Gut Microbial Metabolite Butyrate and Its Therapeutic Role in Inflammatory Bowel Disease: A Literature Review

Gut microbial dysbiosis associated to diarrheic irritable bowel syndrome can be efficiently simulated in the Mucosal ARtificial COLon (M-ARCOL)

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder, with diarrhea-predominant IBS (IBS-D) as the most frequent subtype. The implication of gut microbiota in the disease's etiology is not fully understood. In vitro gut systems can offer a great alternative to in vivo assays in preclinical studies, but no model reproducing IBS-related dysbiotic microbiota has been developed. Thanks to a large literature review, a new Mucosal ARtifical COLon (M-ARCOL) adapted to IBS-D physicochemical and nutritional conditions was set-up. To validate the model and further exploit its potential in a mechanistic study, in vitro fermentations were performed using bioreactors inoculated with stools from healthy individuals (n = 4) or IBS-D patients (n = 4), when the M-ARCOL was set-up under healthy or IBS-D conditions. Setting IBS-D parameters in M-ARCOL inoculated with IBS-D stools maintained the key microbial features associated to the disease in vivo, validating the new system. In particular, compared to the healthy control, the IBS-D model was characterized by a decreased bacterial diversity, together with a lower abundance of Rikenellaceae and Prevotellaceae, but a higher level of Proteobacteria and Akkermansiaceae. Of interest, applying IBS-D parameters to healthy stools was not sufficient to trigger IBS-D dysbiosis and applying healthy parameters to IBS-D stools was not enough to restore microbial balance. This validated IBS-D colonic model can be used as a robust in vitro platform for studies focusing on gut microbes in the absence of the host, as well as for testing food and microbiota-related interventions aimed at personalized restoration of gut microbiota eubiosis.

Recent developments in managing luminal microbial ecology in patients with inflammatory bowel disease: from evidence to microbiome-based diagnostic and personalized therapy

INTRODUCTION

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic condition characterized by abnormal immune responses and intestinal inflammation. Emerging evidence highlights the vital role of gut microbiota in IBD's onset and progression. Recent advances have shaped diagnostic and therapeutic strategies, increasingly focusing on microbiome-based personalized care. Methodology: this review covers studies from 2004 to 2024, reflecting the surge in research on luminal microbial ecology in IBD. Human studies were prioritized, with select animal studies included for mechanistic insights. Only English-language, peer-reviewed articles - clinical trials, systematic reviews, and meta-analyses - were considered. Studies without clinical validation were excluded unless offering essential insights. Searches were conducted using PubMed, Scopus, and Web of Science.

AREAS COVERED

we explore mechanisms for managing IBD-related microbiota, including microbial markers for diagnosis and novel therapies such as fecal microbiota transplantation, metabolite-based treatments, and precision microbiome modulation. Additionally, we review technologies and diagnostic tools used to analyze gut microbiota composition and function in clinical settings. Emerging data supporting personalized therapeutic strategies based on individual microbial profiles are discussed.

EXPERT OPINION

Standardized microbiome research integration into clinical practice will enhance precision in IBD care, signaling a shift toward microbiota-based personalized medicine.

Interplay of Neuroinflammation and Gut Microbiota Dysbiosis in Alzheimer's Disease Using Diffusion Kurtosis Imaging Biomarker in 3 × Tg-AD Mouse Models

The relationship between alterations in brain microstructure and dysbiosis of gut microbiota in Alzheimer's disease (AD) has garnered increasing attention, although the functional implications of these changes are not yet fully elucidated. This research examines how neuroinflammation, systemic inflammation, and gut microbiota interact in male 3 × Tg-AD and B6129SF1/J wild-type (WT) mice at 6 months-old (6-MO) and 12 months-old (12-MO). Employing a combination of behavioral assessments, diffusion kurtosis imaging (DKI), microbiota profiling, cytokine analysis, short-chain fatty acids (SCFAs), and immunohistochemistry, we explored the progression of AD-related pathology. Significant memory impairments in AD mice at both assessed ages were correlated with altered DKI parameters that suggest neuroinflammation and microstructural damage. We observed elevated levels of pro-inflammatory cytokines, such as IL-1β, IL-6, TNFα, and IFN-γ, in the serum, which were associated with increased activity of microglia and astrocytes in brain regions critical for memory. Although gut microbiota analysis did not reveal significant changes in alpha diversity, it did show notable differences in beta diversity and a diminished Firmicutes/Bacteroidetes (F/B) ratio in AD mice at 12-MO. Furthermore, a reduction in six kinds of SCFAs were identified at two time points of 6-MO and 12-MO, indicating widespread disruption in gut microbial metabolism. These findings underscore a complex bidirectional relationship between systemic inflammation and gut dysbiosis in AD, highlighting the gut-brain axis as a crucial factor in disease progression. This study emphasizes the potential of integrating DKI metrics, microbiota profiling, and SCFA analysis to enhance our understanding of AD pathology and to identify new therapeutic targets.

Multi-omics analysis of host-microbiome interactions in a mouse model of congenital hepatic fibrosis

BACKGROUND

Congenital hepatic fibrosis (CHF) caused by mutations in the polycystic kidney and hepatic disease 1 (PKHD1) gene is a rare genetic disorder with poorly understood pathogenesis. We hypothesized that integrating gut microbiome and metabolomic analyses could uncover distinct host-microbiome interactions in CHF mice compared to wild-type controls.

METHODS

Pkhd1del3-4/del3-4 mice were generated using CRISPR/Cas9 technology. Fecal samples were collected from 11 Pkhd1del3-4/del3-4 mice and 10 littermate wild-type controls. We conducted a combined study using 16 S rDNA sequencing for microbiome analysis and untargeted metabolomics. The gut microbiome and metabolome data were integrated using Data Integration Analysis for Biomarker discovery using Latent cOmponents (DIABLO), which helped identify key microbial and metabolic features associated with CHF.

RESULTS

CHF mouse model was successfully established. Our analysis revealed that the genera Mucispirillum, Eisenbergiella, and Oscillibacter were core microbiota in CHF, exhibiting significantly higher abundance in Pkhd1del3-4/del3-4 mice and strong positive correlations among them. Network analysis demonstrated robust associations between the gut microbiome and metabolome. Multi-omics dimension reduction analysis demonstrated that both the microbiome and metabolome could effectively distinguish CHF mice from controls, with area under the curve of 0.883 and 0.982, respectively. A significant positive correlation was observed between the gut microbiome and metabolome, highlighting the intricate relationship between these two components.

CONCLUSION

This study identifies distinct metabolic and microbiome profiles in Pkhd1del3-4/del3-4 mice. Multi-omics analysis effectively differentiates CHF mice from controls and identified potential biomarkers. These findings indicate that gut microbiota and metabolites are integral to the pathogenesis of CHF, offering novel insights into the disease mechanism.

The role of polysaccharides in immune regulation through gut microbiota: mechanisms and implications

Polysaccharides, as complex carbohydrates, play a pivotal role in immune modulation and interactions with the gut microbiota. The diverse array of dietary polysaccharides influences gut microbial ecology, impacting immune responses, metabolism, and overall well-being. Despite their recognized benefits, there is limited understanding of the precise mechanisms by which polysaccharides modulate the immune system through the gut microbiota. A comprehensive search of Web of Science, PubMed, Google Scholar, and Embase up to May 2024 was conducted to identify relevant studies. This study employs a systematic approach to explore the interplay between polysaccharides and the gut microbiota, focusing on cytokine-mediated and short-chain fatty acid (SCFA)-mediated pathways. The findings underscore the significant role of polysaccharides in shaping the composition and function of the gut microbiota, thereby influencing immune regulation and metabolic processes. However, further research is necessary to elucidate the detailed molecular mechanisms and translate these findings into clinical applications.

Butyrate (short-chain fatty acid) alleviates lipopolysaccharide-binding proteins and improves physical function in knee osteoarthritis patients

Knee-osteoarthritis (OA) is often associated with increased intestinal permeability, potentially causing sarcopenia, and mobility issues. Current treatments are ineffective. The objective of this study was to investigate if butyrate improves sarcopenia and physical function in knee-OA patients, and if improvements correlate with changes in gut health, specifically intestinal permeability, and bacterial load. In this double-blind study, 60 OA patients received placebo, 52 received 300 mg butyrate daily for 12-weeks. Gut health (zonulin), and systemic bacterial load (lipopolysaccharide-binding proteins (LBP)) were assessed. Handgrip strength (HGS), Oxford knee scores (OKS), and short physical performance battery (SPPB) were measured at the beginning and end of the study to assess physical functionality. Patients taking butyrate showed improvement in HGS, walking speed, OKS scores, and maintained a better balance, walking ability and no decline in rising from chair, according to SPPB-scores. Butyrate lowered blood levels of zonulin, LBP, and CRP as markers of intestinal permeability, bacterial load, and inflammation, respectively (all p < 0.05). Regression analysis exhibited marked correlations of zonulin with HGS, OKS, walking speed, and SPPB scores in the butyrate-treated group. These observations suggest that butyrate could serve as a therapeutic option for sarcopenia and physical decline in OA, potentially by improving intestinal barrier function.

Advances in intestinal epithelium and gut microbiota interaction

The intestinal epithelium represents a critical interface between the host and external environment, serving as the second largest surface area in the human body after the lungs. This dynamic barrier is sustained by specialized epithelial cell types and their complex interactions with the gut microbiota. This review comprehensively examines the recent advances in understanding the bidirectional communication between intestinal epithelial cells and the microbiome. We briefly highlight the role of various intestinal epithelial cell types, such as Paneth cells, goblet cells, and enteroendocrine cells, in maintaining intestinal homeostasis and barrier function. Gut microbiota-derived metabolites, particularly short-chain fatty acids and bile acids, influence epithelial cell function and intestinal barrier integrity. Additionally, we highlight emerging evidence of the sophisticated cooperation between different epithelial cell types, with special emphasis on the interaction between tuft cells and Paneth cells in maintaining microbial balance. Understanding these complex interactions has important implications for developing targeted therapeutic strategies for various gastrointestinal disorders, including inflammatory bowel disease, metabolic disorders, and colorectal cancer.

BioMapAI: Artificial Intelligence Multi-Omics Modeling of Myalgic Encephalomyelitis / Chronic Fatigue Syndrome

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic illness with a multifactorial etiology and heterogeneous symptomatology, posing major challenges for diagnosis and treatment. Here, we present BioMapAI, a supervised deep neural network trained on a four-year, longitudinal, multi-omics dataset from 249 participants, which integrates gut metagenomics, plasma metabolomics, immune cell profiling, blood laboratory data, and detailed clinical symptoms. By simultaneously modeling these diverse data types to predict clinical severity, BioMapAI identifies disease- and symptom-specific biomarkers and robustly classifies ME/CFS in both held-out and independent external cohorts. Using an explainable AI approach, we construct the first connectivity map spanning the microbiome, immune system, and plasma metabolome in health and ME/CFS, adjusted for age, gender, and additional clinical factors. This map uncovers disrupted associations between microbial metabolism (e.g., short-chain fatty acids, branched-chain amino acids, tryptophan, benzoate), plasma lipids and bile acids, and heightened inflammatory responses in mucosal and inflammatory T cell subsets (MAIT, γδT) secreting IFNγ and GzA. Overall, BioMapAI provides unprecedented systems-level insights into ME/CFS, refining existing hypotheses and hypothesizing new pathways associated to the disease's heterogeneous symptoms.

Unlocking the secrets of the human gut microbiota: Comprehensive review on its role in different diseases

The human gut microbiota, a complex and diverse community of microorganisms, plays a crucial role in maintaining overall health by influencing various physiological processes, including digestion, immune function, and disease susceptibility. The balance between beneficial and harmful bacteria is essential for health, with dysbiosis - disruption of this balance - linked to numerous conditions such as metabolic disorders, autoimmune diseases, and cancers. This review highlights key genera such as Enterococcus, Ruminococcus, Bacteroides, Bifidobacterium, Escherichia coli, Akkermansia muciniphila, Firmicutes (including Clostridium and Lactobacillus), and Roseburia due to their well-established roles in immune regulation and metabolic processes, but other bacteria, including Clostridioides difficile, Salmonella, Helicobacter pylori, and Fusobacterium nucleatum, are also implicated in dysbiosis and various diseases. Pathogenic bacteria, including Escherichia coli and Bacteroides fragilis, contribute to inflammation and cancer progression by disrupting immune responses and damaging tissues. The potential for microbiota-based therapies, such as probiotics, prebiotics, fecal microbiota transplantation, and dietary interventions, to improve health outcomes is examined. Future research directions in the integration of multi-omics, the impact of diet and lifestyle on microbiota composition, and advancing microbiota engineering techniques are also discussed. Understanding the gut microbiota's role in health and disease is essential for formulating personalized, efficacious treatments and preventive strategies, thereby enhancing health outcomes and progressing microbiome research.

Novel Microbial Engraftment Trajectories Following Microbiota Transplant Therapy in Ulcerative Colitis

BACKGROUND AND AIMS

Microbiota transplant therapy (MTT) is an emerging treatment for ulcerative colitis (UC). One proposed mechanism for the benefit of MTT is through engraftment of donor microbiota; however, engraftment kinetics are unknown. We identified SourceTracker as an efficient method both to determine engraftment and for the kinetic study of engrafting donor taxa to aid in determining the mechanism of how this therapy may treat UC.

METHODS

Ulcerative colitis patients received either encapsulated (drug name MTP-101C) or placebo capsules daily for 8 weeks followed by a 4-week washout period. Amplicon sequence data from donors and patients were analyzed using the Bayesian algorithm SourceTracker.

RESULTS

Twenty-seven patients were enrolled, 14 to placebo and 13 to MTT. Baseline Shannon and Chao1 indices negatively correlated with week 12 donor engraftment for patients treated with active drug capsules but not for placebo patients. SourceTracker engraftment positively correlated with the week 12 distance from donors measured using the Bray-Curtis similarity metric in treated patients but not with placebo. Engraftment at week 12 was significantly higher in the MTT group than in the placebo group. We identified engrafting taxa from donors in our patients and quantified the proportion of donor similarity or engraftment during weeks 1 through 8 (active treatment) and week 12, 4 weeks after the last dose.

CONCLUSION

SourceTracker can be used as a simple and reliable method to quantify donor microbial community engraftment and donor taxa contribution in patients with UC and other inflammatory conditions treated with MTT.

Chitosan and its derivatives: A novel approach to gut microbiota modulation and immune system enhancement

Chitosan, a biopolymer derived from the deacetylation of chitin found in crustacean shells and certain fungi, has attracted considerable attention for its promising health benefits, particularly in gut microbiota maintenance and immune system modulation. This review critically examines chitosan's multifaceted role in supporting gut health and enhancing immunity, beginning with a comprehensive overview of its sources, chemical structure, and its dual function as a dietary supplement and biomaterial. Chitosan's prebiotic effects are highlighted, with a focus on its ability to selectively stimulate beneficial gut bacteria, such as Bifidobacteria and Lactobacillus, while enhancing gut barrier integrity and inhibiting the growth of pathogenic microorganisms. The review delves deeply into chitosan's immunomodulatory mechanisms, including its impact on antigen-presenting cells, cytokine profiles, and systemic immune responses. A detailed comparative analysis assesses chitosan's efficacy relative to other prebiotics and immunomodulatory agents, examining challenges related to bioavailability and metabolic activity. Beyond its role in gut health, this review explores chitosan's potential as a dual-action agent that not only supports gut microbiota but also fortifies immune resilience. It introduces emerging research on novel chitosan derivatives, such as chitooligosaccharides, and evaluates their enhanced bioactivity for functional food applications. Special attention is given to sustainability, with an exploration of alternative, plant-based sources of chitosan and their implications for both health and environmental stewardship. Also, the review identifies new research avenues, such as the growing interest in chitosan's role in the gut-brain axis and its potential mental health benefits through microbial interactions. By addressing these innovative areas, the review aims to shift the focus from basic health effects to chitosan's broader impact on public health. The findings encourage further exploration, particularly through human trials, and emphasize chitosan's untapped potential in revolutionizing health and disease management.

Convergent evolution of oxidized sugar metabolism in commensal and pathogenic microbes in the inflamed gut

Inflammation-associated perturbations of the gut microbiome are well characterized, but poorly understood. Here, we demonstrate that disparate taxa recapitulate the metabolism of the oxidized sugars glucarate and galactarate, utilizing enzymatically divergent, yet functionally equivalent, gud/gar pathways. The divergent pathway in commensals includes a putative 5-KDG aldolase (GudL) and an uncharacterized ABC transporter (GarABC) that recapitulate the function of their non-homologous counterparts in pathogens. A systematic bioinformatic search for the gud/gar pathway in gut microbes identified 887 species putatively capable of metabolizing oxidized sugars. Previous studies showed that inflammation-derived nitrate, formed by nitric oxide reacting with superoxide, promotes pathogen growth. Our findings reveal a parallel phenomenon: oxidized sugars, also produced from reactions with nitric oxide, serve as alternative carbon sources for commensal microbes. Previously considered a pathogen virulence factor, oxidized sugar metabolism is also present in specific commensals and may contribute to their increased relative abundance in gastrointestinal inflammation.

Microbiota in patients with cefuroxime resistance and anal fistula revealed by 16S ribosomal DNA

BACKGROUND

Anal fistula is increasingly prevalent due to modern lifestyle factors, and surgery remains the primary treatment. However, the rising incidence of antibiotic resistance, particularly to cefuroxime, complicates perioperative management. The role of gut microbiota in influencing this resistance is not well understood.

AIM

To investigate the relationship between gut microbiota composition and cefuroxime resistance in anal fistula patients and to assess probiotic intervention impact.

METHODS

This study included 30 anal fistula patients categorized into cefuroxime-sensitive (Cefur-S) and cefuroxime-resistant (Cefur-NS) groups. Gut microbiota samples were collected during colonoscopy, and 16S ribosomal DNA sequencing was performed to analyze microbial diversity. Patients in the Cefur-NS group received a 7-day course of Clostridium butyricum tablets. Post-intervention, microbial composition and cefuroxime resistance were reassessed.

RESULTS

Alpha and beta diversity analyses showed no significant differences in microbial diversity between the Cefur-S and Cefur-NS groups. However, effect size analysis identified Roseburia and Butyricicoccus as dominant genera in the Cefur-S group, with higher butyrate production potentially protecting against cefuroxime resistance. Post-intervention, the Cefur-NS group showed a significant reduction in cefuroxime resistance, improved stool consistency, and reduced bowel movement frequency.

CONCLUSION

This study suggests that specific gut microbiota, particularly Butyricicoccus and Roseburia, may mitigate cefuroxime resistance in anal fistula patients by increasing butyrate production. Probiotic intervention targeting gut microbiota composition presents a promising strategy for reducing antibiotic resistance and improving clinical outcomes.

Unraveling the Role of Fusobacterium nucleatum in Colorectal Cancer: Molecular Mechanisms and Pathogenic Insights

Fusobacterium nucleatum, a gram-negative anaerobic bacterium, has emerged as a significant player in colorectal cancer (CRC) pathogenesis. The bacterium causes a persistent inflammatory reaction in the colorectal mucosa by stimulating the release of pro-inflammatory cytokines like IL-1β, IL-6, and TNF-α, creating an environment conducive to cancer progression. F. nucleatum binds to and penetrates epithelial cells through adhesins such as FadA, impairing cell junctions and encouraging epithelial-to-mesenchymal transition (EMT), which is associated with cancer advancement. Additionally, the bacterium modulates the host immune system, suppressing immune cell activity and creating conditions favorable for tumor growth. Its interactions with the gut microbiome contribute to dysbiosis, further influencing carcinogenic pathways. Evidence indicates that F. nucleatum can inflict DNA damage either directly via reactive oxygen species or indirectly by creating a pro-inflammatory environment. Additionally, it triggers oncogenic pathways, especially the Wnt/β-catenin signaling pathway, which promotes tumor cell growth and longevity. Moreover, F. nucleatum alters the tumor microenvironment, impacting cancer cell behavior, metastasis, and therapeutic responses. The purpose of this review is to elucidate the molecular mechanisms by which F. nucleatum contributes to CRC. Understanding these mechanisms is crucial for the development of targeted therapies and diagnostic strategies for CRC associated with F. nucleatum.

Taurine prevents mitochondrial dysfunction and protects mitochondria from reactive oxygen species and deuterium toxicity

Taurine, although not a coding amino acid, is the most common free amino acid in the body. Taurine has multiple and complex functions in protecting mitochondria against oxidative-nitrosative stress. In this comprehensive review paper, we introduce a novel potential role for taurine in protecting from deuterium (heavy hydrogen) toxicity. This can be of crucial impact to either normal or cancer cells that have highly different mitochondrial redox status. Deuterium is an isotope of hydrogen with a neutron as well as a proton, making it about twice as heavy as hydrogen. We first explain the important role that the gut microbiome and the gut sulfomucin barrier play in deuterium management. We describe the synergistic effects of taurine in the gut to protect against the deleterious accumulation of deuterium in the mitochondria, which disrupts ATP synthesis by ATPase pumps. Moreover, taurine's derivatives, N-chlorotaurine (NCT) and N-bromotaurine (NBrT), produced through spontaneous reaction of taurine with hypochlorite and hypobromite, have fascinating regulatory roles to protect from oxidative stress and beyond. We describe how taurine could potentially alleviate deuterium stress, primarily through metabolic collaboration among various gut microflora to produce deuterium depleted nutrients and deuterium depleted water, and in this way protect against leaky gut barrier, inflammatory bowel disease, and colon cancer.

Bacterial dysbiosis and decrease in SCFA correlate with intestinal inflammation following alcohol intoxication and burn injury

Background

Patients intoxicated at the time of burn experience increased rates of sepsis and death compared with that observed in similarly sized burns alone. We sought to characterise changes in the intestinal microbiome and short-chain fatty acids (SCFAs) following alcohol intoxication and burn injury and to determine whether these changes are associated with intestinal inflammation.

Methods

10-12-week-old C57BL/6 male and female mice were subjected to ethanol intoxication and a 12.5% total body surface area scald burn injury. The following day, mice were euthanised and faecal contents from the caecum and small intestine (SI) were harvested for 16S sequencing for microbial analysis and caecum contents underwent high-performance liquid chromatography mass spectroscopy to assess SCFAs.

Results

The intestinal microbiome of ethanol burn (EB) mice exhibited decreased alpha diversity and distinct beta diversity compared with sham vehicle (SV). EB faeces were marked by increased Proteobacteria and many pathobionts. EB caecum faeces exhibited a significant decrease in butyrate and a downward trend in acetate and total SCFAs. SCFA changes correlated with microbial changes particularly in the SI. Treatment of murine duodenal cell clone-K (MODE-K) cells with faecal slurries led to upregulation of interleukin-6 (IL-6) from EB faeces compared with SV faeces which correlated with levels of Enterobacteriaceae. However, supplementation of butyrate reduced faecal slurry-induced MODE-K cells IL-6 release.

Conclusion

Together, these findings suggest that alcohol and burn injury induce bacterial dysbiosis and a decrease in SCFAs, which together can promote intestinal inflammation and barrier disruption, predisposing to postinjury pathology.

Butyric acid alleviates LPS-induced intestinal mucosal barrier damage by inhibiting the RhoA/ROCK2/MLCK signaling pathway in Caco2 cells

Butyric acid (BA) can potentially enhance the function of the intestinal barrier. However, the mechanisms by which BA protects the intestinal mucosal barrier remain to be elucidated. Given that the Ras homolog gene family, member A (RhoA)/Rho-associated kinase 2 (ROCK2)/Myosin light chain kinase (MLCK) signaling pathway is crucial for maintaining the permeability of the intestinal epithelium, we further investigated whether BA exerts a protective effect on epithelial barrier function by inhibiting this pathway in LPS-induced Caco2 cells. First, we aimed to identify the optimal treatment time and concentration for BA and Lipopolysaccharide (LPS) through a CCK-8 assay. We subsequently measured Trans-epithelial electrical resistance (TEER), FITC-Dextran 4 kDa (FD-4) flux, and the mRNA expression of ZO-1, Occludin, RhoA, ROCK2, and MLCK, along their protein expression levels, and average fluorescence intensity following immunofluorescence staining. We then applied the ROCK2 inhibitor Y-27632 and reevaluated the TEER, FD-4 flux, and mRNA, and protein expression of ZO-1, Occludin, RhoA, ROCK2, and MLCK, as well as their distribution in Caco2 cells. The optimal treatment conditions were determined to be 0.2 mmol/L BA and 5 μg/mL LPS for 24 hours. Compared with LPS treatment alone, BA significantly mitigated the reduction in the TEER, decreased FD-4 flux permeability, increased the mRNA expression of ZO-1 and Occludin, and normalized the distribution of ZO-1 and Occludin in Caco2 cells. Furthermore, BA inhibited the expression of RhoA, ROCK2, and MLCK, and normalized their localization within Caco2 cells. Following treatment with Y-27632, the epithelial barrier function, along with the mRNA and protein expression and distribution of ZO-1 and Occludin were further normalized upon inhibition of the pathway. These findings contribute to a deeper understanding of the potential mechanisms through which BA attenuates LPS-induced impairment of the intestinal epithelial barrier.

Effect of sodium butyrate on kidney and liver mitochondrial dysfunction in a lipopolysaccharide mouse model

Sodium butyrate can reduce inflammation, but it is not known if butyrate can improve mitochondrial dysfunction during sepsis. We tested butyrate to prevent or reverse lipopolysaccharide (LPS)-induced mitochondrial dysfunction in murine kidney and liver. C57BL/6 mice were grouped as control (n = 9), intraperitoneal (IP) LPS (n = 8), pretreatment with IP butyrate 600 (n = 3) or 1200 mg/kg (n = 8) followed 2 h later by LPS, posttreatment with IP butyrate 600 (n = 3) or 1200 mg/kg (n = 7) 1 h after LPS, or butyrate 1200 mg/kg only (n = 8). Kidney and liver tissue were collected at 24 h to measure mitochondrial respiration, electron transport system (ETS) complex activity and subunit expression, and content (citrate synthase [CS] activity and mtDNA/nDNA). Kidney mitochondrial respiration was decreased after LPS compared to controls. Pretreatment with butyrate 1200 mg/kg increased kidney OXPHOSCI+II, ETSCI+II, ETSCII, and CIV respiration compared to LPS; posttreatment did not achieve significant increases except for OXPHOSCI. Liver mitochondrial respiration exhibited a similar pattern as in kidney, but differences were not significant. ETS complex and CS activity did not differ between groups, but CI and CII subunit expression trended higher with butyrate in kidney. Changes in mtDNA/nDNA followed a similar pattern as respiration in kidney and liver with a decrease after LPS that was not present with butyrate pretreatment. These data show that butyrate can prevent-but not significantly reverse-the LPS-induced decrease in kidney mitochondrial respiration without a clear effect in liver. Mitochondrial protection was not attributable to changes in ETS complex activity but may reflect maintenance of ETS subunit expression.

Butyrate modulates gut microbiota and anti-inflammatory response in attenuating cisplatin-induced kidney injury

In our previous research, we reported that administering probiotics Lactobacillus reuteri and Clostridium butyricum (LCs) before cisplatin treatment effectively modifies structures of the gut microbiota and restore ecological balance and significantly increases butyrate levels, a process closely associated with reducing cisplatin-induced nephrotoxicity. This study aims to investigate further whether the elevation of metabolite butyrate in the gut, promoted by probiotics LCs, can effectively mitigate the nephrotoxic effects of cisplatin and the progression of renal senescence in rats. Results show that butyrate administration significantly improved kidney function and decreased renal fibrosis in a dose-dependent manner compared to the cisplatin group. Its effects were associated with reductions in inflammatory responses, evidenced by decreased levels of key inflammatory markers, including KIM-1, MPO, NOX2, F4/80, and TGF-β1, alongside increased production of the anti-inflammatory cytokine IL-10. Furthermore, the butyrate intervention ameliorated cisplatin-induced gut microbiota dysbiosis, preserving the structure and diversity of healthy microbial communities. Specifically, we observed a decrease in the abundance of Escherichia_Shigella and Blautia, alongside an increase in the abundance of the butyrate-producing genus Roseburia. Notably, Escherichia_Shigella exhibited a positive correlation with the pro-inflammatory factor MPO, while displaying a negative correlation with the anti-inflammatory cytokine IL-10. Butyrate also attenuated the cisplatin-induced expression of senescence markers p21 and p16 in kidney tissue. It alleviated the cisplatin-increased senescence-associated beta-galactosidase activity and reactive oxygen species production in SV40 MES-13 cells. These results indicate that butyrate, derived from the gut microbiota, may exert a protective effect against cisplatin-induced kidney damage by regulating microbiota balance and anti-inflammatory effects.

PyNetCor: a high-performance Python package for large-scale correlation analysis

The development of multi-omics technologies has generated an abundance of biological datasets, providing valuable resources for investigating potential relationships within complex biological systems. However, most correlation analysis tools face computational challenges when dealing with these high-dimensional datasets containing millions of features. Here, we introduce pyNetCor, a fast and scalable tool for constructing correlation networks on large-scale and high-dimensional data. PyNetCor features optimized algorithms for both full correlation coefficient matrix computation and top-k correlation search, outperforming other tools in the field in terms of runtime and memory consumption. It utilizes a linear interpolation strategy to rapidly estimate P-values and achieve false discovery rate control, demonstrating a speedup of over 110 times compared to existing methods. Overall, pyNetCor supports large-scale correlation analysis, a crucial foundational step for various bioinformatics workflows, and can be easily integrated into downstream applications to accelerate the process of extracting biological insights from data.

Pristimerin Alleviates DSS-Induced Colitis in Mice by Modulating Intestinal Barrier Function, Gut Microbiota Balance and Host Metabolism

Pristimerin is a pentacyclic triterpenoid mainly derived from Celastraceae plants such as Maytenus ilicifolia, which has been traditionally used for the treatment of gastrointestinal disorders. Pharmacological studies have shown that pristimerin exhibited anti-inflammatory, antioxidant, anticancer and antibacterial activities. However, the potential mechanism of pristimerin for the treatment of ulcerative colitis (UC) remains elusive. In the present study, pristimerin could effectively inhibit the NO generation induced by LPS in RAW 264.7 cells and upregulate the decreased expression of tight junction proteins such as occludin and claudin-1. In vivo, oral administration of pristimerin (0.5 mg/kg and 1 mg/kg) could significantly relieve UC symptoms such as body weight loss, disease activity index, shortened colon length and colonic pathological damage. Meanwhile, pristimerin decreased the TNF-α, MPO and MDA levels and increased the levels of IL-10, IL-22, SOD activity, occludin and claudin-1 in colon tissues. Gut microbiota analysis of cecum contents revealed that pristimerin treatment effectively alleviated gut microbiota dysbiosis. Additionally, serum metabolomics showed that 33 potential biomarkers involving lipid and tryptophan metabolism were identified, which may account for the therapeutic effects of pristimerin on UC mice. In conclusion, our findings indicate that pristimerin attenuates UC symptoms in DSS-induced mice through modulating intestinal barrier integrity, gut microbiota composition, lipid and tryptophan metabolism.

The sports performance improving effects of konjac glucomannan with varying molecular weights in overtrained mice

Overtraining affects individuals engaged in high-volume training, potentially hindering athletic performance and revealing shortcomings in suggested solutions. This study evaluated the impact of konjac glucomannan (KGM) with varying molecular weights on the gut microbiome, endurance, and strength in mice subjected to excessive training. The native KGM (1.82 × 107 Da) was enzymatically degraded using endo-1,4-β-mannanase to generate moderate molecular weight KGM (KGM-EM, 1.89 × 105 Da) and low molecular weight KGM (KGM-EL, 1.34 × 104 Da). These fractions were characterized and compared with the native KGM regarding their effects on mice undergoing excessive training. The results demonstrated a positive correlation between KGM's molecular weight and its capacity to mitigate the adverse impacts of excessive training on strength or/and endurance (a significant increase of 55.57 % and 55.70 % by the native KGM compared with the excessive training group). In addition, the native KGM exhibited superior preservation of microbial diversity and composition in fecal samples against excessive training-induced shifts, along with increased production of individual and total short-chain fatty acids in plasma compared with the two degraded products. Overall, these results highlight the potential benefits of high molecular weight KGM for preventing overtraining syndrome and enhancing athletic performance in animal models.

The Impact of Bioactive Molecules from Probiotics on Child Health: A Comprehensive Review

Background: This review investigates the impact of bioactive molecules produced by probiotics on child health, focusing on their roles in modulating gut microbiota, enhancing immune function, and supporting overall development. Key metabolites, including short-chain fatty acids (SCFAs), bacteriocins, exopolysaccharides (EPSs), vitamins, and gamma-aminobutyric acid (GABA), are highlighted for their ability to maintain gut health, regulate inflammation, and support neurodevelopment. Objectives: The aim of this review is to examine the mechanisms of action and clinical evidence supporting the use of probiotics and postbiotics in pediatric healthcare, with a focus on promoting optimal growth, development, and overall health in children. Methods: The review synthesizes findings from clinical studies that investigate the effects of probiotics and their metabolites on pediatric health. The focus is on specific probiotics and their ability to influence gut health, immune responses, and developmental outcomes. Results: Clinical studies demonstrate that specific probiotics and their metabolites can reduce gastrointestinal disorders, enhance immune responses, and decrease the incidence of allergies and respiratory infections in pediatric populations. Additionally, postbiotics-bioactive compounds from probiotic fermentation-offer promising benefits, such as improved gut barrier function, reduced inflammation, and enhanced nutrient absorption, while presenting fewer safety concerns compared to live probiotics. Conclusions: By examining the mechanisms of action and clinical evidence, this review underscores the potential of integrating probiotics and postbiotics into pediatric healthcare strategies to promote optimal growth, development, and overall health in children.

Gut aging: A wane from the normal to repercussion and gerotherapeutic strategies

Globally, age-related diseases represent a significant public health concern among the elderly population. In aging, healthy organs and tissues undergo structural and functional changes that put the aged adults at risk of diseases. Some of the age-related diseases include cancer, atherosclerosis, brain disorders, muscle atrophy (sarcopenia), gastrointestinal (GIT) disorders, etc. In organs, a decline in stem cell function is the starting point of many conditions and is extremely important in GIT disorder development. Many studies have established that aging affects stem cells and their surrounding supportive niche components. Although there is a significant advancement in treating intestinal aging, the rising elderly population coupled with a higher occurrence of chronic gut ailments necessitates more effective therapeutic approaches to preserve gut health. Notable therapeutic strategies such as Western medicine, traditional Chinese medicine, and other health-promotion interventions have been reported in several studies to hold promise in mitigating age-related gut disorders. This review highlights findings across various facets of gut aging with a focus on aging-associated changes of intestinal stem cells and their niche components, thus a deviation from the normal to repercussion, as well as essential therapeutic strategies to mitigate intestinal aging.

Exploring the anti-inflammatory effects of postbiotic proteins from Lactobacillus delbrueckii CIDCA 133 on inflammatory bowel disease model

Lactobacillus delbrueckii CIDCA 133 is a promising health-promoting bacterium shown to alleviate intestinal inflammation. However, the specific bacterial components responsible for these effects remain largely unknown. Here, we demonstrated that consuming extractable proteins from the CIDCA 133 strain effectively relieved acute ulcerative colitis in mice. This postbiotic protein fraction reduced the disease activity index and prevented colon shortening in mice. Furthermore, histological analysis revealed colitis prevention with reduced inflammatory cell infiltration into the colon mucosa. Postbiotic consumption also induced an immunomodulatory profile in colitic mice, as evidenced by both mRNA transcript levels (Tlr2, Nfkb1, Nlpr3, Tnf, and Il6) and cytokines concentration (IL1β, TGFβ, and IL10). Additionally, it enhanced the levels of secretory IgA, upregulated the transcript levels of tight junction proteins (Hp and F11r), and improved paracellular intestinal permeability. More interestingly, the consumption of postbiotic proteins modulated the gut microbiota (Bacteroides, Arkkemansia, Dorea, and Oscillospira). Pearson correlation analysis indicated that IL10 and IL1β levels were positively associated with Bacteroides and Arkkemansia_Lactobacillus abundance. Our study reveals that CIDCA 133-derived proteins possess anti-inflammatory properties in colonic inflammation.

Isoorientin Alleviates DSS-Treated Acute Colitis in Mice by Regulating Intestinal Epithelial P-Glycoprotein (P-gp) Expression

Isoorientin (ISO) is a naturally occurring flavonoid with diverse functional properties that mitigate the risk of diseases stemming from oxidation, inflammation, and cancer cell proliferation. P-glycoprotein (P-gp) is a vital component of the intestinal epithelium and may play a role in the onset of intestinal inflammatory conditions, such as inflammatory bowel disease (IBD). Recent studies have suggested that short-chain fatty acids (SCFAs) and secondary bile acids (SBAs) produced by the gut microbiota stimulate the increase of P-gp expression, alleviating excessive inflammation and thereby preservation of intestinal homeostasis. ISO has been shown to improve colon health and modulate the gut microbiota. In this study, we aimed to explore whether ISO can modulate the microbes and their metabolites to influence P-gp expression to alleviate IBD. First, the impact of ISO on dextran sulfate sodium (DSS)-treated colitis in mice was investigated. Second, 16S rRNA gene sequencing was conducted. The present study indicated that ISO mitigated the symptoms and pathological damage associated with DSS-treated colitis in mice. Western blot analysis revealed ISO upregulated P-gp in colon tissues, suggesting the critical role of P-gp protein in intestinal epithelial cells. 16S microbial diversity sequencing revealed ISO restored the richness and variety of intestinal microorganisms in colitis-bearing mice and enriched SCFA-producing bacteria, such as Lachnospiraceae_NK4A136_group. The experiments also revealed that the ISO fecal microbiota transplantation (FMT) inoculation of DSS-treated mice had similarly beneficial results. FMT mice showed a reduction in colitis symptoms, which was more pronounced in ISO-FMT than in CON-FMT mice. Meanwhile, ISO-FMT expanded the abundance of beneficial microorganisms, increased the expression of metabolites, such as SCFAs and total SBAs, and significantly upregulated the expression of P-gp protein. In addition, Spearman's correlation analysis demonstrated a positive correlation between the production of SCFAs and SBAs and the expression of P-gp. The present study identified that ISO increases the expression of P-gp in the intestinal epithelium by regulating intestinal microorganisms and their metabolites, which maintains colonic homeostasis, improves the integrity of the colonic epithelium, and alleviates colitis.

Matrix metalloproteinase-responsive hydrogels with tunable retention for on-demand therapy of inflammatory bowel disease

Therapeutic options for addressing inflammatory bowel disease (IBD) include the administration of an enema to reduce intestinal inflammation and alleviate associated symptoms. However, uncontrollable retention of enemas in the intestinal tract has posed a long-term challenge for improving their therapeutic efficacy and safety. Herein we have developed a protease-labile hydrogel system as an on-demand enema vehicle with tunable degradation and drug release rates in response to varying matrix metalloproteinase-9 (MMP-9) expression. The system, composed of three tailored hydrogel networks, is crosslinked by poly (ethylene glycol) (PEG) with 2-, 4- and 8-arms through dynamic hydrazone bonds to confer injectability and generate varying network connectivity. The retention time of the hydrogels can be tuned from 12 to 36 h in the intestine due to their different degradation behaviors induced by MMP-9. The drug-releasing rate of the hydrogels can be controlled from 0.0003 mg/h to 0.278 mg/h. In addition, injection of such hydrogels in vivo resulted in significant differences in therapeutic effects including MMP-9 consumption, colon tissue repair, reduced collagen deposition, and decreased macrophage cells, for treating a mouse model of acute colitis. Among them, GP-8/5-ASA exhibits the best performance. This study validates the effectiveness of the tailored design of hydrogel architecture in response to pathological microenvironment cues, representing a promising strategy for on-demand therapy of IBD. STATEMENT OF SIGNIFICANCE: The uncontrollable retention of enemas at the delivery site poses a long-term challenge for improving therapeutic efficacy in IBD patients. MMP-9 is highly expressed in IBD and correlates with disease severity. Therefore, an MMP-9-responsive GP hydrogel system was developed as an enema by linking multi-armed PEG and gelatin through hydrazone bonds. This forms a dynamic hydrogel characterized by in situ gelation, injectability, enhanced bio-adhesion, biocompatibility, controlled retention time, and regulated drug release. GP hydrogels encapsulating 5-ASA significantly improved the intestinal phenotype of acute IBD and demonstrated notable therapeutic differences with increasing PEG arms. This method represents a promising on-demand IBD therapy strategy and provides insights into treating diseases of varying severities using endogenous stimulus-responsive drug delivery systems.

Pre- to Postbiotics: The Beneficial Roles of Pediatric Dysbiosis Associated with Inflammatory Bowel Diseases

Probiotics are "live microorganisms which, when administered in adequate amount, confer health benefits on the host". They can be found in certain foods like yogurt and kefir and in dietary supplements. The introduction of bacterial derivatives has not only contributed to disease control but has also exhibited promising outcomes, such as improved survival rates, immune enhancement, and growth promotion effects. It is interesting to note that the efficacy of probiotics goes beyond the viability of the bacteria, giving rise to concepts like paraprobiotics, non-viable forms of probiotics, and postbiotics. Paraprobiotics offer various health benefits in children with intestinal dysbiosis, contributing to improved digestive health, immune function, and overall well-being. In this review, the potential of these therapeutic applications as alternatives to pharmacological agents for treating pediatric intestinal dysbiosis will be thoroughly evaluated. This includes an analysis of their efficacy, safety, long-term benefits, and their ability to restore gut microbiota balance, improve digestive health, enhance immune function, and reduce inflammation. The aim is to determine if these non-pharmacological interventions can effectively and safely manage intestinal dysbiosis in children, reducing the need for conventional medications and their side effects.

Alleviating Pyroptosis of Intestinal Epithelial Cells to Restore Mucosal Integrity in Ulcerative Colitis by Targeting Delivery of 4-Octyl-Itaconate

Current therapies primarily targeting inflammation often fail to address the root relationship between intestinal mucosal integrity and the resulting dysregulated cell death and ensuing inflammation in ulcerative colitis (UC). First, UC tissues from human and mice models in this article both emphasize the crucial role of Gasdermin E (GSDME)-mediated pyroptosis in intestinal epithelial cells (IECs) as it contributes to colitis by releasing proinflammatory cytokines, thereby compromising the intestinal barrier. Then, 4-octyl-itaconate (4-OI), exhibiting potential for anti-inflammatory activity in inhibiting pyroptosis, was encapsulated by butyrate-modified liposome (4-OI/BLipo) to target delivery for IECs. In brief, 4-OI/BLipo exhibited preferential accumulation in inflamed colonic epithelium, attributed to over 95% of butyrate being produced and absorbed in the colon. As expected, epithelium barriers were restored significantly by alleviating GSDME-mediated pyroptosis in colitis. Accordingly, the permeability of IECs was restored, and the resulting inflammation, mucosal epithelium, and balance of gut flora were reprogrammed, which offers a hopeful approach to the effective management of UC.

Advances and optimization strategies in bacteriophage therapy for treating inflammatory bowel disease

In the advancement of Inflammatory Bowel Disease (IBD) treatment, existing therapeutic methods exhibit limitations; they do not offer a complete cure for IBD and can trigger adverse side effects. Consequently, the exploration of novel therapies and multifaceted treatment strategies provides patients with a broader range of options. Within the framework of IBD, gut microbiota plays a pivotal role in disease onset through diverse mechanisms. Bacteriophages, as natural microbial regulators, demonstrate remarkable specificity by accurately identifying and eliminating specific pathogens, thus holding therapeutic promise. Although clinical trials have affirmed the safety of phage therapy, its efficacy is prone to external influences during storage and transport, which may affect its infectivity and regulatory roles within the microbiota. Improving the stability and precise dosage control of bacteriophages-ensuring robustness in storage and transport, consistent dosing, and targeted delivery to infection sites-is crucial. This review thoroughly explores the latest developments in IBD treatment and its inherent challenges, focusing on the interaction between the microbiota and bacteriophages. It highlights bacteriophages' potential as microbiome modulators in IBD treatment, offering detailed insights into research on bacteriophage encapsulation and targeted delivery mechanisms. Particular attention is paid to the functionality of various carrier systems, especially regarding their protective properties and ability for colon-specific delivery. This review aims to provide a theoretical foundation for using bacteriophages as microbiome modulators in IBD treatment, paving the way for enhanced regulation of the intestinal microbiota.

Resveratrol improves diabetic kidney disease by modulating the gut microbiota-short chain fatty acids axis in db/db mice

Diabetic kidney disease is associated with the dysbiosis of the gut microbiota and its metabolites. db/db mice were fed chow diet with or without 0.4% resveratrol for 12 weeks, after which the gut microbiota, faecal short-chain fatty acids (SCFAs), and renal fibrosis were analysed. Resveratrol ameliorated the progression of diabetic kidney disease and alleviated tubulointerstitial fibrosis. Further studies showed that gut microbiota dysbiosis was modulated by resveratrol, characterised by the expansion of SCFAs-producing bacteria Faecalibaculum and Lactobacillus, which increased the concentrations of SCFAs (especially acetic acid) in the faeces. Moreover, microbiota transplantation experiments found that alteration of the gut microbiota contributed to the prevention of diabetic kidney disease. Acetate treatment ameliorated proteinuria, glomerulosclerosis and tubulointerstitial fibrosis in db/db mice. Overall, resveratrol improved the progression of diabetic kidney disease by suppressing tubulointerstitial fibrosis, which may be involved, at least in part, in the regulation of the gut microbiota-SCFAs axis.

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.

The Regulatory Effect of Huangshui Polysaccharides on Intestinal Microbiota and Metabolites during In Vitro Fermentation

Huangshui polysaccharides (HSPs) have attracted extensive attention recently for their biological activity and physicochemical property. This research investigated the extraction, structural characterization, and prebiotic activity of three different HSPs (HSP40-0, HSP60-0, and HSP80-0) in vitro to reveal the scientific support for the high-value utilization of Huangshui. HSPs were heteropolysaccharide with diverse structures and surface morphologies. Comprehensive analysis was conducted through 16S rRNA gene sequencing and metabolite profiling techniques, and results showed that HSPs had different potentials to regulate the gut microbiota due to their different structures; for instance, both HSP40-0 and HSP80-0 could notably increase the relative abundance of Bacteroidota, whereas HSP60-0 could increase the relative abundance of Phascolarctobacterium. In addition, HSPs upregulated beneficial differential metabolites, especially short-chain fatty acids (SCFAs). Fermentation products containing these metabolites exhibited anti-inflammatory effects on LPS-treated Caco-2 cells. This study will provide reference for exploring the relationship between the natural polysaccharide structure and the prebiotic activity and widen the application of Huangshui.

Longevity-associated BPIFB4 gene counteracts the inflammatory signaling

BACKGROUND

Increased levels of pro-inflammatory proteins in plasma can be detected in older individuals and associate with the so called chronic low-grade inflammation, which contributes to a faster progression of aged-related cardiovascular (CV) diseases, including frailty, neurodegeneration, gastro-intestinal diseases and disorders reflected by alterations in the composition of gut microbiota. However, successful genetic programme of long-living individuals alters the trajectory of the ageing process, by promoting an efficient immune response that can counterbalance deleterious effects of inflammation and the CV complications. This is the case of BPIFB4 gene in which, homozygosity for a four single-nucleotide polymorphism (SNP) haplotype, the Longevity-Associated Variant (LAV) correlates with prolonged health span and reduced risk of CV complications and inflammation. The relation between LAV-BPIFB4 and inflammation has been proven in different experimental models, here we hypothesized that also human homozygous carriers of LAV-BPIFB4 gene may experience a lower inflammatory burden as detected by plasma proteomics that could explain their favourable CV risk trajectory over time. Moreover, we explored the therapeutic effects of LAV-BPIFB4 in inflammatory disease and monolayer model of intestinal barrier.

RESULTS

We used high-throughput proteomic approach to explore the profiles of circulating proteins from 591 baseline participants selected from the PLIC cohort according to the BPIFB4 genotype to identify the signatures and differences of BPIFB4 genotypes useful for health and disease management. The observational analysis identified a panel of differentially expressed circulating proteins between the homozygous LAV-BPIFB4 carriers and the other alternative BPIFB4 genotypes highlighting in the latter ones a higher grade of immune-inflammatory markers. Moreover, in vitro studies performed on intestinal epithelial organs from inflammatory bowel disease (IBD) patients and monolayer model of intestinal barrier demonstrated the benefit of LAV-BPIFB4 treatment.

CONCLUSIONS

Homozygosity for LAV-BPIFB4 results in the attenuation of inflammation in PLIC cohort and IBD patients providing preliminary evidences for its therapeutic use in inflammatory disorders that need to be further characterized and confirmed by independent studies.

A host-microbial metabolite interaction gut-on-a-chip model of the adult human intestine demonstrates beneficial effects upon inulin treatment of gut microbiome

Background: The gut and its microbiome have a major impact on many aspects of health and are therefore also an attractive target for drug- or food-based therapies. Here, we report on the added value of combining a microbiome screening model, the i-screen, with fresh intestinal tissue explants in a microfluidic gut-on-a-chip model, the Intestinal Explant Barrier Chip (IEBC). Methods: Adult human gut microbiome (fecal pool of 6 healthy donors) was cultured anaerobically in the i-screen platform for 24 h, without and with exposure to 4 mg/mL inulin. The i-screen cell-free culture supernatant was subsequently applied to the luminal side of adult human colon tissue explants (n = 3 donors), fixed in the IEBC, for 24 h and effects were evaluated. Results: The supplementation of the media with inulin promoted the growth of Anaerostipes, Bifidobacterium, Blautia, and Collinsella in the in vitro i-screen, and triggered an elevated production of butyrate by the microbiota. Human colon tissue exposed to inulin-treated i-screen cell-free culture supernatant or control i-screen cell-free culture supernatant with added short-chain fatty acids (SCFAs) showed improved tissue barrier integrity measured by a 28.2%-34.2% reduction in FITC-dextran 4000 (FD4) leakage and 1.3 times lower transport of antipyrine. Furthermore, the release of pro-inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α was reduced under these circumstances. Gene expression profiles confirmed these findings, but showed more profound effects for inulin-treated supernatant compared to SCFA-supplemented supernatant. Conclusion: The combination of i-screen and IEBC facilitates the study of complex intestinal processes such as host-microbial metabolite interaction and gut health.

Seasonal variations of airborne microbial diversity in waste transfer stations and preventive effect on Streptococcus pneumoniae induced pulmonary inflammation

Environment, location, and season are important factors that influence the microbiological community, yet, little research on airborne microorganisms in waste transfer stations (WTSs). Here, the airborne bacterial and fungal communities at four WTSs during different seasons were analyzed by high-throughput sequencing. The bacteria were isolated by cultural method and screened bacterium alleviate inflammation induced by Streptococcus pneumoniae (Spn) by regulating gut microbiome. The results revealed that collected bioaerosols from the WTSs varied significantly by location and season. Proteobacteria and Pseudomonadota are prevalent in summer and winter, respectively. Ascomycota was predominant in two seasons. Hazard quotients for adults from four WTSs were below one. Three selected potential probiotics were formulated into a microbial preparation with a carrier that effectively prevented inflammation in bacterial and animal experiments. The expression levels of interleukin-1β, interleukin-6, and tumor necrosis factor-α in Pre group (0.11, 0.17, and 0.48-fold) were significantly lower than Spn group (2.75, 1.71, and 5.01-fold). These mechanisms are associated with changes in gut microbiota composition and short-chain fatty acids (SCFAs) levels, such as affecting Lachnospiraceae lachnospira abundance and acetic acid content. This study provides insights into the potential application of probiotics derived from WTSs as an alternative approach to preventing respiratory infections.

Oral administration of LfcinB alleviates DSS-induced colitis by improving the intestinal barrier and microbiota

Ulcerative colitis (UC) is a kind of inflammatory bowel disease (IBD) that often recurs and is difficult to cure, and no drugs with few side effects are available to treat this disease. LfcinB is a small molecular peptide obtained by the hydrolysis of bovine lactoferrin in the digestive tract of animals. It has strong antibacterial and anti-inflammatory activities. However, direct evidence that LfcinB improves the condition of colitis in mice is rarely reported. In this study, UC was induced in mice by adding 2.5% dextran sulfate (DSS) to drinking water and LfcinB was orally administered. The results showed that oral administration of LfcinB improved colonic tissue damage and inflammatory cell infiltration, increased the expression of tight junction proteins, and down-regulated the phosphorylation of proteins related to the NF-κB/MAPK inflammatory signalling pathway in mice. It also significantly suppressed the relative abundance of potentially pathogenic bacteria (Bacteroides, Barnesiella and Escherichia) in the intestinal flora. In conclusion, oral administration of LfcinB significantly alleviated DSS-induced UC. This may be related to the regulation of inflammatory signalling pathways and gut microbial composition by LfcinB.

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.

A pathophysiologic framework for the overlap of disorders of gut-brain interaction and the role of the gut microbiome

The International Rome Committee defines Disorders of Gut-Brain Interactions (DGBI) based upon distinct combinations of chronic and/or recurrent unexplained gastrointestinal symptoms. Yet patients often experience overlapping DGBI. Patients with DGBI frequently also suffer from extraintestinal symptoms, including fatigue, sleep disturbances, anxiety, and depression. Patients with overlapping DGBI typically experience more severe GI symptoms and increased psychosocial burden. Concerning the pathophysiology, DGBI are associated with disruptions in gut motility, function of the brain and enteric neurons, immune function, and genetic markers, with recent findings revealing gut microbiome alterations linked to these mechanisms of DGBI. Emerging evidence summarized in this review suggests that the microbiome influences various established disease mechanisms of different DGBI groups. Overall, changes in the gastrointestinal microbiome do not seem to be linked to a specific DGBI subgroup but may play a key role in the manifestation of different DGBI and, subsequently, overlap of DGBI. Understanding these shared mechanisms and the role of the gastrointestinal microbiome, particularly for overlapping DGBI, might aid in developing more precise diagnostic criteria and treatment strategies while developing personalized interventions that target specific mechanisms to improve patient outcomes.

Butyrate Protects and Synergizes with Nicotine against Iron- and Manganese-induced Toxicities in Cell Culture

Toxic exposures to heavy metals, such as iron (Fe) and manganese (Mn), can result in long-range neurological diseases and are therefore of significant environmental and medical concerns. We have previously reported that damage to neuroblastoma-derived dopaminergic cells (SH-SY5Y) by both Fe and Mn could be prevented by pre-treatment with nicotine. Moreover, butyrate, a short chain fatty acid (SCFA) provided protection against salsolinol, a selective dopaminergic toxin, in the same cell line. Here, we broadened the investigation to determine whether butyrate might also protect against Fe and/or Mn, and whether, if combined with nicotine, an additive or synergistic effect might be observed. Both butyrate and nicotine concentration-dependently blocked Fe and Mn toxicities. Ineffective concentrations of nicotine and butyrate, when combined, provided full protection against both Fe and Mn. Moreover, the effects of nicotine but not butyrate could be blocked by mecamylamine, a non-selective nicotinic antagonist. On the other hand, the effects of butyrate, but not nicotine, could be blocked by beta-hydroxy butyrate, a fatty acid-3 receptor antagonist. These results not only provide further support for neuroprotective effects of both nicotine and butyrate but also indicate distinct mechanisms of action for each one. Furthermore, potential utility of butyrate and nicotine combination against heavy metal toxicities is suggested.

Houttuynia cordata thunb. alleviates inflammatory bowel disease by modulating intestinal microenvironment: a research review

Inflammatory bowel disease (IBD) is a complex group of chronic intestinal diseases, the cause of which has not yet been clarified, but it is widely believed that the disorder of the intestinal microenvironment and its related functional changes are key factors in the development of the disease. Houttuynia cordata thunb. is a traditional plant with abundant resources and long history of utilization in China, which has attracted widespread attention in recent years due to its potential in the treatment of IBD. However, its development and utilization are limited owing to the aristolochic acid alkaloids contained in it. Therefore, based on the relationship between the intestinal microenvironment and IBD, this article summarizes the potential mechanisms by which the main active ingredients of Houttuynia cordata thunb., such as volatile oils, polysaccharides, and flavonoids, and related traditional Chinese medicine preparations, such as Xiezhuo Jiedu Formula, alleviate IBD by regulating the intestinal microenvironment. At the same time, combined with current reports, the medicinal and edible safety of Houttuynia cordata thunb. is explained for providing ideas for further research and development of Houttuynia chordate thunb. in IBD disease, more treatment options for IBD patients, and more insights into the therapeutic potential of plants with homology of medicine and food in intestinal diseases, and even more diseases.

Butyrate protects and synergizes with nicotine against iron- and manganese-induced toxicities in cell culture: Implications for neurodegenerative diseases

Toxic exposures to heavy metals, such as iron (Fe) and manganese (Mn), can result in long-range neurological diseases and are therefore of significant environmental and medical concerns. We have previously reported that damage to neuroblastoma-derived dopaminergic cells (SH-SY5Y) by both Fe and Mn could be prevented by pre-treatment with nicotine. Moreover, butyrate, a short chain fatty acid (SCFA) provided protection against salsolinol, a selective dopaminergic toxin, in the same cell line. Here, we broadened the investigation to determine whether butyrate might also protect against Fe and/or Mn, and whether, if combined with nicotine, an additive or synergistic effect might be observed. Both butyrate and nicotine concentration-dependently blocked Fe and Mn toxicities. The ineffective concentrations of nicotine and butyrate, when combined, provided full protection against both Fe and Mn. Moreover, the effects of nicotine but not butyrate could be blocked by mecamylamine, a non-selective nicotinic antagonist. On the other hand, the effects of butyrate, but not nicotine, could be blocked by beta-hydroxy butyrate, a fatty acid-3 receptor antagonist. These results not only provide further support for neuroprotective effects of both nicotine and butyrate but indicate distinct mechanisms of action for each one. Furthermore, potential utility of the combination of butyrate and nicotine against heavy metal toxicities is suggested.

The interconnection between obesity and executive function in adolescence: The role of the gut microbiome

In the United States, adolescent obesity is a growing epidemic associated with maladaptive executive functioning. Likewise, data link the microbiome to obesity. Emerging microbiome research has demonstrated an interconnection between the gut microbiome and the brain, indicating a bidirectional communication system within the gut-microbiome-brain axis in the pathophysiology of obesity. This narrative review identifies and summarizes relevant research connecting adolescent obesity as it relates to three core domains of executive functioning and the contribution of the gut microbiome in the relationship between obesity and executive functions in adolescence. The review suggests that (1) the interconnection between obesity, executive function, and the gut microbiome is a bidirectional connection, and (2) the gut microbiome may mediate the neurobiological pathways between obesity and executive function deficits. The findings of this review provide valuable insights into obesity-associated executive function deficits and elucidate the possible mediation role of the gut microbiome.

Circulating short chain fatty acids and fatigue in patients with head and neck cancer: A longitudinal prospective study

Fatigue among patients with head and neck cancer (HNC) has been associated with higher inflammation. Short-chain fatty acids (SCFAs) have been shown to have anti-inflammatory and immunoregulatory effects. Therefore, this study aimed to examine the association between SCFAs and fatigue among patients with HNC undergoing treatment with radiotherapy with or without concurrent chemotherapy. Plasma SCFAs and the Multidimensional Fatigue Inventory-20 were collected prior to and one month after the completion of treatment in 59 HNC patients. The genome-wide gene expression profile was obtained from blood leukocytes prior to treatment. Lower butyrate concentrations were significantly associated with higher fatigue (p = 0.013) independent of time of assessment, controlling for covariates. A similar relationship was observed for iso/valerate (p = 0.025). Comparison of gene expression in individuals with the top and bottom 33% of butyrate or iso/valerate concentrations prior to radiotherapy revealed 1,088 and 881 significantly differentially expressed genes, respectively (raw p < 0.05). The top 10 Gene Ontology terms from the enrichment analyses revealed the involvement of pathways related to cytokines and lipid and fatty acid biosynthesis. These findings suggest that SCFAs may regulate inflammatory and immunometabolic responses and, thereby, reduce inflammatory-related symptoms, such as fatigue.

Imbalance of gut microbiota is involved in the development of chronic obstructive pulmonary disease: A review

Chronic obstructive pulmonary disease (COPD) is a common chronic disease characterized by chronic airway inflammation and remodeling, which seriously endangers human health. Recent developments in genomics and metabolomics have revealed the roles of the gut microbiota and its metabolites in COPD. Dysbiosis of the gut microbiota directly increases gut permeability, thereby promoting the translocation of pathological bacteria. The gut microbiota and associated metabolites may influence the development and progression of COPD by modulating immunity and inflammation. Furthermore, the systemic hypoxia and oxidative stress that occur in COPD may also be involved in intestinal dysfunction. The cross-talk between the gut and lungs is known as the gut-lung axis; however, an overview of its mechanism is lacking. This review highlights the critical and complex interplay of gut microbiota and immune responses in the gut-lung axis, further explores possible links between the gut and lungs, and summarizes new interventions through diet, probiotics, vitamins, and fecal microbiota transplantation, which are critical to COPD.