Intestinal permeability--a new target for disease prevention and therapy. BMC Gastroenterol. 2014;14:189. [PMID: 25407511 PMCID: PMC4253991 DOI: 10.1186/s12876-014-0189-7]

The intestinal mucosa-associated microbiota in IBD-associated arthritis displays lower relative abundance of Roseburia intestinalis

The most common extra-intestinal manifestation (EIM) of inflammatory bowel disease (IBD), IBD-associated arthritis (IAA), occurs in 25-40% of patients and can be debilitating. In IBD, mucosal and stool microbiota richness is decreased, and compositional changes can precede or accompany disease onset. Likewise, spondyloarthritides are associated with altered gut microbiota, with overlapping bacterial signatures observed in IBD, suggesting key shared microbial factors are involved in both conditions. Much has been learned about the role of the intestinal microbiome in IBD, but less is known regarding its role in IAA. To address this knowledge gap, we analyzed the mucosa-associated intestinal microbiota of participants enrolled in the LOCATION-IBD cohort. Microbiota composition was established using 16S rRNA gene amplicon sequencing of intestinal biopsy samples taken from participants with IBD, with or without arthropathy. Microbiota samples clustered predominantly by participant, and similar taxa were present across the colon. The mucosal intestinal microbiota of females with IAA displayed a lower relative abundance of R. intestinalis, while males with IAA had a higher relative abundance of Corynebacterium, even when controlling for IBD-type, whether samples were taken from a site of inflammation and intestinal location. These findings indicate the mucosa-associated intestinal microbiota is associated with IAA in a sex-specific manner.

Bacillus coagulans ameliorates inflammatory bone loss in post-menopausal osteoporosis via modulating the "Gut-Immune-Bone" axis

Osteoporosis is a systemic skeletal disease that leads to lower bone mineral density and intensifies the risk of unexpected fractures. Recently, our group reported that numerical defect in the frequencies of Bregs along with their compromised tendency to produce IL-10 cytokine further aggravates inflammatory bone loss in post-menopausal osteoporosis (PMO). Dysbiosis induced mucosal injury and leaky gut are the predominant contributors involved in the progression of inflammatory diseases including PMO. Furthermore, several evidence suggest that gut microbial composition plays a crucial role in the development and differentiation of Bregs. Nevertheless, the potential role of dysbiotic gut microbiota (GM) and Bregs under estrogen deficient PMO conditions has never been deciphered. Here, we evaluated the role of GM in the onset and progression of PMO along with its role in modulating the anti-osteoporotic potential of Bregs. We found that enhancement in the endotoxin producing bacteria and concomitant reduction in the short chain fatty acids producing bacteria, both under pre-clinical and clinical osteoporotic condition augment inflammatory bone loss. This suggests that dysbiosis of GM potentially exacerbates bone deterioration under estrogen deficient PMO conditions. Remarkably, supplementation of probiotic Bacillus coagulans significantly improved the bone mineral density, bone strength, and bone microarchitecture by modulating the anti-osteoclastogenic, immunosuppressive and immunomodulatory potential of Bregs. The present study delves deeper into the role of immune homeostasis ("Breg-Treg-Th17" cell axis) and GM profile in the pathophysiology of PMO. Altogether, findings of the present study open novel therapeutic avenues, suggesting restoration of GM composition as one of the viable therapeutic options in mitigating inflammatory bone loss under PMO conditions via modulating the "Gut-Immune-Bone" axis.

The gut microbiota: an emerging modulator of drug resistance in hepatocellular carcinoma

Liver cancer is usually diagnosed at an advanced stage and is the third most common cause of cancer-related death worldwide. In addition to the lack of effective treatment options, resistance to therapeutic drugs is a major clinical challenge. The gut microbiota has recently been recognized as one of the key factors regulating host health. The microbiota and its metabolites can directly or indirectly regulate gene expression in the liver, leading to gut-liver axis dysregulation, which is closely related to liver cancer occurrence and the treatment response. Gut microbiota disturbance may participate in tumor progression and drug resistance through metabolite production, gene transfer, immune regulation, and other mechanisms. However, systematic reviews on the role of the gut microbiota in drug resistance in liver cancer are lacking. Herein, we review the relationships between the gut microbiota and the occurrence and drug resistance of hepatocellular carcinoma, summarize the emerging mechanisms underlying gut microbiota-mediated drug resistance, and propose new personalized treatment options to overcome this resistance.

Chronic fluoride induces neurotoxicity in zebrafish through the gut-brain axis

Fluoride (F) is a common pollutant in aquatic environment. Chronic exposure to fluoride can cause toxicity to nervous system and behavior of fish. However, the underlying mechanism is still unclear. This study is designed to explore the effects and potential mechanisms of chronic fluoride exposure on zebrafish behavior. Zebrafish were exposed to CK, LF, MF, and HF for 90 days. The results showed that chronic fluoride exposure caused damage to the brain tissues of adult zebrafish and significantly reduced the total distance of free swimming per min. Fluoride significantly reduced dopamine content and dopamine pathway related gene expression in brain. In addition, fluoride disrupted the intestinal barrier function, reduced the expression of tight junction proteins and mucin related genes in intestinal tissues, increased intestinal permeability. Males in the HF group were more sensitive than the corresponding females. Fluoride significantly decreased the dopamine content in the intestine, disturbed the gene expression of dopamine pathway related genes. Fluoride significantly increased the relative abundance of g_uncultured_bacterium_c_Gammaprotebacteria in three F groups, while significantly reduced the relative abundance of g_lactobacilli and g_Lachnospiraceae NK4A136_group. At the same time, metabolic pathways including amino acid metabolism, nucleotide metabolism, and carbohydrate metabolism were also affected. These indicate that fluoride can result in neurotoxicity and behavioral changes by disrupting intestinal permeability and causing intestinal damage caused by imbalance of gut microbiota nucleotide metabolism, and the abnormal expression of dopamine related genes in the gut in zebrafish. Male zebrafish are more sensitive than female zebrafish.

Photoperiod-Dependent Effects of Phenolic-Enriched Fruit Extracts on Postprandial Triacylglyceride Levels and Acute Inflammatory Responses in F344 Rats

This study investigated the photoperiod-dependent effects of eight phenolic-enriched fruit extracts on postprandial blood triacylglyceride (TAG) levels and serum cytokine and CRP levels in F344 rats after an oral lipid tolerance test (OLTT) and lipopolysaccharide (LPS)-induced inflammatory challenge, respectively. Animals were exposed to short (6-h light, L6) or long (18-h light, L18) photoperiods and orally supplemented with fruit extracts (100 mg/kg) for 2 weeks. Extracts were obtained from seasonal fruits (cherries, plums, apricots, strawberries, persimmon kakis, grapes, oranges, and pomegranates). Temporal homeostasis disruption was induced by an OLTT and LPS challenge. No differences in blood postprandial TAG levels were observed in the L6- and L12-control groups. However, in the experimental groups, the postprandial TAG response depended on the photoperiod and fruit extract consumption, mainly cherry and plum extracts in L6 (p < 0.05). In addition, control rats exposed to L6 exhibited higher blood IL-6 and TNF-α levels after inducing LPS-inflammatory response. Notably, winter-fruit and strawberry extracts were the most efficient at lowering proinflammatory cytokines. These findings show the effectiveness of specific fruit extracts in modulating postprandial TAG levels and acute inflammatory responses, being their effects photoperiod-dependent, opening the door to the design of functional ingredients specific for each season.

The role of circulating zonulin levels in patients with chronic kidney disease stages 3 to 5 not on dialysis

Zonulin (Zo) has recently been identified as a marker of intestinal permeability. It has previously been linked to type 2 diabetes mellitus, obesity, and cardiovascular disease; however, its role in chronic kidney disease (CKD) remains unclear. This study aimed to investigate the relationship between Zo and systemic inflammation (SI), endothelial dysfunction (ED), and renal function in CKD patients. One hundred sixty-three participants were enrolled in this study and divided into 2 groups (patient and control) according to the presence of CKD stage 3 to 5 not on dialysis. Circulating Zo levels have been investigated as markers of intestinal permeability. Furthermore, vascular cell adhesion molecule 1 (VCAM-1) and Interleukin-6 (IL-6) have been used as biomarkers for ED and SI assessments, respectively. A total of 104 patients with CKD (mean age: 58.9 ± 1.4) and 59 control subjects (mean age: 59.0 ± 1.1) were included, with similar age (P = .934) and sex (P = .196) between the groups. In the comparison analysis, plasma Zo levels in the CKD group (166.16 ± 53.54) were significantly higher than those in the control group (143.30 ± 60.92) (P < .001). In the correlation analysis, the serum Zo level showed a positive correlation with claudin-3 (R = 0.612, P < .001), IL-6 (R = 0.307, P < .001), and creatinine (R = 0.313, P < .001) and a negative correlation with glomerular filtration rate (GFR) (r = -0.320, P < .001). On the other hand, there was no correlation between circulating Zo and VCAM-1 levels (r = -0.139, P = .081). Additionally, according to linear regression analysis, Zo level was significantly associated with GFR after adjusting for age and systolic blood pressure (β = -0.918, P = .012). High serum Zo levels in patients with CKD reflect increased intestinal permeability and are associated with impaired renal function. Moreover, it was thought that Zo levels could be associated with SI; however, novel clinical studies are needed to elucidate their relationship with ED.

Linking gut permeability to liver steatosis: Noninvasive biomarker evaluation in MASLD patients - a prospective cross-sectional study

Recent research highlights a potential link between metabolic dysfunction-associated steatotic liver disease (MASLD) and intestinal barrier dysfunction. Increased intestinal permeability (IP) may facilitate the translocation of bacteria, endotoxins (e.g., lipopolysaccharides [LPS]), and pathogen-associated molecular patterns into the portal venous system, fostering a pro-inflammatory environment and contributing to liver inflammation. This study aimed to identify correlations between intestinal barrier biomarkers (occludin, LPS, and intestinal-type fatty-acid-binding proteins [I-FABP]) and MASLD. A single-center prospective cross-sectional study was conducted, including 72 MASLD patients and 68 healthy controls. Fibroscan-controlled attenuation parameter (CAP) was performed in all subjects. Blood samples were analyzed for biochemical parameters, and serum levels of occludin, LPS, and I-FABP were measured using the ELISA method with the Human occludin, LPS, and I-FABP ELISA Kit test systems (FineTest, Wuhan, China). LPS and I-FABP levels were significantly higher in MASLD patients compared to controls, with the highest LPS levels observed in the diabetic MASLD subgroup. Occludin levels showed no statistically significant differences between groups. All 3 biomarkers were positively correlated with BMI, with the highest levels in obese subjects. LPS was positively correlated with CRP levels. Using Fibroscan-CAP, we found a positive correlation between LPS and both liver stiffness and CAP score, as well as between I-FABP and liver stiffness. MASLD patients exhibit increased IP, with enterocyte injury present irrespective of diabetes status, though more pronounced in diabetic MASLD. Occludin does not appear to be a reliable biomarker for evaluating intestinal barrier function in MASLD. Obesity is linked to elevated biomarkers, suggesting an association between increased IP and obesity. I-FABP and LPS may serve as noninvasive biomarkers for assessing hepatic fibrosis and steatosis in MASLD patients. Notably, LPS, given its correlation with elevated CRP levels, could be utilized as a marker of disease progression and severity.

Per- and polyfluoroalkyl substances (PFAS): immunotoxicity at the primary sites of exposure

Per- and polyfluoroalkyl substances (PFAS) are persistent synthetic chemicals widely used in industrial and consumer products, leading to environmental contamination and human exposure. This review focuses on perfluoroalkyl acids, a subset of PFAS, which are primarily encountered through diet, including drinking water, and other pathways such as dust ingestion, and dermal contact. Impaired vaccine antibody response has been identified as the most critical effect for risk assessment by the European Food Safety Authority. Furthermore, human epidemiological studies have linked exposure to certain PFAS to various immune-related outcomes, such as asthma, allergies, and inflammatory bowel disease. This review examines potential immunomodulatory effects of perfluoroalkyl acids at the primary sites of exposure: lungs, intestines, and skin, using human epidemiological data as the basis for investigating these impacts. While animal studies are referenced for context, this paper highlights the need for further human-based research to address key questions about PFAS and their immunological impacts. The state of in vitro toxicity testing related to these effects is thoroughly reviewed and critical issues pertaining to this topic are discussed.

Bacillus licheniformis Alleviates Clostridium perfringens-Induced Intestinal Injury in Mice Model by Modulating Inflammation, Apoptosis, and Cecal Microbial-Metabolic Responses

Bacillus licheniformis (B. licheniformis) is a probiotic known for its ability to enhance host resistance against pathogenic infections. This study aimed to evaluate the protective effects and underlying mechanisms of B. licheniformis in a mouse model challenged with Clostridium perfringens (C. perfringens). C57BL/6J mice were pretreated with B. licheniformis for 21 days before oral infection with C. perfringens. The probiotic administration significantly prevented infection-induced weight loss and immune organ enlargement. Serum cytokine analysis revealed that B. licheniformis increased anti-inflammatory IL-4 and IL-10 levels while reducing pro-inflammatory IL-1β, IL-6, and TNF-α levels. Histological analysis showed that B. licheniformis preserved intestinal morphology and inhibited epithelial cell apoptosis. Moreover, the probiotic mitigated the infection-induced decline in volatile fatty acid (VFA) production. 16S rRNA gene sequencing revealed that B. licheniformis reshaped the cecal microbiota, characterized by the increased abundance of Lachnospiraceae_NK4A136_group, Muribaculaceae, and Parabacteroides, and reduced abundance of Alistipes. Untargeted metabolomic profiling identified differential metabolites-including D-glucono-1,5-lactone, D-erythrose 4-phosphate, and D-sedoheptulose 7-phosphate-enriched in the pentose phosphate pathway, suggesting a regulatory role in redox homeostasis and host response. Collectively, these results indicate that B. licheniformis exerts protective effects against C. perfringens infection by modulating inflammation, apoptosis, microbial composition, and metabolic pathways. This work provides new insights into the application of B. licheniformis as a functional microbial feed additive in livestock disease prevention.

Bacterial Extracellular Vesicles: Bridging Pathogen Biology and Therapeutic Innovation

The main role of bacterial extracellular vesicles (BEVs) has been associated with various processes such as intercellular communication and host-pathogen interactions. This comprehensive review explores the multifaceted functions of BEVs across different biological domains, emphasizing their dual nature as contributors to disease and potential vehicles for therapeutic intervention. We examine the intricate interactions of BEVs within bacterial communities and between bacteria and hosts, their involvement in disease development through cargo delivery mechanisms, and their beneficial impact on microbial ecology. The review also highlights BEVs' applications in biomedical field, where they are revolutionizing vaccine development, targeted drug delivery, and cancer therapy. By utilizing the inherent properties of BEVs for controlled drug release, targeted antigen delivery, and immune modulation, they offer a promising frontier in precision medicine. In addition, the diagnostic potential of BEVs is explored through their utility as biomarkers, providing valuable insights into disease states and treatment efficacy. Looking forward, this review underscores the challenges and opportunities in translating BEV research to clinical practice, promoting the need of standardized methods in BEV characterization and scaling up production. The diverse abilities of BEVs, ranging from contributing to pathogen virulence to driving therapeutic innovation, highlight their potential as a cornerstone in the future of biomedical advancements. STATEMENT OF SIGNIFICANCE: Bacterial extracellular vesicles (BEVs) are emerging as pivotal players in both pathogenesis and therapeutic innovation. This review explores their dual nature as agents of disease and as promising biomaterials for biomedical applications, and provides a comprehensive survey on their involvement in disease mechanisms and microbial ecology, and their potential in biomedical applications such as vaccine development, targeted drug delivery, cancer therapy, and diagnosis. It highlights the complex interactions of BEVs within bacterial communities and between bacteria and hosts. This review also addresses current advancements, challenges, and opportunities in translating BEV research into clinical practice. The insights presented here position BEVs as a cornerstone in the future of biomedical advancements, advocating for standardized methods in BEV characterization and scalable production techniques.

A promising approach to diabetic osteoporosis: oxymatrine's effects on gut microbiota and osteoblasts

OBJECTIVES

Oxymatrine (OMT), a quinolizidine alkaloid derived from Sophora flavescens Ait., has demonstrated therapeutic potential in type 2 diabetes mellitus (T2DM). This study aimed to investigate its effects on diabetic osteoporosis (DOP) and explore the underlying mechanisms involving gut microbiota and osteogenic regulation.

METHODS

In a rat model of T2DM, intragastric Oxymatrine was used to study trabecular bone repair through bone microstructure and histopathology analyses. Changes in gut microbiota, especially Gram-negative bacteria releasing lipopolysaccharides (LPS), were assessed via 16S rRNA sequencing. miRNA sequencing on LPS-induced rat osteoblasts, with and without Oxymatrine, explored osteoblast proliferation, mineralization, and the miR-539-5p/OGN/Runx2 pathway.

RESULTS

The administration of OMT resulted in an enhancement of diabetic osteopathy by reversing trabecular bone loss and modifying the composition of gut microbiota, specifically affecting Gram-negative bacteria that release LPS into the bloodstream. miRNA sequencing revealed that miR-539-5p, which was upregulated in LPS-induced ROBs, was downregulated following OMT treatment. Furthermore, OMT was found to promote osteoblast proliferation and mineralization under conditions of LPS exposure and modulate the miR-539-5p/OGN/Runx2 signaling pathway.

CONCLUSIONS

OMT improves diabetic osteoporosis by altering gut microbiota, decreasing LPS release, and enhancing osteoblast growth and differentiation through the miR-539-5p/OGN/Runx2 pathway, suggesting its potential as a treatment.

Impairment of Esophageal Barrier Integrity: New Insights into Esophageal Symptoms in Post-COVID-19

BACKGROUND

The COVID-19 pandemic, caused by SARS-CoV-2, has unveiled a range of symptoms beyond the respiratory system, including significant gastrointestinal manifestations.

AIMS

This study explores the prevalence and intensity of gastroesophageal symptoms in post-COVID-19 patients and the integrity of the esophageal epithelial barrier.

METHODS

We conducted a prospective longitudinal cohort study with 55 patients hospitalized due to COVID-19 at a University Hospital. Patients were evaluated during hospitalization and between 3 and 6 months post-discharge, using validated questionnaires for gastrointestinal and gastroesophageal reflux symptoms. Additionally, 25 of these patients underwent upper digestive endoscopy, with esophageal mucosal biopsies analyzed for transepithelial electrical resistance (TER), permeability, and expression of inflammatory cytokines and cell junction proteins. Data expressed as mean EPM, inference by two-way ANOVA.

RESULTS

Results were considered statistically significant at p < 0.05. There were significant increases in heartburn and acid reflux symptoms in post-COVID-19 patients, as measured by the GSRS questionnaire. Biopsies from post-COVID patients revealed increased esophageal permeability when compared to non-COVID patients in acidic media (pH 2: non-COVID-19: 717.8 ± 168.2 vs. post-COVID-19: 1377.6 ± 316.4), suggesting compromised mucosal barrier. Furthermore, IL-8 levels and expression of Claudin-2 were elevated in these patients.

CONCLUSIONS

The data suggested that COVID-19 infection may cause lasting damage to the esophageal epithelial barrier, increasing its permeability and provoking an exacerbated inflammatory response. These changes may explain the prevalence of post-infection gastroesophageal symptoms. Our findings underscored the importance of continuous monitoring and the development of therapeutic strategies to mitigate gastroesophageal effects in patients recovering from COVID-19.

Unraveling the protective mechanisms and bioactive components of litchi polysaccharides in intestinal health

In recent years, the rise in intestinal disease has driven the hunt for safer, cost-effective alternatives to traditional, side-effect-laden medications. Litchi polysaccharide (LP), derived from litchi pulp, has emerged as a potential intestinal protector, but its efficacy has not been well-established. Our study have demonstrated LP significantly preserves the integrity of the intestinal barrier in both Caenorhabditis elegans model and antibiotic-exposed mice. Furthermore, LP regulates the gut microbiota, promoting the dominance of beneficial bacteria such as Anaerostipes and Lachnoclostridium in antibiotic-exposed mice and elevating the levels of short-chain fatty acids (SCFAs). LP2-a, a key component making up 11.13 % of LP and with a molecular weight of 72,477 Da, has been isolated and identified as the main active agent. Its molecular structure, featuring galactose and arabinose and possessing a main chain composed of specific sugar units and side chains, is crucial for its protective effects. In C. elegans, LP2-a regulates the expression of intestinal structure-related genes, including up-regulating the expression of act-5 and down-regulating the levels of ajm-1, erm-1, and zoo-1, protecting the integrity of the intestinal barrier. This study provides a theoretical foundation for the potential use of LP, particularly LP2-a, in the treatment of intestinal diseases.

Joint transcriptomics and metabolomics unveil the protective mechanism of tamarind seed polysaccharide against antibiotic-induced intestinal barrier damage

Intestinal barrier damage is frequently caused by antibiotic therapy, potentially leading to bacterial translocation and toxin leakage, which triggers inflammation and increases the risk of various diseases. In this study, Tamarind seed polysaccharides (TSP) with different molecular weights were administered to mice during the recovery phase from clindamycin-induced intestinal barrier damage. The results indicated that TSP restored the shortened colon length, reduced the enlarged cecum index, and decreased the elevated level of inflammatory infiltration. Biochemical testing revealed that TSP decreased the levels of intestinal permeability biomarkers and inflammatory factors that were elevated by clindamycin treatment. Transcriptomics and non-targeted metabolomics analyses respectively uncovered changes in colon gene expression and fecal metabolites. The joint analysis of these omics data identified critical pathways, including arachidonic acid metabolism, retinol metabolism, and steroid hormone biosynthesis. These findings suggest that TSP could be a promising dietary supplement for protecting the intestinal barrier and alleviating inflammation.

The Encapsulation Strategies for Targeted Delivery of Probiotics in Preventing and Treating Colorectal Cancer: A Review

Colorectal cancer (CRC) ranks as the third most prevalent cancer worldwide. It is associated with imbalanced gut microbiota. Probiotics can help restore this balance, potentially reducing the risk of CRC. However, the hostile environment and constant changes in the gastrointestinal tract pose significant challenges to the efficient delivery of probiotics to the colon. Traditional delivery methods are often insufficient due to their low viability and lack of targeting. To address these challenges, researchers are increasingly focusing on innovative encapsulation technologies. One such approach is single-cell encapsulation, which involves applying nanocoatings to individual probiotic cells. This technique can improve their resistance to the harsh gastrointestinal environment, enhance mucosal adhesion, and facilitate targeted release, thereby increasing the effectiveness of probiotic delivery. This article reviews the latest developments in probiotic encapsulation methods for targeted CRC treatment, emphasizing the potential benefits of emerging single-cell encapsulation techniques. It also analyzes and compares the advantages and disadvantages of current encapsulation technologies. Furthermore, it elucidates the underlying mechanisms through which probiotics can prevent and treat CRC, evaluates the efficacy and safety of probiotics in CRC treatment and adjuvant therapy, and discusses future directions and potential challenges in the targeted delivery of probiotics for CRC treatment and prevention.

Antibodies and Inflammation: Fecal Biomarkers of Gut Health in Domestic Ruminants

Gastrointestinal infections present major challenges to ruminant livestock systems, and gut health is a key constraint on fitness, welfare, and productivity. Fecal biomarkers present opportunities to monitor animal health without using invasive methods, and with greater resolution compared to observational metrics. Here we developed enzyme-linked immunosorbent assays for three potential fecal biomarkers of gut health in domestic ruminants: two immunological (total immunoglobulin [Ig]A and total IgG) and one inflammatory (lactoferrin). We analytically validated the assays, then evaluated whether they could be used as a biomarker of clinically diagnosed gastrointestinal pathologies in cattle (Bos taurus), and finally compared them with helminth fecal egg counts in sheep (Ovis aries). The analytes were detected above the lower limits of detection in cattle, sheep, and goats. Fecal IgA and lactoferrin were higher in cattle with infectious pathologies (strongyles, coccidiosis and symptomatic Johne's disease) compared to healthy controls. Lactoferrin was additionally higher in animals with infectious pathologies compared to noninfectious pathologies, and to asymptomatic Johne's cases. No significant relationships were found with sheep fecal egg counts. These initial findings suggest that fecal IgA and lactoferrin may be useful biomarkers of poor gastrointestinal health in cattle, and that fecal lactoferrin is specific to active inflammation caused by infectious agents. These could be incorporated into the growing suite of noninvasive ecoimmunological tools and used to understand ruminant gut health in a range of species. Applications include improving treatment regimens for gastrointestinal infections, and understanding wildlife physiological responses to infectious challenges.

Chronic Heat Stress Can Induce Conjugation of a Novel ermB-Containing ICEFZMF, Increasing Resistance to Erythromycin Among Enterococcus Strains in Diverse Intestinal Segments in the Mouse Model

BACKGROUND

The impact of heat stress on intestinal bacterial antimicrobial resistance (AMR) and its underlying mechanisms is not fully understood. This study aims to explore how heat stress influences AMR in the gut and the mechanisms involved.

METHODS

A Specific-Pathogen-Free (SPF) mouse model was used, divided into a control group (maintained at 25 °C) and a heat stress group (exposed to 42 °C for 30 min twice daily for 55 days). The effectiveness of the model was verified by RT-qPCR and histopathological analysis. Antibiotic susceptibility testing and clonal analysis (ERIC-PCR) were performed. Colonization assays were conducted to determine the accumulation of resistant strains in the gut. Metagenomic sequencing was conducted to investigated microbial composition.

RESULTS

RT-qPCR and Histopathological analysis revealed intestinal damage and significant upregulation of genes related to stress response, intestinal barrier integrity and inflammation, indicating successful model establishment and physiological alterations. Antibiotic susceptibility testing revealed increased resistance to erythromycin, chloramphenicol, and tetracycline among Enterococcus strains. Clonal analysis demonstrated that these resistant strains were clonally unrelated. Sequencing identified a novel ermB-carrying integrative and conjugative element (ICEFZMF) among four erythromycin-resistant strains. The rectum harbored a higher proportion of erythromycin-resistant Enterococcus strains with elevated minimum inhibitory concentrations (MICs) after 25 days of heat stress exposure. Colonization assays confirmed that heat stress led to the accumulation of erythromycin-resistant Enterococcus in the rectum. Metagenomic sequencing revealed significant changes in microbial composition, favoring anaerobic metabolism.

CONCLUSIONS

This study suggests that chronic heat stress can promote the emergence of antibiotic-resistant strains through ICE transfer, providing insight for environmental safety.

Covalent Grafting of Inorganic Selenium to the Water-Soluble and Nondigestive Chinese Yam Polysaccharides Causes Greater Protection of IEC-6 Cells with Acrylamide Injury

Acrylamide, a harmful substance generated during the normal thermal treatment of foods, has been shown to adversely affect human health, particularly the vital intestinal barrier function. Meanwhile, natural polysaccharides are recognized to exert an important biofunction in the intestine by protecting barrier integrity. In this study, the non-starch, water-soluble, and nondigestive yam polysaccharide (YP) was extracted from fresh Chinese yam, while two selenylated derivatives with different extents of selenylation were prepared via the HNO3-Na2SeO3 reaction system, and designated as YPSe-I and YPSe-II, respectively. Their protective activities and the associated molecular mechanisms of these substances against acrylamide-induced damage in rat intestinal epithelial (IEC-6) cells were thereby investigated. The experimental results demonstrated that the selenium contents of YPSe-I and YPSe-II were 0.80 and 1.48 g/kg, respectively, whereas that of the original YP was merely 0.04 g/kg. In IEC-6 cells, in comparison with YP, both YPSe-I and YPSe-II showed higher efficacy than YP in alleviating acrylamide-induced cell toxicity through promoting cell viability, suppressing the release of lactate dehydrogenase, and decreasing the generation of intracellular reactive oxygen species. Both YPSe-I and YPSe-II could also manifest higher effectiveness than YP in maintaining cell barrier integrity against the acrylamide-induced barrier disruption. The mentioned barrier protection was achieved by increasing transepithelial electrical resistance, reducing paracellular permeability, facilitating the distribution and expression of F-actin between the cells, and up-regulating the production of three tight junctions, namely ZO-1, occludin, and claudin-1. Additionally, acrylamide was observed to trigger the activation of the MAPK signaling pathway, thereby leading to cell barrier dysfunction. In contrast, YPSe-I and particularly YPSe-II were capable of down-regulating two MAPK-related proteins, namely p-p38 and p-JNK, and thereby inhibiting the acrylamide-induced activation of the MAPK signaling pathway. Moreover, YPSe-II in the cells was consistently shown to provide greater barrier protection than YPSe-I. In conclusion, chemical selenylation of YP could cause higher activity in mitigating acrylamide-induced cytotoxicity and intestinal barrier dysfunction, while the efficacy of activity enhancement was positively affected by the selenylation extent.

Gut Microbiota and Colorectal Cancer: A Balance Between Risk and Protection

The gut microbiome, a complex community of microorganisms residing in the intestinal tract, plays a dual role in colorectal cancer (CRC) development, acting both as a contributing risk factor and as a protective element. This review explores the mechanisms by which gut microbiota contribute to CRC, emphasizing inflammation, oxidative stress, immune evasion, and the production of genotoxins and microbial metabolites. Fusobacterium nucleatum, Escherichia coli (pks+), and Bacteroides fragilis promote tumorigenesis by inducing chronic inflammation, generating reactive oxygen species, and producing virulence factors that damage host DNA. These microorganisms can also evade the antitumor immune response by suppressing cytotoxic T cell activity and increasing regulatory T cell populations. Additionally, microbial-derived metabolites such as secondary bile acids and trimethylamine-N-oxide (TMAO) have been linked to carcinogenic processes. Conversely, protective microbiota, including Lactobacillus, Bifidobacterium, and Faecalibacterium prausnitzii, contribute to intestinal homeostasis by producing short-chain fatty acids (SCFAs) like butyrate, which exhibit anti-inflammatory and anti-carcinogenic properties. These beneficial microbes enhance gut barrier integrity, modulate immune responses, and inhibit tumor cell proliferation. Understanding the dynamic interplay between pathogenic and protective microbiota is essential for developing microbiome-based interventions, such as probiotics, prebiotics, and fecal microbiota transplantation, to prevent or treat CRC. Future research should focus on identifying microbial biomarkers for early CRC detection and exploring personalized microbiome-targeted therapies. A deeper understanding of host-microbiota interactions may lead to innovative strategies for CRC management and improved patient outcomes.

Recent Advances in Gut Microbiota in Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory disease characterized by joint inflammation and skin lesions. Recent research has underscored the critical role of gut microbiota-comprising bacteria, fungi, viruses, and archaea-in the pathogenesis and progression of PsA. This narrative review synthesizes the latest findings on the influence of gut microbiota on PsA, focusing on mechanisms such as immune modulation, microbial dysbiosis, the gut-joint axis, and its impact on treatment. Advances in high-throughput sequencing and metagenomics have revealed distinct microbial profiles associated with PsA. Studies show that individuals with PsA have a unique gut microbiota composition, differing significantly from healthy controls. Alterations in the abundance of specific bacterial taxa, including a decrease in beneficial bacteria and an increase in potentially pathogenic microbes, contribute to systemic inflammation by affecting the intestinal barrier and promoting immune responses. This review explores the impact of various factors on gut microbiota composition, including age, hygiene, comorbidities, and medication use. Additionally, it highlights the role of diet, probiotics, and fecal microbiota transplantation as promising strategies to modulate gut microbiota and alleviate PsA symptoms. The gut-skin-joint axis concept illustrates how gut microbiota influences not only gastrointestinal health but also skin and joint inflammation. Understanding the complex interplay between gut microbiota and PsA could lead to novel, microbiome-based therapeutic approaches. These insights offer hope for improved patient outcomes through targeted manipulation of the gut microbiota, enhancing both diagnosis and treatment strategies for PsA.

The Gut-Heart Axis and Its Role in Doxorubicin-Induced Cardiotoxicity: A Narrative Review

Doxorubicin is a widely used chemotherapy for the treatment of several types of cancer. However, its application is restricted due to adverse effects, particularly cardiotoxicity, which can progress to heart failure-a chronic and debilitating condition. Several mechanisms have been identified in the pathophysiology of doxorubicin-induced cardiotoxicity, including oxidative stress, mitochondrial dysfunction, inflammation, and disruption of collagen homeostasis. More recently, dysbiosis of the gut microbiota has been implicated in the development and perpetuation of cardiac injury. Studies have reported alterations in the composition and abundance of the microbiota during doxorubicin treatment. Therefore, as of recent, there is a new field of research in order to develop strategies involving the gut microbiota to prevent or attenuate cardiotoxicity since there is no effective therapy at the moment. This narrative review aims to provide an update on the role of gut microbiota and intestinal permeability in the pathophysiology of cardiovascular diseases, and more specifically doxorubicin-induced cardiotoxicity. Additionally, it seeks to establish a foundation for future research targeting gut microbiota to alleviate cardiotoxicity.

Ferulic acid mediates microbial fermentation of arabinoxylan to enhance host immunity by suppressing TLR4/NF-κB signaling

The study was conducted to explore the relationship between arabinoxylan (AX) structure and microbial fermentation characteristics, and reveal molecular mechanism of AX on regulating immune function of the host. Results indicated that the group of wheat bran AX showed greater activity of feruloyl esterase, production of short chain fatty acids and ferulic acid compared with the blank group (P < 0.05). The AX increased sIgA concentration and protein expression of protein expression of TLR4 and NF-κB (p65), but decreased mRNA expression of pro-inflammatory cytokines in the ileum of weaned pig model, leading to the reduced diarrhea (P < 0.05). The AX increased an abundance of Bifidobacterium pseudocatenulatum, production of butyric acid and ferulic acid in the ileal digesta of pigs (P < 0.05). In a LPS-treated mouse model, butyric acid and ferulic acid combination increased IL-10 concentration and abundance of Bifidobacterium pseudocatenulatum, but reduced mRNA expression of IL-6 and gene expression of TLR4 and NF-κB (p65) in the jejunum. In summary, AX is fermented by gut microbiota to produce ferulic acid, as well as butyric acid, which improved host immunity by promoting relative abundance of Bifidobacterium pseudocatenulatum and suppressing activation of TLR4/NF-κB signaling.

Role of Cytochromes P450 in Intestinal Barrier Function: Possible Involvement in the Pathogenesis of Leaky Gut Syndrome

The intestinal barrier constitutes the largest surface of the human body communicating with the external environment. Alterations affecting elements of intestinal wall may lead to increased intestinal permeability and resulting translocation of bacteria or its components to the bloodstream in the form of the "leaky gut syndrome" (LGS). One of the most common causes of LGS is the disruption of tight junctions (TJ) maintained by tight junction proteins (TJP). LGS and associated alterations in TJP are observed in numerous gastrointestinal (GI) diseases, including inflammatory bowel diseases (IBD) such as Crohn's disease (CD) and ulcerative colitis (UC). Current literature indicates the key role of LGS in many pathological processes, further emphasizing the need for effective pharmacological approaches to treat this syndrome. One of the potential pharmacological targets in LGS treatment are members of the cytochrome P450 (CYP450) superfamily. By affecting intestinal permeability, they may lead to LGS development. It was found that the expression of CYP8B1 synthesizing cholic acid and CYP26 degrading all-trans retinoic acid indirectly influence TJs. CYP2E1 responsible for the metabolism of a wide variety of chemicals, including ethanol, plays a crucial role in the impairment of the intestinal wall. Contrarily, the overexpression of CYP27B1 has a protective effect on the intestinal integrity. CYP1A1, CYP2A6, CYP2J2 and CYP3A were also suggested to influence the GI tract, through their capability to metabolize serotonin, nicotine, endocannabinoids and gemcitabine, respectively. This review summarizes the findings on the role of CYP450 isoforms in intestinal hyperpermeability and their potential involvement in the pathophysiology of LGS.

Consensus gene co-expression analysis across multiple intestinal tissues to identify key genes and pathways associated with abdominal fat deposition in broilers

1. Abdominal fat deposition (AFD) is regulated by multiple intestinal tissues, and changes in the function of intestinal tissues are associated with AFD. Currently, integration of transcriptomic data across multiple intestinal tissues to explore excessive AFD has rarely been reported in broilers.2. In this study, a consensus gene co-expression network across the duodenum, jejunum, ileum and caecum of high- and low-abdominal fat broiler lines (HL and LL) was constructed using a publicly available transcriptomic data set. Combining the results of functional enrichment analyses and differential gene expression analyses, this investigated the genes and biological pathways across the four intestinal tissues that might influence AFD.3. In one expression module, NDUFA5, NDUFS6, NDUFA4, NDUFS4, ATP5H, ATP5J and ATP5C1 were significantly enriched in the oxidative phosphorylation pathway, with GPX2 and GSR significantly enriched in the glutathione metabolism pathway. These genes were significantly downregulated in the four intestinal tissues of the HL compared to LL chickens, which may be associated with AFD by increasing intestinal permeability.4. Lipid metabolism relevant genes were identified in other modules (ALDH7A1, ACSBG1, THEM4 and DECR1), which may be linked to AFD through regulation of lipid metabolism. Interestingly, in the first module, 12 genes were significantly enriched in the proteasome pathway and significantly downregulated in the four intestinal tissues in HL birds compared to LL birds, indicating a link between the proteasome and AFD.

Immune cells mediated the causal relationship between the gut microbiota and anxiety disorders: A Mendelian randomization study

BACKGROUND

Studies have demonstrated that the gut microbiome-immune system-brain axis plays an important role in neurological disorders. Furthermore, recent studies have shown that the gut microbiota influences the occurrence and progression of anxiety disorders, with potential involvement of immune cells. We aimed to investigate the causal impact of gut microbiota on anxiety disorders and identify potential immune cell mediators.

METHODS

We made use of the summary statistics of 196 gut microbiota (MiBioGen consortium), 731 immune cells, and anxiety disorders (Medical Research Council Integrative Epidemiology Unit consortium), from the extensive genome-wide association studies to date. To determine the causal links between gut microbiota and anxiety disorders, we employed bidirectional Mendelian randomization (MR) analyses, and further employed 2-step MR to confirm potential mediating roles of immune cells. Moreover, we conducted rigorous sensitivity analyses to assess the heterogeneity, robustness, and horizontal pleiotropy of our findings.

RESULTS

Bi-directional MR analysis revealed that 11 gut microbiota species can affect anxiety disorders, while the reversed causal relationship was not existed. Mediation analysis revealed that three immune cells mediated the causal relationships between two gut microbiota species and anxiety disorders. Specifically, "CD39+ resting Treg %resting Treg", "CD39+ resting Treg % CD4 Treg", and "BAFF-R on IgD+ CD38- naive B cell" mediated the effects of class Melainabacteria on anxiety disorders, with mediating impacts of 0.000075, 0.000096, and 0.000263, representing 5.98 %, 7.67 %, and 21.01 % of the total effects, respectively. Additionally, "BAFF-R on IgD+ CD38- naive B cell" also mediated the effects of order Gastranaerophilales on anxiety disorders, with a mediating impact of 0.000266, accounting for 19.06 % of the total effects.

LIMITATIONS

The bacterial analysis was limited to genus level, overlooking species or strains. We used a lenient p-value threshold of p < 1.0 × 10-5 for instrumental variables, instead of the typical p < 5 × 10-8. Lastly, the GWAS focused on European participants, potentially limiting the generalizability of our findings to other ethnicities.

CONCLUSION

The risk of anxiety disorders has been linked causally to gut microbiota, with three distinct immunophenotypes acting as potential mediators in this relationship. The role of gut microbiota in modulating immune cells, thereby influencing anxiety disorders, may offer new therapeutic strategies and management approaches.

Therapeutic potential of fecal microbiota transplantation in colorectal cancer based on gut microbiota regulation: from pathogenesis to efficacy

Colorectal cancer (CRC) remains a leading cause of cancer-related deaths worldwide, with its progression intricately linked to gut microbiota dysbiosis. Disruptions in microbial homeostasis contribute to tumor initiation, immune suppression, and inflammation, establishing the microbiota as a key therapeutic target. Fecal microbiota transplantation (FMT) has emerged as a transformative approach to restore microbial balance, enhance immune responses, and reshape the tumor microenvironment. This review explores the mechanisms underlying FMT's therapeutic potential, evaluates its advantages over other microbiota-based interventions, and addresses challenges such as donor selection, safety concerns, and treatment standardization. Looking forward, the integration of FMT into personalized CRC therapies requires robust clinical trials and the identification of predictive biomarkers to optimize its efficacy and safety.

Grape pomace extract attenuates high fat diet-induced endotoxemia and liver steatosis in mice

Obesity is a prominent global health concern associated with chronic inflammation and metabolic disorders, such as insulin resistance, type 2 diabetes, and non-alcoholic fatty liver disease (NAFLD). Excessive consumption of saturated fats exacerbates these conditions by increasing intestinal barrier permeability and circulating endotoxins. This study aims to investigate, in a murine model of high-fat diet (HFD)-induced obesity, the potential beneficial effects of a grape pomace extract (GPE), rich in phenolic compounds, at mitigating endotoxemia, and liver steatosis. Underlying mechanisms were characterized in an in vitro model of intestinal inflammation and permeabilization, as induced by tumor necrosis factor alpha (TNFα) in Caco-2 cell monolayers. Consumption of a HFD (60% calories from fat) for 13 weeks induced obesity, insulin resistance, and liver damage, evidenced by higher levels of plasma alanine aminotransferase (ALT), hepatic triglycerides content, and steatosis. In addition, HFD caused metabolic endotoxemia, hepatic toll-like receptor 4 (TLR4) upregulation and inflammation. GPE supplementation significantly reduced body weight and subcutaneous and visceral adipose tissue weight, and attenuated metabolic dysregulation. Furthermore, GPE decreased circulating LPS levels and mitigated HFD-mediated hepatic TLR4 upregulation, nuclear factor kappa B (NF-κB) activation, and downstream expression of proteins involved in oxidative stress and inflammation (NOX4, TNFα, and F4/80). In Caco-2 cells, GPE mitigated TNFα-induced monolayer permeabilization, decreased tight junction (TJ) protein levels, enhanced cellular oxidant production, activated redox-sensitive signaling, i.e., NF-κB and ERK1/2, and increased NOX1 and MLCK mRNA levels, the latter being a key regulator of monolayer permeability. The above findings suggest that GPE may protect against HFD-induced obesity and associated metabolic dysfunction (insulin resistance and NAFLD) by modulating intestinal barrier integrity and related endotoxemia.

Polystyrene Microplastics Can Aggravate the Damage of the Intestinal Microenvironment Caused by Okadaic Acid: A Prevalent Algal Toxin

As emerging contaminants, microplastics (MPs) may pose a threat to human health. Their co-exposure with the widespread phycotoxin okadaic acid (OA), a marine toxin known to cause gastrointestinal toxicity, may exacerbate health risk and raise public safety concern. In this study, the toxicity mechanisms of MPs and OA on intestinal microenvironment was explored using human Caco-2 cells as the model, which was combined with an in vitro fecal fermentation experiment. Our results showed that co-exposure to MPs (80 μg/mL) and OA (20 ng/mL) significantly decreased cell viability, increased intracellular reactive oxygen species (ROS) production, elevated lactate dehydrogenase release, impaired ABC transporter activity, promoted OA accumulation, and triggered inflammatory response compared to the control, MPs, and OA groups, indicating that co-exposure directly compromises intestinal epithelial integrity. In vitro fermentation experiments revealed that co-exposure disrupted gut microbial composition, decreasing the relative abundance of some bacteria, such as Parasutterella and Adlercreutzia, while increasing opportunistic pathogens, such as Escherichia-Shigella, increased. These findings provide new insights into the impact and underlying mechanisms of MPs and OA co-exposure on intestinal homeostasis, highlighting the potential health risks associated with MPs.

A smart probe for detection of sugar markers for applications in gastrointestinal barrier dysfunction

Gastrointestinal (GI) barrier dysfunction is an early pathogenic event in many complex diseases. Despite the routine applications of invasive tests, saccharide molecules are used noninvasively for assessing GI tract mucosal barrier function. However, currently available methods for quantification of saccharides molecules are costly and laborious. Simplified, reliable, and high-throughput methods are desired so that GI permeability testing can become routine and widely used. Here, we have developed a one-component system comprising of a naphthyl-pyridine core coupled to a boronic acid receptor, which can be used for early detection of saccharide biomarkers (i.e., lactulose) for applications related to GI barrier dysfunction. For quantitation of lactulose as a model biomarker, we have designed gold nanoparticle decorated surfaces in a highly scalable 96-well format to enable sensitive testing of lactulose within a broad range of concentrations. To tackle current challenges in saccharide biomarker sensing, we developed a hybrid sensing principle integrating two optical modalities (plasmonics and fluorescence) with a synthetic smart-probe (naphthyl-pyridinium) for monitoring GI permeability. This technology can be further developed as an affordable and portable diagnostic tool for GI permeability screening for routine use, facilitating early detection of various diseases affecting the GI tract.

Inflammation and gut barrier function-related genes and colorectal cancer risk in western European populations

Gut barrier dysfunction and related inflammation are known to be associated with the development and progression of colorectal cancer (CRC). We investigated associations of 292 single-nucleotide polymorphisms (SNPs) from 27 genes related to endotoxins/lipopolysaccharide (LPS) sensing and tolerance, mucin synthesis, inflammation, and Crohn's disease with colon and rectal cancer risks. Incident CRC cases (N = 1374; colon = 871, rectum = 503) were matched 1:1 to controls nested within the European Prospective Investigation into Cancer and Nutrition cohort. Previously measured serum concentrations of gut barrier function and inflammation biomarkers (flagellin/LPS-specific immunoglobulins and C-reactive protein [CRP]) were available for a sub-set of participants (Ncases = 1001; Ncontrols = 667). Forty-two unique SNPs from 19 different genes were associated with serum biomarkers at Punadjusted ≤ 0.05 among controls. Among SNPs associated with a gut permeability score, 24 SNPs were in genes related to LPS sensing and mucin synthesis. Nine out of 12 SNPs associated with CRP were in genes related to inflammation or Crohn's disease. TLR4 was associated with colon cancer at the SNP level (nine SNPs, all Punadjusted ≤ 0.04) and at the gene level (Punadjusted ≤ 0.01). TLR4 rs10759934 was associated with rectal cancer but not colon cancer. Similarly, IL10 was associated with rectal cancer risk at an SNP and gene level (both Punadjusted ≤ 0.01), but not colon cancer. Genes and SNPs were selected a priori; therefore, we present unadjusted P-values. However, no association was statistically significant after multiple testing correction. This large and comprehensive study has identified gut barrier function and inflammation-related genes possibly contributing to CRC risk in European populations and is consistent with potential etiological links between host genetic background, gut barrier permeability, microbial endotoxemia, and CRC development.

An exploratory multi-omics study reveals distinct molecular signatures of ulcerative colitis and Crohn's disease and their correlation with disease activity

Clinically heterogeneous spectrum and molecular phenotypes of inflammatory bowel disease (IBD) remain to be comprehensively elucidated. This exploratory multi-omics study investigated the serum molecular profiles of Crohn's disease (CD) and ulcerative colitis (UC), in association with elevated fecal calprotectin and disease activity states. The serum proteome, metabolome, and lipidome of 75 treated IBD patients were profiled. Single- and multi-omic data analysis was performed to determine differential analytes and integrative biosignatures for biological interpretations. We found that chronic inflammation, phosphatidylcholines and bile acid homeostasis disturbances underlined the differences between CD and UC. Besides, elevated calprotectin was associated with higher levels of inflammatory proteins and sphingomyelins (SM) and lower levels of bile acids, amino acids, and triacylglycerols (TG). Relative to the remission disease state, the active form was characterized by decreased abundances of SMs and increased abundances of inflammatory proteins and TGs. We also observed that molecular changes upon treatment escalation were putatively related to altered levels of inflammatory response proteins, amino acids, and TGs. ISM1, ANGPTL4, chenodeoxycholate, Cer(18:1;2 O/24:1), and TG were identified as candidates subject to further investigation. Altogether, our study revealed that disturbances in immune response, bile acid homeostasis, amino acids, and lipids potentially underlie the clinically heterogeneous spectrum of IBD.

The Epithelial Barrier Hypothesis in Food Allergies: The State of the Art

Recently, the "epithelial barrier hypothesis" has been proposed as a key factor in the development of allergic diseases, such as food allergies. Harmful environmental factors can damage epithelial barriers, with detrimental effects on the host immune response and on the local microbial equilibrium, resulting in chronic mucosal inflammation that perpetuates the dysfunction of the epithelial barrier. The increased epithelial permeability allows allergens to access the submucosae, leading to an imbalance between type 1 T-helper (Th1) and type 2 T-helper (Th2) inflammation, with a predominant Th2 response that is the key factor in food allergy development. In this article on the state of the art, we review scientific evidence on the "epithelial barrier hypothesis", with a focus on food allergies. We describe how loss of integrity of the skin and intestinal epithelial barrier and modifications in gut microbiota composition can contribute to local inflammatory changes and immunological unbalance that can lead to the development of food allergies.

Serum intestinal permeability biomarkers are associated with erosive hand osteoarthritis and radiographic severity: results from the DIGICOD cohort

OBJECTIVE

To investigate the association between intestinal permeability alteration and erosive hand osteoarthritis (EHOA).

METHODS

Serum concentrations of four intestinal permeability biomarkers (lipopolysaccharide binding protein (LBP), FABP2, sCD14, Zonulin-related proteins (ZRP) along with calprotectin, and high-sensitivity C-Reactive Protein (hs-CRP) were assessed in 410 patients of the DIGICOD cohort. The study compared patients with EHOA (≥ 2 erosion in Verbruggen score N=140) to those without EHOA (N=270) using the Mann-Whitney U test. Logistic regression was performed to adjust for potential covariates. The Spearman rank test was used to investigate the correlation between intestinal permeability biomarkers and seven clinical variables associated with HOA clinical and radiographic severity.

RESULTS

Serum levels of LBP and ZRP were found to be higher in patients with EHOA compared to those without EHOA (p=0.001, p=0.04). Additionally, LBP and ZRP remained associated with EHOA in a logistic regression model adjusted for age, body mass index, and sex (p=0.017, p=0.005). ZRP was positively correlated with Verbruggen score and Kellgren-Lawrence sum score of both hands (r=0.14 p=0.005, r=0.12 p=0.023). LBP was positively correlated with the number of erosive joints (r=0.14 p=0.0006). Hs-CRP and LBP were positively correlated with AUSCAN pain (r=0.14 p=0.008, r=0.10 p=0.042).

CONCLUSIONS

LBP and ZRP were associated with EHOA with clinical and radiographic severity in HOA. These results overall support the role of intestinal permeability in both symptoms and structural alteration in HOA.

Tryptophan Attenuates Chronic Restraint Stress-Induced Intestinal Injury Through Modulation of Intestinal Barrier Integrity and Gut Microbiota Homeostasis

Background: Chronic stress is associated with detrimental effects on physical health, such as chronic restraint stress (CRS), which can damage the intestinal tract. Although tryptophan has many benefits in maintaining intestinal health, the underlying mechanism of its protective effects against stress-induced intestinal injury remains unclear. Methods: In this study, we constructed a CRS model by using a behavioral restraint device in which mice were restrained for 6 h per day over 14 days and investigated the effects, as well as the potential mechanism of a high-tryptophan diet (0.4% tryptophan), on CRS-induced intestinal injury using scanning electron microscopy, 16S rRNA sequencing, and LC-MS. Results: A 0.4% tryptophan diet (fed ad libitum for 24 days) attenuated CRS-induced pathologies, including weight loss, elevated corticosterone, intestinal barrier injury, increased permeability, and epithelial apoptosis. Tryptophan modulated the gut microbiota composition in CRS-induced mice, increasing the abundance of Bacteroidota and decreasing the abundance of Firmicutes, as well as enhancing metabolic function through pathways identified by KEGG analysis. Additionally, tryptophan restored the levels of short-chain fatty acids (SCFAs), including acetic, propionic, isobutyric, butyric, and valeric acids. Correlation analyses showed interactions between tryptophan, intestinal permeability, SCFAs, and gut microbiota. Conclusions: Tryptophan supplementation attenuates CRS-induced intestinal injury by modulating intestinal barrier integrity and gut microbiota homeostasis, and the beneficial effects are largely associated with the SCFA-mediated regulation of intestinal permeability and microbiota-associated energy metabolism.

A pumpless microfluidic co-culture system to model the effects of shear flow on biological barriers

Biological barriers formed by the endothelium and epithelium regulate nutrient exchange, disease development, and drug delivery. Organ-on-chip (OOC) systems effectively model these barriers by incorporating key biophysical cues like microscale dimensions, co-culture, and fluid flow-induced shear stress. The majority of microfluidic OOC platforms, however, require syringe and pump systems which are hindered by several limitations, including large footprints, elaborate designs, long setup times, and a high rate of failure (contamination, leakage, etc.). Here we describe VitroFlo, a pump-free microfluidic device designed for in vitro biological barrier modeling with 12 independent co-culture modules that can be simultaneously subjected to tunable, unidirectional flow with physiological shear stresses ranging from 0.01-10 dyn/cm2. We demonstrate application of the device to model vascular endothelial, blood-brain, and intestinal epithelial barriers, and confirm shear stress-dependent cell alignment, tight junction protein expression, barrier maturation, permeability, and paracrine signaling between co-cultured cells. The VitroFlo platform enables scalable and cost-effective modeling of physiological barriers to facilitate the translation of findings from in vitro systems to preclinical models.

Neuromodulatory effect of troxerutin against doxorubicin and cyclophosphamide-induced cognitive impairment in rats: Potential crosstalk between gut-brain and NLRP3 inflammasome axes

"Chemobrain" refers to the cognitive impairment induced by chemotherapy. The doxorubicin and cyclophosphamide cocktail has been used for various cancers, especially breast cancer. However, both have been linked to chemobrain as well as gastrointestinal toxicity. Despite being distinct organs, the gut and the brain have a bidirectional connection between them known as the gut-brain axis. This research aimed to study the neuroprotective effect of troxerutin, a rutin derivative, in chemobrain induced by doxorubicin and cyclophosphamide via a potential impact on the gut-inflammasome-brain axis. Troxerutin was administered at 75, 150, and 300 mg/kg doses. Furthermore, behavioral, histological, and acetylcholinesterase assessments were performed. Accordingly, the highest dose of troxerutin was selected to investigate the potential underlying mechanisms. Troxerutin treatment reversed the chemotherapy-fecal metabolite alterations. Additionally, troxerutin demonstrated positive effects against deterioration of intestinal integrity, permeability, and microbial endotoxins translocation, as evidenced by its effect on tight junction proteins; ZO-1, and claudin-1 expression, and lipopolysaccharide serum levels. Consequently, troxerutin hindered lipopolysaccharide-induced oxidative damage, systemic inflammation, and neuroinflammation. Moreover, troxerutin demonstrated antioxidant effects via its impact on lipid peroxidation, catalase levels, and the Nrf2/HO-1 pathway. Furthermore, chemotherapy-induced inflammation was opposed by troxerutin via downregulation of NLRP3, caspase-1, and the downstream cytokines; IL-18 and IL-1β. Importantly, troxerutin did not abrogate the anticancer activity of doxorubicin and cyclophosphamide in human MCF7 cells. Collectively, our study suggested the potentiality of troxerutin as a therapeutic choice against chemobrain by inhibiting the gut-inflammasome-brain axis and hindering acetylcholinesterase, oxidative stress, and neuroinflammation.

Oxidized Polyunsaturated Fatty Acid Promotes Colitis and Colitis-Associated Tumorigenesis in Mice

BACKGROUND AND AIMS

Human studies suggest that a high intake of polyunsaturated fatty acid (PUFA) is associated with an increased risk of inflammatory bowel disease (IBD). PUFA is highly prone to oxidation. To date, it is unclear whether unoxidized or oxidized PUFA is involved in the development of IBD. Here, we aim to compare the effects of unoxidized PUFA vs oxidized PUFA on the development of IBD and associated colorectal cancer.

METHODS

We evaluated the effects of unoxidized and oxidized PUFA on dextran sodium sulfate (DSS)-induced and IL-10 knockout-induced colitis, and azoxymethane/DSS-induced colon tumorigenesis in mice. Additionally, we studied the roles of gut microbiota and Toll-like receptor 4 (TLR4) signaling involved.

RESULTS

Administration of a diet containing oxidized PUFA, at human consumption-relevant levels, increases the severity of colitis and exacerbates the development of colitis-associated colon tumorigenesis in mice. Conversely, a diet rich in unoxidized PUFA does not promote colitis. Furthermore, oxidized PUFA worsens colitis-associated intestinal barrier dysfunction and leads to increased bacterial translocation, and it fails to promote colitis in TLR4 knockout mice. Finally, oxidized PUFA alters the diversity and composition of gut microbiota, and it fails to promote colitis in mice lacking the microbiota.

CONCLUSIONS

These results support that oxidized PUFA promotes the development of colitis and associated tumorigenesis in mouse models via TLR4- and gut microbiota-dependent mechanisms. Our findings highlight the potential need to update regulation policies and industrial standards for oxidized PUFA levels in food.

Bifidobacterium bifidum CCFM1163 alleviates cathartic colon by activating the BDNF-TrkB-PLC/IP3 pathway to reconstruct the intestinal nerve and barrier

Introduction: Cathartic colon (CC) is a type of slow-transit constipation caused by a patient's long-term use of irritating laxatives. Probiotics play a crucial role in managing constipation. Objectives: This study aims to identify probiotics that can alleviate CC and explore their specific mechanisms of action. Methods: The CC-model was constructed using senna leaf extract. Bifidobacterium bifidum was applied to the mice for intervention. Relevant marker changes were then examined using ELISA and RT-qPCR. Furthermore, 16S rDNA sequencing was utilized for functional prediction of intestinal microorganisms, while GC-MS analysis was performed to determine the content of short-chain fatty acids (SCFAs) in feces. Results: Senna damages the intestinal nerve and the intestinal barrier while inducing CC. In contrast, Bifidobacterium bifidum CCFM1163 may enhance the brain-derived neurotrophic factor (BDNF) expression in the colon by altering the intestinal microbiota composition (e.g., increasing Lactobacillus and Bacteroides, and decreasing Faecalibaculum) and by elevating SCFA levels (e.g., acetic and isobutyric acid). Subsequently, elevated BDNF expression activates the BDNF-tyrosine kinase receptor B-phospholipase C/inositol trisphosphate (BDNF-TrkB-PLC/IP3) pathway, which upregulates the gene expression of Uchl1, S100β, and Acta2; repairs the enteric nervous system-interstitial cells of Cajal-smooth muscle cells (ENS-ICC-SMC) network; upregulates the gene expression of Ocln and Tjp1; improves intestinal permeability in CC mice; and modulates the immune response by upregulating Tlr4, downregulating Il1b, and upregulating Il10, ultimately alleviating CC. Conclusion: Bifidobacterium bifidum CCFM1163 was identified as a probiotic that can promote BDNF expression in the colon, activate the BDNF-TrkB-PLC/IP3 signaling pathway, and effectively alleviate CC.

Carotenoids Improve Obesity and Fatty Liver Disease via Gut Microbiota: A Narrative Review

Carotenoids are natural micronutrients found in plants and microorganisms, but not synthesized by animals. Carotenoids show various biological activities, including antioxidant properties, regulation of cell growth, and modulation of gene expression and immune responses. The rising global incidence of fatty liver disease (FLD) and obesity highlights the importance of carotenoids in chronic progressive conditions. Gut microbiota (GM) dysbiosis is associated with the development and progression of obesity and FLD due to the effects of metabolites such as lipopolysaccharide (LPS), bile acids (BAs), and short-chain fatty acids (SCFAs). Furthermore, GM may affect intestinal barrier integrity. This review evaluates the potential impact of carotenoids on GM and intestinal barrier function, and their subsequent effects on obesity and FLD. We searched through a wide range of databases, such as Web of Science, Scopus, EMBASE, and PubMed, to collect data for our non-systematic review of English literature. Carotenoids such as lycopene, zeaxanthin, fucoxanthin, capsanthin, astaxanthin, and lutein can regulate GM composition and improve obesity and FLD by affecting energy expenditure, food intake, lipid profile, liver fat deposition, liver enzymes, inflammatory markers, glucose homeostasis, and bile acids. These carotenoids improve obesity and FLD through GM metabolites such as SCFAs and LPS. Our findings show that dietary supplementation of lycopene, zeaxanthin, fucoxanthin, capsanthin, astaxanthin, and lutein can positively affect obesity and FLD by regulating GM and intestinal barrier integrity.

Clinical significance of perioperative probiotic intervention on recovery following intestinal surgery

Restoring the balance of gut microbiota has emerged as a critical strategy in treating intestinal disorders, with probiotics playing a pivotal role in maintaining bacterial equilibrium. Surgical preparations, trauma, and digestive tract reconstruction associated with intestinal surgeries often disrupt the intestinal flora, prompting interest in the potential role of probiotics in postoperative recovery. Lan et al conducted a prospective randomized study on 60 patients with acute appendicitis, revealing that postoperative administration of Bacillus licheniformis capsules facilitated early resolution of inflammation and restoration of gastrointestinal motility, offering a novel therapeutic avenue for accelerated postoperative recovery. This editorial delves into the effects of perioperative probiotic supplementation on physical and intestinal recovery following surgery. Within the framework of enhanced recovery after surgery, the exploration of new probiotic supplementation strategies to mitigate surgical complications and reshape gut microbiota is particularly intriguing.

Intestinal Microbiota Dysbiosis Role and Bacterial Translocation as a Factor for Septic Risk

The human immune system is closely linked to microbiota such as a complex symbiotic relationship during the coevolution of vertebrates and microorganisms. The transfer of microorganisms from the mother's microbiota to the newborn begins before birth during gestation and is considered the initial phase of the intestinal microbiota (IM). The gut is an important site where microorganisms can establish colonies. The IM contains polymicrobial communities, which show complex interactions with diet and host immunity. The tendency towards dysbiosis of the intestinal microbiota is influenced by local but also extra-intestinal factors such as inflammatory processes, infections, or a septic state that can aggravate it. Pathogens could trigger an immune response, such as proinflammatory responses. In addition, changes in the host immune system also influence the intestinal community and structure with additional translocation of pathogenic and non-pathogenic bacteria. Finally, local intestinal inflammation has been found to be an important factor in the growth of pathogenic microorganisms, particularly in its role in sepsis. The aim of this article is to be able to detect the current knowledge of the mechanisms that can lead to dysbiosis of the intestinal microbiota and that can cause bacterial translocation with a risk of infection or septic state and vice versa.

The causal relationships between gut microbiota and venous thromboembolism: a Mendelian randomization study

BACKGROUND

Venous thromboembolism (VTE) is still one of the most severe health issues, increasing mortality and lengthening hospital stays. Different abundances of gut microbiota have been clinically linked to VTE and coagulopathy. However, whether gut microbiota affected VTE formation remained uncertain.

METHODS

The causative links between VTE and 211 gut microbiota at phylum, class, order, family and genus level were separately investigated using two-sample Mendelian Randomization (MR) analysis. Firstly, single nucleotide polymorphisms (SNPs) locus-wide significantly (P < 1.0 × 10- 5) related with gut microbiome abundance were extracted from large genome-wide analysis (GWAS) meta-analysis summary data. Instrumental variables (IVs) without pleiotropy were selected using the PhenoScanner and MR PRESSO test. Then, the MR analysis was implemented using the inverse variance weighted (IVW) method. Moreover, weighted median method, MR Egger method, simple median method and MR PRESSO were conducted to validate the causal associations. The reliability of the results was also assessed utilizing various sensitivity analyses, reverse MR analysis and multivariate Mendelian Randomization analysis (MVMR).

RESULTS

We found the phylum Firmicutes was robustly protective against VTE with MR analysis. Moreover, five taxa of Actinobacteria phylum (Bifidobacteriales order, Actinomycetales order, Bifidobacteriaceae family, Actinomycetaceae family, Slackia genus) and two taxa of Firmicutes phylum (Bacillales order, Lachnospiraceae UCG-010 genus) were suggestively protective for VTE. While three taxa of Firmicutes phylum (Bacilli class, Lactobacillales order and Lactococcus genus) might suggestively increase the risk of VTE. Sensitivity analyses indicated no significant horizontal pleiotropy, heterogeneity, or reverse causal associations. Furthermore, MVMR analysis unveiled independently positive causal association of Firmicutes phylum and Lachnospiraceae UCG-010 genus with risk of VTE.

CONCLUSION

Two taxa of gut microbes (Firmicutes phylum and Lachnospiraceae UCG-010 genus) were independently protective against VTE, which suggests a potential avenue for developing new cost-effective strategies with minor side effects for VTE prevention and treatment.

Pleurotus eryngii Mushrooms Fermented with Human Fecal Microbiota Protect Intestinal Barrier Integrity: Immune Modulation and Signalling Pathways Counter Deoxycholic Acid-Induced Disruption in Healthy Colonic Tissue

Background: This study explores the potential of the Pleurotus eryngii mushroom fermentation supernatant (FS-PEWS) as an intervention for mitigating sodium deoxycholate (SDC)-induced intestinal barrier dysfunction and inflammation. Methods: FS-PEWS was assessed for its protective effects against SDC-induced barrier dysfunction and inflammation using an in vitro Caco-2 cell model and ex vivo colonic biopsies from healthy adult donors, where barrier integrity, permeability, immunomodulation and receptor-mediated pathways were evaluated. Results: In Caco-2 cells, SDC exposure downregulated ZO-1, occludin, and claudin-1 expression, with FS-PEWS restoring ZO-1 and claudin-1 levels while maintaining cell viability. In colonic biopsies from healthy adults, FS-PEWS maintained tissue integrity and selectively mitigated transcellular permeability without affecting paracellular permeability when combined with the stressor. Additionally, FS-PEWS exhibited potent anti-inflammatory effects, reducing pro-inflammatory cytokines, e.g., TNF-α, IL-6, and IL-1β and modulating receptor-mediated pathways, i.e., TLR-4, dectin-1. Conclusions: These results demonstrate the potential of FS-PEWS to sustain intestinal barrier function and modulate immune responses under stress, highlighting its therapeutic potential for managing gut barrier dysfunction and inflammation associated with microbial metabolite-induced disruptions.

Effects of In Vitro Fermented Pleurotus eryngii on Intestinal Barrier Integrity and Immunomodulation in a Lipopolysaccharide-Induced Colonic Model

Background: This study investigates the impact of fermentation supernatants (FSs) from Pleurotus eryngii whole mushrooms (PEWS), as well as its subcomponents, digested (PEWSD) and extracted (PEWSE) forms, on intestinal barrier function and immune modulation in lipopolysaccharide (LPS) -stimulated Caco-2 cells. Methods: Gene expression of tight junction (TJs) genes, cytokines, and key immune/metabolic receptors was assessed via qRT-PCR, while cytokine protein levels were measured using ELISA to explore post-transcriptional regulation. Results: LPS challenge significantly downregulated TJs zonula occludens-1 (ZO-1,) occludin, and claudin-1, compromising epithelial integrity. Treatment with FS-PEWS notably restored ZO-1 and occludin expression, outperforming FS-PEWSD and FS-PEWSE, which only partially mitigated the LPS-induced damage. FS-PEWS further demonstrated potent immunomodulatory effects, upregulating anti-inflammatory IL-10 and pro-inflammatory cytokines such as IL-8 and TNF-α. The activation of key receptors like TLR-2 and mTOR suggests that FS-PEWS modulates critical immune and metabolic pathways, such as NF-kB signaling, to maintain immune homeostasis. Although mRNA expression of pro-inflammatory cytokines was altered, no corresponding protein release was detected, suggesting potential post-transcriptional regulation. Conclusions: FS-PEWS preserves intestinal barrier integrity and modulates immune responses, particularly in low-grade inflammation, highlighting the whole food matrix's role in enhancing its bioactivity and functional food potential.

Dysbiosis and extraintestinal cancers

The gut microbiota plays a crucial role in safeguarding host health and driving the progression of intestinal diseases. Despite recent advances in the remarkable correlation between dysbiosis and extraintestinal cancers, the underlying mechanisms are yet to be fully elucidated. Pathogenic microbiota, along with their metabolites, can undermine the integrity of the gut barrier through inflammatory or metabolic pathways, leading to increased permeability and the translocation of pathogens. The dissemination of pathogens through the circulation may contribute to the establishment of an immune-suppressive environment that promotes carcinogenesis in extraintestinal organs either directly or indirectly. The oncogenic cascade always engages in the disruption of hormonal regulation and inflammatory responses, the induction of genomic instability and mutations, and the dysregulation of adult stem cell proliferation. This review aims to comprehensively summarize the existing evidence that points to the potential role of dysbiosis in the malignant transformation of extraintestinal organs such as the liver, breast, lung, and pancreas. Additionally, we delve into the limitations inherent in current methodologies, particularly the challenges associated with differentiating low loads gut-derived microbiome within tumors from potential sample contamination or symbiotic microorganisms. Although still controversial, an understanding of the contribution of translocated intestinal microbiota and their metabolites to the pathological continuum from chronic inflammation to tumors could offer a novel foundation for the development of targeted therapeutics.

Changes of diamine oxidase and D-lactate in human breast and gynecologic cancers after chemotherapy

This study investigates the changes in diamine oxidase (DAO) and D-lactate levels in cancer patients undergoing chemotherapy and their clinical significance in evaluating intestinal barrier function. Breast and gynecologic cancer patients who received chemotherapy between January 2020 and December 2023 were enrolled from our hospital. Blood samples were taken before chemotherapy, within 3 days after chemotherapy, and before the next course of chemotherapy. The level of plasma DAO and D-lactate were measured by enzyme-linked immunosorbent assay (ELISA). After chemotherapy, nutritional markers such as albumin (ALB) and prealbumin (PAB) were evaluated. Anorexia, vomiting, nausea and diarrhea were evaluated during the chemotherapy cycle. There were no notable differences in serum DAO and D-lactate levels before chemotherapy among different tumor types, tumor stage and chemotherapy type. Serum DAO and D-lactate levels after chemotherapy were significantly elevated compared to their levels before chemotherapy (P < .05). The plasma DAO and D-lactate levels in cancer patients before the next course of chemotherapy were higher than those observed before the initial treatment, but the difference failed to achieve statistical significance (P > .05). The levels of DAO before chemotherapy were higher in patients with diarrhea and anorexia after chemotherapy than those without diarrhea and anorexia (P < .05). The levels of D-lactate before chemotherapy were notably elevated in patients with vomiting, diarrhea and nausea after chemotherapy than those without vomiting, diarrhea and nausea (P < .05). Monitoring serum levels of DAO and D-lactate in cancer patients undergoing chemotherapy can serve as indicators for evaluating gastrointestinal dysfunction and nutritional status.

Gut Microecological Prescription: A Novel Approach to Regulating Intestinal Micro-Ecological Balance

The intestinal microecology is comprises intestinal microorganisms and other components constituting the entire ecosystem, presenting characteristics of stability and dynamic balance. Current research reveals intestinal microecological imbalances are related to various diseases. However, fundamental research and clinical applications have not been effectively integrated. Considering the importance and complexity of regulating the intestinal microecological balance, this study provides an overview of the high-risk factors affecting intestinal microecology and detection methods. Moreover, it proposes the definition of intestinal microecological imbalance and the definition, formulation, and outcomes of gut microecological prescription to facilitate its application in clinical practice, thus promoting clinical research on intestinal microecology and improving the quality of life of the population.

A review on the effects of flavan-3-ols, their metabolites, and their dietary sources on gut barrier integrity

Impairment of gut barrier integrity is associated with the pathogenesis of gastrointestinal diseases, including inflammatory bowel disease, colorectal cancer, and coeliac disease. While many aspects of diet have been linked to improved barrier function, (poly)phenols, a broad group of bioactive phytochemicals, are of potential interest. The (poly)phenolic sub-class, flavan-3-ols, have been investigated in some detail owing to their abundance in commonly consumed foods, including grapes, tea, apples, cocoa, berries, and nuts. This review summarises studies on the effects of flavan-3-ols, their microbiome-mediated metabolites, and food sources of these compounds, on gut barrier structure. Extensive evidence demonstrates that flavan-3-ol rich foods, individual flavan-3-ols (e.g., (epi)catechin, epi(gallo)catechin-3-O-gallate, and pro(antho)cyanidins), and their related microbiota-mediated metabolites, could be effective in protecting and restoring the integrity of the gut barrier. In this context, various endpoints are assessed, including transepithelial electrical resistance of the epithelial layer and expression of tight junction proteins and mucins, in ex vivo, in vitro, and animal models. The differences in bioactivity reported for barrier integrity are structure-function dependent, related to the (poly)phenolic source or the tested compound, as well as their dose, exposure time, and presence or absence of a stressor in the experimental system. Overall, these results suggest that flavan-3-ols and related compounds could help to maintain, protect, and restore gut barrier integrity, indicating that they might contribute to the beneficial properties associated with the intake of their dietary sources. However, rigorous and robustly designed human intervention studies are needed to confirm these experimental observations.

Gut microbiota in Alzheimer's disease: Understanding molecular pathways and potential therapeutic perspectives

Accumulating evidence suggests that gut microbiota (GM) plays a crucial role in Alzheimer's disease (AD) pathogenesis and progression. This narrative review explores the complex interplay between GM, the immune system, and the central nervous system in AD. We discuss mechanisms through which GM dysbiosis can compromise intestinal barrier integrity, enabling pro-inflammatory molecules and metabolites to enter systemic circulation and the brain, potentially contributing to AD hallmarks. Additionally, we examine other pathophysiological mechanisms by which GM may influence AD risk, including the production of short-chain fatty acids, secondary bile acids, and tryptophan metabolites. The role of the vagus nerve in gut-brain communication is also addressed. We highlight potential therapeutic implications of targeting GM in AD, focusing on antibiotics, probiotics, prebiotics, postbiotics, phytochemicals, and fecal microbiota transplantation. While preclinical studies showed promise, clinical evidence remains limited and inconsistent. We critically assess clinical trials, emphasizing challenges in translating GM-based therapies to AD patients. The reviewed evidence underscores the need for further research to elucidate precise molecular mechanisms linking GM to AD and determine whether GM dysbiosis is a contributing factor or consequence of AD pathology. Future studies should focus on large-scale clinical trials to validate GM-based interventions' efficacy and safety in AD.

Parasite infections: how inflammation alters brain function

Parasitic infections can profoundly impact brain function through inflammation within the central nervous system (CNS). Once viewed as an immune-privileged site, the CNS is now recognized as vulnerable to immune disruptions from both local and systemic infections. Recent studies reveal that certain parasites, such as Toxoplasma gondii and Plasmodium falciparum, can invade the CNS or influence it indirectly by triggering neuroinflammation. These processes may disrupt brain homeostasis, influence neurotransmission, and lead to significant behavioral or cognitive changes. This review discusses the pathways by which parasites disrupt CNS function and highlights systemic inflammation as a critical link between peripheral infections and neuroinflammatory conditions, advancing understanding of parasite-associated neurological complications.