (especially propionate and butyrate) in feces, gut, serum, and lungs were observed, generally consistent with changes in microbes. Western-blot analysis and RT-qPCR results indicated that the AMPK/NF-κB/NLRP3 signaling pathway was activated after oral administration of QYD, which was found to be possibly related to the regulatory effects on SCFAs in the intestine and lungs. In conclusion, our study provides new insights into treating SAP-ALI through modulating the gut microbiota and has prospective practical value for clinical use in the future. IMPORTANCE Gut microbiota affects the severity of SAP-ALI and intestinal barrier function. During SAP, a significant increase in the relative abundance of gut pathogens (Escherichia, Enterococcus, Enterobacter, Peptostreptococcus, Helicobacter) was observed. At the same time, QYD treatment decreased pathogenic bacteria and increased the relative abundance of SCFAs-producing bacteria (Bacteroides, Roseburia, Parabacteroides, Prevotella, Akkermansia). In addition, The AMPK/NF-κB/NLRP3 pathway mediated by SCFAs along the gut-lung axis may play an essential role in preventing the pathogenesis of SAP-ALI, which allows for reduced systemic inflammation and restoration of the intestinal barrier.

Gut microbiota-derived tryptamine and phenethylamine impair insulin sensitivity in metabolic syndrome and irritable bowel syndrome

The incidence of metabolic syndrome is significantly higher in patients with irritable bowel syndrome (IBS), but the mechanisms involved remain unclear. Gut microbiota is causatively linked with the development of both metabolic dysfunctions and gastrointestinal disorders, thus gut dysbiosis in IBS may contribute to the development of metabolic syndrome. Here, we show that human gut bacterium Ruminococcus gnavus-derived tryptamine and phenethylamine play a pathogenic role in gut dysbiosis-induced insulin resistance in type 2 diabetes (T2D) and IBS. We show levels of R. gnavus, tryptamine, and phenethylamine are positively associated with insulin resistance in T2D patients and IBS patients. Monoassociation of R. gnavus impairs insulin sensitivity and glucose control in germ-free mice. Mechanistically, treatment of R. gnavus-derived metabolites tryptamine and phenethylamine directly impair insulin signaling in major metabolic tissues of healthy mice and monkeys and this effect is mediated by the trace amine-associated receptor 1 (TAAR1)-extracellular signal-regulated kinase (ERK) signaling axis. Our findings suggest a causal role for tryptamine/phenethylamine-producers in the development of insulin resistance, provide molecular mechanisms for the increased prevalence of metabolic syndrome in IBS, and highlight the TAAR1 signaling axis as a potential therapeutic target for the management of metabolic syndrome induced by gut dysbiosis.

Gut Microbiota Participates in Polystyrene Microplastics-Induced Hepatic Injuries by Modulating the Gut-Liver Axis

Dietary pollution by polystyrene microplastics (MPs) can cause hepatic injuries and microbial dysbiosis. Epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, exerts beneficial effects on the liver by modulating the gut microbiota. However, the role of microbiota in MPs-induced hepatic injuries and the protective effect of EGCG have not been clarified. Here, 5 μm MPs were orally administered to mice to induce hepatic injuries. Subsequently, antibiotic cocktail (ABX) and fecal microbial transplant (FMT) experiments were performed to investigate the underlying microbial mechanisms. Additionally, EGCG was orally administered to mice to explore its protection against MPs-induced hepatic injuries. Our results showed that MPs activated systemic and hepatic inflammation, promoted fibrosis, and altered the liver metabolome; meanwhile, MPs damaged the gut homeostasis by disturbing the gut microbiome, promoting colonic inflammation, and impairing the intestinal barrier. Notably, MPs reduced the abundance of the probiotics Akkermansia, Mucispirillum, and Faecalibaculum while increasing the pathogenic Tuzzerella. Interestingly, the elimination of gut microbiota mitigated MPs-induced colonic inflammation and intestinal barrier impairment. Moreover, ABX ameliorated MPs-induced systemic and hepatic inflammation but not fibrosis. Correspondingly, microbiota from MPs-administered mice induced colonic, systemic, and hepatic inflammation, while their profibrosis effect on the liver was not observed. Finally, EGCG elevated the abundance of probiotics and effectively repressed MPs-induced colonic inflammation. MPs-induced systemic and hepatic inflammation, fibrosis, and remodeling of the liver metabolome were also attenuated by EGCG. These findings illustrated that gut microbiota contributed to MPs-induced colonic and hepatic injuries, while EGCG could serve as a potential prevention strategy for these adverse consequences.

Current status and advancements in research of gut microecology in acute pancreatitis

Acute pancreatitis (AP) is one of the most common acute abdominal conditions in clinical practice, with increasing incidence and substantial healthcare burden. In recent years, substantial research with high-throughput sequencing technologies has revealed the imbalance between beneficial and pathogenic microbiomes as well as their metabolites during the clinical course of AP. Furthermore, disruption of the intestinal barrier and microbial translocation have been identified as important factors exacerbating systemic inflammatory response and subsequent infectious complications in AP. Maintaining a stable gastrointestinal microecology in patients may help prevent gut-derived infection and attenuate the "second hit" of inflammation induced by AP, thereby improving patient outcomes. This article provides a systematic review of the role of intestinal microbiota and microbial metabolites in the progression of AP, as well as potential therapeutic strategies, in order to offer insights into the understanding of AP pathogenesis and the identification of novel therapeutic targets.

Gut microbiota mediated the therapeutic efficiency of Simiao decoction in the treatment of gout arthritis mice

BACKGROUND

Gut microbiota plays a significant role in the development and treatment of gouty arthritis. Simiao decoction has been shown to alleviate gouty arthritis by inhibiting inflammation, regulating NLRP3 inflammasome, and altering gut microbiota. However, there is no evidence to prove whether gut microbiota directly mediates the therapeutic efficiency of Simiao decoction in treating gout arthritis.

METHODS

In this study, fecal microbiota transplantation (FMT) was used to transfer the gut microbiota of gout arthritis mice treated with Simiao decoction or allopurinol to blank gout arthritis mice, in order to investigate whether FMT had therapeutic effects on gout arthritis.

RESULTS

Both Simiao decoction and allopurinol effectively reduced the levels of serum uric acid, liver XOD activity, foot thickness, serum IL-1β, and G-CSF in gout arthritis mice. However, Simiao decoction also had additional benefits, including raising the pain threshold, reducing serum TNF-α and IL-6, alleviating gut inflammation, and repairing intestinal pathology, which were not observed with allopurinol treatment. Moreover, Simiao decoction had a greater impact on gut microbiota than allopurinol, as it was able to restore the abundance of phylum Proteobacteria and genus Helicobacter. After transplantation into gout arthritis mice, gut microbiota altered by Simiao decoction exhibited similar therapeutic effects to those of Simiao decoction, but gut microbiota altered by allopurinol showed no therapeutic effect.

CONCLUSIONS

These findings demonstrates that Simiao decoction can alleviate gout arthritis symptoms by regulating gut microbiota.

Gut microbiota decreased inflammation induced by chronic unpredictable mild stress through affecting NLRP3 inflammasome

Dysbiosis of the gut microbiota is associated with the development of depression, but the underlying mechanism remains unclear. The aim of this study was to determine the relationship between microbiota and NLRP3 inflammasome induced by chronic unpredictable mild stress (CUMS). Fecal transplantation (FMT) experiment was conducted to elucidate the potential mechanism. Levels of NLRP3 inflammasome, microbiota, inflammatory factors and tight junction proteins were measured. CUMS stimulation significantly increased the levels of NLRP3, Caspase-1 and ASC in brain and colon(p<0.05), decreased the levels of tight junction proteins Occludin and ZO-1 (p<0.05). Interestingly, increased NLRP3 inflammasome and inflammatory cytokines and decreased tight junction proteins were found in antibiotic-treated (Abx) rats received CUMS rat fecal microbiota transplantation. Furthermore, fecal microbiota transplantation altered the microbiota in Abx rats, which partially overlapped with that of the donor rats. Importantly, probiotic administration amended the alteration of microbiota induced by CUMS treatment, then reduced the levels of NLRP3 inflammasome and inflammatory factors. In conclusion, these findings suggested that depression-like behaviors induced by CUMS stimulation were related to altered gut microbiota, broke the intestinal barrier, promoted the expression of NLRP3 inflammasome and elevated inflammation. Therefore, improving the composition of microbiota via probiotic can attenuate inflammation by amending the microbiota and suppressing the activation of NLRP3 inflammasome, which is considered as a novel therapeutic strategy for depression.

Biochanin A ameliorates caerulein-induced acute pancreatitis and associated intestinal injury in mice by inhibiting TLR4 signaling

Acute pancreatitis (AP) is an acute inflammatory abdominal disease frequently associated with intestinal barrier dysfunction. Biochanin A (BCA), a dietary isoflavone, has gained increasing interest with its pronounced biological activities. However, its potential beneficial effects on AP have not been demonstrated. Herein, we explored the protective effect of BCA on caerulein-induced AP in BALB/c mice and underlying mechanisms. BCA alleviated AP as evidenced by reduced serum amylase and lipase levels, pancreatic edema, pancreatic myeloperoxidase activity, and improved pancreatic morphology. Amelioration of pancreatic damage by BCA was associated with reduced levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and monocyte chemotactic protein-1 in both pancreas and colon. Moreover, BCA attenuated AP-associated barrier damage by upregulating the expression of tight junction proteins zonulin occluding (ZO)-1, ZO-2, occludin, and claudin-1. Concomitantly, the translocation of pathogenic bacteria Escherichia coli (E. coli) to pancreas was reduced by BCA. More importantly, reduction of E. coli dissemination by BCA inhibited the TLR4-MAPK/NF-κB signaling and NLRP3 inflammasome activation, thereby protecting against AP and related intestinal injury. Consistently, TLR4 inhibition by TAK-242 pre-treatment counteracted the anti-inflammatory effects of BCA in acinar cells. Taken together, our study extends beneficial effects of BCA to AP prevention, and dietary BCA supplement may be a potential strategy to safeguard AP.

Protopanaxadiol manipulates gut microbiota to promote bone marrow hematopoiesis and enhance immunity in cyclophosphamide-induced immunosuppression mice

Protopanaxadiol (PPD) has potential immunomodulatory effects, but the underlying mechanism remains unclear. Here, we explored the potential roles of gut microbiota in the immunity regulation mechanisms of PPD using a cyclophosphamide (CTX)-induced immunosuppression mouse model. Our results showed that a medium dose of PPD (PPD-M, 50 mg/kg) effectively ameliorated the immunosuppression induced by CTX treatment by promoting bone marrow hematopoiesis, increasing the number of splenic T lymphocytes and regulating the secretion of serum immunoglobulins and cytokines. Meanwhile, PPD-M protected against CTX-induced gut microbiota dysbiosis by increasing the relative abundance of Lactobacillus, Oscillospirales, Turicibacter, Coldextribacter, Lachnospiraceae, Dubosiella, and Alloprevotella and reducing the relative abundance of Escherichia-Shigella. Importantly, PPD-M lost the ability to promote bone marrow hematopoiesis and enhance immunity when the gut microbiota was depleted by broad-spectrum antibiotics. Moreover, PPD-M promoted the production of microbiota-derived immune-enhancing metabolites including cucurbitacin C, l-gulonolactone, ceramide, DG, prostaglandin E2 ethanolamide, palmitoyl glucuronide, 9R,10S-epoxy-stearic acid, and 9'-carboxy-gamma-chromanol. KEGG topology analysis showed that the PPD-M treatment significantly enriched the sphingolipid metabolic pathway with ceramide as a main metabolite. Our findings reveal that PPD enhances immunity by manipulating gut microbiota and has the potential to be used as an immunomodulator in cancer chemotherapy.

Gut microbiota affects pancreatic fibrotic progression through immune modulation in chronic pancreatitis

Chronic pancreatitis (CP) is characterized by chronic progressive pancreatic inflammation, which leads to the permanent damage of exocrine and endocrine cells. CP causes irreversible morphological and functional changes, and the clinical manifestations includes abdomen pain, steatorrhea and diabetes. CP induces changes in the composition of gut microbiota that could be used as potential biomarkers for pancreatic fibrosis evaluation. Gut microbiota has emerged as key regulator of immunomodulation and gut microbiota-induced immune activation has not been explored in CP. In current study, we profiled gut microbial signatures in mouse CP model, and found that higher proportion of Streptomyces, Turicibacter, Methylobacterium, Enterococcus and Candidatus_Paenicardiniummore were positively associated with the occurrence of pancreatic fibrosis. We then identified increased CD3⁺T cells and macrophage infiltration in mouse and human CP tissues by transcriptome sequencing data from GEO database. Subsequently, we demonstrated that fecal microbiota transplantation (FMT) from CP mouse (FMT-CP) exacerbated pancreatic fibrosis by increasing CD4⁺T cells and macrophage infiltration compared to fecal samples obtained from healthy mouse donor (FMT-HC). Our study describes the link between gut microbiota dysbiosis and immune activation in pancreatic fibrotic progression, and highlights the potential therapeutic roles of FMT and CP treatment.

The Multifaceted Role and Regulation of Nlrp3 Inflammasome in Colitis-Associated Colo-Rectal Cancer: A Systematic Review

Colitis-associated colo-rectal cancer remains the leading cause of mortality in inflammatory bowel diseases, with inflammation remaining one of the bridging points between the two pathologies. The NLRP3 inflammasome complex plays an important role in innate immunity; however, its misregulation can be responsible for the apparition of various pathologies such as ulcerative colitis. Our review focuses on the potential pathways of upregulation or downregulation of the NLRP3 complex, in addition to evaluating its role in the current clinical setting. Eighteen studies highlighted the potential pathways of NLRP3 complex regulation as well as its role in the metastatic process in colo-rectal cancer, with promising results. Further research is, however, needed in order to validate the results in a clinical setting.

Ruminococcus gnavus plays a pathogenic role in diarrhea-predominant irritable bowel syndrome by increasing serotonin biosynthesis

Diarrhea-predominant irritable bowel syndrome (IBS-D), a globally prevalent functional gastrointestinal (GI) disorder, is associated with elevated serotonin that increases gut motility. While anecdotal evidence suggests that the gut microbiota contributes to serotonin biosynthesis, mechanistic insights are limited. We determined that the bacterium Ruminococcus gnavus plays a pathogenic role in IBS-D. Monocolonization of germ-free mice with R. gnavus induced IBS-D-like symptoms, including increased GI transit and colonic secretion, by stimulating the production of peripheral serotonin. R. gnavus-mediated catabolism of dietary phenylalanine and tryptophan generated phenethylamine and tryptamine that directly stimulated serotonin biosynthesis in intestinal enterochromaffin cells via a mechanism involving activation of trace amine-associated receptor 1 (TAAR1). This R. gnavus-driven increase in serotonin levels elevated GI transit and colonic secretion but was abrogated upon TAAR1 inhibition. Collectively, our study provides molecular and pathogenetic insights into how gut microbial metabolites derived from dietary essential amino acids affect serotonin-dependent control of gut motility.

Microbiota of the gastrointestinal tract: Friend or foe?

The gut microbiota is currently considered an external organ of the human body that provides important mechanisms of metabolic regulation and protection. The gut microbiota encodes over 3 million genes, which is approximately 150 times more than the total number of genes present in the human genome. Changes in the qualitative and quantitative composition of the microbiome lead to disruption in the synthesis of key bacterial metabolites, changes in intestinal barrier function, and inflammation and can cause the development of a wide variety of diseases, such as diabetes, obesity, gastrointestinal disorders, cardiovascular issues, neurological disorders and oncological concerns. In this review, I consider issues related to the role of the microbiome in the regulation of intestinal barrier function, its influence on physiological and pathological processes occurring in the body, and potential new therapeutic strategies aimed at restoring the gut microbiome. Herewith, it is important to understand that the gut microbiota and human body should be considered as a single biological system, where change of one element will inevitably affect its other components. Thus, the study of the impact of the intestinal microbiota on health should be considered only taking into account numerous factors, the role of which has not yet been fully elucidated.

Traditional Chinese medicine improves myasthenia gravis by regulating the symbiotic homeostasis of the intestinal microbiota and host

Myasthenia gravis (MG) is an autoimmune disease caused by autoantibodies that is dependent on T-cell immunity and complement participation and mainly involves neuromuscular junctions. In this study, 30 patients with myasthenia gravis were selected and divided into pretreatment (Case group) and posttreatment (Treatment group) and 30 healthy volunteers (CON group) were included. Among them, the treatment group was treated with Modified Buzhong Yiqi Decoction (MBZYQD), and the levels of antibodies such as AChR, Musk and Titin in blood and intestinal microbiota were compared before treatment (Case group), after treatment (Treatment group) and in healthy volunteers (CON group). The results showed that after treatment with MBZYQD, the antibody levels of AChR, MuSK, and Titin and the inflammatory factor level of IL-6, IL-1β, and IL-22 in MG patients decreased significantly and nearly returned to a healthy level. In addition, after treatment with MBZYQD, the diversity, structure and function of intestinal microorganisms in MG patients also recovered to a healthy level. At the phylum level, the relative abundance of Proteobacteria in the Case group increased significantly, accompanied by a significant decrease in the relative abundance of Bacteroides compared with that in the CON group, the relative abundance of Proteobacteria and Bacteroides in the Treatment group was similar to that in the CON group. At the genus level, the relative abundance of Shigella in the Case group was significantly increased, accompanied by a significant decrease in the relative abundance of Prevotella, and the relative abundance of Shigella and Prevotella in Treatment group was similar to that in the CON group. Moreover, the fluorobenzoate degradation pathway (KO00364) was significantly increased in the Case group, while this pathway was significantly decreased in the Treatment group. In conclusion, MBZYQD can improve the immune function of the host by regulating the diversity, structure and function of the intestinal microbiota to treat myasthenia gravis.

Imbalance of Microbacterial Diversity Is Associated with Functional Prognosis of Stroke

Objectives

There is mounting evidence to suggest that the pathophysiology of stroke is greatly influenced by the microbiota of the gut and its metabolites, in particular short-chain fatty acids (SCFAs). The primary purpose of the study was to evaluate whether the levels of SCFAs and the gut microbiota are altered in poststroke patients and to examine the relationship between these alterations and the physical condition, intestinal health, pain, or nutritional status of patients.

Methods

Twenty stroke patients and twenty healthy controls were enrolled in the current study, and their demographics were matched. Gas chromatography was used to determine the fecal SCFAs, and 16S rRNA gene sequencing was used to evaluate their fecal microbiota. Microbial diversity and richness were examined using the diversity indices alpha and beta, and taxonomic analysis was utilized to determine group differences. The relationships between the gut microbiome and fecal SCFAs, discriminant bacteria, and poststroke clinical outcomes were analyzed.

Results

Less community richness (ACE and Chao) was observed in the poststroke patients (P < 0.05), but the differences between the poststroke group and the healthy control group in terms of species diversity (Shannon and Simpson) were not statistically significant. The makeup of the poststroke gut microbiota was distinct from that of the control group, as evidenced by beta diversity. Then, the relative abundances of the taxa in the poststroke and control groups were compared in order to identify the specific microbiota changes. At the level of phylum, the poststroke subjects showed a significant increase in the relative abundances of Akkermansiaceae, Fusobacteriota, Desulfobacterota, Ruminococcaceae, and Oscillospirales and a particularly noticeable decrease in the relative abundance of Acidobacteriota compared to the control subjects (P < 0.05). In regard to SCFA concentrations, lower levels of fecal acetic acid (P = 0.001) and propionic acid (P = 0.049) were found in poststroke subjects. Agathobacter was highly correlated with acetic acid level (r = 0.473, P = 0.002), whereas Fusobacteria (r = -0.371, P = 0.018), Flavonifractor (r = -0.334, P = 0.034), Desulfovibrio (r = -0.362, P = 0.018), and Akkermansia (r = -0.321, P = 0.043) were negatively related to acetic acid levels. Additionally, the findings of the correlation analysis revealed that Akkermansia (r = -0.356, P = 0.024), Desulfovibrio (r = -0.316, P = 0.047), and Alloprevotella (r = -0.366, P = 0.020) were significantly negatively correlated with high-density lipoprotein cholesterol. In addition, the Neurogenic Bowel Dysfunction score (r = 0.495, P = 0.026), Barthel index (r = -0.531, P = 0.015), Fugl-Meyer Assessment score (r = -0.565, P = 0.009), Visual Analogue Scale score (r = 0.605, P = 0.005), and Brief Pain Inventory score (r = 0.507, P = 0.023) were significantly associated with alterations of distinctive gut microbiota.

Conclusions

Stroke generates extensive and substantial alterations in the gut microbiota and SCFAs, according to our findings. The differences of intestinal flora and lower fecal SCFA levels are closely related to the physical function, intestinal function, pain, or nutritional status of poststroke patients. Treatment strategies aimed at modulating the gut microbiota and SCFAs may have the potential to enhance the clinical results of patients.

Interactions between gut microbes and NLRP3 inflammasome in the gut-brain axis

The role of the gut-brain axis in maintaining the brain's and gut's homeostasis has been gradually recognized in recent years. The connection between the gut and the brain takes center stage. In this scenario, the nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) inflammasome promotes inflammatory cell recruitment. It plays a crucial role in coordinating host physiology and immunity. Recent evidence shows how vital the gut-brain axis is for maintaining brain and gut homeostasis. However, more research is needed to determine the precise causal link between changed gut microbiota structure and NLRP3 activation in pathogenic circumstances. This review examines the connection between gut microbiota and the NLRP3 inflammasome. We describe how both dynamically vary in clinical cases and the external factors affecting both. Finally, we suggest that the crosstalk between the gut microbiota and NLRP3 is involved in signaling in the gut-brain axis, which may be a potential pathological mechanism for CNS diseases and intestinal disorders.

The role of NLRP3 inflammasome in digestive system malignancy

Digestive system malignancies, the most common types of cancer and a major cause of death in the worldwide, are generally characterized by high morbidity, insidious symptoms and poor prognosis. NLRP3 inflammasome, the most studied inflammasome member, is considered to be crucial in tumorigenesis. In this paper, we reviewed its pro-tumorigenic and anti-tumorigenic properties in different types of digestive system malignancy depending on the types of cells, tissues and organs involved, which would provide promising avenue for exploring new anti-cancer therapies.

Expansion of Escherichia-Shigella in Gut Is Associated with the Onset and Response to Immunosuppressive Therapy of IgA Nephropathy

BACKGROUND

Gut dysbiosis is postulated to participate in the pathogenesis of IgA nephropathy (IgAN). However, the key bacterial taxa closely associated with IgAN onset and treatment response have not been identified.

METHODS

We recruited 127 patients with IgAN who were treatment naive and 127 matched healthy controls (HCs) who were randomly divided into discovery and validation cohorts to investigate the characteristics of their gut microbiota and establish a bacterial diagnosis model for IgAN. A separate cohort of 56 patients and HCs was investigated to assess crossregional validation. A further 40 patients with primary membranous nephropathy (MN) were enrolled to probe disease-specific validation. A subgroup of 77 patients was prospectively followed to further dissect the association between alterations in gut microbiota and treatment response after 6 months of immunosuppressive therapy. Fecal microbiota samples were collected from all participants and analyzed using 16S ribosomal RNA sequencing.

RESULTS

Decreased α-diversity (Shannon, P=0.03), altered microbial composition (Adonis, P=0.0001), and a striking expansion of the taxonomic chain Proteobacteria-Gammaproteobacteria-Enterobacteriales-Enterobacteriaceae-Escherichia-Shigella (all P<0.001) were observed in patients with IgAN who were treatment naive, which reversed only in patients who achieved clinical remission after 6 months of immunosuppressive therapy. Importantly, seven operational taxa units, of which Escherichia-Shigella contributed the most, were determined to be the optimal bacterial classifier of IgAN (AUC=0.8635, 0.8551, 0.8026 in discovery, validation, and cross-regional validation sets, respectively), but did not effectively distinguish patients with IgAN versus those with MN (AUC=0.6183). Bacterial function prediction further verified enrichment of the shigellosis infection pathway in IgAN.

CONCLUSION

Gut dysbiosis, characterized by a striking expansion of genus Escherichia-Shigella, is a hallmark of patients with IgAN and may serve as a promising diagnostic biomarker and therapeutic target for IgAN. Further studies are warranted to investigate the potential contribution of Escherichia-Shigella in IgAN pathogenesis.

NLRP3 inflammasome inhibitor MCC950 can reduce the damage of pancreatic and intestinal barrier function in mice with acute pancreatitis

PURPOSE

Abnormal activation of NOD-like receptor protein 3 (NLRP3) inflammasome can lead to the occurrence and progression of acute pancreatitis. This study investigated the protective effect of MCC950 on pancreatitis mice.

METHODS

Eighteen mice were randomly divided into control group, severe acute pancreatitis (SAP) group and SAP+MCC950 group. Serum interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) were measured by ELISA. Hematoxylin and eosin (HE) staining was used to evaluate the pathological damage. Western blotting was used to detect the expression of NLRP3 inflammasome and tight junction proteins in the small intestine and pancreas.

RESULTS

MCC950 could reduce the levels of IL-6 and IL-1β in SAP mice. After treatment with MCC950, the expression levels of NLRP3 inflammasome in the pancreas of SAP mice were significantly reduced and the pathological damage to the pancreas and intestine was alleviated. Compared with the control group, the expression of tight junction protein (ZO-1,occludin and claudin-4) in the intestinal mucosa of SAP mice was decreased, and the expression of claudin-4 and occludin were upregulated after MCC950 treatment.

CONCLUSIONS

MCC950 can inhibit NLRP3 inflammasome activation and significantly reduce the inflammatory response and delay the process of pancreatitis. It has therapeutic potential in the treatment of acute pancreatitis.

Bifidobacterium spp. and their metabolite lactate protect against acute pancreatitis via inhibition of pancreatic and systemic inflammatory responses

Severe acute pancreatitis (SAP) is a critical illness characterized by a severe systemic inflammatory response resulting in persistent multiple organ failure and sepsis. The intestinal microbiome is increasingly appreciated to play a crucial role in modulation of AP disease outcome, but limited information is available about the identity and mechanism of action for specific commensal bacteria involved in AP-associated inflammation. Here we show that Bifidobacteria, particularly B. animalis, can protect against AP by regulating pancreatic and systemic inflammation in germ-free (GF) and oral antibiotic-treated (Abx) mouse models. Colonization by B. animalis and administration of its metabolite lactate protected Abx and GF mice from AP by reducing serum amylase concentration, ameliorating pancreatic lesions and improving survival rate after retrograde injection of sodium taurocholate. B. animalis relieved macrophage-associated local and systemic inflammation of AP in a TLR4/MyD88- and NLRP3/Caspase1-dependent manner through its metabolite lactate. Supporting our findings from the mouse study, clinical AP patients exhibited a decreased fecal abundance of Bifidobacteria that was inversely correlated with the severity of systemic inflammatory responses. These results may shed light on the heterogeneity of clinical outcomes and drive the development of more efficacious therapeutic interventions for AP, and potentially for other inflammatory disorders.

Infection of (Peri-)Pancreatic Necrosis Is Associated with Increased Rates of Adverse Events during Endoscopic Drainage: A Retrospective Study

Pancreatic necroses are a major challenge in the treatment of patients with pancreatitis, causing high morbidity. When indicated, these lesions are usually drained endoscopically using plastic or metal stents. However, data on factors associated with the occurrence of failure or adverse events during stent therapy are scarce. We retrospectively analyzed all adverse events and their associated features which occurred in patients who underwent a first-time endoscopic drainage of pancreatic necrosis from 2009 to 2019. During the observation period, a total of 89 eligible cases were identified. Adverse events occurred in 58.4% of the cases, of which 76.9% were minor (e.g., stent dislocation, residual lesions, or stent obstruction). However, these events triggered repeated interventions (63.5% vs. 0%, p < 0.001) and prolonged hospital stays (21.0 [11.8−63.0] vs. 14.0 [7.0−31.0], p = 0.003) compared to controls without any adverse event. Important factors associated with the occurrence of adverse events during endoscopic drainage therapy were positive necrosis cultures (6.1 [2.3−16.1], OR [95% CI], p < 0.001) and a larger diameter of the treated lesion (1.3 [1.1−1.5], p < 0.001). Superinfection of pancreatic necrosis is the most significant factor increasing the likelihood of adverse events during endoscopic drainage. Therefore, control of infection is crucial for successful drainage therapy, and future studies need to consider superinfection of pancreatic necrosis as a possible confounding factor when comparing different therapeutic modalities.

Microbiota-driven mechanisms at different stages of cancer development

A myriad of microbes living together with the host constitutes the microbiota, and the microbiota exerts very diverse functions in the regulation of host physiology. Microbiota regulates cancer initiation, progression, metastasis, and responses to therapy. Here we review known pro-tumorigenic and anti-tumorigenic functions of microbiota, and mechanisms of how microbes can shape tumor microenvironment and affect cancer cells as well as activation and functionality of immune and stromal cells within the tumor. While some of these mechanisms are distal, often distinct members of microbiota travel with and establish colonization with the tumors in the distant organs. We further briefly describe recent findings regarding microbiota composition in metastasis and highlight important future directions and considerations for the manipulation of microbiota for cancer treatment.

Surfactin Mitigates a High-Fat Diet and Streptozotocin-Induced Type 2 Diabetes through Improving Pancreatic Dysfunction and Inhibiting Inflammatory Response

Surfactin from Bacillus amyloliquefaciens fmb50 was utilized to treat mice with type 2 diabetes (T2DM) induced by a high-fat diet/streptozotocin (HFD/STZ). Our group’s earlier research indicated that surfactin could lower blood glucose and mitigate liver dysfunction to further improve HFD/STZ-induced T2DM through modulating intestinal microbiota. Thus, we further investigated the effects of surfactin on the pancreas and colon in mice with T2DM to elucidate the detailed mechanism. In the present study, mice with HFD/STZ-induced T2DM had their pancreatic and colon inflammation, oxidative stress, and endoplasmic reticulum stress (ERS) reduced when given oral surfactin at a dose of 80 mg/kg body weight. According to further research, surfactin also improved glucose metabolism by activating the phosphatidylinositol kinase (PI3K)/protein kinase B (Akt) signaling pathway, further protecting islets β-cell, promoting insulin secretion, inhibiting glucagon release and mitigating pancreas dysfunction. Additionally, after surfactin treatment, the colon levels of the tight junction proteins Occludin and Claudin-1 of T2DM mice were considerably increased by 130.64% and by 36.40%, respectively. These findings revealed that surfactin not only ameliorated HFD/STZ-induced pancreas inflammation and dysfunction and preserved intestinal barrier dysfunction and gut microbiota homeostasis but also enhanced insulin sensitivity and glucose homeostasis in T2DM mice. Finally, in the further experiment, we were able to demonstrate that early surfactin intervention might delay the development of T2DM caused by HFD/STZ, according to critical biochemical parameters in serum.

USP25 Deficiency Exacerbates Acute Pancreatitis via Up-Regulating TBK1-NF-κB Signaling in Macrophages

BACKGROUND & AIMS

Severe acute pancreatitis can easily lead to systemic inflammatory response syndrome and death. Macrophages are known to be involved in the pathophysiology of acute pancreatitis (AP), and macrophage activation correlates with disease severity. In this study, we examined the role of ubiquitin-specific protease 25, a deubiquitinating enzyme and known regulator of macrophages, in the pathogenesis of AP.

METHODS

We used L-arginine, cerulein, and choline-deficient ethionine-supplemented diet-induced models of AP in Usp25^-/- mice and wild-type mice. We also generated bone marrow Usp25^-/- chimeric mice and initiated L-arginine-mediated AP. Primary acinar cells and bone marrow-derived macrophages were isolated from wild-type and Usp25^-/- mice to dissect molecular mechanisms.

RESULTS

Our results show that Usp25 deficiency exacerbates pancreatic and lung injury, neutrophil and macrophage infiltration, and systemic inflammatory responses in L-arginine, cerulein, and choline-deficient ethionine-supplemented diet-induced models of AP. Bone marrow Usp25^-/- chimeric mice challenged with L-arginine show that Usp25 deficiency in macrophages exaggerates AP by up-regulating the TANK-binding kinase 1 (TBK1)-nuclear factor-κB (NF-κB) signaling pathway. Similarly, in vitro data confirm that Usp25 deficiency enhances the TBK1-NF-κB pathway, leading to increased expression of inflammatory cytokines in bone marrow-derived macrophages.

CONCLUSIONS

Usp25 deficiency in macrophages enhances TBK1-NF-κB signaling, and the induction of inflammatory chemokines and type I interferon-related genes exacerbates pancreatic and lung injury in AP.

Cardioprotection effect of Yiqi-Huoxue-Jiangzhuo formula in a chronic kidney disease mouse model associated with gut microbiota modulation and NLRP3 inflammasome inhibition

BACKGROUND

The pathogenesis and treatment of cardiovascular disease mediated by chronic kidney disease (CKD) are key research questions. Specifically, the mechanisms underlying the cardiorenal protective effect of Yiqi-Huoxue-Jiangzhuo formula (YHJF), a traditional Chinese herbal medicine, have not yet been clarified.

METHODS

A classical CKD mouse model was constructed by 5/6 nephrectomy (Nx) to study the effects of YHJF intervention on 5/6 Nx mice cardiorenal function, gut microbial composition, gut-derived metabolites, and NLRP3 inflammasome pathways.

RESULTS

YHJF improved cardiac dysfunction and reversed left ventricular hypertrophy, myocardial hypertrophy, and interstitial fibrosis in 5/6 Nx mice. In addition, YHJF inhibited activation of the NLRP3 inflammasome and downregulated the expression of TNF-α and IL-1β both in the heart and serum; reconstitution of the intestinal flora imbalance was also found in 5/6 Nx mice treated with YHJF. Spearman's correlation and redundancy analyses showed that changes in the intestinal flora of 5/6 Nx mice were related to clinical phenotype and serum inflammatory levels.

CONCLUSIONS

Treatment with YHJF effectively protected the heart function of 5/6 Nx mice; this effect was attributed to inhibition of NLRP3 inflammasome activation and regulation of intestinal microbial composition and derived metabolites. YHJF has potential for improving intestinal flora imbalance and gut-derived toxin accumulation in patients with CKD, thereby preventing cardiovascular complications.

Effect of aging on acute pancreatitis through gut microbiota

Background

Compared to younger people, older people have a higher risk and poorer prognosis of acute pancreatitis, but the effect of gut microbiota on acute pancreatitis is still unknown. We aim to investigate the effect of aging gut microbiota on acute pancreatitis and explore the potential mechanism of this phenomenon.

Methods

Eighteen fecal samples from healthy adult participants, including nine older and nine younger adults were collected. C57BL/6 mice were treated with antibiotics for fecal microbiota transplantation from older and younger participants. Acute pancreatitis was induced by cerulein and lipopolysaccharide in these mice. The effect of the aged gut microbiota was further tested via antibiotic treatment before or after acute pancreatitis induction.

Results

The gut microbiota of older and younger adults differed greatly. Aged gut microbiota exacerbated acute pancreatitis during both the early and recovery stages. At the same time, the mRNA expression of multiple antimicrobial peptides in the pancreas and ileum declined in the older group. Antibiotic treatment before acute pancreatitis could remove the effect of aging gut microbiota, but antibiotic treatment after acute pancreatitis could not.

Conclusion

Aging can affect acute pancreatitis through gut microbiota which characterizes the deletion of multiple types of non-dominant species. This change in gut microbiota may potentially regulate antimicrobial peptides in the early and recovery stages. The level of antimicrobial peptides has negative correlations with a more severe phenotype.

The crosstalk between NLRP3 inflammasome and gut microbiome in atherosclerosis

Atherosclerosis (AS) is chronic pathological process based on the inflammatory reaction associated with factors including vascular endothelial dysfunction, inflammation, and autoimmunity. Inflammasomes are known to be at the core of the inflammatory response. As a pattern recognition receptor of innate immunity, the NLRP3 inflammasome mediates the secretion of inflammatory factors by activating the Caspase-1, which is important for maintaining the immune system and regulating the gut microbiome, and participates in the occurrence and development of AS. The intestinal microecology is composed of a large number of complex structures of gut microbiota and its metabolites, which play an important role in AS. The gut microbiota and its metabolites regulate the activation of the NLRP3 inflammasome. Targeting the NLRP3 inflammasome and regulating intestinal microecology represent a new direction for the treatment of AS. This paper systematically reviews the interaction between the NLRP3 inflammasome and gut microbiome in AS, strategies for targeting the NLRP3 inflammasome and gut microbiome for the treatment of AS, and provides new ideas for the research and development of drugs for the treatment of AS.

Fentanyl alleviates intestinal mucosal barrier damage in rats with severe acute pancreatitis by inhibiting the MMP-9/FasL/Fas pathway

BACKGROUND

Fentanyl is an analgesic used against pancreatitis-related pain, while whether it ameliorates severe acute pancreatitis (SAP) has yet to be checked. The present study aims to determine fentanyl-delivered effect on SAP and the mechanism underlying this effect.

METHODS

Rat SAP models were established, following fentanyl treatment. The serum activity of amylase (AMY), lipase (LIP) and diamine oxidase (DAO) was detected by enzyme-linked immunosorbent assay. Histological examination was performed in the pancreatic and intestinal tissues with hematoxylin-eosin staining. After transfection with matrix metalloproteinase (MMP)9 overexpression plasmids, Caco-2 monolayers were treated with fentanyl and subsequently exposed to lipopolysaccharide (LPS). The transepithelial electrical resistance (TEER) value was determined in rat intestinal mucosa through an Ussing chamber assisted by Analyze & Acquire, and in Caco-2 cell monolayers through a voltohmmeter. Intestinal mucosa and paracellular permeabilities were determined by fluorescein isothiocyanate (FITC)-labeled dextran assay. The expressions of ZO-1, Occludin, MMP9, Fas and Fas ligand (FasL) in rat intestinal mucosa and/or Caco-2 monolayers were analyzed by qRT-PCR or/and western blot.

RESULTS

Fentanyl alleviated SAP-related histological alterations in the pancreas and intestines, reduced the elevated levels of SAP-related AMY, LIP and DAO, but promoted the levels of ZO-1 and Occludin. In SAP rats and Caco-2 monolayers, SAP-related or LPS-induced TEER value decreases, permeability increases, and increases in the expressions of MMP9, Fas and FasL were reversed partly by fentanyl. Notably, MMP9 overexpression could reverse the above fentanyl-delivered in vitro effects.

CONCLUSION

Fentanyl alleviates intestinal mucosal barrier damage in rats with SAP by inhibiting the MMP9/FasL/Fas pathway.