Sodium Butyrate Inhibits Inflammation and Maintains Epithelium Barrier Integrity in a TNBS-induced Inflammatory Bowel Disease Mice Model. EBioMedicine. 2018;30:317-325. [PMID: 29627390 PMCID: PMC5952406 DOI: 10.1016/j.ebiom.2018.03.030]

Fructus Jujubae cooperated with water-expelling members in Shizao decoction alleviated intestinal injury and malignant ascites by modulating gut microbiota and metabolic homeostasis

BACKGROUND

Shizao decoction (SZD) consisted of Euphorbia kansui (EK), Euphorbia pekinensis (EP), Daphne genkwa (DG), and Fructus Jujubae (FJ) is a classic Chinese herbal medicine formula for treating malignant ascites, which is closely related to the modulation of gut microbiota by our previous study. For water-expelling members (WEM) including EK, EP, and DG may have side effects on the intestine, FJ is employed for detoxification and effectivity enhancement of WEM. However, the underlying mechanism for the compatibility of WEM and FJ is still unknown.

PURPOSE

To investigate the effect of the compatibility of WEM with FJ in SZD on malignant ascites and elucidate the potential mechanism from the perspective of the modulation of gut microbiota and related metabolic function.

METHODS

Qualitative and quantitative evaluation of main components was conducted for comprehensive characterization of SZD and WEM. The effect of WEM and SZD was compared on malignant ascites effusion (MAE) rats. The intestinal injury was evaluated by HE staining and oxidative damage. Ascites weight, urine amount, fecal water content, the expression of aquaporins, and cytokines in ascites (IL-6, VEGF, and TNF-α) were measured to estimate the water-expelling activity. The intestinal flora was detected by 16S rDNA sequencing and the content of fecal short-chain fatty acids (SCFAs) was analyzed using gas chromatography-mass spectrometry. Pseudo-germ-free (PGF) and fecal bacteria transplantation animal experiments were subsequently employed to validate this finding. The fecal metabolomics and correlation analysis were finally conducted to explore the related metabolic changes.

RESULTS

51 and 33 components were identified in SZD and WEM, respectively. Compared to WEM alone, the compatibility with FJ remarkably reduced intestinal oxidative damage in MAE rats. Ascites was also relieved by downregulating the expression of AQP3 in the colon and decreasing the levels of IL-6, TNF-α and VEGF in ascites. The diversity of gut microbiota was reversed with an increase in Lactobacillus and Clostridia_UCG-014 while a decrease in Colidextribacter. Under the PGF condition, compatibility of WEM with FJ failed to reduce intestinal injury and alleviate MA significantly, but this effect was further enhanced after FMT. 23 potential fecal metabolites were finally identified. Correlation analysis further showed that Lactobacillus and Clostridia_UCG-014 were positively correlated with SCFAs and l-tryptophan. Colidextribacter was negatively correlated with thymidine but positively correlated with ursodeoxycholic acid and deoxycholic acid.

CONCLUSION

FJ cooperated with WEM reduced intestinal injury and alleviated malignant ascites by modulating gut microbiota, short-chain fatty and tryptophan metabolism. These findings provide a scientific basis for the clinical application of FJ from SZD and the safe usage of SZD.

Greater adherence to the Mediterranean Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet is associated with lower risk of inflammatory bowel disease: a prospective cohort study

Background: The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet is emerging as a promising candidate for preventive measures against inflammatory bowel disease (IBD), though there is currently no direct evidence from population-based studies. This study aims to bridge the gap in understanding of the association of the MIND diet with IBD risk. Methods: We utilized data from 187 490 participants in the UK Biobank who provided dietary information and were free of IBD at baseline. Dietary information was obtained using a validated web-based 24-hour dietary recall questionnaire. A MIND diet score was evaluated based on the intake of ten beneficial and five unhealthy food groups and the scores were further grouped into tertiles. The outcome of interest was incident IBD, Crohn's disease (CD), and ulcerative colitis (UC). Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard models adjusted for demographic characteristics, lifestyle factors, cancer history, and other dietary factors. Mediation analyses were performed to evaluate the role of systemic inflammation and metabolic disorders represented by the integrated biomarkers in the MIND diet-IBD association. Results: After a mean follow-up of 10.7 years, we documented 825 incident IBD cases (250 CD and 575 UC). The average age of the participants was 56.2 years, of which 55.0% were females. We found that greater adherence to the MIND diet, represented by a higher diet score, was associated with a lower risk of IBD (HRcomparing extreme tertiles 0.74, 95% CI 0.62-0.90, p = 0.002; p for trend = 0.005), CD (HR 0.66, 95% CI 0.47-0.94, p = 0.022; p for trend = 0.023), and UC (HR 0.78, 95% CI 0.62-0.98, p = 0.031; p for trend = 0.022). The associations were partially mediated by metabolic and inflammation status (mediation proportion: 5.5-15.9%). Conclusion: We found higher adherence to the MIND diet was associated with a lower risk of IBD, and that inflammatory and metabolic conditions may play an important role in the underlying mechanistic pathways.

Ameliorating effect of 2'-fucosyllactose and 6'-sialyllactose on lipopolysaccharide-induced intestinal inflammation

Human milk oligosaccharides (HMO) affect gut microbiota during neonatal development, particularly with respect to the immune system. Bovine milk-based infant formulas have low oligosaccharide contents. Thus, efforts to fortify infant formulas with HMO are being undertaken. Two major HMO, 2'-fucosyllactose (2'-FL) and 6'-sialyllactose (6'-SL), exert anti-inflammatory effects; however, the associations between anti-inflammatory effects induced by 2'-FL and 6'-SL cotreatment and gut microbiota composition and metabolite modulation remain unclear. Therefore, in this study, we evaluated the effects of a mixture of these HMO. To determine the optimal HMO ratio for anti-inflammatory effects and elucidate its mode of action, LPS-induced inflammatory HT-29 epithelial cells and intestinal-inflamed suckling mice were treated with various mixtures of 2'-FL and 6'-SL. A 2'-FL:6'-SL ratio of 5:1 was identified as the most effective pretreatment HMO mixture in vitro; thus, this ratio was selected and used for low-, middle-, and high-dose treatments for subsequent in vivo studies. In vivo, high-dose HMO treatment restored LPS-induced inflammation symptoms, such as BW loss, colon length reduction, histological structural damage, and intestinal gene expression related to inflammatory responses. High-dose HMO was the only treatment that modulated the major phyla Bacteroidetes and Firmicutes and the genera Ihubacter, Mageeibacillus, and Saccharofermentans. These changes in microbial composition were correlated with intestinal inflammation-related gene expression and short-chain fatty acid production. To our knowledge, our study is the first to report the effects of Ihubacter, Mageeibacillus, and Saccharofermentans on short-chain fatty acid levels, which can subsequently affect inflammatory cytokine and tight junction protein levels. Conclusively, the HMO mixture exerted anti-inflammatory effects through changes in microbiota and metabolite production. These findings suggest that supplementation of infant formula with HMO may benefit formula-fed infants by forming unique microbiota contributing to neonatal development.

Butyrate improves recovery from experimental necrotizing enterocolitis by metabolite hesperetin through potential inhibition the PI3K-Akt pathway

Necrotizing enterocolitis (NEC) is one of the most common and serious intestinal illnesses in newborns and seriously affects their long-term prognosis and survival. Butyrate is a short-chain fatty acid that can relieve intestinal inflammation, but its mechanism of action is unclear. Results from an in vivo neonatal rat model has shown that butyrate caused an improved recovery from NEC. These protective effects were associated with the metabolite of hesperetin, as determined by metabolomics and molecular biological analysis. Furthermore, transcriptomics combined with inhibitor assays were used to investigate the mechanism of action of hesperetin in an in vitro NEC model (IEC-6 cells exposed to LPS) to further investigate the mechanism by which butyrate attenuates NEC. The transcriptomics analysis showed that the PI3K-Akt signaling pathway was involved in the anti-NEC effect of hesperitin. Subsequently, the results using an inhibitor of PI3K (LY294002) indicated that the suppression could be explained by the hesperetin-induced expression of tight junction (TJ) proteins by potentially blocking the PI3K-Akt signaling pathway. In summary, the present study demonstrated that butyrate could improve recovery from NEC with a hesperetin metabolite, causing potential inhibition of the phosphorylation of the PI3K-Akt signaling pathway, resulting in the increased expression of TJ proteins. These findings reveal a potential new therapeutic pathway for the treatment of NEC.

Impact of high-fat diet on ovarian epigenetics: Insights from altered intestinal butyric acid levels

Objective

To investigate the effects of a high-fat diet (HFD) on the gut bacterium Roseburia intestinalis and butyric acid levels, and to assess their impact on ovarian function and epigenetic markers in mice.

Methods

A total of 20 female ICR mice aged 4 weeks were randomly assigned to two groups and fed either a control diet (CD) or an HFD for 36 weeks. Post-intervention, ileal contents were analyzed for the quantification of butyric acid using ELISA, while feces were obtained for Roseburia intestinalis expression assessment via qPCR. Histological evaluations of intestinal and ovarian tissues included H&E and Alcian Blue-Periodic Acid Schiff (AB-PAS) staining, alongside immunohistochemical analysis for F4/80, and immunofluorescent detection of Occludin, ZO-1, 5 mC, and H3K36me3. Ovarian health was assessed through follicle counts and morphological evaluations. Statistical analyses were performed using GraphPad Prism 8.0, with P < 0.05 considered significant.

Results

After 36 weeks, the HFD group showed significantly higher body weight compared to the CD group (P < 0.01). The HFD led to a decrease in Roseburia intestinalis and butyric acid levels, a reduction in intestinal goblet cells, and an increase in intestinal inflammation. Histological analyses revealed impaired ovarian follicular development and enhanced inflammation in the HFD mice, with immunofluorescent staining showing downregulation of the ovarian epigenetic markers 5 mC and H3K36me3.

Conclusion

Our study demonstrates that long-term HFD negatively impacts ovarian function and epigenetic regulation. We found decreased levels of the gut bacterium Roseburia intestinalis and its metabolite, butyric acid, which contribute to these adverse effects. Additionally, the associated intestinal inflammation and compromised mucosal barrier may contribute to these adverse outcomes on female reproductive health.

The Impact of Surgical Bowel Preparation on the Microbiome in Colon and Rectal Surgery

Preoperative bowel preparation, through iterations over time, has evolved with the goal of optimizing surgical outcomes after colon and rectal surgery. Although bowel preparation is commonplace in current practice, its precise mechanism of action, particularly its effect on the human gut microbiome, has yet to be fully elucidated. Absent intervention, the gut microbiota is largely stable, yet reacts to dietary influences, tissue injury, and microbiota-specific byproducts of metabolism. The routine use of oral antibiotics and mechanical bowel preparation prior to intestinal surgical procedures may have detrimental effects previously thought to be negligible. Recent evidence highlights the sensitivity of gut microbiota to antibiotics, bowel preparation, and surgery; however, there is a lack of knowledge regarding specific causal pathways that could lead to therapeutic interventions. As our understanding of the complex interactions between the human host and gut microbiota grows, we can explore the role of bowel preparation in specific microbiome alterations to refine perioperative care and improve outcomes. In this review, we outline the current fund of information regarding the impact of surgical bowel preparation and its components on the adult gut microbiome. We also emphasize key questions pertinent to future microbiome research and their implications for patients undergoing colorectal surgery.

Effectiveness of Psychobiotic Bifidobacterium breve BB05 in Managing Psychosomatic Diarrhea in College Students by Regulating Gut Microbiota: A Randomized, Double-Blind, Placebo-Controlled Trial

Diarrhea of college students (DCS) is a prevalent issue among college students, affecting their daily lives and academic performance. This study aims to explore the potential effect of Bifidobacterium breve BB05 supplements on the DCS. Initially, fifty healthy and fifty diarrheal students were recruited in the observational experiment and allocated into control and diarrhea groups, respectively. Subsequently, one hundred diarrheal students were newly recruited in the intervention experiment and randomly allocated into placebo and probiotic groups, both treated for 2 weeks. Questionnaires (BSS, HAMA-14, and HDRS-17) were performed to assess the students' diarrheal states and mental health at baseline and post-treatment. Fecal samples underwent 16S rRNA sequencing and Enzyme-Linked Immunosorbent Assay to evaluate gut microbiota and fecal metabolite alternations. Results indicated that B. breve BB05 supplementation significantly enriched (p < 0.05) the reduced gut microbial diversity caused by diarrhea. Diarrhea resulted in notable alterations in gut microbiota composition, as exhibited by elevated Collinsella and Streptococcus, alongside substantially decreased Bifidobacterium, Bacteroides, and Prevotella, while B. breve BB05 supplementation partially restored the compromised gut microbiota at both the phylum and genus levels, particularly by increasing Bifidobacterium and Roseburia (p < 0.05). Importantly, questionnaire results suggested that B. breve BB05 administration achieved superior efficacy in relieving diarrhea symptoms and the associated anxiety and depression in college students. An increased fecal concentration of 5-hydroxytryptamine (5-HT) was also observed in the probiotic group, while Acetylcholine (ACH), Epinephrine (EPI), and Noradrenaline/Norepinephrine (NANE) reduced, revealing the potential of B. breve BB05 in alleviating anxiety and depression via modulating the microbiota-gut-brain axis. Furthermore, correlation analysis suggested that the altered microbiota and fecal neurotransmitters were closely associated with the mental symptoms. These results endorse B. breve BB05 intervention as a promising and innovative approach to alleviate both diarrhea and mental health conditions among college students.

Magnolin inhibits intestinal epithelial cell apoptosis alleviating Crohn's disease-like colitis by suppressing the PI3K/AKT signalling pathway

BACKGROUND AND AIMS

Previous reports have shown that preventing excessive intestinal epithelial cell (IEC) apoptosis is a crucial approach for protecting the intestinal barrier in patients with Crohn's disease (CD). Magnolin (MGL) has various biological activities, including antiapoptotic activities, but its role in CD has largely not been determined. This study investigated how MGL impacts CD-like colitis and the underlying mechanism involved.

METHODS

Mice were treated with TNBS to establish a disease model, and these mice were used to assess the therapeutic effects of MGL on CD-like colitis. TNF-α-treated colon organoids were used to evaluate the impact of MGL on intestinal barrier function and IEC apoptosis. Enrichment analysis was performed to examine the potential pathways through which MGL inhibits IEC apoptosis. Finally, rescue experiments showed the mechanism by which MGL suppresses IEC apoptosis.

RESULTS

The animal experiments demonstrated that MGL treatment alleviated the weight loss, colon shortening, elevated disease activity index (DAI) scores, increased colitis histological scores and upregulated inflammatory factor expression that were observed in model mice. MGL ameliorated intestinal barrier dysfunction and the loss of tight junction (TJ) proteins (ZO-1 and Claudin-1) by inhibiting IEC apoptosis in both TNBS-treated mice and TNF-α-treated colon organoids. MGL inhibited the PI3K/AKT signalling pathway, thus safeguarding the intestinal barrier and alleviating CD-like colitis in vivo and in vitro.

CONCLUSIONS

MGL improves the intestinal barrier integrity and prevents CD-like colitis by inhibiting IEC apoptosis. The potential mechanism of its anti-apoptotic impact on IECs could be associated with the PI3K/AKT pathway, presenting novel approaches and avenues for the clinical management of CD.

Uncovering the mechanism of Clostridium butyricum CBX 2021 to improve pig health based on in vivo and in vitro studies

Introduction

As a symbiotic probiotic for the host, Clostridium butyricum (CB) has the potential to strengthen the body's immune system and improve intestinal health. However, the probiotic mechanism of CB is not completely understood. The Clostridium butyricum CBX 2021 strain isolated by our team from a health pig independently exhibits strong butyric acid production ability and stress resistance. Therefore, this study comprehensively investigated the efficacy of CBX 2021 in pigs and its mechanism of improving pig health.

Methods

In this study, we systematically revealed the probiotic effect and potential mechanism of the strain by using various methods such as microbiome, metabolites and transcriptome through animal experiments in vivo and cell experiments in vitro.

Results

Our in vivo study showed that CBX 2021 improved growth indicators such as daily weight gain in weaned piglets and also reduced diarrhea rates. Meanwhile, CBX 2021 significantly increased immunoglobulin levels in piglets, reduced contents of inflammatory factors and improved the intestinal barrier. Subsequently, 16S rRNA sequencing showed that CBX 2021 treatment implanted more butyric acid-producing bacteria (such as Faecalibacterium) in piglets and reduced the number of potentially pathogenic bacteria (like Rikenellaceae RC9_gut_group). With significant changes in the microbial community, CBX 2021 improved tryptophan metabolism and several alkaloids synthesis in piglets. Further in vitro experiments showed that CBX 2021 adhesion directly promoted the proliferation of a porcine intestinal epithelial cell line (IPEC-J2). Moreover, transcriptome analysis revealed that bacterial adhesion increased the expression of intracellular G protein-coupled receptors, inhibited the Notch signaling pathway, and led to a decrease in intracellular pro-inflammatory molecules.

Discussion

These results suggest that CBX 2021 may accelerate piglet growth by optimizing the intestinal microbiota, improving metabolic function and enhancing intestinal health.

Effects of the gut microbiota and its metabolite short-chain fatty acids on endometriosis

In recent years, a growing body of research has confirmed that the gut microbiota plays a major role in the maintenance of human health and disease. A gut microbiota imbalance can lead to the development of many diseases, such as pregnancy complications, adverse pregnancy outcomes, polycystic ovary syndrome, endometriosis, and cancer. Short-chain fatty acids are metabolites of specific intestinal bacteria and are crucial for maintaining intestinal homeostasis and regulating metabolism and immunity. Endometriosis is the result of cell proliferation, escape from immune surveillance, and invasive metastasis. There is a strong correlation between the anti-proliferative and anti-inflammatory effects of short-chain fatty acids produced by gut microbes and the development of endometriosis. Given that the mechanism of action of gut microbiota and Short-chain fatty acids in endometriosis remain unclear, this paper aims to provide a comprehensive review of the complex interactions between intestinal flora, short-chain fatty acids and endometriosis. In addition, we explored potential microbial-based treatment strategies for endometriosis, providing new insights into the future development of diagnostic tests and prevention and treatment methods for endometriosis.

Butyrate as a potential therapeutic agent for neurodegenerative disorders

Maintaining an optimum microbial community within the gastrointestinal tract is intricately linked to human metabolic, immune and brain health. Disturbance to these microbial populations perturbs the production of vital bioactive compounds synthesised by the gut microbiome, such as short-chain fatty acids (SCFAs). Of the SCFAs, butyrate is known to be a major source of energy for colonocytes and has valuable effects on the maintenance of intestinal epithelium and blood brain barrier integrity, gut motility and transit, anti-inflammatory effects, and autophagy induction. Inducing endogenous butyrate production is likely to be beneficial for gut-brain homeostasis and for optimal neuronal function. For these reasons, butyrate has gained interest as a potential therapy for not only metabolic and immunological disorders, but also conditions related to the brain, including neurodegenerative diseases. While direct and indirect sources of butyrate, including prebiotics, probiotics, butyrate pro-drugs and glucosidase inhibitors, offer a promising therapeutic avenue, their efficacy and dosage in neurodegenerative conditions remain largely unknown. Here, we review current literature on effects of butyrate relevant to neuronal function, the impact of butyrate in a range of neurodegenerative diseases and related treatments that may have potential for the treatment of neurodegenerative diseases.

The in vitro intestinal cell model: different co-cultured cells create different applications

As a vitro absorption model, the Caco-2 cells originate from a human colon adenocarcinomas and can differentiate into a cell layer with enterocyte-like features. The Caco-2 cell model is popularly applied to explore drug transport mechanisms, to evaluate the permeability of drug and to predict the absorption of drugs or bioactive substances in the gut. However, there are limitations to the application of Caco-2 cell model due to lack of a mucus layer, the long culture period and the inability to accurately simulate the intestinal environment. The most frequent way to expand the Caco-2 cell model and address its limitations is by co-culturing it with other cells or substances. This article reviews the culture methods and applications of 3D and 2D co-culture cell models established around Caco-2 cells. It also concludes with a summary of model strengths and weaknesses.

Octreotide attenuates intestinal barrier damage by maintaining basal autophagy in Caco2 cells

The intestinal mucosal barrier is of great importance for maintaining the stability of the internal environment, which is closely related to the occurrence and development of intestinal inflammation. Octreotide (OCT) has potential applicable clinical value for treating intestinal injury according to previous studies, but the underlying molecular mechanisms have remained elusive. This article is based on a cell model of inflammation induced by lipopolysaccharide (LPS), aiming to explore the effects of OCT in protecting intestinal mucosal barrier function. A Cell Counting Kit‑8 assay was used to determine cell viability and evaluate the effectiveness of OCT. Gene silencing technology was used to reveal the mediated effect of somatostatin receptor 2 (SSTR2). The changes in intestinal permeability were detected through trans‑epithelial electrical resistance and fluorescein isothiocyanate‑dextran 4 experiments, and the alterations in tight junction proteins were detected using immunoblotting and reverse transcription fluorescence‑quantitative PCR technology. Autophagosomes were observed by electron microscopy and the dynamic changes of the autophagy process were characterized by light chain (LC)3‑II/LC3‑I conversion and autophagic flow. The results indicated that SSTR2‑dependent OCT can prevent the decrease in cell activity. After LPS treatment, the permeability of monolayer cells decreased and intercellular tight junctions were disrupted, resulting in a decrease in tight junction protein zona occludens 1 in cells. The level of autophagy‑related protein LC3 was altered to varying degrees at different times. These abnormal changes gradually returned to normal levels after the combined application of LPS and SSTR2‑dependent OCT, confirming the role of OCT in protecting intestinal barrier function. These experimental results suggest that OCT maintains basal autophagy and cell activity mediated by SSTR2 in intestinal epithelial cells, thereby preventing the intestinal barrier dysfunction in inflammation injury.

Sodium Butyrate Ameliorates Atopic Dermatitis-Induced Inflammation by Inhibiting HDAC3-Mediated STAT1 and NF-κB Pathway

A topic dermatitis (AD) is a common chronic and recurrent skin disorder. The protective effects of sodium butyrate (NaB), a metabolite of short-chain fatty acid breakdown by the gut microbiota, have been widely reported in numerous inflammatory diseases. However, the effect of NaB treatment alone on AD has not been reported. In the current study, AD was induced in BALB/c mice with 2,4-dinitrochlorobenzene (DNCB) for 28 days with NaB (200 mg/kg) treatment by gavage. NaB attenuated AD-induced skin bleeding, scarring, dryness, abrasions and erosions. In addition, NaB inhibited inflammatory cells infiltration and attenuated the expression of inflammatory cytokines and chemokines. Mechanistically, NaB reduced histone deacetylase 3 (HDAC3) expression and NF-κB p65 nuclear translocation by increasing the lysine acetylation levels of STAT1 and NF-κB p65 in AD. Taken together, our study suggests that NaB inhibits inflammatory mediators and ameliorates AD by inhibiting HDAC3 expression, thereby upregulating STAT1 and NF-κB p65 lysine acetylation levels and reducing NF-κB p65 nuclear translocation. Therefore, this study provides a new theoretical basis for NaB in the treatment of AD.

Exploring the therapeutic potential of porphyran extracted from Porphyra haitanensis in the attenuation of DSS-induced intestinal inflammation

Ulcerative colitis is a chronic, spontaneous inflammatory bowel disease that primarily affects the colon. This study aimed to explore how Porphyra haitanensis porphyran (PHP) modulates the immune response and the associated mechanisms that alleviate dextran sulphate sodium-induced colitis in mice. Histological assessments via H&E staining and AB-PAS staining revealed that PHP intervention partially restored the number of goblet cells and improved intestinal mucosal function. Immunohistochemical and Western blot analyses of claudin-1, occludin, and MUC-2 demonstrated that PHP could repair the intestinal barrier and reduce colon damage by upregulating the expression of these proteins. PHP intervention was associated with a decrease in pro-inflammatory cytokine expression and an increase in anti-inflammatory cytokine expression. Moreover, the expression of proteins involved in intestinal immune homing, such as CCR-9, CCL-25, MAdCAM-1, and α4β7, was significantly suppressed in response to PHP treatment. Conversely, PHP upregulates the expression of CD40 and TGF-β1, both of these can promote healing and reduce inflammation in the gut lining. This study demonstrates that PHP can ameliorate ulcerative colitis by enhancing the intestinal barrier and modulating immune responses. These findings offer valuable insights into the potential utility of P. haitanensis as a promising natural product for managing ulcerative colitis.

Current applications of intestinal organoids: a review

In the past decade, intestinal organoid technology has paved the way for reproducing tissue or organ morphogenesis during intestinal physiological processes in vitro and studying the pathogenesis of various intestinal diseases. Intestinal organoids are favored in drug screening due to their ability for high-throughput in vitro cultivation and their closer resemblance to patient genetic characteristics. Furthermore, as disease models, intestinal organoids find wide applications in screening diagnostic markers, identifying therapeutic targets, and exploring epigenetic mechanisms of diseases. Additionally, as a transplantable cellular system, organoids have played a significant role in the reconstruction of damaged epithelium in conditions such as ulcerative colitis and short bowel syndrome, as well as in intestinal material exchange and metabolic function restoration. The rise of interdisciplinary approaches, including organoid-on-chip technology, genome editing techniques, and microfluidics, has greatly accelerated the development of organoids. In this review, VOSviewer software is used to visualize hot co-cited journal and keywords trends of intestinal organoid firstly. Subsequently, we have summarized the current applications of intestinal organoid technology in disease modeling, drug screening, and regenerative medicine. This will deepen our understanding of intestinal organoids and further explore the physiological mechanisms of the intestine and drug development for intestinal diseases.

Sclareol protected against intestinal barrier dysfunction ameliorating Crohn's disease-like colitis via Nrf2/NF-B/MLCK signalling

BACKGROUND

Inflammation-induced intestinal barrier dysfunction is not only a pathological feature of Crohn's disease (CD) but also an important therapeutic target. Sclareol (SCL) is a nontoxic natural plant compound with anti-inflammatory effect, but its role in CD has not been established.

METHODS

In vivo studies of mice with TNBS-induced colitis were carried out to evaluate the effects of SCL on CD-like colitis and intestinal barrier function. In vitro, a TNF-α-induced colonic organoid model was established to test the direct effect of SCL on inflammation-induced intestinal barrier injure and inflammatory response. The Nrf2/NF-κB/MLCK signalling was analysed to explore the mechanism of SCL.

RESULTS

In vivo, SCL largely alleviated the colitis in TNBS mice, as evidenced by improvements in the weight loss, colitis symptoms, endoscopic score, macroscopic histological score, and histological inflammation score. Moreover, SCL significantly improved intestinal barrier dysfunction, manifested as reduced intestinal permeability and decreased intestinal bacterial translocation in TNBS mice. Importantly, SCL antagonised the intestinal mucosal inflammation while protecting tight junctions in TNBS mice. In vitro, SCL largely depressed pro-inflammatory cytokines levels and improved intestinal epithelial permeability in a TNF-α-induced colonic organoid model. In the context of CD, the protective effects of SCL against inflammation and intestinal barrier damage are at least partially results from the Nrf2 signalling activation and the NF-κB/MLCK signalling inhibition.

CONCLUSIONS

SCL improved intestinal barrier dysfunction and alleviated CD-like colitis, possibly through modulation of Nrf2/NF-κB/MLCK signalling. In view of SCL's safety profile, there is hope that it will be useful in the clinic.

Association between gut microbiota and common overlapping gastrointestinal disorders: a bidirectional two-sample Mendelian randomization study

Background

The main functional gastrointestinal disorders (FGIDs) include functional dyspepsia (FD) and irritable bowel syndrome (IBS), which often present overlapping symptoms with gastroesophageal reflux disease (GERD), posing a challenge for clinical diagnosis and treatment. The gut microbiota is closely associated with FGIDs and GERD, although the causal relationship has not been fully elucidated. Therefore, we aimed to investigate the potential causal relationship using bidirectional two-sample Mendelian randomization (MR) analysis.

Materials and methods

The genetic data of the 211 gut microbiota were obtained from the MiBioGen consortium (N = 14,306, from phylum to genus level) and species level of gut microbiota were acquired from the Dutch Microbiome Project (N = 7,738). For FD and IBS, we utilized the FinnGen consortium, whereas, for GERD data analysis, we obtained the IEU OpenGWAS project. The inverse-variance weighted (IVW) method was used as the primary method to calculate causal effect values. Sensitivity analyses were also performed to confirm the robustness of the primary findings of the MR analyses. Moreover, a reverse MR analysis was conducted to assess the likelihood of reverse causality.

Results

Combining the results of the preliminary and sensitivity analyses, we identified that 8 gut microbial taxa were associated with FD. Genus Lachnospiraceae NK4A136 group (p = 3.63 × 10-3) and genus Terrisporobacter (p = 1.13 × 10-3) were strongly associated with FD. At the same time, we found that 8 gut microbial taxa were associated with IBS. Family Prevotellaceae (p = 2.44 × 10-3) and species Clostridium leptum (p = 7.68 × 10-3) display a robust correlation with IBS. In addition, 5 gut microbial taxa were associated with GERD using the IVW approach. In the reverse MR analysis, 2 gut microbial taxa were found to be associated with FD, 5 gut microbial taxa were found to be associated with IBS, and 21 gut microbial taxa were found to be associated with GERD.

Conclusion

The study reveals the potential causal effects of specific microbial taxa on FD, IBS, and GERD and may offer novel insights into the diagnosis and treatment of these conditions.

Silent information regulator 2 deficiency exacerbates chronic cold exposure-induced colonic injury and p65 activation in mice

Cold is a common stressor that threatens colonic health by affecting internal homeostasis. From the literature, Silent information regulator 2 (SIRT2) may have important roles during cold stress, but this conjecture requires investigation. To address this knowledge gap, we investigated the effects of SIRT2 on colonic injury in chronically cold-exposure mice. In a previous study, we showed that SIRT2 regulated p65 activation after cold exposure. In the current study, mice were exposed to 4 °C for 3 h/day for 3 weeks to simulate a chronic cold exposure environment. Chronic cold exposure shortened colon length, disrupted tight junctions in colonic epithelial tissue, and disordered colonic flora. Chronic cold exposure also increased p65 acetylation levels, promoted nuclear factor (NF)-κB activation, and increased the expression of its downstream pro-inflammatory factors, while SIRT2 knockdown aggravated the consequences of tissue structure disruption and increased inflammatory factors brought about by chronic cold exposure to some extent, but could alleviate the downregulation of colonic tight junction-related proteins to some extent. We also observed direct SIRT2 regulatory effects toward p65, and in Caco-2 cells treated with lipopolysaccharide (LPS), SIRT2 knockdown increased p65 acetylation levels and pro-inflammatory factor expression, while SIRT2 overexpression reversed these phenomena. Therefore, SIRT2 deletion exacerbated chronic cold exposure-induced colonic injury and p65 activation in mice. Mechanistically, p65 modification by SIRT2 via deacetylation may affect NF-κB signaling. These findings suggest that SIRT2 is a key target of colonic health maintenance under chronic cold exposure conditions.

Ziziphus jujuba Miller Ethanol Extract Restores Disrupted Intestinal Barrier Function via Tight Junction Recovery and Reduces Inflammation

Inflammatory bowel disease (IBD) is a chronic inflammatory condition caused by the disruption of the intestinal barrier. The intestinal barrier is maintained by tight junctions (TJs), which sustain intestinal homeostasis and prevent pathogens from entering the microbiome and mucosal tissues. Ziziphus jujuba Miller (Z. jujuba) is a natural substance that has been used in traditional medicine as a therapy for a variety of diseases. However, in IBD, the efficacy of Z. jujuba is unknown. Therefore, we evaluated ZJB in Caco2 cells and a dextran sodium sulfate (DSS)-induced mouse model to demonstrate its efficacy in IBD. Z. jujuba extracts were prepared using 70% ethanol and were named ZJB. ZJB was found to be non-cytotoxic and to have excellent antioxidant effects. We confirmed its anti-inflammatory properties via the down-regulation of inflammatory factors, including inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). To evaluate the effects of ZJB on intestinal barrier function and TJ improvement, the trans-epithelial electrical resistance (TEER) and fluorescein isothiocyanate-dextran 4 kDa (FITC-Dextran 4) permeability were assessed. The TEER value increased by 61.389% and permeability decreased by 27.348% in the 200 μg/mL ZJB group compared with the 50 ng/mL IL-6 group after 24 h. Additionally, ZJB alleviated body weight loss, reduced the disease activity index (DAI) score, and induced colon shortening in 5% DSS-induced mice; inflammatory cytokines, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 were down-regulated in the serum. TJ proteins, such as Zonula occludens (ZO)-1 and occludin, were up-regulated by ZJB in an impaired Caco2 mouse model. Additionally, according to the liquid chromatography results, in tandem with mass spectrometry (LC-MS/MS) analysis, seven active ingredients were detected in ZJB. In conclusion, ZJB down-regulated inflammatory factors, protected intestinal barrier function, and increased TJ proteins. It is thus a safe, natural substance with the potential to be used as a therapeutic agent in IBD treatment.

Short-Chain Fatty Acids and Human Health: From Metabolic Pathways to Current Therapeutic Implications

The gastrointestinal tract is home to trillions of diverse microorganisms collectively known as the gut microbiota, which play a pivotal role in breaking down undigested foods, such as dietary fibers. Through the fermentation of these food components, short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate are produced, offering numerous health benefits to the host. The production and absorption of these SCFAs occur through various mechanisms within the human intestine, contingent upon the types of dietary fibers reaching the gut and the specific microorganisms engaged in fermentation. Medical literature extensively documents the supplementation of SCFAs, particularly butyrate, in the treatment of gastrointestinal, metabolic, cardiovascular, and gut-brain-related disorders. This review seeks to provide an overview of the dynamics involved in the production and absorption of acetate, propionate, and butyrate within the human gut. Additionally, it will focus on the pivotal roles these SCFAs play in promoting gastrointestinal and metabolic health, as well as their current therapeutic implications.

Stored white tea ameliorates DSS-induced ulcerative colitis in mice by modulating the composition of the gut microbiota and intestinal metabolites

Changes in the chemical composition of white tea during storage have been studied extensively; however, whether such chemical changes impact the efficacy of white tea in ameliorating colitis remains unclear. In this study, we compared the effects of new (2021 WP) and 10-year-old (2011 WP) white tea on 3% dextrose sodium sulfate (DSS)-induced ulcerative colitis in mice by gavaging mice with the extracts at 200 mg kg-1 day-1. Chemical composition analysis showed that the levels of 50 compounds, such as flavanols, dimeric catechins, and amino acids, were significantly lower in the 2011 WP extract than in the 2021 WP extract, whereas the contents of 21 compounds, such as N-ethyl-2-pyrrolidinone-substituted flavan-3-ols, theobromine, and (-)-epigallocatechin-3-(3''-O-methyl) gallate, were significantly higher. Results of the animal experiments showed that 2011 WP ameliorated the pathological symptoms of colitis, which was superior to the activity of 2021 WP, and this effect was likely enhanced based on the decreasing of the relative abundance of the g_bacteroides and g_Escherichia-Shigella flora in mice with colitis and promoting the conversion of primary bile acids to secondary bile acids in the colon. These results will facilitate the development of novel functional products from white tea.

Host-gut microbiota derived secondary metabolite mediated regulation of Wnt/β-catenin pathway: a potential therapeutic axis in IBD and CRC

The intestinal tract encompasses one of the largest mucosal surfaces with a well-structured layer of intestinal epithelial cells supported by a network of underlying lamina propria immune cells maintaining barrier integrity. The commensal microflora in this environment is a major contributor to such functional outcomes due to its prominent role in the production of secondary metabolites. Of the several known metabolites of gut microbial origin, such as Short Chain Fatty Acids (SCFAs), amino acid derivatives, etc., secondary bile acids (BAs) are also shown to exhibit pleiotropic effects maintaining gut homeostasis in addition to their canonical role in dietary lipid digestion. However, dysbiosis in the intestine causes an imbalance in microbial diversity, resulting in alterations in the functionally effective concentration of these secondary metabolites, including BAs. This often leads to aberrant activation of the underlying lamina propria immune cells and associated signaling pathways, causing intestinal inflammation. Sustained activation of these signaling pathways drives unregulated cell proliferation and, when coupled with genotoxic stress, promotes tumorigenesis. Here, we aimed to discuss the role of secondary metabolites along with BAs in maintaining immune-gut homeostasis and regulation of inflammation-driven tumorigenesis with emphasis on the classical Wnt/β-Catenin signaling pathway in colon cancer.

Mechanism of sodium butyrate, a metabolite of gut microbiota, regulating cardiac fibroblast transdifferentiation via the NLRP3/Caspase-1 pyroptosis pathway

BACKGROUND

Cardiac fibroblasts (CFs) are activated after initial injury, and then differentiate into myofibroblasts (MFs), which play a pivotal role as the primary mediator cells in pathological remodeling. Sodium butyrate (NaB), being a metabolite of gut microbiota, exhibits anti-inflammatory property in local therapies on sites other than the intestine. Thus, this study aimed to probe the mechanism by which NaB regulates CFs transdifferentiation through the NLRP3/Caspase-1 pyroptosis pathway.

METHODS

CFs were cultured in vitro and induced into MFs by TGFβ1. CFs were identified by immunofluorescence labelling technique of vimentin and α-SMA, followed by treatment with NaB or NLRP3 inflammasome inhibitor (CY-09) and its activator [nigericin sodium salt (NSS)]. The expression levels of α-SMA, GSDMD-N/NLRP3/cleaved Caspase-1 proteins, and inflammatory factors IL-1β/IL-18/IL-6/IL-10 were determined using immunofluorescence, Western blot and ELISA. Cell proliferation and migration were evaluated using the CCK-8 assay and the cell scratch test, respectively.

RESULTS

Following the induction of TGFβ1, CFs exhibited increased expression levels of α-SMA proteins and IL-6/IL-10, as well as cell proliferative and migratory abilities. TGFβ1 induced CFs to differentiate into MFs, while NaB inhibited this differentiation. NaB inactivated the NLRP3/Caspase-1 pyroptosis pathway. CY-09 demonstrated inhibitory effects on the NLRP3/Caspase-1 pyroptosis pathway, leading to a reduction in TGFβ1-induced CFs transdifferentiation. NSS activated the NLRP3/Caspase-1 pyroptosis pathway, and thus partially counteracting the inhibitory effect of intestinal microbiota metabolite NaB on CFs transdifferentiation.

CONCLUSION

NaB, a metabolite of the gut microbiota, inhibited the activation of the NLRP3/Caspase-1 pyroptosis pathway in TGFβ1-induced CFs, repressed the transdifferentiation of CFs into MFs.

Exploring Microbial Metabolite Receptors in Inflammatory Bowel Disease: An In Silico Analysis of Their Potential Role in Inflammation and Fibrosis

Metabolites produced by dysbiotic intestinal microbiota can influence disease pathophysiology by participating in ligand-receptor interactions. Our aim was to investigate the differential expression of metabolite receptor (MR) genes between inflammatory bowel disease (IBD), healthy individuals (HIs), and disease controls in order to identify possible interactions with inflammatory and fibrotic pathways in the intestine. RNA-sequencing datasets containing 643 Crohn's disease (CD) patients, 467 ulcerative colitis (UC) patients and 295 HIs, and 4 Campylobacter jejuni-infected individuals were retrieved from the Sequence Read Archive, and differential expression was performed using the RaNA-seq online platform. The identified differentially expressed MR genes were used for correlation analysis with up- and downregulated genes in IBD, as well as functional enrichment analysis using a R based pipeline. Overall, 15 MR genes exhibited dysregulated expression in IBD. In inflamed CD, the hydroxycarboxylic acid receptors 2 and 3 (HCAR2, HCAR3) were upregulated and were associated with the recruitment of innate immune cells, while, in the non-inflamed CD ileum, the cannabinoid receptor 1 (CNR1) and the sphingosine-1-phospate receptor 4 (S1PR4) were downregulated and were involved in the regulation of B-cell activation. In inflamed UC, the upregulated receptors HCAR2 and HCAR3 were more closely associated with the process of TH-17 cell differentiation, while the pregnane X receptor (NR1I2) and the transient receptor potential vanilloid 1 (TRPV1) were downregulated and were involved in epithelial barrier maintenance. Our results elucidate the landscape of metabolite receptor expression in IBD, highlighting associations with disease-related functions that could guide the development of new targeted therapies.

Mitigation of Osteoclast-Mediated Arthritic Bone Remodeling By Short Chain Fatty Acids

OBJECTIVE

The objective for this study was to evaluate the effects of short chain fatty acids (SCFAs) on arthritic bone remodeling.

METHODS

We treated a recently described preclinical murine model of psoriatic arthritis (PsA), R26STAT3Cstopfl/fl CD4Cre mice, with SCFA-supplemented water. We also performed in vitro osteoclast differentiation assays in the presence of serum-level SCFAs to evaluate the direct impact of these microbial metabolites on maturation and function of osteoclasts. We further characterized the molecular mechanism of SCFAs by transcriptional analysis.

RESULTS

The osteoporosis condition in R26STAT3Cstopfl/fl CD4Cre animals is attributed primarily to robust osteoclast differentiation driven by an expansion of osteoclast progenitor cells (OCPs), accompanied by impaired osteoblast development. We show that SCFA supplementation can rescue the osteoporosis phenotype in this model of PsA. Our in vitro experiments revealed an inhibitory effect of the SCFAs on osteoclast differentiation, even at very low serum concentrations. This suppression of osteoclast differentiation enabled SCFAs to impede osteoporosis development in R26STAT3Cstopfl/fl CD4Cre mice. Further interrogation revealed that bone marrow-derived OCPs from diseased mice expressed a higher level of SCFA receptors than those of control mice and that the progenitor cells in the bone marrow of SCFA-treated mice presented a modified transcriptomic landscape, suggesting a direct impact of SCFAs on bone marrow progenitors in the context of osteoporosis.

CONCLUSION

We demonstrated how gut microbiota-derived SCFAs can regulate distal pathology (ie, osteoporosis) and identified a potential therapeutic option for restoring bone density in rheumatic disease, further highlighting the critical role of the gut-bone axis in these disorders.

Butyrate as a promising therapeutic target in cancer: From pathogenesis to clinic (Review)

Cancer is one of the leading causes of mortality worldwide. The etiology of cancer has not been fully elucidated yet, and further enhancements are necessary to optimize therapeutic efficacy. Butyrate, a short‑chain fatty acid, is generated through gut microbial fermentation of dietary fiber. Studies have unveiled the relevance of butyrate in malignant neoplasms, and a comprehensive understanding of its role in cancer is imperative for realizing its full potential in oncological treatment. Its full antineoplastic effects via the activation of G protein‑coupled receptors and the inhibition of histone deacetylases have been also confirmed. However, the underlying mechanistic details remain unclear. The present study aimed to review the involvement of butyrate in carcinogenesis and its molecular mechanisms, with a particular emphasis on its association with the efficacy of tumor immunotherapy, as well as discussing relevant clinical studies on butyrate as a therapeutic target for neoplastic diseases to provide new insights into cancer treatment.

Integrated annotation prioritizes metabolites with bioactivity in inflammatory bowel disease

Microbial biochemistry is central to the pathophysiology of inflammatory bowel diseases (IBD). Improved knowledge of microbial metabolites and their immunomodulatory roles is thus necessary for diagnosis and management. Here, we systematically analyzed the chemical, ecological, and epidemiological properties of ~82k metabolic features in 546 Integrative Human Microbiome Project (iHMP/HMP2) metabolomes, using a newly developed methodology for bioactive compound prioritization from microbial communities. This suggested >1000 metabolic features as potentially bioactive in IBD and associated ~43% of prevalent, unannotated features with at least one well-characterized metabolite, thereby providing initial information for further characterization of a significant portion of the fecal metabolome. Prioritized features included known IBD-linked chemical families such as bile acids and short-chain fatty acids, and less-explored bilirubin, polyamine, and vitamin derivatives, and other microbial products. One of these, nicotinamide riboside, reduced colitis scores in DSS-treated mice. The method, MACARRoN, is generalizable with the potential to improve microbial community characterization and provide therapeutic candidates.

Asiaticoside ameliorates DSS-induced colitis in mice by inhibiting inflammatory response, protecting intestinal barrier and regulating intestinal microecology

Ulcerative colitis (UC) is one of the most prevalent inflammatory bowel diseases and poses a serious threat to human health. Currently, safe and effective preventive measures are unavailable. In this study, the protective effects of asiaticoside (AS) on dextran sodium sulfate (DSS)-induced colitis in mice and the underlying molecular mechanism were investigated. In this experiment, colitis was induced in mice with DSS. Subsequently, the role of AS in colitis and its underlying mechanisms were examined using H&E staining, immunofluorescence staining, western blot, Elisa, FMT, and other assays. The results showed that AS significantly attenuated the related symptoms of DSS-induced colitis in mice. In addition, AS inhibited the activation of signaling pathways TLR4/NF-κB and MAPK reduced the release of inflammatory factors, thereby attenuating the inflammatory response in mice. AS administration also restored the permeability of the intestinal barrier by increasing the levels of tight junction-associated proteins (claudin-3, occludin, and ZO-1). In addition, AS rebalanced the intestinal flora of DSS-treated mice by increasing the diversity of the flora. AS can alleviate DSS-induced ulcerative colitis in mice by maintaining the intestinal barrier, thus inhibiting the signaling pathways TLR4/NF-κB and MAPK activation, reducing the release of inflammatory factors, and regulating intestinal microecology.

Harnessing and delivering microbial metabolites as therapeutics via advanced pharmaceutical approaches

Microbial metabolites have emerged as key players in the interplay between diet, the gut microbiome, and host health. Two major classes, short-chain fatty acids (SCFAs) and tryptophan (Trp) metabolites, are recognized to regulate inflammatory, immune, and metabolic responses within the host. Given that many human diseases are associated with dysbiosis of the gut microbiome and consequent reductions in microbial metabolite production, the administration of these metabolites represents a direct, multi-targeted treatment. While a multitude of preclinical studies showcase the therapeutic potential of both SCFAs and Trp metabolites, they often rely on high doses and frequent dosing regimens to achieve systemic effects, thereby constraining their clinical applicability. To address these limitations, a variety of pharmaceutical formulations approaches that enable targeted, delayed, and/or sustained microbial metabolite delivery have been developed. These approaches, including enteric encapsulations, esterification to dietary fiber, prodrugs, and nanoformulations, pave the way for the next generation of microbial metabolite-based therapeutics. In this review, we first provide an overview of the roles of microbial metabolites in maintaining host homeostasis and outline how compromised metabolite production contributes to the pathogenesis of inflammatory, metabolic, autoimmune, allergic, infectious, and cancerous diseases. Additionally, we explore the therapeutic potential of metabolites in these disease contexts. Then, we provide a comprehensive and up-to-date review of the pharmaceutical strategies that have been employed to enhance the therapeutic efficacy of microbial metabolites, with a focus on SCFAs and Trp metabolites.

Restoring Treg/Th17 cell balance in ulcerative colitis through HRas silencing and MAPK pathway inhibition

This study investigates HRas-dependent mechanisms in the disruption of regulatory T (Treg) cells and T helper 17 (Th17) cells balance in ulcerative colitis (UC). Comprehensive RNA sequencing and bioinformatics analyses revealed elevated HRas and MAPK pathway-related protein expression in UC samples. Using a murine UC model induced by dextran sulfate sodium (DSS), HRas silencing was found to promote Treg cell differentiation and suppress Th17 cell production, effectively restoring balance. Inactivation of the MAPK pathway played a pivotal role in this rebalancing effect. In vivo experiments further confirmed that HRas silencing mitigated colon tissue damage in DSS-induced mice, emphasizing its potential as a therapeutic strategy for UC.

The effect of oral butyrate on colonic short-chain fatty acid transporters and receptors depends on microbial status

Butyrate, a metabolite produced by gut bacteria, has demonstrated beneficial effects in the colon and has been used to treat inflammatory bowel diseases. However, the mechanism by which butyrate operates remains incompletely understood. Given that oral butyrate can exert either a direct impact on the gut mucosa or an indirect influence through its interaction with the gut microbiome, this study aimed to investigate three key aspects: (1) whether oral intake of butyrate modulates the expression of genes encoding short-chain fatty acid (SCFA) transporters (Slc16a1, Slc16a3, Slc16a4, Slc5a8, Abcg2) and receptors (Hcar2, Ffar2, Ffar3, Olfr78, Olfr558) in the colon, (2) the potential involvement of gut microbiota in this modulation, and (3) the impact of oral butyrate on the expression of colonic SCFA transporters and receptors during colonic inflammation. Specific pathogen-free (SPF) and germ-free (GF) mice with or without DSS-induced inflammation were provided with either water or a 0.5% sodium butyrate solution. The findings revealed that butyrate decreased the expression of Slc16a1, Slc5a8, and Hcar2 in SPF but not in GF mice, while it increased the expression of Slc16a3 in GF and the efflux pump Abcg2 in both GF and SPF animals. Moreover, the presence of microbiota was associated with the upregulation of Hcar2, Ffar2, and Ffar3 expression and the downregulation of Slc16a3. Interestingly, the challenge with DSS did not alter the expression of SCFA transporters, regardless of the presence or absence of microbiota, and the effect of butyrate on the transporter expression in SPF mice remained unaffected by DSS. The expression of SCFA receptors was only partially affected by DSS. Our results indicate that (1) consuming a relatively low concentration of butyrate can influence the expression of colonic SCFA transporters and receptors, with their expression being modulated by the gut microbiota, (2) the effect of butyrate does not appear to result from direct substrate-induced regulation but rather reflects an indirect effect associated with the gut microbiome, and (3) acute colon inflammation does not lead to significant changes in the transcriptional regulation of most SCFA transporters and receptors, with the effect of butyrate in the inflamed colon remaining intact.

Sodium butyrate ameliorated diabetic nephropathy-associated tubulointerstitial inflammation by modulating the tight junctions of renal tubular epithelial cells

As one of the most significant pathological changes of diabetic nephropathy (DN), tubulointerstitial fibrosis (TIF) had a close relationship with tubulointerstitial inflammation (TI), and the occurrence of TI could have resulted from the disrupted tight junctions (TJs) of renal tubular epithelial cells (RTECs). Studies have demonstrated that sodium butyrate (NaB), a typical short chain fatty acid (SCFA), played an important regulatory role in intestinal TJs and inflammation. In this study, our in vivo and in vitro results showed that accompanied by TI, renal tubular TJs were gradually disrupted in the process of DN-related TIF. In HG and LPS co-cultured HK-2 cells and db/db mice, NaB treatment regained the TJs of RTECs via the sphingosine 1-phosphate receptor-1 (S1PR1)/AMPK signaling pathway, relieving inflammation. Small interfering RNA of S1PR1, S1PR1 antagonist W146 and agonist SEW2871, and AMPK agonist AICAR were all used to further confirm the essential role of the S1PR1/AMPK signaling pathway in NaB's TJ protection in RTECs in vitro. Finally, NaB administration not only improved the renal function and TIF, but also relieved the TI of db/db mice. These findings suggested that the use of NaB might be a potential adjuvant treatment strategy for DN-associated TIF, and this protective effect was linked to the TJ modulation of RTECs via the S1PR1/AMPK signaling pathway, leading to the improvement of TI.

Fucoxanthin Alleviates Dextran Sulfate Sodium-Induced Colitis and Gut Microbiota Dysbiosis in Mice

The purpose of this study was to evaluate the preventive role and underlying mechanisms of fucoxanthin (Fx) on dextran sulfate sodium (DSS)-induced colitis in mice. The present data demonstrated that oral administration of Fx (50 and 200 mg/kg body weight/day) for 36 days significantly alleviated the severity of colitis in DSS-treated mice, as evidenced by attenuating body weight loss, bloody stool, diarrhea, shortened colon length, colonic epithelium distortion, a thin mucus layer, goblet cell depletion, damaged crypts, and extensive infiltration of inflammatory cells in the colonic mucosa. Additionally, Fx notably relieved DSS-induced intestinal epithelial barrier dysfunction via maintaining the tight junction function and preventing excessive apoptosis of colonic epithelial cells. Moreover, Fx effectively diminished colonic inflammation and oxidative stress in DSS-treated mice, and its mechanisms might be due to blunting the activation of NF-κB and NLRP3 inflammasome signaling pathways. Furthermore, Fx also modulates DSS-induced gut microbiota dysbiosis via recovering the richness and diversity of gut microbiota and reshaping the structure of gut microbiota, such as increasing the Firmicutes and Bacteroidota (F/B) ratio and elevating the relative abundance of some potential beneficial bacteria, including Lactobacillaceae and Lachnospiraceae. Overall, Fx might be developed as a promising functional ingredient to prevent colitis and maintain intestinal homeostasis.

A Dual Therapeutic Approach to Diabetes Mellitus via Bioactive Phytochemicals Found in a Poly Herbal Extract by Restoration of Favorable Gut Flora and Related Short-Chain Fatty Acids

Diabetes mellitus (DM), a metabolic and endocrine condition, poses a serious threat to human health and longevity. The emerging role of gut microbiome associated with bioactive compounds has recently created a new hope for DM treatment. UHPLC-HRMS methods were used to identify these compounds in a poly herbal ethanolic extract (PHE). The effects of PHE on body weight (BW), fasting blood glucose (FBG) level, gut microbiota, fecal short-chain fatty acids (SCFAs) production, and the correlation between DM-related indices and gut microbes, in rats were investigated. Chebulic acid (0.368%), gallic acid (0.469%), andrographolide (1.304%), berberine (6.442%), and numerous polysaccharides were the most representative constituents in PHE. A more significant BW gain and a reduction in FBG level towards normal of PHE 600 mg/kg treated rats group were resulted at the end of 28th days of the study. Moreover, the composition of the gut microbiota corroborated the study's hypothesis, as evidenced by an increased ratio of Bacteroidetes to Firmicutes and some beneficial microbial species, including Prevotella copri and Lactobacillus hamster. The relative abundance of Bifidobacterium pseudolongum, Ruminococcus bromii, and Blautia producta was found to decline in PHE treatment groups as compared to diabetic group. The abundance of beneficial bacteria in PHE 600 mg/kg treatment group was concurrently associated with increased SCFAs concentrations of acetate and propionate (7.26 nmol/g and 4.13 nmol/g). The findings of this study suggest a promising approach to prevent DM by demonstrating that these naturally occurring compounds decreased FBG levels by increasing SCFAs content and SCFAs producing gut microbiota.

Lactate Protects Intestinal Epithelial Barrier Function from Dextran Sulfate Sodium-Induced Damage by GPR81 Signaling

The dysregulation of the intestinal epithelial barrier significantly contributes to the inflammatory progression of ulcerative colitis. Recent studies have indicated that lactate, produced by gut bacteria or derived from fermented foods, plays a key role in modulating inflammation via G-protein-coupled receptor 81 (GPR81). In this study, we aimed to investigate the potential role of GPR81 in the progression of colitis and to assess the impact of lactate/GPR81 signaling on intestinal epithelial barrier function. Our findings demonstrated a downregulation of GPR81 protein expression in patients with colitis. Functional verification experiments showed that Gpr81-deficient mice exhibited more severe damage to the intestinal epithelial barrier and increased susceptibility to DSS-induced colitis, characterized by exacerbated oxidative stress, elevated inflammatory cytokine secretion, and impaired expression of tight-junction proteins. Mechanistically, we found that lactate could suppress TNF-α-induced MMP-9 expression and prevent the disruption of tight-junction proteins by inhibiting NF-κB activation through GPR81 in vitro. Furthermore, our study showed that dietary lactate could preserve intestinal epithelial barrier function against DSS-induced damage in a GPR81-dependent manner in vivo. Collectively, these results underscore the crucial involvement of the lactate/GPR81 signaling pathway in maintaining intestinal epithelial barrier function, providing a potential therapeutic strategy for ulcerative colitis.

Autoinducer-2 promotes the colonization of Lactobacillus rhamnosus GG to improve the intestinal barrier function in a neonatal mouse model of antibiotic-induced intestinal dysbiosis

BACKGROUND

Human health is seriously threatened by antibiotic-induced intestinal disorders. Herein, we aimed to determine the effects of Autoinducer-2 (AI-2) combined with Lactobacillus rhamnosus GG (LGG) on the intestinal barrier function of antibiotic-induced intestinal dysbiosis neonatal mice.

METHODS

An antibiotic-induced intestinal dysbiosis neonatal mouse model was created using antibiotic cocktails, and the model mice were randomized into the control, AI-2, LGG, and LGG + AI-2 groups. Intestinal short-chain fatty acids and AI-2 concentrations were detected by mass spectrometry and chemiluminescence, respectively. The community composition of the gut microbiota was analyzed using 16S rDNA sequencing, and biofilm thickness and bacterial adhesion in the colon were assessed using scanning electron microscopy. Transcriptome RNA sequencing of intestinal tissues was performed, and the mRNA and protein levels of HCAR2 (hydroxycarboxylic acid receptor 2), claudin3, and claudin4 in intestinal tissues were determined using quantitative real-time reverse transcription PCR and western blotting. The levels of inflammatory factors in intestinal tissues were evaluated using enzyme-linked immunosorbent assays (ELISAs). D-ribose, an inhibitor of AI-2, was used to treat Caco-2 cells in vitro.

RESULTS

Compared with the control, AI-2, and LGG groups, the LGG + AI-2 group showed increased levels of intestinal AI-2 and proportions of Firmicutes and Lacticaseibacillus, but a reduced fraction of Proteobacteria. Specifically, the LGG + AI-2 group had considerably more biofilms and LGG on the colon surface than those of other three groups. Meanwhile, the combination of AI-2 and LGG markedly increased the concentration of butyric acid and promoted Hcar2, claudin3 and claudin4 expression levels compared with supplementation with LGG or AI-2 alone. The ELISAs revealed a significantly higher tumor necrosis factor alpha (TNF-α) level in the control group than in the LGG and LGG + AI-2 groups, whereas the interleukin 10 (IL-10) level was significantly higher in the LGG + AI-2 group than in the other three groups. In vitro, D-ribose treatment dramatically suppressed the increased levels of Hcar2, claudin3, and claudin4 in Caco-2 cells induced by AI-2 + LGG.

CONCLUSIONS

AI-2 promotes the colonization of LGG and biofilm formation to improve intestinal barrier function in an antibiotic-induced intestinal dysbiosis neonatal mouse model.

Sodium butyrate restricts neutrophils migration and NETs formation through reducing macrophage-derived CXCL16 in calculous cholecystitis

Background

Neutrophil extracellular traps (NETs) havebeen demonstrated to initiate gallstone formation. Cholecystitis is a common complication of gallstones. As short-chain fatty acids (SCFAs), Butyrate acid has anti-inflammatory effects and alleviates cholesterol gallstones. However, the role of Butyrate acid in NETs of calculous cholecystitis and the molecular mechanism remains unclear. The effect of Sodium butyrate on neutrophil migration and NETs formation involved in macrophages polarization and exosomalCXCL16 in calculous cholecystitis was explored in our study.

Methods

The number of neutrophils and NETs, macrophages polarization and exosomal CXCL16 level were analyzed in clinic samples from patients. Exosomes were obtained and verified by gradient centrifugation, transmission electron microscopy, NanoSight analysis and Western blotting. Transwell, immunofluorescence and ELISA were used to detect neutrophil migration and NETs formation.

Results

Our results demonstrated that a large number of neutrophils and NETs, as well as M1 macrophages and exosomal CXCL16, were found in the blood of gallstones patients, especially patients with acute calculous cholecystitis. Exosomal CXCL16 was upregulated in plasma of calculous cholecystitis patients or Lipopolysaccharide induced macrophages, and promoted neutrophil cell migration and NETs formation. Sodium butyrate reduced exosomal CXCL16 secretion through the inhibition of M1 macrophage polarization to suppress neutrophils migration and NETs formation.

Conclusion

Our study suggested that Sodium butyrate may inhibit neutrophils migration and NETs formation to alleviate calculous cholecystitis by reducing exosomal CXCL16 secretion from macrophage and macrophage polarization.

General significance

Our finding may provide a link between exosomes and neutrophils to serve as a potential therapeutic intervention in calculous cholecystitis.

Hypersampsonone H attenuates ulcerative colitis via inhibition of PDE4 and regulation of cAMP/PKA/CREB signaling pathway

BACKGROUND AND OBJECTIVES

Ulcerative colitis (UC) is a recurrent intestinal inflammatory disease which poses a serious threat to the life of patients. However, there are no specific drugs for UC yet. Hypericum sampsonii Hance (HS) is a Chinese herbal medicine traditionally used to treat enteritis and dysentery. Our previous studies have demonstrated that HS holds potential anti-UC effects, and a novel compound named Hypersampsonone H (HS-1) isolated from HS possesses significant anti-inflammatory activity. However, the beneficial effects of HS-1 on UC remain unclear. This study aimed to investigate the therapeutic effects of HS-1 on UC and its potential mechanisms, both in vitro and in vivo.

METHODS

The in vitro model was employed using LPS-induced RAW264.7 cells to investigate the anti-inflammatory effects of HS-1 and its possible mechanisms. Furthermore, the therapeutic efficacy and potential mechanisms of HS-1 against dextran sulfate sodium (DSS)-induced acute colitis were assessed through histopathological examination, biochemical analysis, and molecular docking.

RESULTS

In vitro, HS-1 significantly reduced LPS-induced inflammatory responses, as indicated by inhibiting NO production, down-regulating the overexpression of COX-2 and iNOS, as well as regulating the imbalanced levels of IL-6, TNF-α, and IL-10. Moreover, HS-1 also inhibited the expression of PDE4, elevated the intracellular cAMP level, and promoted the phosphorylation of CREB, thereby activating the PKA/CREB pathway in RAW264.7 cells. In vivo, HS-1 demonstrated therapeutic capacity against DSS-induced colitis by alleviating the symptoms of colitis mice, regulating the abnormal expression of inflammatory mediators, protecting the integrity of intestinal epithelial barrier, and reducing tissue fibrosis. Consistently, HS-1 was found to decrease the expression of PDE4 isoforms, subsequently activating the cAMP/PKA/CREB signaling pathway. Furthermore, the molecular docking results indicated that HS-1 exhibited a high affinity for PDE4, particularly PDE4D. Further mechanistic validation in vitro demonstrated that HS-1 possessed a synergistic effect on forskolin and an antagonistic effect on H-89 dihydrochloride, thereby exerting anti-inflammatory effects through the cAMP/PKA/CREB signaling pathway.

CONCLUSION

We disclose that HS-1 serves as a promising candidate drug for the treatment of UC by virtue of its ability to reduce DSS-induced colitis via the inhibition of PDE4 and the activation of cAMP/PKA/CREB signaling pathway.

Effects of Clostridium tyrobutyricum on Lipid Metabolism, Intestinal Barrier Function, and Gut Microbiota in Obese Mice Induced by High-Fat Diet

Obesity and its complications constitute a main threat to global human health. The purpose of this investigation was to explore the influences of Clostridium tyrobutyricum (Ct) on lipid metabolism, intestinal barrier function, and intestinal microbiome in obese mice induced by a high-fat diet (HFD). After establishing the obesity model, 107 CFU/mL and 108 CFU/mL C. tyrobutyricum were used to intervene in HFD-fed mice by gavage for six weeks, and indexes related to obesity were measured. In the liver of HFD-fed mice, the results revealed that C. tyrobutyricum reduced liver weight and the levels of triglyceride (TG), total cholesterol (TC), and nonesterified fatty acid (NEFA), along with decreasing red lipid droplets and fat vacuoles. After C. tyrobutyricum intervention, the mRNA expression of peroxisome proliferator-activated receptor-γ (PPARγ) was downregulated, and AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor-α (PPARα), adipose triglyceride lipase (ATGL), and hormone-sensitive lipase (HSL) were upregulated in the liver. Additionally, C. tyrobutyricum alleviated intestinal morphology injury caused by HFD, decreased the expression of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and IL-1β in the colon, and upregulated tight junction protein expression. In addition, 16S rRNA sequencing revealed that C. tyrobutyricum increases the diversity of intestinal microbiota. Overall, C. tyrobutyricum improved HFD-induced lipid metabolism disorders, preserved the intestinal barrier's integrity, and modulated the structure of the intestinal microbiome. These findings provide a novel insight into the role of C. tyrobutyricum as a probiotic in regulating lipid metabolism.

Syringaldehyde Exhibits Antibacterial and Antioxidant Activities against Mycobacterium marinum Infection

Tuberculosis (TB) is caused by infection with Mycobacterium tuberculosis (Mtb), which has a unique resistance to many antimicrobial agents. TB has emerged as a significant worldwide health issue because of the rise of multidrug-resistant strains causing drug-resistant TB (DR-TB). As a result, the development of new drugs or effective strategies is crucial for patients with TB. Mycobacterium marinum (Mm) and Mtb are both species of mycobacteria. In zebrafish, Mm proliferates and forms chronic granulomatous infections, which are similar to Mtb infections in lung tissue. Syringaldehyde (SA) is a member of the phenolic aldehyde family found in various plants. Here, we investigated its antioxidative and antibacterial properties in Mm-infected cells and zebrafish. Our results demonstrated that SA inhibits Mm-infected pulmonary epithelial cells and inhibits the proliferation of Mm in Mm-infected zebrafish, suggesting that SA provides an antibacterial effect during Mm infection. Further study demonstrated that supplementation with SA inhibits the production of malondialdehyde (MDA) and reactive oxygen species (ROS) and increases the levels of reduced glutathione (GSH) in Mm-infection-induced macrophages. SA inhibits the levels of MDA in Mm-infected zebrafish, suggesting that SA exerts antioxidative effects in vivo. Additionally, we found that SA promotes the expression of NRF2/HO-1/NQO-1 and the activation of the AMPK-α1/AKT/GSK-3β signaling pathway. In summary, our data demonstrated that SA exerts antioxidative and antibacterial effects during Mm infection both in vivo and in vitro and that the antioxidative effects of SA may be due to the regulation of NRF2/HO-1/NQO-1 and the AMPK-α1/AKT/GSK-3β signaling pathway.

Autophagy activation alleviates the LPS-induced inflammatory response in endometrial epithelial cells in dairy cows

PROBLEM

Endometritis is a common disease that affects dairy cow reproduction. Autophagy plays a vital role in cellular homeostasis and modulates inflammation by regulating interactions with innate immune signaling pathways. However, little is known about the regulatory relationship between autophagy and inflammation in bovine endometrial epithelial cells (BEECs). Thus, we aimed to determine the role of autophagy in the inflammatory response in BEECs.

METHODS OF STUDY

In the present study, the expression levels of proinflammatory cytokines were measured by quantitative real-time polymerase chain reaction. Changes in the nuclear factor-κB (NF-κB) pathway and autophagy were determined using immunoblotting and immunocytochemistry. The induction of autophagosome formation was visualized by transmission electron microscopy.

RESULTS

Our results demonstrated that autophagy activation was inhibited in LPS-treated BEECs, while activation of the NF-κB pathway and the mRNA expression of IL-6, IL-8, and TNF-α were increased. Furthermore, blocking autophagy with the inhibitor chloroquine increased NF-κB signaling pathway activation and proinflammatory factor expression in LPS-treated BEECs. Conversely, activation of autophagy with the agonist rapamycin inhibited the NF-κB signaling pathway and downregulated proinflammatory factors.

CONCLUSIONS

These data indicated that LPS-induced inflammation was related to the inhibition of autophagy in BEECs. Thus, the activation of autophagy may represent a novel therapeutic strategy for eliminating inflammation in BEECs.

Microbiota-Gastric Cancer Interactions and the Potential Influence of Nutritional Therapies

Gastric cancer (GC) is one of the most common causes of cancer deaths, and GC treatments represent a large area of research. Although initially regarded as a sterile organ and unsuitable for microbial communities, the discovery of Helicobacter pylori made us realize that some microbes can colonize the stomach. In recent years, growing interest in gastric bacteria has expanded to the gut microbiota and, more recently, to the oral microbiota. Indeed, the oral-gastric-gut microbiota axis may play a crucial role in maintaining homeostasis, while changes in microbiota composition in GC patients can influence clinical outcomes. On the one hand, the microbiota and its metabolites may significantly influence the progression of GC, while anti-GC treatments such as gastrectomy and chemotherapy may significantly impact the oral-gastric-gut microbiota axis of GC patients. In this context, the role of nutritional therapies, including diet, prebiotics, and probiotics, in treating GC should not be underestimated. Wit this review, we aim to highlight the main role of the gastric, oral, and gut microbiota in GC onset and progression, representing potential future biomarkers for early GC detection and a target for efficient nutritional therapies during the course of GC.

Fufangxiaopi formula alleviates DSS-induced colitis in mice by inhibiting inflammatory reaction, protecting intestinal barrier and regulating intestinal microecology

ETHNOPHARMACOLOGICAL RELEVANCE

Fufangxiaopi Formula (FF) is a modified form of Sishen Wan, traditionally used for treating diarrhea. The application of FF for treating ulcerative colitis (UC) has achieved desirable outcomes in clinical settings. However, the underlying mechanism of the effect of FF on UC is yet to be determined.

AIM OF STUDY

This study aimed to evaluate the protective effect and underlying mechanism of FF on mice with dextran sodium sulfate (DSS)-induced colitis.

MATERIALS AND METHODS

In vivo, the efficacy of FF on the symptoms associated with DSS-induced colitis in mice was clarified by observing the body weight change, colon length, DAI score, and H&E staining. The release of inflammatory mediators in mouse colon tissues was detected by ELISA and MPO, and the contents of TLR4/NF-κB signaling pathway and MAPK signaling pathway-related proteins, as well as intestinal barrier-related proteins, were detected in mouse colon tissues by western blot method. Changes in the content of barrier proteins in mouse colon tissues were detected by immunofluorescence. 16S rRNA sequencing and FMT were performed to clarify the effects of FF on intestinal flora. In vitro, the effect of FF-containing serum on LPS-induced inflammatory mediator release from RAW264.7 cells were detected by qRT-PCR. The contents of TLR4/NF The effects of FF-containing serum on B signaling pathway and MAPK signaling pathway related proteins in RAW264.7 cells and intestinal barrier related proteins in Caco-2 cells were detected by western blot. The effects of FF-containing serum on LPS-induced nuclear translocation of p65 protein in RAW264.7 cells and barrier-associated protein in Caco-2 cells were detected by immunofluorescence.

RESULTS

In vivo studies showed that FF could significantly alleviate the symptoms of UC, including reducing colon length, weight loss, clinical score, and colon tissue injury in mice. FF could significantly reduce the secretion of proinflammatory cytokines by suppressing the activation of the TLR4/NF-κB and MAPK signaling pathways. Moreover, FF could protect the integrity of intestinal barriers by significantly increasing claudin-3, occludin, and ZO-1 expression levels. 16S rRNA sequencing and FMT elucidate that FF can alleviate symptoms associated with colitis in mice by interfering with intestinal flora. In vitro studies showed that FF drug-containing serum could significantly inhibit proinflammatory responses and attenuate the secretion of iNOS, IL-1β, TNF-α, IL-6, and COX-2 by suppressing the activation of TLR4/NF-κB and MAPK signaling pathways in RAW264.7 cells. Furthermore, FF could protect the Caco-2 cell epithelial barrier.

CONCLUSION

FF could alleviate DSS-induced colitis in mice by maintaining the intestinal barrier, inhibiting the activation of TLR4/NF-κB and MAPK signaling pathways, reducing the release of proinflammatory factors, and regulating intestinal microecology.

Role and intervention of PAD4 in NETs in acute respiratory distress syndrome

BACKGROUND

Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection. Acute respiratory distress syndrome (ARDS) is a common sepsis-associated injury that can increase postoperative mortality but the mechanism is still unclear.

MAIN TEXT

The role of neutrophils in the pathophysiology of sepsis was deeply challenged after the discovery of NETosis, a process resulting in neutrophil extracellular traps (NETs) release. NETs can support thrombin generation and the concept of immunothrombosis has emerged as a new innate response to infection. Immunothrombosis leads to thrombosis in microvessels and supports immune cells together with specific thrombus-related molecules. ARDS is a common sepsis-associated organ injury. Immunothrombosis participates in thrombosis in pulmonary capillaries. Intervention regarding immunothrombosis in ARDS is a key scientific problem. PAD4 is the key enzyme regulating the NET skeleton protein histone H3 to citrulline histone to form NETs in immune thrombosis. This review summarizes NETosis and immunohaemostasis, ARDS and therapeutic opportunities targeting PAD4 via PAD4 inhibitors and lncRNAs potentially, providing future therapies.

CONCLUSIONS

We identified and summarized the fundamental definition of ARDS and the concept of immune thrombosis and its composition. NETs activation has become particularly relevant in the formation of immune thrombosis. The taskforce highlighted the intervention targets of PAD4, including noncoding RNAs, potentially providing future therapeutic targets to confront the high postoperative mortality of ARDS.

Short-chain fatty acids (SCFAs) from gastrointestinal disorders, metabolism, epigenetics, central nervous system to cancer - A mini-review

Short-chain fatty acids (SCFAs), generated through microbial fermentation of dietary fibers and proteins in the gut, play a pivotal role in maintaining intestinal integrity, cellular function, and the immune response. SCFAs, including butyrate, acetate, and propionate, are absorbed in the colon or excreted through feces, contributing to essential physiological processes. Butyrate, a primary energy source for colonocytes, exhibits anti-inflammatory properties and regulates key pathways, such as nuclear factor-κB (NF-κB) inhibition. SCFAs' impact extends beyond the intestines, influencing the gut-brain axis, systemic circulation, and folate metabolism. A decline in colonic SCFAs has been linked to gastrointestinal diseases, emphasizing their clinical relevance, while their effects on immune checkpoints, such as ipilimumab, provide intriguing prospects for cancer therapy. This mini-review explores SCFAs' diverse roles, shedding light on their significance in health and potential implications for disease management. Understanding SCFAs' intricate mechanisms enhances our knowledge of their therapeutic potential and highlights their emerging importance in various physiological contexts.

Sialyllactose Enhances the Short-Chain Fatty Acid Production and Barrier Function of Gut Epithelial Cells via Nonbifidogenic Modification of the Fecal Microbiome in Human Adults

Although various benefits of human milk oligosaccharides (HMOs) have been reported, such as promoting Bifidobacterium growth in the infant gut, their effects on adults have not been fully studied. This study investigated the effects of two types of sialyllactose, 3'-sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL), on the adult intestinal microbiome using the simulator of human intestinal microbial ecosystem (SHIME®), which can simulate human gastrointestinal conditions. HPLC metabolite analysis showed that sialyllactose (SL) supplementation increased the short-chain fatty acid content of SHIME culture broth. Moreover, 16S rRNA gene sequencing analysis revealed that SL promoted the growth of Phascolarctobacterium and Lachnospiraceae, short-chain fatty acid-producing bacteria, but not the growth of Bifidobacterium. Altogether, both types of SL stimulated an increase in short-chain fatty acids, including propionate and butyrate. Additionally, SHIME culture supernatant supplemented with SL improved the intestinal barrier function in Caco-2 cell monolayers. These results suggest that SL could act as a unique prebiotic among other HMOs with a nonbifidogenic effect, resulting in intestinal barrier protection.

Causal relationship between gut microbiota and gastrointestinal diseases: a mendelian randomization study

BACKGROUND

Recent research increasingly highlights a strong correlation between gut microbiota and the risk of gastrointestinal diseases. However, whether this relationship is causal or merely coincidental remains uncertain. To address this, a Mendelian randomization (MR) analysis was undertaken to explore the connections between gut microbiota and prevalent gastrointestinal diseases.

METHODS

Genome-wide association study (GWAS) summary statistics for gut microbiota, encompassing a diverse range of 211 taxa (131 genera, 35 families, 20 orders, 16 classes, and 9 phyla), were sourced from the comprehensive MiBioGen study. Genetic associations with 22 gastrointestinal diseases were gathered from the UK Biobank, FinnGen study, and various extensive GWAS studies. MR analysis was meticulously conducted to assess the causal relationship between genetically predicted gut microbiota and these gastrointestinal diseases. To validate the reliability of our findings, sensitivity analyses and tests for heterogeneity were systematically performed.

RESULTS

The MR analysis yielded significant evidence for 251 causal relationships between genetically predicted gut microbiota and the risk of gastrointestinal diseases. This included 98 associations with upper gastrointestinal diseases, 81 with lower gastrointestinal diseases, 54 with hepatobiliary diseases, and 18 with pancreatic diseases. Notably, these associations were particularly evident in taxa belonging to the genera Ruminococcus and Eubacterium. Further sensitivity analyses reinforced the robustness of these results.

CONCLUSIONS

The findings of this study indicate a potential genetic predisposition linking gut microbiota to gastrointestinal diseases. These insights pave the way for designing future clinical trials focusing on microbiome-related interventions, including the use of microbiome-dependent metabolites, to potentially treat or manage gastrointestinal diseases and their associated risk factors.

Gut Microbiota-Gut Metabolites and Clostridioides difficile Infection: Approaching Sustainable Solutions for Therapy

Clostridioides difficile (C. difficile) infection (CDI) is the most common hospital-acquired infection. With the combination of a high rate of antibiotic resistance and recurrence, it has proven to be a debilitating public health threat. Current treatments for CDI include antibiotics and fecal microbiota transplantation, which contribute to recurrent CDIs and potential risks. Therefore, there is an ongoing need to develop new preventative treatment strategies for CDI. Notably, gut microbiota dysbiosis is the primary risk factor for CDI and provides a promising target for developing novel CDI therapy approaches. Along with gut microbiota dysbiosis, a reduction in important gut metabolites like secondary bile acids and short-chain fatty acids (SCFAs) were also seen in patients suffering from CDI. In this review study, we investigated the roles and mechanisms of gut microbiota and gut microbiota-derived gut metabolites, especially secondary bile acids and SCFAs in CDI pathogenesis. Moreover, specific signatures of gut microbiota and gut metabolites, as well as different factors that can modulate the gut microbiota, were also discussed, indicating that gut microbiota modulators like probiotics and prebiotics can be a potential therapeutic strategy for CDI as they can help restore gut microbiota and produce gut metabolites necessary for a healthy gut. The understanding of the associations between gut microbiota-gut metabolites and CDI will allow for developing precise and sustainable approaches, distinct from antibiotics and fecal transplant, for mitigating CDI and other gut microbiota dysbiosis-related diseases.

An Engineered Butyrate-Derived Polymer Nanoplatform as a Mucosa-Healing Enhancer Potentiates the Therapeutic Effect of Magnolol in Inflammatory Bowel Disease

Colonic epithelial damage and dysregulated immune response are crucial factors in the progression and exacerbation of inflammatory bowel disease (IBD). Nanoenabled targeted drug delivery to the inflamed intestinal mucosa has shown promise in inducing and maintaining colitis remission, while minimizing side effects. Inspired by the excellent antioxidative and anti-inflammatory efficacy of naturally derived magnolol (Mag) and gut homeostasis regulation of microbiota-derived butyrate, we developed a pH/redox dual-responsive butyrate-rich polymer nanoparticle (PSBA) as an oral Mag delivery system for combinational therapy of IBD. PSBA showed a high butyrate content of 22% and effectively encapsulated Mag. The Mag-loaded nanoparticles (PSBA@Mag) demonstrated colonic pH and reduction-responsive drug release, ensuring efficient retention and adhesion in the colon of colitis mice. PSBA@Mag not only normalized the level of reactive oxygen species and inflammatory effectors in inflamed colonic mucosa but also restored the epithelial barrier function in both ulcerative colitis and Crohn's disease mouse models. Importantly, PSBA promoted the migration and healing ability of intestinal epithelial cells in vitro and in vivo, sensitizing the therapeutic efficacy of Mag in animal models. Moreover, transcriptomics and metabolism analyses revealed that PSBA@Mag mitigated inflammation by suppressing the production of pro-inflammatory cytokines and chemokines and restoring the lipid metabolism. Additionally, this nanomedicine modulated the gut microbiota by inhibiting pathogenic Proteus and Escherichia-Shigella and promoting the proliferation of beneficial probiotics, including Lachnoclostridium, Lachnospiraceae_NK4A136_group and norank_f_Ruminococcaceae. Overall, our findings highlight the potential of butyrate-functionalized polymethacrylates as versatile and effective nanoplatforms for colonic drug delivery and mucosa repair in combating IBD and other gastrointestinal disorders.