Gut microbiota-derived metabolites in the regulation of host immune responses and immune-related inflammatory diseases

Role of gut microbiome in suppression of cancers

The pathogenesis of cancer is closely related to the disruption of homeostasis in the human body. The gut microbiome plays crucial roles in maintaining the homeostasis of its host throughout lifespan. In recent years, a large number of studies have shown that dysbiosis of the gut microbiome is involved in the entire process of cancer initiation, development, and prognosis by influencing the host immune system and metabolism. Some specific intestinal bacteria promote the occurrence and development of cancers under certain conditions. Conversely, some other specific intestinal bacteria suppress the oncogenesis and progression of cancers, including inhibiting the occurrence of cancers, delaying the progression of cancers and boosting the therapeutic effect on cancers. The promoting effects of the gut microbiome on cancers have been comprehensively discussed in the previous review. This article will review the latest advances in the roles and mechanisms of gut microbiome in cancer suppression, providing a new perspective for developing strategies of cancer prevention and treatment.

Microbial succinate promotes the response to metformin by upregulating secretory immunoglobulin a in intestinal immunity

Metformin is the first-line pharmacotherapy for type 2 diabetes mellitus; however, many patients respond poorly to this drug in clinical practice. The potential involvement of microbiota-mediated intestinal immunity and related signals in metformin responsiveness has not been previously investigated. In this study, we successfully constructed a humanized mouse model by fecal transplantation of the gut microbiota from clinical metformin-treated - responders and non-responders, and reproduced the difference in clinical phenotypes of responsiveness to metformin. The abundance of Bacteroides thetaiotaomicron, considered a representative differential bacterium of metformin responsiveness, and the level of secretory immunoglobulin A (SIgA) in intestinal immunity increased significantly in responder recipient mice following metformin treatment. In contrast, no significant alterations in B. thetaiotaomicron and SIgA were observed in non-responder recipient mice. The study of IgA-/- mice confirmed that downregulated expression or deficiency of SIgA resulted in non-response to metformin, meaning that metformin was unable to improve dysfunctional glucose metabolism and reduce intestinal and adipose tissue inflammation, ultimately leading to systemic insulin resistance. Furthermore, supplementation with succinate, a microbial product of B. thetaiotaomicron, potentially reversed the non-response to metformin by inducing the production of SIgA. In conclusion, we demonstrated that upregulated SIgA, which could be regulated by succinate, was functionally involved in metformin response through its influence on immune cell-mediated inflammation and insulin resistance. Conversely, an inability to regulate SIgA may result in a lack of response to metformin.

Mouse strain-specific responses along the gut-brain axis upon fecal microbiota transplantation from children with autism

Several factors are linked to the pathophysiology of autism spectrum disorders (ASD); however, the molecular mechanisms of the condition remain unknown. As intestinal problems and gut microbiota dysbiosis are associated with ASD development and severity, recent studies have focused on elucidating the microbiota-gut-brain axis' involvement. This study aims to explore mechanisms through which gut microbiota might influence ASD. Briefly, we depleted the microbiota of conventional male BALB/cAnNCrl (Balb/c) and C57BL/6J (BL/6) mice prior to human fecal microbiota transplantation (hFMT) with samples from children with ASD or their neurotypical siblings. We found mouse strain-specific responses to ASD hFMT. Notably, Balb/c mice exhibit decreased exploratory and social behavior, and show evidence of intestinal, systemic, and central inflammation accompanied with metabolic shifts. BL/6 mice show less changes after hFMT. Our results reveal that gut microbiota alone induce changes in ASD-like behavior, and highlight the importance of mouse strain selection when investigating multifactorial conditions like ASD.

Microbial diversity and fitness in the gut-brain axis: influences on developmental risk for Alzheimer's disease

The gut-brain axis (GBA) denotes the dynamic and bidirectional communication system that connects the gastrointestinal tract and the central nervous system (CNS). This review explored this axis, focusing on the role of microbial diversity and fitness in maintaining gastrointestinal health and preventing neurodegeneration, particularly in Alzheimer's disease (AD). Gut dysbiosis, characterized by the imbalance in populations of beneficial and harmful bacteria, has been associated with increased systemic inflammation, neuroinflammation, and the progression of AD through pathogenic mechanisms involving amyloid deposition, tauopathy, and increased blood-brain barrier (BBB) permeability. Emerging evidence highlighted the therapeutic potential of probiotics, dietary interventions, and intermittent fasting in restoring microbial balance, reducing inflammation, and minimizing neurodegenerative risks. Probiotics and synbiotics are promising in helping improve cognitive function and metabolic health, while dietary patterns like the Mediterranean diet were linked to decreased neuroinflammation and enhanced gut-brain communication. Despite significant advancement, further research is needed to elucidate the specific microbial strains, metabolites, and mechanisms influencing brain health. Future studies employing longitudinal designs and advanced omics technologies are essential to developing targeted microbiome-based therapies for managing AD-related disorders.

Microbiota and metabolite profiles of saliva, oral swab and cancer tissue from patients with oral squamous cell carcinoma (OSCC)

Oral squamous cell carcinoma (OSCC) was the most common malignant type of head and neck squamous cell carcinoma (HNSCC) with a low survival rate. The microbiota in oral cavity or tumor tissues may play a critical role in the OSCC. In this study, we characterized the microbiota from oral cancer tissues, oral swabs and saliva of patients with OSCC using 16S rRNA sequencing. We found differential profiles and amounts of microbiota in oral cancer tissues compared with adjacent tissues, as well as in oral swabs and saliva from OSCC patients compared with healthy individuals. Fusobacterium nucleatum and Porphyromonas endodontalis were found increased in cancer tissues and saliva from OSCC patients. Prevotella melaninogenica was found increased in the saliva and oral swabs from OSCC patients. These data suggested that microbiota varied according to different samples. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated an important role of metabolic pathways in the interaction between microbiota and cancers. Then we analyzed the metabolites from cancer tissues and saliva of OSCC patients by liquid chromatograph-mass spectrometry/mass spectrometry (LC-MS/MS) and gas chromatograph-mass spectrometry (GC-MS). Differential profiles of metabolites were also observed in the cancer tissues compared with adjacent tissues and in the saliva from OSCC patients compared with healthy individuals. It showed that denticulaflavonol was significantly increased while D-mannose was significantly decreased in both cancer tissues and saliva of OSCC patients. Taken together, these results suggested an association between microbiota/metabolites (such as Fusobacterium and mannose) and OSCC, in which the molecular mechanism need further investigated.

Lactobacillus kefiranofaciens and its enhancement effect on the anti-inflammatory function of CII/Gln in MIA-induced osteoarthritis by protecting the intestinal barrier and gut microecology

Osteoarthritis (OA) is a globally chronic disease affecting middle-aged and elderly individuals, with growing evidences implicating gut microbiota in its pathogenesis. Lactobacillus kefiranofaciens ZW3 (ZW3) shows potential in modulating gut microbiota, protecting intestinal barrier, and regulating immunity. This study explored the therapeutic effects of ZW3, alone and combined with CII/Gln, using a monoiodoacetate (MIA)-induced OA model. Results indicated that ZW3 significantly mitigated cartilage damage and inflammation alone or combined with CII/Gln, possibly by improving intestinal integrity, reduced oxidative stress, and regulated MMPs expression. 16S rDNA sequencing showed ZW3, especially with CII/Gln, increased beneficial bacteria of Ruminococcaceae and Lachnospiraceae abundances. Furthermore, ZW3 or with CII/Gln elevated SCFAs levels in intestinal contents in OA rats. These findings propose a novel probiotic-based strategy, potentially combined with functional foods, for OA intervention and treatment.

Microbe-dependent and independent effects of diet on metabolic inflammation in glucose metabolism regulation

Diet can contribute to the development of metabolic disease including type 2 diabetes (T2D) by inducing metabolic inflammation. While the gut microbiota mediates the effects of diet, the diet can also exert its effects independent of gut microbes. The microbe-dependent and -independent effects of diet on inflammation remain to be elucidated. This review examines recent advances and dissects the specifics of both gut microbe-dependent and independent mechanisms through which diet impacts inflammation and glucose metabolism. We delineate how diet interacts with the gut microbiome and induces metabolic inflammation. We also describe the direct effects of dietary components and their related metabolites on the immune system, and explore how diet-induced sterile inflammation may contribute to metabolic disorders. It is important to consider both microbe-dependent and independent pathways when developing therapeutic approaches aimed at preventing T2D.

Murine gut microbiota dysbiosis via enteric infection modulates the foreign body response to a distal biomaterial implant

The gut microbiota influences systemic immunity and the function of distal tissues, including the brain, liver, skin, lung, and muscle. However, the role of the gut microbiota in the foreign body response and fibrosis is largely unexplored. To investigate this connection, we perturbed the homeostasis of the murine gut microbiota via infection with the pathogenic bacterial species enterotoxigenic Bacteroides fragilis (ETBF) and implanted particulate material (mean particle size <600 μm) of the synthetic polymer polycaprolactone (PCL) into a distal muscle injury. ETBF infection in mice led to increased neutrophil and γδ T cell infiltration into the PCL implant site. ETBF infection alone promoted systemic inflammation, increased levels of neutrophils in lymphoid tissues, and altered skeletal muscle gene expression. At the PCL implant site, we found significant changes in the transcriptome of sorted stromal cells between infected and control mice, including differences related to ECM components such as proteoglycans and glycosaminoglycans. However, we did not observe ETBF-induced differences in fibrosis levels. These results demonstrate the ability of the gut microbiota to mediate long-distance effects such as immune and stromal responses to a distal biomaterial implant.

Links between short-chain fatty acids and osteoarthritis from pathology to clinic via gut-joint axis

Short-chain fatty acids (SCFAs), the primary metabolites produced by the microbial fermentation of dietary fibers in the gut, have a key role in protecting gut health. Increasing evidence indicates SCFAs can exert effects on distant tissues and organs beyond the gut via blood circulation. Osteoarthritis (OA) is a chronic inflammatory joint disease that severely diminishes the physical function and quality of life. However, effective clinical treatments for OA remain elusive. Recent studies have shown that SCFAs can exert beneficial effects on damaged joints in OA. SCFAs can mitigate OA progression by preserving intestinal barrier function and maintaining the integrity of cartilage and subchondral bone, suggesting that they have substantial potential to be the adjunctive treatment strategy for OA. This review described the SCFAs in the human body and their cellular signaling mechanism, and summarized the multiple effects of SCFAs (especially butyrate, propionate, and acetate) on the prevention and treatment of OA by regulating the gut-joint axis, providing novel insights into their promising clinical applications.

Gut Microbiota Modulates Obesity-Associated Skeletal Deterioration Through Macrophage Aging and Grancalcin Secretion

Obesity is associated with skeletal deterioration and increased fracture risk, but the underlying mechanism is unclear. Herein, it is shown that obese gut microbiota promotes skeletal deterioration by inducing bone marrow macrophages (BMMs) senescence and grancalcin (GCA) secretion. Obese mice and those receiving obese fecal microbiota transplants exhibit increased senescent macrophages and elevated GCA expression in the bone marrow. In a study of 40 participants, it is found that obese patients are associated with higher serum GCA levels. It is further revealed that obese gut-microbiota derived lipopolysaccharides (LPS) stimulate GCA expression in senescent BMMs via activating Toll-like receptor 4 pathway. Mice with depletion of the Gca gene are resistant to the negative effects of obesity and LPS on bone. Moreover, neutralizing antibody against GCA mitigates skeletal deterioration in obese mice and LPS-induced chronic inflammation mouse model. The data suggest that the interaction between gut microbiota and the immune system contributes to obesity-associated skeletal deterioration, and targeting senescent macrophages and GCA shows potential of protecting skeletal health in obese population.

Microbiota, mitochondria, and epigenetics in health and disease: converging pathways to solve the puzzle

Dysbiosis, which refers to an imbalance in the composition of the gut microbiome, has been associated with a range of metabolic disorders, including type 2 diabetes, obesity, and metabolic syndrome. Although the exact mechanisms connecting gut dysbiosis to these conditions are not fully understood, various lines of evidence strongly suggest a substantial role for the interaction between the gut microbiome, mitochondria, and epigenetics. Current studies suggest that the gut microbiome has the potential to affect mitochondrial function and biogenesis through the production of metabolites. A well-balanced microbiota plays a pivotal role in supporting normal mitochondrial and cellular functions by providing metabolites that are essential for mitochondrial bioenergetics and signaling pathways. Conversely, in the context of illnesses, an unbalanced microbiota can impact mitochondrial function, leading to increased aerobic glycolysis, reduced oxidative phosphorylation and fatty acid oxidation, alterations in mitochondrial membrane permeability, and heightened resistance to cellular apoptosis. Mitochondrial activity can also influence the composition and function of the gut microbiota. Because of the intricate interplay between nuclear and mitochondrial communication, the nuclear epigenome can regulate mitochondrial function, and conversely, mitochondria can produce metabolic signals that initiate epigenetic changes within the nucleus. Given the epigenetic modifications triggered by metabolic signals from mitochondria in response to stress or damage, targeting an imbalanced microbiota through interventions could offer a promising strategy to alleviate the epigenetic alterations arising from disrupted mitochondrial signaling.

Inflammatory bowel disease and neuropsychiatric disorders: Mechanisms and emerging therapeutics targeting the microbiota-gut-brain axis

Crohn's disease (CD) and ulcerative colitis (UC) are the two major entities of inflammatory bowel disease (IBD). These disorders are known for their relapsing disease course and severe gastrointestinal symptoms including pain, diarrhoea and bloody stool. Accumulating evidence suggests that IBD is not only restricted to the gastrointestinal tract and that disease processes are able to reach distant organs including the brain. In fact, up to 35 % of IBD patients also suffer from neuropsychiatric disorders such as generalized anxiety disorder and major depressive disorder. Emerging research in this area indicates that in many cases these neuropsychiatric disorders are a secondary condition as a consequence of the disturbed communication between the gut and the brain via the microbiota-gut-brain axis. In this review, we summarise the current knowledge on IBD-associated neuropsychiatric disorders. We examine the role of different pathways of the microbiota-gut-brain axis in the development of CNS disorders highlighting altered neural, immunological, humoral and microbial communication. Finally, we discuss emerging therapies targeting the microbiota-gut-brain axis to alleviate IBD and neuropsychiatric symptoms including faecal microbiota transplantation, psychobiotics, microbial metabolites and vagus nerve stimulation.

Fibre: The Forgotten Carbohydrate in Sports Nutrition Recommendations

Although dietary guidelines concerning carbohydrate intake for athletes are well established, these do not include recommendations for daily fibre intake. However, there are many scenarios in sports nutrition in which common practice involves the manipulation of fibre intake to address gastrointestinal comfort around exercise, or acute or chronic goals around the management of body mass or composition. The effect of fibre intake in overall health is also important, particularly in combination with other dietary considerations such as the elevated protein requirements in this population. An athlete's habitual intake of dietary fibre should be assessed. If less than 20 g a day, athletes may consider dietary interventions to gradually increase intake. It is proposed that a ramp phase is adopted to gradually increase fibre ingestion to ~ 30 g of fibre a day (which includes ~ 2 g of beta-glucan) over a duration of 6 weeks. The outcomes of achieving a daily fibre intake are to help preserve athlete gut microbiome diversity and stability, intestinal barrier function as well as the downstream effects of short-chain fatty acids produced following the fermentation of microbiome accessible carbohydrates. Nevertheless, there are scenarios in which daily manipulation of fibre intake, either to reduce or increase intake, may be valuable in assisting the athlete to maintain gastrointestinal comfort during exercise or to contribute to body mass/composition goals. Although further research is required, the aim of this current opinion paper is to ensure that fibre is not forgotten as a nutrient in the athlete's diet.

Association between dietary index for gut microbiota and metabolic syndrome risk: a cross-sectional analysis of NHANES 2007-2018

Metabolic syndrome (MetS) poses a significant global health challenge, closely associated with cardiovascular diseases, diabetes, and other conditions. With the global prevalence of MetS steadily rising, the potential role of gut microbiota in its development has garnered increasing attention. Against this backdrop, the present study aims to explore the association between the dietary index for gut microbiota (DI-GM) score and MetS. This cross-sectional study utilized data from the 2007-2018 U.S. National Health and Nutrition Examination Survey (NHANES), including 339,242 adults aged ≥ 18 years. The DI-GM score, constructed based on 14 food or nutrient components, served as the exposure variable. MetS was defined according to the Adult Treatment Panel III (ATP III) criteria, including abdominal obesity (waist circumference ≥ 102 cm in men and ≥ 88 cm in women), elevated triglycerides (≥ 150 mg/dL), reduced HDL cholesterol (< 40 mg/dL in men and < 50 mg/dL in women), elevated blood pressure (≥ 130/85 mmHg), and elevated fasting glucose (≥ 100 mg/dL). Multivariable logistic regression analyses were performed to adjust for demographic characteristics, lifestyle factors, and other potential confounders. Higher DI-GM scores were significantly associated with a reduced risk of MetS. After adjusting for all confounders, individuals in the highest quartile (Q4) of DI-GM scores had a 16% lower risk of MetS compared to those in the lowest quartile (Q1) (OR: 0.84; 95%CI: 0.70-1.01). Mediation analyses revealed that systemic immune-inflammation index (SII) and neutrophil-to-lymphocyte ratio (NLR) mediated 4.63% and 3.83% of the association between DI-GM and MetS, respectively. There is an inverse association between DI-GM scores and the risk of MetS, potentially mediated in part by inflammatory markers. These findings provide new evidence supporting dietary interventions aimed at improving gut microbiota to prevent MetS.

Modulating Gut Microbiota with Dietary Components: A Novel Strategy for Cancer-Depression Comorbidity Management

BACKGROUND

Gut microbiota play a critical role in mediating the bidirectional association between cancer and depression. Emerging evidence indicates that adjusting the dietary component intake can significantly alter gut microbiota composition, thereby influencing the host's metabolism and immune function. Changes in gut microbiota and their metabolites may represent key factors in preventing cancer-depression comorbidity.

METHODS

English publications were searched in databases including the Web of Science, Scopus, and PubMed using a series of keywords: "cancer", "depression", "gut microbiota", "dietary components", and related terms, individually or in combination. The search focused on preclinical and clinical studies describing the regulatory effects of dietary component interventions.

RESULTS

This narrative review summarizes the associations among gut microbiota, cancer, and depression, and synthesizes current evidence on the modulatory effects and mechanisms of specific dietary component interventions, including dietary patterns, probiotics, prebiotics, and diet-derived phytochemicals, on gut microbiota. On the one hand, these interventions inhibit abnormal proliferation signals in the tumor microenvironment and enhance anticancer immune responses; on the other hand, they modulate neurotransmitter homeostasis, suppress neuroinflammation, and improve mood behaviors through the gut-brain axis interactions mediated by microbial metabolites.

CONCLUSIONS

The complex associations among cancer, depression, and gut microbiota require further clarification. Modulating gut microbiota composition through dietary components represents a novel therapeutic strategy for improving cancer-depression comorbidity. Regulated gut microbiota enhance immune homeostasis and intestinal barrier function, while their metabolites bidirectionally modulate one another via systemic circulation and the gut-brain axis, thereby improving both the tumor microenvironment and depressive-like behaviors in cancer patients while reducing the adverse effects of cancer.

Human microbiota in dengue infection: A narrative review

Dengue fever, a widespread mosquito-borne viral infection in tropical regions, typically manifests fever and gastrointestinal symptoms, including nausea, vomiting, and diarrhea. However, the human gut microbiota's role in dengue pathogenesis remains incompletely understood. Studies have demonstrated dysbiosis during dengue virus infection, characterized by increased abundance of potentially pathogenic bacteria like Bacteroidaceae and Proteobacteria, particularly during the critical phase. Furthermore, microbial translocation and leaky gut syndrome, characterized by the translocation of intestinal microbial products, have been observed in dengue patients and are associated with hypercytokinemia, plasma leakage, and disease severity. These findings underscore the necessity for an in-depth investigation into the role of human intestinal microbiota as a potential contributing factor in the pathogenesis and progression of dengue. Further research focusing on human intestinal microbiota, leaky gut syndrome, and the potential implications of treatment with oral bacteriotherapy, as previously observed in other viral diseases, is essential to clarify dengue pathology and evaluate new therapeutic strategies.

Human Gut Microbiome: A Connecting Organ Between Nutrition, Metabolism, and Health

The gut microbiome plays a vital role in human health, functioning as a metabolic organ that influences nutrient absorption and overall well-being. With growing evidence that dietary interventions can modulate the microbiome and improve health, this review examines whether healthcare systems should prioritize personalized microbiome-targeted therapies, such as probiotics, prebiotics, and microbiota transplants, over traditional pharmaceutical treatments for chronic diseases like obesity, diabetes, cardiovascular risk, and inflammatory conditions. A systematic review using Web of Science and Scopus databases was conducted, followed by a scientometric analysis. Key metabolic pathways, such as dietary fiber fermentation and short-chain fatty acid production, were explored, focusing on their impact on lipid and glucose metabolism. The interactions between microbial metabolites and the immune system were also investigated. Dietary interventions, including increased fiber and probiotic intake, show potential for addressing dysbiosis linked to conditions, such as type 2 diabetes, obesity, and autoimmune diseases. The review emphasizes the need to incorporate microbiome modulation strategies into clinical practice and research, calling for a multidisciplinary approach that integrates nutrition, microbiology, and biochemistry to better understand the gut microbiome's complex role in health.

3-Fucosyllactose Prevents Nonalcoholic Fatty Liver Disease by Modulating the Gut Microbiota-Derived Pantothenate in Mice

Nonalcoholic fatty liver disease (NAFLD) is a growing global health threat. Human milk oligosaccharides (HMOs) exhibit prebiotic properties that may alleviate NAFLD progression. Herein, our study demonstrates that 3-fucosyllactose (3-FL), a distinctive and crucial HMO, significantly attenuates body weight gain, enhances hepatic lipid metabolism, and reduces inflammation in a high-fat diet (HFD)-induced NAFLD mouse model. These findings suggest its potential as a dietary supplement for preventing and alleviating NAFLD progression. Subsequently, fecal metagenomic and nontargeted metabolomics analyses revealed that 3-FL treatment significantly alleviated HFD-induced gut microbiota dysbiosis, with a specific enhancement of the pantothenate (vitamin B5) metabolic pathways. Our targeted metabolite analysis further revealed a significant increase in both hepatic and fecal pantothenate concentrations, which contributed to the enhancement of the coenzyme A (CoA)-mediated lipid metabolism pathway. Furthermore, the subsequent population cohort analyses revealed a significant correlation between serum pantothenate levels and the progression of NAFLD, thereby reinforcing its candidacy as a noninvasive diagnostic biomarker. These findings show that 3-FL acts as an effective prebiotic to alleviate NAFLD symptoms, in part by enhancing the gut microbiota-mediated pantothenate/CoA metabolic pathway.

Gut microbiota derived indole-3-acetic acid ameliorates precancerous inflammatory intestinal milieu to inhibit tumorigenesis through IL-35

BACKGROUND

Gut microbiota can significantly alter the risk or progression of cancer by maintaining gut immune system homeostasis. However, the exact mechanism by which the gut microbiota and its metabolites influence colorectal tumorigenesis is unclear.

METHODS

The roles of tryptophan metabolite indole-3-acetic acid (IAA) in inflammation and tumor development were investigated in dextran sodium sulfate (DSS) and azoxymethane (AOM)-DSS mouse models with or without IAA supplementation and with or without Lactobacillus reuteri-produced IAA. Pregnane X receptor (PXR) knockout (KO) mice and aryl hydrocarbon receptor KO mice were used to explore the mechanism by which IAA regulates interleukin (IL)-35 expression. IL-35+ immune cells were stimulated in vitro and analyzed by flow cytometry. Additionally, metabolites were analyzed by liquid chromatography-mass spectrometry.

RESULTS

We found that IAA, a metabolite of tryptophan produced in the gut by L. reuteri, can inhibit the development of colitis by inducing IL-35 expression in immunosuppressant cells. HuREG3αIECtg mice had high levels of intestinal microbiota-derived IAA, and these mice were resistant to AOM-DSS-induced cancer. Patients with colorectal cancer also had low peripheral blood levels of IAA. Further studies revealed that IAA-producing L. reuteri alleviated colitis symptoms and inhibited colon tumors by inducing macrophages, T cells, and B cells to produce IL-35. Finally, PXR KO completely abolished the effects of IAA on immune cells.

CONCLUSION

We demonstrate that gut microbiota-derived IAA can improve the precancerous colon inflammatory environment through IL-35, thereby inhibiting tumorigenesis, suggesting that IAA may be a preventive factor for colitis-related cancers.

Bacteroides fragilis and propionate synergize with low-dose methimazole to treat Graves' disease

Graves' disease (GD) is a common autoimmune thyroid disease with limited treatment efficacy, high relapse rates, and severe adverse effects. Gut microbiota dysbiosis is thought to play a critical role in GD, with the potential for microbiota-based therapies in GD treatment. However, experimental evidence is needed to validate this hypothesis. In this study, we evaluated the therapeutic effects of the commensal bacterium B. fragilis and its metabolite, propionate, in a GD mouse model. We found that oral supplementation with B. fragilis or propionate significantly reduced serum levels of inflammatory cytokines, total thyroxine (TT4), and TSH receptor antibodies (TRAb). It also decreased the proportion of circulating Th17 cells while increasing the proportion of circulating regulatory T cells (Tregs), thus mitigating systemic inflammation, hyperthyroidism, and the autoimmune response against TSHR. In addition, B. fragilis and propionate significantly decreased the levels of inflammatory cytokines and the proportion of M1 macrophages in thyroid tissue, while increasing the proportions of Treg cells and M2 macrophages, thereby reducing thyroid inflammation and size. Notably, the combination of B. fragilis or propionate with methimazole (MMI) significantly ameliorated pathological changes in GD mice and markedly reduced MMI dosage requirements, demonstrating a synergistic therapeutic effect. Our findings suggest that B. fragilis and propionate could serve as effective adjuvant agents in combination with MMI, thereby enhancing therapeutic efficacy while reducing drug dosage and minimizing side effects. This study opens a new avenue for microbiota-based treatments in managing GD.IMPORTANCEThis study explores a new approach to treat Graves' disease (GD), a major type of hyperthyroidism. Traditional treatments for GD often come with significant side effects and high relapse rates. Researchers found that Bacteroides fragilis, a gut commensal bacterium, and its metabolite propionate can improve the condition of GD mice. When combined with methimazole, a conventional medication for GD treatment, these natural agents demonstrated enhanced therapeutic efficacy, enabling dose reduction of methimazole and consequently reducing adverse effects. This research suggests that combining gut microbiota-based treatments with standard therapies may offer a more effective and safer way to manage GD.

Research Progress on the Therapeutic Mechanisms of Stigmasterol for Multiple Diseases

Stigmasterol is a plant-derived phytosterol that has attracted considerable attention because of its diverse biological activities and potential therapeutic applications. In this review, the chemical properties, biosynthesis, and biological effects of stigmasterol are exhaustively summarized. Furthermore, the anti-inflammatory, antioxidant, anticancer, neuroprotective, and hypolipidemic activities of stigmasterol have been discussed. Findings from various in vitro and in vivo studies have revealed its potential in treating various diseases, including cancer, diabetes, neurological disorders, and inflammatory conditions. The mechanisms underlying these effects are also discussed, particularly emphasizing the regulation of key signaling pathways and molecular targets, to further clarify the therapeutic role of stigmasterol. This review would provide a reference for further exploring the utility of stigmasterol as a therapeutic agent, thereby contributing to the improvement of human health.

Lactobacillus acidophilus extracellular vesicles-coated UiO-66-NH2@siRNA nanoparticles for ulcerative colitis targeted gene therapy and gut microbiota modulation

Ulcerative colitis (UC) is a complex and chronic inflammatory bowel disease whose pathogenesis involves genetic and environmental factors, which poses a challenge for treatment. Here, we have designed an innovative integrated therapeutic strategy using Lactobacillus acidophilus extracellular vesicles (EVs) to encapsulate UiO-66-NH2 nanoparticles bounded with TNF-α siRNA (EVs@UiO-66-NH2@siRNA) for UC treatment. This system shows superior affinity to inflammation-related cells due to the Lactobacillus acidophilus EVs can maintain immune homeostasis by regulating the secretion of cytokines in vitro. siRNA can specifically target the key inflammatory TNF-α in UC and silence its gene expression, thereby regulating the process of inflammatory response. After oral administration, EVs@UiO-66-NH2@siRNA demonstrates an accurate delivery of TNF-α siRNA to colonize the colon site and exerts a siRNA therapeutic effect by inhibiting the expression of TNF-α, which alleviates the intestinal inflammation in DSS-induced UC model. Moreover, this system can modulate the types and compositional structures of gut microbiota and metabolites to achieve an anti-inflammatory phenotype, which is helpful for the repair of intestinal homeostasis. We also have proved that UiO-66-NH2 nanoparticles exhibit a high loading capacity for TNF-α siRNA and good pH responsiveness, improving the potent release of siRNA in colon tissue. Collectively, the EVs@UiO-66-NH2@siRNA nano-delivery system demonstrate a feasible combination therapeutic strategy for UC through gut microecology modulation, immune regulation and TNF-α siRNA silence, which may provide a potential targeted treatment approach for inflammatory bowel disease.

Persea americana Peel: A Promising Source of Nutraceutical for the Mitigation of Cardiovascular Risk in Arthritic Rats Through the Gut-Joint Axis

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by the inflammation of synovial fluid. The incidence of cardiovascular diseases (CVDs) is increasing in RA patients. This research is the first report to investigate the anti-arthritic effect of avocado peel nutraceutical (APN) and its potential in mitigating the cardiovascular risk associated with RA. The antioxidant activity and phytochemical composition of APN were assessed. The potential interaction of APN's active compounds with protein tyrosine phosphatase non-receptor type 22 (PTPN22) was studied using molecular docking. The impact of APN on the plasma lipid profile, oxidative and inflammatory markers, and the indices of coronary risk and atherogenicity as CVD markers were evaluated. The gene expression of COX-2, IL-6, IL-1β, IL-10, and TNF-α in liver and spleen tissues were measured. The rat gut microbiota profile was investigated using 16S rRNA amplicon sequencing. APN exhibited high antioxidant activity, low atherogenicity and thrombogenicity indices, and a high ratio of hypocholesterolemic to hypercholesterolemic fatty acids indicating its cardioprotective potential. The administration of APN led to a reduction in oxidative stress markers, inflammatory markers, dyslipidemia, and CVD markers. APN administration downregulated the expression of COX-2, IL-6, IL-1β, and TNF-α genes, while the IL-10 gene was significantly upregulated in the liver and spleen. Treatment with APN was favorable in restoring eubiosis in the gut by modulating RA-associated bacterial taxa linked to impaired immune function and cardiometabolic diseases. In molecular docking, β-amyrin and ellagic acid showed the highest binding affinity for PTPN22. APN may represent a promising approach to ameliorating the cardiovascular risk of RA. The present results will be offering a foundation for future in-depth research in nutraceuticals from agriculture by-products. Additionally, they will be supporting the public health policies aimed at preventing and controlling rheumatoid arthritis.

Triple-Functional Probiotics with Intracellularly Synthesized Selenium Nanoparticles for Colitis Therapy by Regulating the Macrophage Phenotype and Modulating Gut Microbiota

The dysregulated macrophage phenotype, as the main cause of colitis, not only enhanced oxidative stress to exacerbate inflammatory responses but was closely related with gut microbial dysbiosis. It was needed to simultaneously address the three issues for the effective treatment of colitis, but it was not satisfied. Here, we developed "three-birds-one-stone" probiotics, named Se@EcN-C2/A2, for colitis treatment. Escherichia coli Nissle 1917 (EcN), a clinically approved probiotic, was used to intracellularly synthesize selenium (Se) nanoparticles by biomineralization, giving Se@EcN. Coating glycol chitosan and sodium alginate on the surface of Se@EcN (Se@EcN-C2/A2) endowed probiotics with high resistance to the harsh gastrointestinal tract environment and strong adhesion and targeting ability to the inflamed site of the colon to facilitate the uptake by M1 macrophages. Se@EcN-C2/A2 was metabolized to SeCys2 and MetSeCys to be involved in the synthesis of GPX2 and TXNRD1, which led to reaction oxygen species clearance to inhibit Toll-like receptor and nuclear factor κB signaling pathways to suppress inflammatory response and polarize M1 macrophages to M2 phenotypes by activating PI3K/AKT signaling pathways. In DSS-induced colitis mice, Se@EcN-C2/A2 exerted satisfactory therapeutic and prophylactic effects, including scavenging oxidative stress and regulating macrophage phenotypes to suppress inflammatory response and restore gut barrier functions. Moreover, the living probiotic EcN in the colon effectively regulated microbial dysbiosis by decreasing the abundance of Escherichia-Shigella and increasing the abundance of Lactobacillus and Bifidobacterium.

Antimicrobial Effects of Kelisha Capsule on Escherichia coli Induced Diarrhea in Mice

Background

Kelisha capsule (KLSC), listed in the Chinese Pharmacopoeia, has been employed for the treatment of infectious diarrhea. Nevertheless, the precise mechanism of KLSC remains to be elucidated.

Aim of the Study

This work was to investigate the antibacterial mode and therapeutic mechanism of KLSC towards E. coli infected diarrhea.

Materials and Methods

HPLC identified the primary chemical constituents of KLSC. A model of diarrhea was induced via E. coli injection. The impact of KLSC on E. coli-induced diarrhea was evaluated using a diarrhea score in Babl/c mice. The integrity of the intestinal barrier was assessed through staining and measuring levels of specific proteins. Furthermore, immunofluorescence staining was conducted to identify tight junction proteins in the small intestinal tissue. The full-length 16S rRNA was used to examine gut microbiota. Network pharmacology, molecular docking, and molecular dynamic simulation were used to investigate the impact of KLSC on diarrhea-related inflammation and quantify the expression levels of IL-6 and TNF-α in the blood and small intestine. The in vivo antibacterial activity and mode of action of KLSC were also investigated using IVIS imaging, transmission electron microscopy, scanning electron microscopy, and molecular dynamic simulation.

Results

KLSC exhibited a positive effect on E. coli infected diarrhea. The content of IL-6 and TNF-α in mice with KLSC was significantly reduced. Additionally, KLSC could restore the intestinal barrier function by reversing small intestine structure and up-regulating the expression of tight junction proteins. The KLSC significantly inhibit pathogenic bacteria and restore the gut microbiota diversity. IVIS Imaging System was visually observed significant antibacterial efficacy of KLSC in vivo. The KLSC disrupted the cell membrane system of E. coli through the interaction between bioactive molecule and bilayer.

Conclusion

KLSC normalized the gut barrier function, reshaped gut microbiota balance, suppressed the inflammatory pathways, and inhibited the bacterial activity, thereby relieving the diarrhea caused by E. coli.

Identification of potential shared gene signatures between periodontitis and breast cancer by integrating bulk RNA-seq and scRNA-seq data

Studies have shown that patients with periodontitis (PD) have an increased risk of breast cancer (BC). However, the exact mechanism remains to be further investigated. This study aimed to investigate the genes, pathways and immune cells that may interact with PD and BC. From the Gene Expression Omnibus (GEO) and TCGA databases, we retrieved the gene expression profiles of samples with PD and BC, respectively. Common genes between two diseases were found using differential expression analysis and weighted gene co-expression network analysis (WGCNA). Machine learning methods were used to find shared diagnostic genes. Single-sample GSEA (ssGSEA) was performed to study the expression profiles of 28 immune cells in PD and BC, and single-cell RNA sequencing (scRNA-seq) data was used to visualize localization of shared genes. Finally, we employed qRT-PCR and immunohistochemistry staining to confirm the expression of hub genes in two diseases. PD and BC had 21 shared crosstalk genes, which were primarily related to peptide hormone response, organic acid transmembrane transport, and carboxylic acid transmembrane transport. By using machine learning methods, ANKRD29 and TDO2 were the most efficient shared diagnostic biomarkers, which were confirmed by Immunohistochemical staining and qRT-PCR. ssGSEA showed that immunology was involved in both diseases and that ANKRD29 and TDO2 may be involved in both diseases by mediating immune cells. scRNA-seq further confirms the importance of these genes in regulating immunity in both diseases. In brief, our study identified 2 genes that may serve as biomarkers and targets for the diagnosis and treatment of PD and BC.

Qing-Re-Hua-Shi Decoction ameliorates DSS-induced colitis by modulating multiple signaling pathways and remodeling the gut microbiota and metabolite profile

Background

Clinically, Qing-Re-Hua-Shi Decoction (QRHSD) has been clinically used to treat ulcerative colitis (UC) with satisfactory outcomes and minimal side effects. However, its molecular mechanisms remain unclear.

Purpose

This study investigates the effects of QRHSD on DSS-induced colitis in mice, employing multi-omics analyses, including RNA-seq transcriptomics, 16S rRNA microbiomics, non-targeted metabolomics, and network pharmacology analysis.

Methods

The chemical composition of QRHSD was analyzed using quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). A UC mice model was induced by 3% DSS for 7 days. The effects and mechanisms of QRHSD on UC were evaluated via hematoxylin and eosin, immunofluorescence assay, flow cytometry, western blot, RNA-seq transcriptomics, 16S rRNA microbiomics, non-targeted metabolomics, and network pharmacology. Correlation analyses and validation experiments explored links between transcriptomic, microbiome, metabolomic profiles, and UC-related clinical indices.

Results

UPLC-Q-TOF/MS identified 55 compounds in QRHSD. QRHSD significantly reduced clinical activity, histological changes, and inflammatory factors in UC mice, regulated Th17/Treg balance, and enhanced intestinal barrier integrity. 16S rRNA analysis showed that QRHSD altered gut microbiota composition, increasing beneficial bacteria (e.g., Lactobacillus) and decreasing harmful bacteria (e.g., Morganella). Non-targeted metabolomics revealed 507 metabolites associated with UC amelioration, enriched in pathways like bile secretion, ABC transporters, and amino acid biosynthesis. RNA-seq analysis, network pharmacology, and experimental verification showed that QRHSD significantly regulated key signaling pathways, including PI3K/AKT, NF-κB, and MAPK signaling pathways. Finally, correlation analysis highlighted connections among UC-related clinical factors, gut microbiota, and metabolites.

Conclusion

QRHSD could modulate the gut microbiota, metabolic homeostasis, and multiple signal pathways in the treatment of DSS-induced UC, revealing the mechanism of traditional Chinese medicine therapy for UC.

Targeting the gut microbiota-inflammation-brain axis as a potential therapeutic strategy for psychiatric disorders: A Mendelian randomization analysis

BACKGROUND

Extensive research indicates a link between gut microbiota dysbiosis and psychiatric disorders. However, the causal relationships between gut microbiota and different types of psychiatric disorders, as well as whether inflammatory factors mediate these relationships, remain unclear.

METHODS

We utilized summary statistics from the largest genome-wide association studies to date for gut microbiota (n = 18,340 in MiBioGen consortium), circulating inflammatory factors (n = 8293 for 41 factors and n = 14,824 for 91 factors in GWAS catalog), and six major psychiatric disorders from the Psychiatric Genomics Consortium (PGC): attention deficit hyperactivity disorder (ADHD, n = 38,691), anxiety disorder (ANX, n = 2248), bipolar disorder (BIP, n = 41,917), anorexia nervosa (AN, n = 16,992), schizophrenia (SCZ, n = 36,989), and autism spectrum disorder (ASD, n = 18,381). We conducted bidirectional Mendelian randomization (MR) analysis to explore the causal relationships between gut microbiota and psychiatric disorders. Additionally, we performed two-step MR and multivariable MR (MVMR) analyses to identify potential mediating inflammatory factors.

RESULTS

We found significant causal relationships between 11 gut microbiota and ADHD, 2 gut microbiota and ANX, 11 gut microbiota and BIP, 8 gut microbiota and AN, 15 gut microbiota and SCZ, and 5 gut microbiota and ASD. There were 16 positive and 15 negative causal effects between inflammatory factors and psychiatric disorders. Furthermore, MVMR analysis results indicated that the correlation between genus Roseburia and ADHD was mediated by MCSF, with a mediation proportion of 3.3 %; the correlation between genus Erysipelotrichaceae UCG003 and BIP was mediated by GDNF, with a mediation proportion of 3.7 %; and the correlation between family Prevotellaceae and SCZ was mediated by CD40, with a mediation proportion of 8.2 %.

CONCLUSIONS

The MR analysis results supported causal relationships between gut microbiota and six psychiatric disorders, as well as the potential mediating role of inflammatory factors. This study highlights the potential role of the gut microbiota-inflammation-brain axis in psychiatric disorders.

Antigen Uptake in the Gut: An Underappreciated Piece to the Puzzle?

The mammalian gut is a vast, diverse, and dynamic single-layer epithelial surface exposed to trillions of microbes, microbial products, and the diet. Underlying this epithelium lies the largest collection of immune cells in the body; these cells encounter luminal substances to generate antigen-specific immune responses characterized by tolerance at homeostasis and inflammation during enteric infections. How the outcomes of antigen-specific tolerance and inflammation are appropriately balanced is a central question in mucosal immunology. Furthermore, how substances large enough to generate antigen-specific responses cross the epithelium and encounter the immune system in homeostasis and during inflammation remains largely unexplored. Here we discuss the challenges presented to the gut immune system, the identified pathways by which luminal substances cross the epithelium, and insights suggesting that the pathways used by substances to cross the epithelium affect the ensuing immune response.

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.

Gut virome and its implications in the pathogenesis and therapeutics of inflammatory bowel disease

Inflammatory bowel disease (IBD) refers to chronic, recurrent inflammatory intestinal disorders, primarily including Crohn's disease (CD) and Ulcerative colitis (UC). Numerous studies have elucidated the importance of the gut microbiome in IBD. Recently, numerous studies have focused on the gut virome, an intriguing and enigmatic aspect of the gut microbiome. Alterations in the composition of phages, eukaryotic viruses, and human endogenous retroviruses that occur in IBD suggest potential involvement of the gut virome in IBD. Nevertheless, the mechanisms by which it maintains intestinal homeostasis and interacts with diseases are only beginning to be understood. Here, we thoroughly reviewed the composition of the gut virome in both healthy individuals and IBD patients, emphasizing the key viruses implicated in the onset and progression of IBD. Furthermore, the complex connections between the gut virome and the intestinal barrier, immunity, and gut microbiome were dissected to advance the interpretation of IBD pathogenesis. The updated discussion of the evidence regarding the gut virome will advance our knowledge in gut virome and chronic gastrointestinal diseases. Targeting the gut virome is a promising avenue for IBD treatment in future.

Bacteria-derived 3-hydroxydodecanoic acid induces a potent anti-tumor immune response via the GPR84 receptor

Despite advances in cancer treatment, the development of effective therapies remains an urgent unmet need. Here, we investigate the potential of bacteria-derived metabolites as a therapeutic alternative for the treatment of cancer. We detect 3-hydroxydodecanedioic acid in the serum of tumor-bearing mice treated with serum from mice previously supplemented with a mix of Clostridiales bacteria. Further, 3-hydroxydodecanoic acid, an intermediate derivative between dodecanoic and 3-hydroxydodecanedioic acids, exhibits a strong anti-tumor response via GPR84 receptor signaling and enhances CD8+ T cell infiltration and cytotoxicity within tumor tissue in multiple cancer models. Metabolomics analysis of colorectal cancer patient serum reveals an inverse correlation between the abundance of these metabolites and advanced disease stages. Our findings provide a strong rationale for 3-hydroxydodecanoic acid and the GPR84 receptor to be considered as promising therapeutic targets for cancer treatment.

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

Introduction

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

Methods

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

Results

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

Discussion

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

Research Status and Trends of Gut Microbiota and Intestinal Diseases Based on Bibliometrics

Gut microbiota plays an important role in gut health, and its dysbiosis is closely related to the pathogenesis of various intestinal diseases. The field of gut microbiota and intestinal diseases has not yet been systematically quantified through bibliometric methods. This study conducted bibliometric analysis to delineate the evolution of research on gut microbiota and intestinal diseases. Data were sourced from the Web of Science Core Collection database from 2009 to 2023 and were scientometrically analyzed using CiteSpace. We have found that the number of annual publications has been steadily increasing and showing an upward trend. China and the Chinese Academy of Sciences are the country and institution with the most contributions, respectively. Frontiers in Microbiology and Nutrients are the journals with the most publications, while Plos One and Nature are the journals with the most citations. The field has shifted from focusing on traditional descriptive analysis of gut microbiota composition to exploring the causal relationship between gut microbiota and intestinal diseases. The research hotspots and trends mainly include the correlation between specific intestinal diseases and gut microbiota diversity, the mechanism of gut microbiota involvement in intestinal diseases, the exploration of important gut microbiota related to intestinal diseases, and the relationship between gut microbiota and human gut health. This study provides a comprehensive knowledge map of gut microbiota and intestinal diseases, highlights key research areas, and outlines potential future directions.

Harnessing the human gut microbiota: an emerging frontier in combatting multidrug-resistant bacteria

Antimicrobial resistance (AMR) has become a major and escalating global health threat, undermining the effectiveness of current antibiotic and antimicrobial therapies. The rise of multidrug-resistant bacteria has led to increasingly difficult-to-treat infections, resulting in higher morbidity, mortality, and healthcare costs. Tackling this crisis requires the development of novel antimicrobial agents, optimization of current therapeutic strategies, and global initiatives in infection surveillance and control. Recent studies highlight the crucial role of the human gut microbiota in defending against AMR pathogens. A balanced microbiota protects the body through mechanisms such as colonization resistance, positioning it as a key ally in the fight against AMR. In contrast, gut dysbiosis disrupts this defense, thereby facilitating the persistence, colonization, and dissemination of resistant pathogens. This review will explore how gut microbiota influence drug-resistant bacterial infections, its involvement in various types of AMR-related infections, and the potential for novel microbiota-targeted therapies, such as fecal microbiota transplantation, prebiotics, probiotics, phage therapy. Elucidating the interactions between gut microbiota and AMR pathogens will provide critical insights for developing novel therapeutic strategies to prevent and treat AMR infections. While previous reviews have focused on the general impact of the microbiota on human health, this review will specifically look at the latest research on the interactions between the gut microbiota and the evolution and spread of AMR, highlighting potential therapeutic strategies.

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

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

In-depth profile of biosignatures for T2DM cohort utilizing an integrated targeted LC-MS platform

The profiling of metabolites provides an immediate snapshot that depicts crucial physiological information, holding immense potential for the early diagnosis and prognosis of diseases, including diabetes. Herein, we proposed an optimized and in-depth target-based metabolome platform through an integration of six distinct conditions, including a normal phase, a pre-column chemical derivatization and four reversed phase separation methods for the quantification of a total of 1609 small molecules (32 sub-classes) in serum after normalization using isotope-labeled internal standards. After undergoing rigorous methodological validation and comprehensive comparison with untargeted strategies, we present a new dataset of metabolomic profile encompassing a cohort of 200 healthy individuals and 100 newly diagnosed Type 2 diabetes mellitus (T2DM) patients from the northern region of China. The overall differential analysis results indicated obvious metabolic disturbance of amino acid, fatty acids, lysophosphatidyl-choline and triacylglycerol in T2DM. We hereby make these technical validation results and the profiling dataset publicly available to the scientific community, showcasing its exceptional sensitivity and robustness as an invaluable tool for the comprehensive targeted metabolome analysis.

Gut Microbiota and Metabolic Biomarkers Associated With Longevity

The dynamic balance between pro- and anti-inflammatory networks decreases as individuals age, and intestinal dysbiosis can initiate and maintain low-grade systemic inflammation. Interactions between the microbiota and humans occur from the beginning of life and, in general, the diversity of microbiota decreases with aging. The microbiome produces different metabolites with systemic effects, including immune system regulation. This understanding will be useful in controlling inflammation and preventing metabolic changes. Therefore, this review aims to identify the main metabolites synthesized by the intestinal microbiota to be used as biomarkers associated with longevity. This is a narrative review using scientific articles published in the last 10 years in the following databases: PubMed, Scielo, and Lilacs, using the Boolean operators "and" or "or." For this review, we identified 5 articles. The main metabolites described in the literature to date are organic acids, bile acids (BAs), short-chain fatty acids, branched-chain amino acids, trimethylamine N-oxide (TMAO), and derivatives of tryptophan and indole. Among these, the only ones not yet well characterized in studies on longevity were BAs and TMAO. Glutamate and p-cresol were also highlighted in the literature, with a negative association with longevity. The others showed an association, mostly positive, and can be used as potential biomarkers correlated with healthy aging and, if better studied, as targets for intervention to promote health and well-being.

Intestinal mucosal immunity and type 1 diabetes: Non-negligible communication between gut and pancreas

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by T cell-mediated pancreatic β cell loss, resulting in lifelong absolute insulin deficiency and hyperglycaemia. Environmental factors are recognized as a key contributor to the development of T1D, with the gut serving as a primary interface for environmental stimuli. Recent studies have revealed that the alterations in the intestinal microenvironment profoundly affect host immune responses, contributing to the aetiology and pathogenesis of T1D. However, the dominant intestinal immune cells and the underlying mechanisms remain incompletely elucidated. In this review, we provide an overview of the possible mechanisms of the intestinal mucosal system that underpin the pathogenesis of T1D, shedding light on the roles of both non-classical and classical immune cells in T1D. Our goal is to gain insights into how modulating these immune components may hold potential implications for T1D prevention and provide novel perspectives for immune-mediated therapy.

Genetically predicted inflammatory proteins mediate the association between gut microbiota and renal cell carcinoma

BACKGROUND

Studies have indicated a potential relationship between gut microbiota and renal cell carcinoma. However, the causal relationship between various types of gut microbiota and renal cell carcinoma, as well as the role of inflammatory protein as mediators, remains unclear.

METHODS

This study aimed to identify the relationship between gut microbiota, inflammatory protein, and renal cell cancer through a large-scale genome-wide association study (GWAS) utilizing pooled data. We employed Mendelian randomization (MR) to investigate the causal relationship among these variables. Inverse variance weighting (IVW) was utilized as the primary statistical method. Furthermore, we examined the mediating role of inflammatory protein in the pathway through which gut microbiota influences the development of renal cell cancer.

RESULTS

The analysis revealed 12 positive causal relationships and 15 negative causal relationships between the genetic liability of gut microbiota and renal cell cancer. Furthermore, there were three positive causal relationships and one negative causal relationship between inflammatory proteins and renal cell cancer. There were two axes of relationships in which gut microbiota promote the development of renal cell cancer. through inflammatory proteins acting as mediators.

CONCLUSIONS

Gut microbiota and inflammatory protein were causally related to renal cell cancer, and inflammatory protein were intermediary factors in the pathway between gut microbiota and renal cell cancer.

Transcriptomics and microbiome insights reveal the protective mechanism of mulberry-derived postbiotics against inflammation in LPS-induced mice

Background

Natural food-derived bioactive compounds have garnered increasing attention for their potential to modulate immune responses and promote gut health. In particular, compounds like mulberry-derived postbiotics (MDP) may offer novel therapeutic strategies to address inflammation, a key driver of many metabolic disorders.

Methodology

This study examines the protective effects of MDP against inflammation in LPS-induced mice, using transcriptomic and microbiome analyses to explore underlying mechanisms.

Results

MDP pretreatment alleviates LPSinduced villous atrophy and intestinal barrier damage, promoting recovery of intestinal morphology. Transcriptomic profiling revealed significant changes in gene expression, with 983 upregulated and 1220 downregulated genes in the NC vs LPS comparison, and 380 upregulated and 204 downregulated genes in the LPS vs LPS+MDP comparison. Enrichment analysis using GO and KEGG pathways revealed significant associations with transcriptional regulatory activity, and the NOD-like receptor signaling pathway among the differentially expressed genes. Protein-protein interaction analysis identified key genes involved in inflammation and immune regulation, with hub genes like IL6, CXCL10, and MYD88 in the LPS group and CD74, CIITA, and H2-AB1 in the MDP-treated group.

Conclusion

Microbiome analysis suggested MDP may also influence gut microbiota composition, supporting systemic immune regulation. These findings highlight MDP's potential as a food additive for immune modulation and gut health.

Perturbations of the endometrial immune microenvironment in endometriosis and adenomyosis: their impact on reproduction and pregnancy

The impact of endometriosis and adenomyosis on reproduction and pregnancy is significant, with both conditions linked to increased rates of infertility, poor ovarian function in women with endometriosis, and elevated pregnancy complications in those with adenomyosis. However, the underlying mechanisms remain largely unclear. Both conditions share a similar pathophysiological process characterized by the growth of ectopic endometrium, which may originate from the eutopic endometrium. Notably, surgical removal of ectopic lesions does not appear to significantly improve reproductive and pregnancy outcomes, further underscoring the importance of eutopic endometrium in these adverse effects. Emerging evidence indicates substantial differences in endometrial NK cells, macrophages, and T cells, leading to inflammatory responses in women with endometriosis and adenomyosis. These alterations may contribute not only to disease progression but also to defective endometrial receptivity, insufficient angiogenesis remodeling, impaired maternal-fetal immune tolerance, and poor placentation, thereby influencing embryo implantation and pregnancy maintenance. This provides an immunological perspective to explain the higher rates of infertility and pregnancy complications observed in affected women. Therefore, we systematically review the alterations in endometrial immune cells in women with endometriosis and adenomyosis compared to healthy controls, exploring the potential impacts of these changes on reproduction and pregnancy. This review aims to lay the groundwork for future studies on the immunopathogenesis associated with endometriosis and adenomyosis-related reproductive failure and pregnancy complications, shedding lights on the development of immunotherapeutic strategies to mitigate these adverse impacts in affected women.

Modulation of the Neuro-Cancer Connection by Metabolites of Gut Microbiota

The gut-brain-cancer axis represents a novel and intricate connection between the gut microbiota, neurobiology, and cancer progression. Recent advances have accentuated the significant role of gut microbiota metabolites in modulating systemic processes that influence both brain health and tumorigenesis. This paper explores the emerging concept of metabolite-mediated modulation within the gut-brain-cancer connection, focusing on key metabolites such as short-chain fatty acids (SCFAs), tryptophan derivatives, secondary bile acids, and lipopolysaccharides (LPS). While the gut microbiota's impact on immune regulation, neuroinflammation, and tumor development is well established, gaps remain in grasping how specific metabolites contribute to neuro-cancer interactions. We discuss novel metabolites with potential implications for neurobiology and cancer, such as indoles and polyamines, which have yet to be extensively studied. Furthermore, we review preclinical and clinical evidence linking gut dysbiosis, altered metabolite profiles, and brain tumors, showcasing limitations and research gaps, particularly in human longitudinal studies. Case studies investigating microbiota-based interventions, including dietary changes, fecal microbiota transplantation, and probiotics, demonstrate promise but also indicate hurdles in translating these findings to clinical cancer therapies. This paper concludes with a call for standardized multi-omics approaches and bi-directional research frameworks integrating microbiome, neuroscience, and oncology to develop personalized therapeutic strategies for neuro-cancer patients.

Early-life gut mycobiome core species modulate metabolic health in mice

The gut microbiome causally contributes to obesity; however, the role of fungi remains understudied. We previously identified three core species of the infant gut mycobiome (Rhodotorula mucilaginosa, Malassezia restricta and Candida albicans) that correlated with body mass index, however their causal contributions to obesity development are unknown. Here we show the effects of early-life colonization by these fungal species on metabolic health in gnotobiotic mice fed standard (SD) or high-fat-high-sucrose (HFHS) diets. Each species resulted in bacterial microbiome compositional and functional differences. R. mucilaginosa and M. restricta increased adiposity in mice fed SD, while only R. mucilaginosa exacerbated metabolic disease. In contrast, C. albicans resulted in leanness and resistance to diet-induced obesity. Intestinal nutrient transporter expression was unaffected by the presence of fungi in jejunal enteroids, yet the immune landscape in white adipose tissue was distinctly impacted by each fungal species, suggesting that these phenotypes may be a result of fungal immune regulation. This work revealed that three common fungal colonizers have distinct causal influences on obesity and metabolic inflammation and justifies the consideration of fungi in microbiome research on host metabolism.

The Inflammatory Mechanism of Parkinson's Disease: Gut Microbiota Metabolites Affect the Development of the Disease Through the Gut-Brain Axis

Parkinson's disease is recognized as the second most prevalent neurodegenerative disorder globally, with its incidence rate projected to increase alongside ongoing population growth. However, the precise etiology of Parkinson's disease remains elusive. This article explores the inflammatory mechanisms linking gut microbiota to Parkinson's disease, emphasizing alterations in gut microbiota and their metabolites that influence the disease's progression through the bidirectional transmission of inflammatory signals along the gut-brain axis. Building on this mechanistic framework, this article further discusses research methodologies and treatment strategies focused on gut microbiota metabolites, including metabolomics detection techniques, animal model investigations, and therapeutic approaches such as dietary interventions, probiotic treatments, and fecal transplantation. Ultimately, this article aims to elucidate the relationship between gut microbiota metabolites and the inflammatory mechanisms underlying Parkinson's disease, thereby paving the way for novel avenues in the research and treatment of this condition.

Gut microbiota and their metabolites in the immune response of rheumatoid arthritis: Therapeutic potential and future directions

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent joint inflammation, damage, and loss of function. In recent years, the role of gut microbiota and its metabolites in immune regulation has attracted increasing attention. The gut microbiota influences the host immune system's homeostasis through various mechanisms, regulating the differentiation, function, and immune tolerance of immune cells. Dysbiosis of the gut microbiota in RA patients is closely associated with abnormal activation of immune cells and excessive secretion of inflammatory cytokines. Metabolites produced by the gut microbiota, such as short-chain fatty acids (SCFAs), tryptophan metabolites, bile acids, and amino acid metabolites, play a critical role in immune responses, regulating the functions of immune cells like T cells, B cells, and macrophages, and inhibiting the release of pro-inflammatory cytokines. Restoring the balance of the gut microbiota and optimizing the production of metabolic products may become a new strategy for RA treatment. This review discusses the role of gut microbiota and its metabolites in the immune response of RA, exploring how they influence the immunopathological process of RA through the regulation of immune cells and key immune factors. It also provides a theoretical basis for future therapeutic strategies based on gut microbiota modulation.

Gut microbiota and atrial cardiomyopathy

Atrial cardiomyopathy is a multifaceted heart disease characterized by structural and functional abnormalities of the atria and is closely associated with atrial fibrillation and its complications. Its etiology involves a number of factors, including genetic, infectious, immunologic, and metabolic factors. Recent research has highlighted the critical role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, and this is consistent with the gut-heart axis having major implications for cardiac health. The aim of this work is to bridge the knowledge gap regarding the interactions between the gut microbiota and atrial cardiomyopathy, with a particular focus on elucidating the mechanisms by which gut dysbiosis may induce atrial remodeling and dysfunction. This article provides an overview of the role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, including changes in the composition of the gut microbiota and the effects of its metabolites. We also discuss how diet and exercise affect atrial cardiomyopathy by influencing the gut microbiota, as well as possible future therapeutic approaches targeting the gut-heart axis. A healthy gut microbiota can prevent disease, but ecological dysbiosis can lead to a variety of symptoms, including the induction of heart disease. We focus on the pathophysiological aspects of atrial cardiomyopathy, the impact of gut microbiota dysbiosis on atrial structure and function, and therapeutic strategies exploring modulation of the microbiota for the treatment of atrial cardiomyopathy. Finally, we discuss the role of gut microbiota in the treatment of atrial cardiomyopathy, including fecal microbiota transplantation and oral probiotics or prebiotics. Our study highlights the importance of gut microbiota homeostasis for cardiovascular health and suggests that targeted interventions on the gut microbiota may pave the way for innovative preventive and therapeutic strategies targeting atrial cardiomyopathy.

Navigating liver health with metabolomics: A comprehensive review

Non-alcoholic fatty liver disease (NAFLD) is the main cause of chronic liver disease worldwide, affecting one-fourth of the world's population. With more than half of the world's population, the Asia-Pacific region contributed 62.6 % of liver-related fatal incidents in 2015. Currently, liver imaging techniques such as computed tomography (CT), nuclear magnetic resonance (NMR) spectroscopy, and ultrasound are non-invasive imaging methods to diagnose the disease. A liver biopsy is the gold standard test for establishing the definite diagnosis of non-alcoholic steatohepatitis (NASH). However, there are still significant problems with sample variability and the procedure's invasiveness. Numerous studies have indicated various non-invasive biomarkers for both fibrosis and steatosis to counter the invasiveness of diagnostic procedures. Metabolomics could be a promising method for detecting early liver diseases, investigating pathophysiology, and developing drugs. Metabolomics, when utilized with other omics technologies, can result in a deeper understanding of biological systems. Metabolomics has emerged as a prominent research topic, offering extensive opportunities to investigate biomarkers for liver diseases that are both sensitive and specific. In this review, we have described the recent studies involving the use of a metabolomics approach in the diagnosis of liver diseases, which would be beneficial for the early detection and treatment of liver diseases.

Specific Composition Diets and Improvement of Symptoms of Immune-Mediated Inflammatory Diseases in Adulthood-Could the Comparison Between Diets Be Improved?

Diet is considered a possible cofactor, which affects the immune system and potentially causes dysregulation of intestinal homeostasis and inflammation. This study aimed to review the quality of evidence on the effects of specific diet composition on symptoms of immune-mediated inflammatory diseases (IMIDs), including rheumatoid arthritis (RA), spondyloarthritis, multiple sclerosis (MS), inflammatory bowel disease (IBD) [remission maintenance of Crohn's disease and ulcerative colitis], psoriasis and psoriatic arthritis in adult patients. We conducted a review of meta-analyses and Cochrane systematic reviews using PubMed and EMBASE, from inception to September 2024, and Google Scholar. The methodological quality of the meta-analyses was assessed using the AMSTAR 2 rating system. Three Cochrane systematic reviews and eight meta-analyses were evaluated. Some specific composition diets have been shown to reduce the symptoms of RA, IBD, and MS and improve activity parameters in IBD and RA, with critically low or low levels of evidence. The reduction in inflammatory biomarker levels is unclear. This review summarizes the global evidence for specific dietary interventions, mostly with anti-inflammatory properties due to their components, to improve IMID symptoms, clarifying the weaknesses of clinical trials and dietary meta-analyses with critically low or low levels of evidence; and shows the need to use indices such as the Dietary Inflammatory Index, which allows diets to be classified by their pro-inflammatory or anti-inflammatory food content, to better compare diet groups in clinical trials. The difficulty of obtaining high-level evidence from dietary studies is apparent and may delay the application of the results. Clinicians should be aware of the role of diets with anti-inflammatory properties as a complement to pharmacological treatments in IMIDs.

Short-Chain Fatty Acids: Promising Therapeutic Targets for Respiratory Syncytial Virus Infection

The intestinal microbiota is a complex community of organisms present in the human gastrointestinal tract, some of which can produce short-chain fatty acids (SCFAs) through the fermentation of dietary fiber. SCFAs play a major role in mediating the intestinal microbiota's regulation of host immunity and intestinal homeostasis. Respiratory syncytial virus (RSV) can cause an imbalance between anti-inflammatory and proinflammatory responses in the host. In addition, changes in SCFA levels and the structure of the intestinal microbiota have been observed after RSV infection. Therefore, there may be a link between SCFAs and RSV infection, and SCFAs are expected to be therapeutic targets for RSV infection.