The short-chain fatty acid pentanoate suppresses autoimmunity by modulating the metabolic-epigenetic crosstalk in lymphocytes

The impact of gut microbial short-chain fatty acids on colorectal cancer development and prevention

Cancer is a long-term illness that involves an imbalance in cellular and immune functions. It can be caused by a range of factors, including exposure to environmental carcinogens, poor diet, infections, and genetic alterations. Maintaining a healthy gut microbiome is crucial for overall health, and short-chain fatty acids (SCFAs) produced by gut microbiota play a vital role in this process. Recent research has established that alterations in the gut microbiome led to decreased production of SCFA's in lumen of the colon, which associated with changes in the intestinal epithelial barrier function, and immunity, are closely linked to colorectal cancer (CRC) development and its progression. SCFAs influence cancer progression by modifying epigenetic mechanisms such as DNA methylation, histone modifications, and non-coding RNA functions thereby affecting tumor initiation and metastasis. This suggests that restoring SCFA levels in colon through microbiota modulation could serve as an innovative strategy for CRC prevention and treatment. This review highlights the critical relationship between gut microbiota and CRC, emphasizing the potential of targeting SCFAs to enhance gut health and reduce CRC risk.

Advancements in the study of short-chain fatty acids and their therapeutic effects on atherosclerosis

Atherosclerosis (AS) remains a leading cause of cardiovascular disease and mortality globally. This chronic condition is characterized by inflammation, lipid accumulation, and the deposition of cellular components within arterial walls. Emerging evidence has highlighted the multifaceted therapeutic potential of short-chain fatty acids (SCFAs) in mitigating AS progression. SCFAs have demonstrated anti-inflammatory properties and the ability to regulate immune responses, metabolic pathways, vascular integrity, and intestinal barrier function in animal models of AS. Consequently, SCFAs have garnered significant attention as a promising approach for the prevention and treatment of AS. However, further clinical trials and studies are necessary to fully elucidate the underlying mechanisms and effects of SCFAs. Additionally, different types of SCFAs may exert distinct impacts, necessitating more in-depth investigation into their specific roles and mechanisms. This review provides an overview of the diverse cellular mechanisms contributing to AS formation, as well as a discussion of the significance of SCFAs in AS pathogenesis and their multifaceted therapeutic potential. Nonetheless, additional research is warranted to comprehensively understand and harness the potential of various SCFAs in the context of AS.

Progress of research on the gut microbiome and its metabolite short-chain fatty acids in postmenopausal osteoporosis: a literature review

Postmenopausal osteoporosis (PMOP) is a systemic metabolic bone disease caused by the decrease in estrogen levels after menopause. It leads to bone loss, microstructural damage, and an increased risk of fractures. Studies have found that the gut microbiota and its metabolites can regulate bone metabolism through the gut-bone axis and the gut-brain axis. As research progresses, PMOP has been found to be associated with gut microbiota dysbiosis and Th17/Treg imbalance. The gut microbiota is closely related to the development and differentiation of Treg and Th17 cells. Among them, the metabolites of the gut microbiota such as short-chain fatty acids (SCFAs) can regulate the differentiation of effector T cells by acting on molecular receptors on immune cells, thereby regulating the bone immune process. The multifaceted relationship among the gut microbiota, SCFAs, Th17/Treg cell-mediated bone immunity, and bone metabolism is eliciting attention from researchers. Through a review of existing literature, we have comprehensively summarized the effects of the gut microbiota and SCFAs on PMOP, especially from the perspective of Th17/Treg balance. Regulating this balance may provide new opportunities for PMOP treatment.

New insights into gut microbiota-prostate cancer crosstalk

Recent evidence underscores a reciprocal relationship between the gut microbiota and prostate cancer (PCa). Dysbiosis, often driven by Western dietary habits and antibiotic use, can heighten systemic inflammation and hinder antitumor immunity, thereby fostering PCa onset and progression. Conversely, certain gut microbes and their metabolites may protect against tumor growth by modulating immune and hormonal pathways that impact therapeutic responses, including androgen deprivation therapy (ADT). Emerging evidence links gut microbial shifts to PCa aggressiveness, potentially sustaining local androgen production and promoting resistance. In this review, we explore current understanding of the gut-PCa interplay, highlighting key knowledge gaps and the need for further research to clarify how targeting the microbiome might influence PCa outcomes.

Gut Microbiota Dysbiosis: Pathogenesis, Diseases, Prevention, and Therapy

Dysbiosis refers to the disruption of the gut microbiota balance and is the pathological basis of various diseases. The main pathogenic mechanisms include impaired intestinal mucosal barrier function, inflammation activation, immune dysregulation, and metabolic abnormalities. These mechanisms involve dysfunctions in the gut-brain axis, gut-liver axis, and others to cause broader effects. Although the association between diseases caused by dysbiosis has been extensively studied, many questions remain regarding the specific pathogenic mechanisms and treatment strategies. This review begins by examining the causes of gut microbiota dysbiosis and summarizes the potential mechanisms of representative diseases caused by microbiota imbalance. It integrates clinical evidence to explore preventive and therapeutic strategies targeting gut microbiota dysregulation, emphasizing the importance of understanding gut microbiota dysbiosis. Finally, we summarized the development of artificial intelligence (AI) in the gut microbiota research and suggested that it will play a critical role in future studies on gut dysbiosis. The research combining multiomics technologies and AI will further uncover the complex mechanisms of gut microbiota dysbiosis. It will drive the development of personalized treatment strategies.

Short-Chain Fatty Acids Modulate Anti-ROR1 CAR T-Cell Function and Exhaustion in an Intestinal Adenocarcinoma-on-Chip Model

Chimeric antigen receptor (CAR) T-cell therapy represents a promising approach for cancer treatment, with receptor tyrosine kinase-like orphan receptor 1 (ROR1) emerging as a novel target in malignancies. This study investigates how short-chain fatty acids (SCFAs), key microbiota-derived metabolites, modulate anti-ROR1 CAR T-cell efficacy using a physiologically relevant intestinal adenocarcinoma-on-chip model that replicates the human intestinal microenvironment. The findings demonstrate that propionate and butyrate inhibit anti-ROR1 CAR T-cell function by reducing infiltration, cytotoxicity, and cytokine release while preserving junctional integrity within the tumor model. Mechanistically, these SCFAs inhibit histone deacetylase activity and promote a phenotype switch toward regulatory T-cells, as indicated by increased expression of FoxP3 and RORγt. Additionally, propionate and butyrate upregulate PD-1 and TIM-3, markers of T-cell exhaustion and immune tolerance, and induce a dose- and time-dependent reduction in proinflammatory cytokines. In contrast, acetate and pentanoate promote a proinflammatory T helper 17 phenotype. These results highlight the immunomodulatory effects of SCFAs on CAR T-cell function, emphasizing the need to consider microbiota-derived metabolites in CAR T-cell therapies.

Physicochemical characterization and protective effects of raw and nine-steamed Polygonatum cyrtonema polysaccharides on cyclophosphamide-induced immunosuppression in mice

Polygonatum cyrtonema (PC) is a traditional Chinese herb used in both food and medicine with considerable bioactivity. The nine-steam processed pieces of PC are the main form of clinical application, while research has focused on the polysaccharide of their crude form. This study evaluated the physicochemical characteristics and protective effects of polysaccharides from both crude PC (PCP) and nine-steamed PC (NPCP) against cyclophosphamide (CTX)-induced immunosuppression. The findings indicate significant differences in the physicochemical characteristics of PCP and NPCP. The nine steaming treatments reduced the polysaccharide content by 8.15 %, and significantly altered monosaccharide proportion. Both polysaccharides accelerated the recovery of spleen and thymus indexes and restored the levels of TNF-α, IL-1β, IL-6, IgA, IgM, and IgG in the serum of CTX-treated mice in a dose-dependent manner as well as improved the morphology of spleen, thymus, and colon tissues. Furthermore, PCP and NPCP promoted the production of SCFAs and the recovery of intestinal flora in CTX-induced immunosuppressed mice. NPCP exhibited a better protective effect against CTX-induced immunosuppression. The results of this study confirm the importance of the nine-steaming method for PC and provide a basis for the further development of NPCP as a functional food to alleviate CTX-induced immunosuppression.

Metabolomic and functional analyses of small molecules secreted by intestinal nematodes in the activation of epithelial tuft cells

INTRODUCTION

Intestinal helminth parasites trigger the host immune response through epithelial sensory tuft cells, but helminth-derived molecules that may activate tuft cells are poorly characterized.

OBJECTIVES

The study aimed to identify small molecules released in vitro by two nematode parasites, that infect rodents (Nippostrongylus brasiliensis) and ruminants (Haemonchus contortus), and to test candidate ligands in an in vivo model of tuft cell differentiation.

METHODS

Small molecules were analyzed by hydrophilic interaction liquid chromatography (HILIC) of material released by adult parasites incubated in serum-free media, followed by mass spectrometry; selected molecules were administered to mice and tuft cell expansion enumerated after 5 days.

RESULTS

A range of different conditions (culture media, timing, oxygenation) were tested, and comparisons made between the conditions, and between the two nematode species at selected points. Common products across the conditions and species included carboxylic acids (malate, succinate), medium chain fatty acids (such as decanoic and undecanoic acids), purines (guanine, xanthine and their derivatives), and phosphocholine compounds. We selected 19 of the prominent molecules for in vivo testing by oral administration, including succinate, a known activator of tuft cell differentiation. Malate elicited a low but significant level of tuft cell expansion, while undecanoic acids with or without a bromine substitution were also able to induce significant differentiation comparable to succinate. Other molecules including phosphorylcholine had no effect.

CONCLUSION

Multiple molecular species including decanoic and undecanoic acids released by helminths may contribute to activation of tuft cells in vivo.

Microbiota-Driven Mechanisms in Multiple Sclerosis: Pathogenesis, Therapeutic Strategies, and Biomarker Potential

Multiple sclerosis (MS) is a well-known, chronic autoimmune disorder of the central nervous system (CNS) involving demyelination and neurodegeneration. Research previously conducted in the area of the gut microbiome has highlighted it as a critical contributor to MS pathogenesis. Changes in the commensal microbiota, or dysbiosis, have been shown to affect immune homeostasis, leading to elevated levels of pro-inflammatory cytokines and disruption of the gut-brain axis. In this review, we provide a comprehensive overview of interactions between the gut microbiota and MS, especially focusing on the immunomodulatory actions of microbiota, such as influencing T-cell balance and control of metabolites, e.g., short-chain fatty acids. Various microbial taxa (e.g., Prevotella and Faecalibacterium) were suggested to lay protective roles, whereas Akkermansia muciniphila was associated with disease aggravation. Interventions focusing on microbiota, including probiotics, prebiotics, fecal microbiota transplantation (FMT), and dietary therapies to normalize gut microbial homeostasis, suppress inflammation and are proven to improve clinical benefits in MS patients. Alterations in gut microbiota represent opportunities for identifying biomarkers for early diagnosis, disease progression and treatment response monitoring. Further studies need to be conducted to potentially address the interplay between genetic predispositions, environmental cues, and microbiota composition to get the precise mechanisms of the gut-brain axis in MS. In conclusion, the gut microbiota plays a central role in MS pathogenesis and offers potential for novel therapeutic approaches, providing a promising avenue for improving clinical outcomes in MS management.

MultiOmics analysis of metabolic dysregulation and immune features in breast cancer

Metabolic disorders and diminished immune response are hallmark characteristics of tumors. However, limited studies have comprehensively integrated metabolic and immunological factors to evaluate or predict the prognosis of cancer patients. In this study, we utilized 72 metabolic pathway gene sets from the MsigDB database to conduct GSVA, univariate regression, and prognostic analyses on 247 breast cancer samples sourced from the TCGA and GEO databases. Consequently, five metabolic pathways with significant research value were identified. Based on these findings, unsupervised clustering was performed on the breast cancer samples to compare differences in gene expression, clinicopathological features, immune infiltration levels, and prognosis across different clusters. This process led to the identification of nine metabolism-related characteristic genes. Additionally, single-cell sequencing analysis was employed to assess the spatial expression patterns of these characteristic genes, revealing significantly higher expression indices in tumor cells compared to non-tumor cells. Subsequently, machine learning algorithms were applied to reconstruct metabolic risk models for evaluating the prognosis of breast cancer patients. The results indicated that the high metabolic risk group exhibited higher gene mutation scores, a greater proportion of unfavorable clinicopathological parameters, and lower chemokine and immune scores compared to the low-risk group. In conclusion, the metabolic risk model constructed using metabolism-related characteristic genes can accurately distinguish and predict the survival prognosis and immunotherapy outcomes of breast cancer patients, offering novel targets and insights for personalized treatment strategies.

The microbiota-m6A-metabolism axis: Implications for therapeutic strategies in gastrointestinal cancers

Gastrointestinal (GI) cancers remain a leading cause of cancer-related mortality worldwide, with metabolic reprogramming recognized as a central driver of tumor progression and therapeutic resistance. Among the key regulatory layers, N6-methyladenosine (m6A) RNA modification-mediated by methyltransferases (writers such as METTL3/14), RNA-binding proteins (readers like YTHDFs and IGF2BPs), and demethylases (erasers including FTO and ALKBH5), plays a pivotal role in controlling gene expression and metabolic flux in the tumor context. Concurrently, the gut microbiota profoundly influences GI tumorigenesis and immune evasion by modulating metabolite availability and remodeling the tumor microenvironment. Recent evidence has uncovered a bidirectional crosstalk between microbial metabolites and m6A methylation: microbiota-derived signals dynamically regulate m6A deposition on metabolic and immune transcripts, while m6A modifications, in turn, regulate the stability and translation of key mRNAs such as PD-L1 and FOXP3. This reciprocal interaction forms self-reinforcing epigenetic circuits that drive tumor plasticity, immune escape, and metabolic adaptation. In this review, we dissect the molecular underpinnings of the microbiota-m6A-metabolism axis in GI cancers and explore its potential to inform novel strategies in immunotherapy, metabolic intervention, and microbiome-guided precision oncology.

Low-protein diet supplemented with isomalto-oligosaccharide reduces diarrhea rate of weaned piglets by regulating intestinal function

Excess protein in infant formula can harm the health of infants. Isomalto-oligosaccharide (IMO), a prebiotic, can be incorporated into infant formula. This study employed weaned piglets as a model to establish varying protein levels, investigating the impact of IMO in low-protein diets on the intestinal health. A total of 192 weaned piglets were randomly assigned to four groups, with each group containing six pens of eight piglets each. The control group was fed a diet containing 19% crude protein (CP), while the other three experimental groups were supplemented with 0.2% IMO, with CP levels of 19%, 18%, and 17%, respectively. The experiment lasted 28 days, with one piglet from each pen slaughtered at the end. There were no differences in growth performance among the groups. Nonetheless, the diarrhea rate in an 18% protein diet supplemented with IMO (18CP + IMO group) was reduced during d1-21 and 1-28 (p < 0.05). The diarrhea rate and the apparent total tract digestibility (ATTD) of acid detergent fiber (ADF) showed a quadratic correlation (p < 0.05). Meanwhile, 18CP + IMO group showed that the ATTD of dry matter and ADF increased (p < 0.05); the crypt depth of the jejunum decreased (p < 0.05), while the expression of intestinal barrier (ZO-1) and intestinal development (CDX2) related genes increased (p < 0.05); the abundance of beneficial bacteria (Bifidobacterium) increased (p = 0.06). Compared with 19CP group, the other three groups had lower contents of indole and skatole (p < 0.05). Our results showed that supplementing an 18% CP diet with 0.2% IMO decreased diarrhea incidence in weaned piglets, enhanced nutrient digestibility, intestinal barrier and microbiota, and reduced harmful metabolite production.

Role of the microbiome in regulation of the immune system

Immune health and metabolic functions are intimately connected via diet and the microbiota. Immune cells are continuously exposed to a wide range of microbes and microbial-derived compounds, with important mucosal and systemic ramifications. Microbial fermentation of dietary components in vivo generates thousands of molecules, some of which are integral components of the molecular circuitry that regulates immune and metabolic functions. These in turn protect against aberrant inflammatory or hyper-reactive processes and promote effector immune responses that quickly eliminate pathogens, such as SARS-CoV-2. Potent tolerance mechanisms should ensure that these immune cells do not over-react to non-pathogenic factors (e.g. food proteins), while maintaining the ability to respond to infectious challenges in a robust, effective and well controlled manner. In this review we examine the factors and mechanisms that shape microbiota composition and interactions with the host immune system, their associations with immune mediated disorders and strategies for intervention.

Unveiling the Mystery of the Stimulatory Effects of Arecoline: Its Relevance to the Regulation of Neurotransmitters and the Microecosystem in Multi-Ecological Intestinal Sites

The dried ripe seeds and pericarp of Areca catechu L., a palm species, possess significant economic value. Masticating betel nut is also a long-standing and widely prevalent lifestyle habit rooted in history, known for its stimulating effect. This effect stems primarily from arecoline, the principal active compound in betel nut. This study investigates the potential mechanisms underlying the stimulating effects of arecoline, focusing on neurotransmitters, neurotrophic factors, and the microecosystem in multi-ecological intestinal sites. After arecoline intervention in mice, significant changes were observed in locomotor activity. The levels of dopamine (DA) in liver tissue and 5-hydroxytryptamine (5-HT) in brain tissue were significantly reduced. There was a significant increase in microbial activity in the feces and in the level of n-valeric acid in the intestinal content. At the genus level, the relative abundance of Clostridium was significantly reduced, whereas the relative abundances of Helicobacter and Aquincola were markedly increased. Helicobacter, Aquincola, Faecalibaculum, and Liquorilactobacillus were signature genera in the arecoline-treated group. The 5-HT level was significantly negatively correlated with the abundance of the signature genera Aquincola, Helicobacter, and Liquorilactobacillus in the arecoline group. The ingestion of arecoline can alter the behavioral patterns of mice, causing significant changes in the 5-HT levels in brain tissue and exerting regulatory effects on the microecosystem in multi-ecological intestinal sites. These findings will provide a reference for the future development and utilization of betel nut.

Comparative Analysis of Short-Chain Fatty Acids and the Immune Barrier in Cecum of Dahe Pigs and Dahe Black Pigs

The intestinal immune barrier is a developed and complex immune system, and there is a fine synergy between it and the induced immune response. Short-chain fatty acids (SCFAs) are the main metabolites of intestinal microbial fermentation. In the cecum of pigs, SCFAs not only provide energy for the host but also participate in regulating the function of the intestinal immune system. The purpose of this study was to explore the mechanism of SCFAs in the regulation of immune gene expression in porcine cecum. SCFAs content and mRNA expression levels of immune genes in cecum were detected, and Gene Ontology (GO) function annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, Protein-Protein Interaction Networks (PPI) network construction, key gene identification, and correlation analysis were performed. The results showed that the content of SCFAs in the cecum of Dahe black pigs (DHB) was lower than that of Dahe pigs (DH). There were significant differences in mRNA expression of some immune genes between the two groups. GO functional annotation found terms related to cytokine activity and protein heterodimerization activity; the KEGG pathway was enriched in several pathways related to intestinal immunity. The PPI network identified Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), Interleukin-17A (IL-17A), and Interleukin-18 (IL-18) as key proteins. The correlation analysis showed that acetic acid and valerate were closely related to the immune response. In this study, the differences in cecal short-chain fatty acids and the immune barrier between Dahe pigs and Dahe black pigs were compared, which provided a theoretical basis for improving the intestinal immunity of pigs.

Oral probiotic extracellular vesicle therapy mitigates Influenza A Virus infection via blunting IL-17 signaling

The influenza A virus (IAV) damages intestinal mucosal tissues beyond the respiratory tract. Probiotics play a crucial role in maintaining the balance and stability of the intestinal microecosystem. Extracellular vesicles (EVs) derived from probiotics have emerged as potential mediators of host immune response and anti-inflammatory effect. However, the specific anti-inflammatory effects and underlying mechanisms of probiotics-derived EVs on IAV remain unclear. In the present study, we investigated the therapeutic efficacy of Lactobacillus reuteri EHA2-derived EVs (LrEVs) in a mouse model of IAV infection. Oral LrEVs were distributed in the liver, lungs, and gastrointestinal tract. In mice infected with IAV, oral LrEVs administration alleviated IAV-induced damages in the lungs and intestines, modified the microbiota compositions, and increased the levels of short-chain fatty acids in those organs. Mechanistically, LrEVs exerted their protective effects against IAV infection by blunting the pro-inflammatory IL-17 signaling. Furthermore, FISH analysis detected miR-4239, one of the most abundant miRNAs in LrEVs, in both lung and intestinal tissues. We confirmed that miR-4239 directly targets IL-17a. Our findings paved the ground for future application of LrEVs in influenza treatment and offered new mechanistic insights regarding the anti-inflammatory role of miR-4239.

B cell immunometabolism in health and disease

B cells have crucial roles in the initiation and progression of many pathological conditions, and several therapeutic strategies have targeted the function of these cells. The advent of immunometabolism has provided compelling evidence that the metabolic reprogramming of immune cells can dramatically alter physiopathological immune activities. A better knowledge of the metabolic profiles of B cells can provide valuable means for developing therapies tuning defined cell pathways. Here we review the cellular and molecular mechanisms by which immunometabolism controls the physiology and pathophysiology of B cells and discuss the experimental evidence linking B cell metabolism to health, autoimmunity, and cancer. Considering that several metabolic pathways in B cells are involved differently, or even in opposite ways, in health and disease, we discuss how targeted modulation of B cell immunometabolism could be exploited mechanistically to rebalance abnormal B cell functions that have become altered in disease states.

Antibiotic-induced loss of gut microbiome metabolic output correlates with clinical responses to CAR T-cell therapy

ABSTRACT

Antibiotic (ABX)-induced microbiome dysbiosis is widespread in oncology, adversely affecting outcomes and side effects of various cancer treatments, including immune checkpoint inhibitors and chimeric antigen receptor T-cell (CAR-T) therapies. In this study, we observed that prior exposure to broad-spectrum ABXs with extended anaerobic coverage such as piperacillin-tazobactam and meropenem was associated with worse anti-CD19 CAR-T therapy survival outcomes in patients with large B-cell lymphoma (N = 422) than other ABX classes. In a discovery subset of these patients (n = 67), we found that the use of these ABXs was in turn associated with substantial dysbiosis of gut microbiome function, resulting in significant alterations of the gut and blood metabolome, including microbial effectors such as short-chain fatty acids (SCFAs) and other anionic metabolites, findings that were largely reproduced in an external validation cohort (n = 58). Broader evaluation of circulating microbial metabolites revealed reductions in indole and cresol derivatives, as well as trimethylamine N-oxide, in patients who received ABX treatment (discovery, n = 40; validation, n = 28). These findings were recapitulated in an immune-competent CAR-T mouse model, in which meropenem-induced dysbiosis led to a systemic dysmetabolome and decreased murine anti-CD19 CAR-T efficacy. Furthermore, we demonstrate that SCFAs can enhance the metabolic fitness of CAR-Ts, leading to improved tumor killing capacity. Together, these results suggest that broad-spectrum ABX deplete metabolically active commensals whose metabolites are essential for enhancing CAR-T efficacy, shedding light on the intricate relationship between ABX exposure, microbiome function and their impact on CAR-T efficacy. This highlights the potential for modulating the microbiome to augment CAR-T immunotherapy. This trial was registered at www.clinicaltrials.gov as #NCT06218602.

Perturbations in gut microbiota composition in patients with autoimmune neurological diseases: a systematic review and meta-analysis

Studies suggest that gut dysbiosis occurs in autoimmune neurological diseases, but a comprehensive synthesis of the evidence is lacking. Our aim was to systematically review and meta-analyze the correlation between the gut microbiota and autoimmune neurological disorders to inform clinical diagnosis and therapeutic intervention. We searched the databases of PubMed, Embase, Web of Science, and the Cochrane Library until 1 March 2024 for research on the correlation between gut microbiota and autoimmune neurological disorders. A total of 62 studies provided data and were included in the analysis (n = 3,126 patients, n = 2,843 healthy individuals). Among the included studies, 42 studies provided data on α-diversity. Regarding α-diversity, except for Chao1, which showed a consistent small decrease (SMD = -0.26, 95% CI = -0.45 to -0.07, p < 0.01), other indices demonstrated no significant changes. While most studies reported significant differences in β-diversity, consistent differences were only observed in neuromyelitis optica spectrum disorders. A decrease in short-chain fatty acid (SCFA)-producing bacteria, including Faecalibacterium and Roseburia, was observed in individuals with autoimmune encephalitis, neuromyelitis optica spectrum disorders, myasthenia gravis, and multiple sclerosis. Conversely, an increase in pathogenic or opportunistic pathogens, including Streptococcus and Escherichia-Shigella, was observed in these patients. Subgroup analyses assessed the confounding effects of geography and immunotherapy use. These findings suggest that disturbances of the gut flora are associated with autoimmune neurological diseases, primarily manifesting as non-specific and shared microbial alterations, including a reduction in SCFA-producing bacteria and an increase in pathogenic or opportunistic pathogens.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023410215.

Metabolization of microbial postbiotic pentanoate drives anti-cancer CAR T cells

The microbiome is a complex host factor and key determinant of the outcome of antibody-based and cellular immunotherapy. Its postbiotics are a blend of soluble commensal byproducts that are released into the host environment and have been associated with the regulation of immune homeostasis, particularly through impacts on epigenetics and cell signaling. In this study, we show that the postbiotic pentanoate is metabolized to citrate within the TCA cycle via both the acetyl- and succinyl-CoA entry points, a feature uniquely enabled by the chemical structure of the C5 aliphatic chain. We identified ATP-citrate lyase as the crucial factor that redirects pentanoate-derived citrate from the succinyl-CoA route to the nucleus, thereby linking metabolic output and histone acetylation. This epigenetic-metabolic crosstalk mitigated T cell exhaustion and promoted naive-like differentiation in pentanoate-programmed chimeric antigen receptor (CAR) T cells. The predictive and therapeutic potential of pentanoate was corroborated in two independent patient cohorts and three syngeneic models of CAR T adoptive therapy. Our data demonstrate that postbiotics are integrated into mitochondrial metabolism and subsequently incorporated as epigenetic imprints. This bridge between microbial and mammalian interspecies communication can ultimately impact T cell differentiation and efficacy.

Transcription Factor Blimp-1: A Central Regulator of Oxidative Stress and Metabolic Reprogramming in Chronic Inflammatory Diseases

B-lymphocyte-induced maturation protein 1 (Blimp-1) is a transcription factor that, among other functions, modulates metabolism and helps to regulate antioxidant pathways, which is important in the context of chronic inflammatory diseases like diabetes, cardiovascular disease, and autoimmune disease. In immune cell function, Blimp-1 has a modulatory role in the orchestration of metabolic reprogramming and as a promoter of anti-inflammatory cytokines, including IL-10, responsible for modulating oxidative stress and immune homeostasis. Moreover, Blimp-1 also modulates key metabolic aspects, such as glycolysis and fatty acid oxidation, which regulate reactive oxygen species levels, as well as tissue protection. This review depicts Blimp-1 as an important regulator of antioxidant defenses and anti-inflammation and suggests that the protein could serve as a therapeutic target in chronic inflammatory and metabolic dysregulation conditions. The modulation of Blimp-1 in diseases such as diabetic coronary heart disease and atherosclerosis could alleviate oxidative stress, augment the protection of tissues, and improve disease outcomes. The therapeutic potential for the development of new treatments for these chronic conditions lies in the synergy between the regulation of Blimp-1 and antioxidant therapies, which are future directions that may be pursued. This review emphasizes Blimp-1's emerging importance as a novel regulator in the pathogenesis of inflammatory diseases, providing new opportunities for therapeutic intervention.

Lipids in Clinical Nutrition and Health: Narrative Review and Dietary Recommendations

Lipids are essential components of human health, serving as critical structural elements of cell membranes, energy sources, and precursors for bioactive molecules. This narrative review aims to examine the multifaceted roles of lipids in clinical nutrition and health, focusing on their impact on chronic disease prevention, management, and the potential of lipid-based therapies. A narrative review was conducted utilizing Scopus, Google Scholar, and Web of Science databases. Key terms such as lipids, dietary fats, and cholesterol were used to identify and analyze relevant studies. A total of 145 articles meeting inclusion criteria were reviewed for their insights into lipid metabolism, dietary sources, and clinical implications. The analysis highlighted the metabolic significance of various lipid classes-saturated, monounsaturated, and polyunsaturated fatty acids-along with evidence-based recommendations for their dietary intake. Lipids were shown to play a pivotal role in managing chronic diseases such as cardiovascular disease, obesity, and metabolic syndrome. Emerging therapies, including omega-3 fatty acids and medium-chain triglycerides, demonstrated potential benefits in clinical practice. By synthesizing current knowledge, this narrative review provides healthcare professionals with an updated understanding of the roles of lipids in clinical nutrition. The findings emphasize the importance of tailored dietary interventions and lipid-based therapies in optimizing health and managing chronic diseases effectively. Additionally, this review successfully presents practical dietary recommendations to guide clinical practice.

Dissecting the metabolic signaling pathways by which microbial molecules drive the differentiation of regulatory B cells

The host-microbiome axis has been implicated in promoting anti-inflammatory immune responses. Yet, the underlying molecular mechanisms of commensal-mediated IL-10 production by regulatory B cells (Bregs) are not fully elucidated. Here, we demonstrate that bacterial CpG motifs trigger the signaling downstream of TLR9 promoting IκBNS-mediated expression of Blimp-1, a transcription regulator of IL-10. Surprisingly, this effect was counteracted by the NF-κB transcription factor c-Rel. A functional screen for intestinal bacterial species identified the commensal Clostridium sporogenes, secreting high amounts of short-chain fatty acids (SCFAs) and branched-chain fatty acids (BCFAs), as an amplifier of IL-10 production by promoting sustained mTOR signaling in B cells. Consequently, enhanced Breg functionality was achieved by combining CpG with the SCFA butyrate or the BCFA isovalerate thereby synergizing TLR- and mTOR-mediated pathways. Collectively, Bregs required two bacterial signals (butyrate and CpG) to elicit their full suppressive capacity and ameliorate T cell-mediated intestinal inflammation. Our study has dissected the molecular pathways induced by bacterial factors, which might contribute not only to better understanding of host-microbiome interactions, but also to exploration of new strategies for improvement of anti-inflammatory cellular therapy.

Observational study protocol: the faecal microbiome in the acute stage of new-onset paediatric type 1 diabetes in an Irish cohort

INTRODUCTION

Type 1 diabetes (T1D) is an autoimmune-mediated disorder caused by the destruction of pancreatic beta cells. Although there is an underlying genetic predisposition to developing T1D, the trigger is multifactorial and likely includes environmental factors. The intestinal microbiome has been identified as one such factor. Previous studies have illustrated differences in the microbiota of people with T1D compared with healthy controls. This study aims to describe the evolution of the microbiome and metabolome during the first year of clinical T1D, or stage 3 T1D diagnosis, and investigate whether there are differences in the microbiome and metabolome of children who present with and without diabetic ketoacidosis. The study will also explore possible associations between the microbiome, metabolome, glycaemic control and beta cell reserve.

METHODS AND ANALYSIS

This prospective cohort study will include children with newly diagnosed T1D and sibling controls (n=100, males and females) and their faecal microbiome will be characterised using shotgun metagenomic sequencing at multiple time points during the first year of diagnosis. We will develop a microbial culture biobank based on culturomic studies of stool samples from the healthy controls that will support future investigation. Metabolomic analysis will aim to identify additional biomarkers which may be involved in disease presentation and progression. Through this initial exploratory study, we aim to identify specific microbial biomarkers which may be used as future interventional targets throughout the various stages of T1D progression.

ETHICS AND DISSEMINATION

This study has been approved by the Clinical Research Ethics Committee of the Cork Teaching Hospitals. Study results will be available to patients with T1D and their families, carers, support networks and microbiome societies and other researchers.

TRIAL REGISTRATION NUMBER

The clinicaltrials.gov registration number for this trial is NCT06157736.

Metabolic changes during evolution of Sjögren's in both an animal model and human patients

Sjögren's (SS) involves salivary and lacrimal gland dysfunction. These studies examined metabolic profiles in the B6. Il14α transgene mouse model of SS and a cohort of human SS patients at different stages of disease. In B6. Il14α mice, products of glucose and fatty acid were common at 6 months of age, while products of amino acid metabolism were common at 12 months of age. Treating B6. Il14α mice with the glycolysis inhibitor 2-deoxyglucose from 6 to 10 months of age normalized salivary gland secretions, dacryoadenitis, hypergammaglobulinemia and physical performance, while treatment from 10 to 14 months of age failed to improve any of the clinical manifestations. Similarly, SS patients at an early stage of disease showed high glycolysis. SS patients with long-standing disease utilized predominantly amino acid metabolism, like B6. Il14α mice at 10-12 months of age. Additional studies are suggested to further define metabolic activities at the various disease stages.

Th17/Treg balance is regulated during the suppression of experimental autoimmune encephalomyelitis treated by Astragalus polysaccharides via the microbiota-gut-brain axis

The Th17/Treg imbalance is an important cause of immune cell infiltration into the central nervous system (CNS) in multiple sclerosis (MS). The gut microbiota affects the Th17/Treg balance in the gut and in distal areas, such as the CNS, which further contributes to the onset and progression of MS. Our previous studies have shown that Astragalus polysaccharide (APS) has a role in alleviating the clinical symptoms and demyelination of experimental autoimmune encephalomyelitis (EAE) mice, a classic MS model. However, the mechanism of action is not fully understood. In this study, we found that APS suppressed inflammation and regulated the Th17/Treg balance in the CNS and peripheral blood of EAE mice. It was further shown that APS inhibited gut inflammation and reduced Th17 function. The experiment with an antibiotic cocktail interfering with the gut microbiota proved that APS alleviated EAE by regulating the gut microbiota. Through 16S rRNA sequencing, we showed that APS regulated gut microbiota diversity and composition in EAE mice. Then, we found that APS regulated metabolite composition in feces and plasma, thus altering gut and blood metabolic functions. Metabolites related to this pathway, including sphingosine 1 phosphate (S1P), prostaglandin E2 (PGE2), ADP, and ATP, were downregulated by APS. The levels of bile acid metabolites such as taurochenodeoxycholate-7-sulfate and N-palmitoyl aspartic acid were upregulated by APS. In summary, our study demonstrated that APS exerts a suppressive effect on EAE by regulating gut microbiota composition, affecting metabolite composition, and improving the Th17/Treg balance in the peripheral blood and CNS.

Rosavin derived from Rhodiola alleviates colitis in mice through modulation of Th17 differentiation

BACKGROUND

Rosavin (RSV) is a naturally occurring compound isolated from Rhodiola species. While RSV has been reported with pharmacological activities of anti-oxidation, anti-inflammation, anti-stress and immunomodulation, its effect on colitis and the underlying mechanisms remain unclear.

PURPOSE

This study aims to investigate whether and how RSV alleviated colitis in mice.

STUDY DESIGN AND METHODS

The protective effect of RSV (50, 100, 200 mg/kg, p.o.) was investigated in dextran sulfate sodium (DSS) mediated mouse models of acute and chronic colitis. Alterations in fecal microbiota were evaluated by 16S rRNA sequencing. Pseudo germ-free mice achieved by antibiotics treatment were applied to assess the RSV-mediated functional role of gut microbiota in colitis. RNA sequencing was performed to determine RSV-induced colonic response. Primary T cell culture was conducted to examine the effect of RSV on Th17 and Treg differentiation. Whole blood assay, dual luciferase reporter assay, and molecular docking methods were applied to investigate the mechanisms and targets of RSV in Th17 regulation.

RESULTS

Oral RSV significantly relieved DSS-mediated acute and chronic colitis in mice, which recovered body weight loss, reduced disease activity index, alleviated colon injury, inhibited inflammation, suppressed the apoptosis of intestinal epithelia, and maintained intestinal barrier function. Moreover, RSV specifically regulated intestinal microbiota by recovering DSS-mediated microbial changes and elevating beneficial microbes such as Lactobacillus and Akkermansia. Antibiotics treatment experiment showed that the protective role of RSV was at least partially dependent on gut microbiota; however, in vitro incubation showed that RSV did not directly promote the growth of Lactobacillus and Akkermansia strains. Further analysis showed that RSV-mediated genetic alterations in colon were enriched in pathways related to lymphocyte regulation. Additionally, RSV regulated the balance of Th17/Treg in colitis mice. Importantly, RSV inhibited the differentiation of Th17 cell in vitro, suppressed the production of IL-17 by Th17 cells, and downregulated Rorc encoding RORγt and its downstream Il17. RSV significantly inhibited the RORγt transcription activity and bound to its ligand binding domain.

CONCLUSION

RSV alleviates murine colitis through regulating intestinal immunity. Notably, RSV is identified as a novel regulator of Th17 cells that inhibits RORγt-mediated Th17 differentiation. These findings potentiate the Rhodiola-derived natural chemicals as novel anti-colitis agents.

The cross-talk between the metabolome and microbiome in a double-hit neonatal rat model of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD), a chronic lung disease in preterm infants, is associated with inflammation and high oxygen exposure. However, the effects of antenatal inflammation and postnatal extended hyperoxia on the metabolome and microbiome remain unclear. In this study, pregnant rats received lipopolysaccharide or saline injections on gestational day 20 and were exposed to either 21 % or 80 % oxygen for 4 weeks post-birth. Analysis revealed an increase in Firmicutes, Proteobacteria, and Actinobacteria, with a decrease in Bacteroidetes in BPD rats. Metabolomic analysis identified 78 altered metabolites, primarily lipids, enriched in pathways including arginine biosynthesis, sphingolipid metabolism, and primary bile acid biosynthesis in BPD rats. Integration analysis revealed strong correlations between intestinal microbiota and metabolites in BPD rats. These findings underscored the impact of antenatal inflammation and prolonged postnatal hyperoxia on gut microbiota and serum metabolome, suggesting their role in BPD pathogenesis.

The effect of microbial metabolites from colonic protein fermentation on bacteria-induced cytokine production in dendritic cells

Compared to the well-defined immune-modulating effect of butyrate, the understanding of the effect of other protein fermentation metabolites is limited. This study aimed to investigate the impact of protein-derived metabolites (valerate, branched-chain fatty acids, ammonium, phenol, p-Cresol, indole, and hydrogen sulfide) on cytokine production in murine bone marrow-derived dendritic cells (BMDCs) stimulated with lipopolysaccharides (LPS), Lactobacillus acidophilus NCFM, or Staphylococcus aureus USA300. Some of the metabolites, but not the short-chain fatty acids (SCFAs), strongly affected cell viability. After short-term treatment and depending on the microbial stimulus, SCFAs affected the cytokine profile similarly but weaker than butyrate, as reflected by inhibition of IL-12p70 and IL-10 but enhanced IL-23 (LPS and S. aureus USA300) and IL-1β production. Compared to butyrate, valerate exhibited a weaker and slower effect on cytokine expression. Two-day treatment with valerate and butyrate resulted in similar effects, that is, LPS-induced IL-12 abrogation and IL-10 enhancement, increased aryl hydrocarbon receptor (Ahr) expression, and after LPS stimulation, increased expression of dual specificity phosphatase 1 (Dusp1). In conclusion, SCFAs exhibited low toxicity and modulated microbially stimulated BMDCs. Valerate and butyrate showed the strongest effect, which was dependent on the specific microbial stimulation and the course of the SCFA treatment. Our work adds knowledge regarding the role of protein-derived metabolites from gut bacterial fermentation on the immune system.

Distinct gut microbial signature and altered short chain fatty acid metabolism at disease onset in a rat preclinical model of superimposed preeclampsia

Chronic hypertension is an increasingly prevalent condition that constitutes a risk factor for superimposed preeclampsia during pregnancy. In this study, we assessed the gut microbiome in a rat model of superimposed preeclampsia to characterize the microbial signature associated with defective placentation processes identified at the preclinical disease stage. The blood pressure profile, renal function parameters and fetal phenotype were evaluated in pregnant Stroke-prone Spontaneously Hypertensive Rats (SHRSP) and their normotensive controls. On gestation day (GD)14, feces were collected and gut microbiome composition and short-chain fatty acid concentrations were determined by 16S rRNA sequencing and gas chromatography respectively. At disease onset on GD14, the fecal gut microbiome of SHRSP showed a lower alpha diversity and significant differences in beta diversity when compared with control animals. In the feces, Prevotella, Bifidobacterium, Parasutterella and Roseburia were enriched in SHRSP pregnancies compared to controls, showing a strong correlation with clinical parameters. Bacteria from the families Ruminococcaceae, Oscillospiraceae and the genera Blautia and Faecalibacterium were depleted. Considering short-chain fatty acids, acetate, propionate and valerate were increased in the SHRSP model, showing a strong positive correlation with the relative abundance of enriched taxa. We show that on GD14, at the asymptomatic SPE onset stage, pregnant SHRSP display a distinct gut microbiome signature and altered short chain fatty acid metabolism compared to control animals.

Green Radish Polysaccharides Ameliorate Hyperlipidemia in High-Fat-Diet-Induced Mice via Short-Chain Fatty Acids Production and Gut Microbiota Regulation

The objective of this study was to examine the hypolipidemic effect and potential mechanism of action of green radish polysaccharide (GRP) in hyperlipidemic mice. We found that in mice fed a high-fat diet, supplementing with GRP reduced body weight and liver index, significantly improved serum lipid levels and markers of liver damage, and mitigated oxidative stress and inflammation. Mechanistically, in these hyperlipidemic mice, the size of fat cells was reduced by GRP, and the abnormal accumulation of lipid droplets was reduced. We also found that GRP regulates the composition of the intestinal microbiota, including the ratio of Firmicutes to Mycobacteria F/B and the levels of Blautia spp., which have been shown to alleviate liver damage and treat hyperlipidemia. Metabolite pathway analysis using the Kyoto Encyclopedia of Genes and Genomes identified the glycolysis/glycolytic metabolism and propionate metabolism pathways as potential targets for GRP in the amelioration of hyperlipidemia.

Gut microbiota mediated T cells regulation and autoimmune diseases

Gut microbiota regulates the immune system, the development and progression of autoimmune diseases (AIDs) and overall health. Recent studies have played a crucial part in understanding the specific role of different gut bacterial strains and their metabolites in different AIDs. Microbial signatures in AIDs are revealed by advanced sequencing and metabolomics studies. Microbes such as Faecalibacterium prausnitzii, Akkermansia muciniphila, Anaerostipes caccae, Bacteroides sp., Roseburia sp., Blautia sp., Blautia faecis, Clostridium lavalense, Christensenellaceae sp., Coprococcus sp., Firmicutes sp., Ruminococcaceae sp., Lachnospiraceae sp., Megamonas sp., Monoglobus sp., Streptococcus pneumoniae and Bifidobacterium sp. help maintain immune homeostasis; whereas, Prevotella copri, Ruminococcus gnavus, Lactobacillus salivarius, Enterococcus gallinarum, Elizabeth menigoseptica, Collinsella sp., Escherichia sp., Fusobacterium sp., Enterobacter ludwigii, Enterobacteriaceae sp., Proteobacteria, Porphyromonas gingivalis, Porphyromonas nigrescens, Dorea sp., and Clostridium sp. cause immuno-pathogenesis. A complex web of interactions is revealed by understanding the influence of gut microbiota on immune cells and various T cell subsets such as CD4+ T cells, CD8+ T cells, natural killer T cells, γδ T cells, etc. Certain AIDs, including rheumatoid arthritis, diabetes mellitus, atopic asthma, inflammatory bowel disease and non-alcoholic fatty liver disease exhibit a state of dysbiosis, characterized by alterations in microbial diversity and relative abundance of specific taxa. This review summarizes recent developments in understanding the role of certain microbiota composition in specific AIDs, and the factors affecting specific regulatory T cells through certain microbial metabolites and also focuses the potential application and therapeutic significance of gut microbiota-based interventions as novel adjunctive therapies for AIDs. Further research to determine the precise association of each gut bacterial strain in specific diseases is required.

Control of T-cell immunity by fatty acid metabolism

Fatty acids play critical roles in maintaining the cellular functions of T cells and regulating T-cell immunity. This review synthesizes current research on the influence of fatty acids on T-cell subsets, including CD8+ T cells, TH1, TH17, Treg (regulatory T cells), and TFH (T follicular helper) cells. Fatty acids impact T cells by modulating signaling pathways, inducing metabolic changes, altering cellular structures, and regulating gene expression epigenetically. These processes affect T-cell activation, differentiation, and function, with implications for diseases such as autoimmune disease and cancer. Based on these insights, fatty acid pathways can potentially be modulated by novel therapeutics, paving the way for novel treatment approaches for immune-mediated disorders and cancer immunotherapy.

The interplay of metabolic and epigenetic players in disease development

Epigenetic modifications and their alterations can cause variation in gene expression patterns which can ultimately affect a healthy individual. Until a few years ago, it was thought that the epigenome affects the transcriptome which can regulate the proteome and the metabolome. Recent studies have shown that the metabolome independently also plays a major role in regulating the epigenome bypassing the need for transcriptomic control. Alternatively, an imbalanced metabolome, stemming from transcriptome abnormalities, can further impact the transcriptome, creating a self-perpetuating cycle of interconnected occurrences. As a result, external factors such as nutrient intake and diet can have a direct impact on the metabolic pools and its reprogramming can change the levels and activity of epigenetic modifiers. Thus, the epigenetic landscape steers toward a diseased condition. In this review, we have discussed how different metabolites and dietary patterns can bring about changes in different arms of the epigenetic machinery such as methylation, acetylation as well as RNA mediated epigenetic mechanisms. We checked for limiting metabolites such as αKG, acetyl-CoA, ATP, NAD+, and FAD, whose abundance levels can lead to common diseases such as cancer, neurodegeneration etc. This gives a clearer picture of how an integrated approach including both epigenetics and metabolomics can be used for therapeutic purposes.

Advances in the mechanism of action of short-chain fatty acids in psoriasis

Psoriasis is a prevalent chronic inflammatory and immunological disorder. Its lesions are present as scaly erythema or plaques. Disruptions in the body's immune system play a significant role in developing psoriasis. Recent evidence suggests a potential role of the gut microbiome in autoimmune diseases. Short-chain fatty acids (SCFAs) are the primary metabolites created by gut microbes and play a crucial fuction in autoimmunity. SCFAs act on various cells by mediating signaling to participate in host physiological and pathological processes. These processes encompass body metabolism, maintenance of intestinal barrier function, and immune system modulation. SCFAs can regulate immune cells to enhance the body's immune function, potentially influencing the prevention and treatment of psoriasis. However, the mechanisms underlying the role of SCFAs in psoriasis remain incompletely understood. This paper examines the relationship between SCFAs and psoriasis, elucidating how SCFAs influence the immune system, inflammatory response, and gut barrier in psoriasis. According to the study, in psoriasis, SCFAs have been shown to regulate neutrophils, macrophages, and dendritic cells in the adaptive immune system, as well as T and B cells in the innate immune system. Additionally, we explore the role of SCFAs in psoriasis by maintaining intestinal barrier function, restoring intestinal ecological homeostasis, and investigating the potential therapeutic benefits of SCFAs for psoriasis.

Propionic Acid Impact on Multiple Sclerosis: Evidence and Challenges

Accumulating evidence suggests that multiple sclerosis (MS) is an environmentally influenced disorder with contributions from life-time exposure to factors including Epstein-Barr virus infection or shifts in microbiome, diet and lifestyle. One suggested factor is a deficiency in propionic acid, a short-chain fatty acid produced by gut bacteria that may contribute to the disease pathology both in animal models and in human cases of MS. Propionate appears to exert beneficial effects on the immune, peripheral and central nervous systems of people with MS (pwMS), showing immunoregulatory, neuroprotective and neurogenerative effects. These functions are crucial, given that MS is characterized by immune-mediated damage of myelin in the central nervous system. Accordingly, propionate supplementation or a modulated increase in its levels through the microbiome and diet may help counteract the pro-inflammatory state in MS by directly regulating immune system and/or by decreasing permeability of gut barrier and blood-brain barrier. This could potentially improve outcomes when used with immune-modulating therapy. However, while its broad effects are promising, further large clinical trials are necessary to evaluate its efficacy and safety in pwMS and clarify its role as a complementary therapeutic strategy. This review provides a comprehensive analysis of the evidence, challenges and limitations concerning propionic acid supplementation in MS.

Dietary amino acids, macronutrients, vaginal birth, and breastfeeding are associated with the vaginal microbiome in early pregnancy

The vaginal microbiome is a key player in the etiology of spontaneous preterm birth. This study aimed to illustrate maternal environmental factors associated with vaginal microbiota composition and function in pregnancy. Women in healthy pregnancy had vaginal microbial sampling from the posterior vaginal fornix performed at 16 weeks gestation. After shotgun metagenomic sequencing, heatmaps of relative abundance data were generated. Community state type (CST) was assigned, and alpha diversity was calculated. Demography, obstetric history, well-being, exercise, and diet using food frequency questionnaires were collected and compared against microbial parameters. A total of 119 pregnant participants had vaginal metagenomic sequencing performed. Factors with strongest association with beta diversity were dietary lysine (adj-R2 0.113, P = 0.002), valine (adj-R2 0.096, P = 0.004), leucine (adj-R2 0.086, P = 0.003), and phenylalanine (adj-R2 0.085, P = 0.005, Fig. 2D). Previous vaginal delivery and breastfeeding were associated with vaginal beta diversity (adj-R2 0.048, P = 0.003; adj-R2 0.045, P = 0.004), accounting for 8.5% of taxonomy variation on redundancy analysis. Dietary fat, starch, and maltose were positively correlated with alpha diversity (fat +0.002 SD/g, P = 0.025; starch +0.002 SD/g, P = 0.043; maltose +0.440 SD/g, P = 0.013), particularly in secretor-positive women. Functional signature was associated with CST, maternal smoking, and dietary phenylalanine, accounting for 8.9%-11% of the variation in vaginal microbiome functional signature. Dietary amino acids, previous vaginal delivery, and breastfeeding history were associated with vaginal beta diversity. Functional signature of the vaginal microbiome differed with community state type, smoking, dietary phenylalanine, and vitamin K. Increased alpha diversity correlated with dietary fat and starch. These data provide a novel snapshot into the associations between maternal environment, nutrition, and the vaginal microbiome.

IMPORTANCE

This secondary analysis of the MicrobeMom randomized controlled trial reveals that dietary amino acids, macronutrients, previous vaginal birth, and breastfeeding have the strongest associations with vaginal taxonomy in early pregnancy. Function of the vaginal niche is associated mainly by species composition, but smoking, vitamin K, and phenylalanine also play a role. These associations provide an intriguing and novel insight into the association between host factors and diet on the vaginal microbiome in pregnancy and highlight the need for further investigation into the complex interactions between the diet, human gut, and vaginal microbiome.

Fatty acids and epigenetics in health and diseases

Lipids are crucial for human health and reproduction and include diverse fatty acids (FAs), notably polyunsaturated FAs (PUFAs) and short-chain FAs (SCFAs) that are known for their health benefits. Bioactivities of PUFAs, including ω-6 and ω-3 FAs as well as SCFAs, have been widely studied in various tissues and diseases. Epigenetic regulation has been suggested as a significant mechanism affecting the progression of various diseases, including cancers and metabolic and inflammatory diseases. Epigenetics encompasses the reversible modulation of gene expression without altering the DNA sequence itself, mediated by mechanisms such as DNA methylation, histone acetylation, and chromatin remodeling. Bioactive FAs have been demonstrated to regulate gene expression via epigenetic modifications that are potentially important for modulating metabolic control and disease risk. This review paper discusses the evidence in support of bioactive FAs, including ω-6 and ω-3 FAs and SCFAs, eliciting various disease prevention via epigenetic regulation including methylation or acetylation.

Graphical abstract

New therapeutic avenues in multiple sclerosis: Is there a place for gut microbiota-based treatments?

The bidirectional interaction between the gut and the central nervous system (CNS), the so-called gut microbiota-brain axis, is reported to influence brain functions, thus having a potential impact on the development or the progression of several neurodegenerative disorders. Within this context, it has been documented that multiple sclerosis (MS), an autoimmune inflammatory, demyelinating, and neurodegenerative disease of the CNS, is associated with gastrointestinal symptoms, including constipation, dysphagia, and faecal incontinence. Moreover, some evidence suggests the existence of an altered gut microbiota (GM) composition in MS patients with respect to healthy individuals, as well as the potential influence of GM dysbiosis on typical MS features, including increased intestinal permeability, disruption of blood-brain barrier integrity, chronic inflammation, and altered T cells differentiation. Starting from these assumptions, the possible involvement of GM alteration in MS pathogenesis seems likely, and its restoration could represent a supplemental beneficial strategy against this disabling disease. In this regard, the present review will explore possible preventive approaches (including several dietary interventions, the administration of probiotics, prebiotics, synbiotics, and postbiotics, and the use of faecal microbiota transplantation) to be pursued as prophylaxis or in combination with pharmacological treatments with the aim of re-establishing a proper GM, thus helping to prevent the development of this disease or to manage it by alleviating symptoms or slowing down its progression.

A Mix of Probiotic Strains Prevents Hepatic Steatosis, and Improves Oxidative Stress Status and Gut Microbiota Composition in Obese Mice

SCOPE

The gut microbiota plays a role in fat accumulation and energy homeostasis. Therefore, probiotic supplementation may improve metabolic parameters and control body weight.

METHODS AND RESULTS

In this study, mice are fed either a high-fat diet (HFD) or an HFD supplemented with oral gavage of a mixture of three probiotic strains, Bifidobacterium lactis Lafti B94, Lactobacillus plantarum HA-119, and Lactobacillus helveticus Lafti L10 for 7 weeks. It finds that probiotic supplementation modulates body weight gain, food energy efficiency, and fat accumulation caused by the HFD. This probiotic mix prevents liver damage and lipid metabolic disorders in HFD-fed obese mice. The probiotic supplementation significantly downregulates the expression of the proinflammatory cytokines interleukin-1β, tumor necrosis factor-α, and malondialdehyde (MDA) in the liver and upregulated catalase (CAT), superoxide dismutase (SOD), and nuclear respiratory factor 1 (Nrf1) expression. Mice supplemented with the probiotic mix also show different microbiota compositions, with an increase in Clostridia_UCG-014 and Lachnospiraceae_nk4a136_group and a decrease in the Dubosiella genus compared with those in mice fed only an HFD. Finally, the amounts of fecal pentanoic acid and the three bile acid species increase in mice with probiotic supplementation.

CONCLUSION

Treatment with a combination of a mixture of three probiotic strains, B. lactis Lafti B94, L. plantarum HA-119, and L. helveticus Lafti L10 for 7 weeks, ameliorates the effects of HFD induced obesity in mice.

Differences in salivary microbiome among children with tonsillar hypertrophy and/or adenoid hypertrophy

Children diagnosed with severe tonsillar hypertrophy display discernible craniofacial features distinct from those with adenoid hypertrophy, prompting illuminating considerations regarding microbiota regulation in this non-inflammatory condition. The present study aimed to characterize the salivary microbial profile in children with tonsillar hypertrophy and explore the potential functionality therein. A total of 112 children, with a mean age of 7.79 ± 2.41 years, were enrolled and divided into the tonsillar hypertrophy (TH) group (n = 46, 8.4 ± 2.5 years old), adenoid hypertrophy (AH) group (n = 21, 7.6 ± 2.8 years old), adenotonsillar hypertrophy (ATH) group (n = 23, 7.2 ± 2.1 years old), and control group (n = 22, 8.6 ± 2.1 years old). Unstimulated saliva samples were collected, and microbial profiles were analyzed by 16S rRNA sequencing of V3-V4 regions. Diversity and composition of salivary microbiome and the correlation with parameters of overnight polysomnography and complete blood count were investigated. As a result, children with tonsillar hypertrophy had significantly higher α-diversity indices (P＜0.05). β-diversity based on Bray-Curtis distance revealed that the salivary microbiome of the tonsillar hypertrophy group had a slight separation from the other three groups (P＜0.05). The linear discriminant analysis effect size (LEfSe) analysis indicated that Gemella was most closely related to tonsillar hypertrophy, and higher abundance of Gemella, Parvimonas, Dialister, and Lactobacillus may reflect an active state of immune regulation. Meanwhile, children with different degrees of tonsillar hypertrophy shared similar salivary microbiome diversity. This study demonstrated that the salivary microbiome in pediatric tonsillar hypertrophy patients had different signatures, highlighting that the site of upper airway obstruction primarily influences the salivary microbiome rather than hypertrophy severity.IMPORTANCETonsillar hypertrophy is the most frequent cause of upper airway obstruction and one of the primary risk factors for pediatric obstructive sleep apnea (OSA). Studies have discovered that children with isolated tonsillar hypertrophy exhibit different craniofacial morphology features compared with those with isolated adenoid hypertrophy or adenotonsillar hypertrophy. Furthermore, characteristic salivary microbiota from children with OSA compared with healthy children has been identified in our previous research. However, few studies provided insight into the relationship between the different sites of upper airway obstruction resulting from the enlargement of pharyngeal lymphoid tissue at different sites and the alterations in the microbiome. Here, to investigate the differences in the salivary microbiome of children with tonsillar hypertrophy and/or adenoid hypertrophy, we conducted a cross-sectional study and depicted the unique microbiome profile of pediatric tonsillar hypertrophy, which was mainly characterized by a significantly higher abundance of genera belonging to phyla Firmicutes and certain bacteria involving in the immune response in tonsillar hypertrophy, offering novel perspectives for future related research.

Integrated serum pharmacochemistry, 16S rDNA sequencing, and metabolomics to reveal the material basis and mechanism of Shouhui Tongbian capsule against diphenoxylate-induced slow transit constipation in rats

BACKGROUND

Slow transit constipation (STC) is highly prevalent and has rising incidence. Shouhui Tongbian capsule (SHTB) is a traditional Chinese Medicine formula with extensive and highly efficacious usage in STC treatment, however, its mechanism of action, especially the regulation of microbiome and lipid metabolites, remains unclear.

METHODS

After quality control of SHTB using LC‒MS to obtain its material basis, we tried to elucidate the cohesive modulatory network of SHTB against STC using hyphenated methods from microbiomics, lipidomics, mass spectrometry imaging (MSI) and molecular methods.

RESULTS

SHTB could repair intestinal barrier damage, reduce systemic inflammation and increase intestinal motility in a diphenoxylate-induced STC rat model. Based on 16S rDNA sequencing results, SHTB rehabilitated the abnormal changes in Alloprevotella, Coprococcus, Marvinbryantia, etc., which were associated with STC symptoms. Meanwhile, microbial functional prediction showed that lipid metabolism was improved with SHTB administration. The differential lipids, including fatty acids, lysophosphatidylcholine, phosphatidylcholine, sphingomyelin triglyceride and ceramide, that are closely related to STC disease and SHTB efficacy. Furthermore, SHTB significantly reversed the abnormal expression of these key target enzymes in colon samples, including CTP-phosphocholine cytidylyltransferase, CTP-phosphoethanolamine cytidylyltransferase, phosphatidic acid phosphatase, acid sphingomyelinase etc. CONCLUSIONS: Combined analysis demonstrated that SHTB reducing lipid accumulation and recovery of intestinal microbial homeostasis was the critical mechanism by which SHTB treats STC.

Causal effect of gut microbiota on juvenile idiopathic arthritis: A two-sample Mendelian a randomization study

There is increasing evidence of a significant association between the gut microbiome and juvenile idiopathic arthritis (JIA). However, whether this association is causal remains to be determined. This study was a two-sample Mendelian randomization (MR) study using publicly available genome-wide association study (GWAS) summary data to investigate the causal relationship between the gut microbiome and JIA. We used summary data on gut flora and JIA obtained from genome-wide association studies (GWAS) from MiBioGen and NHGRI-EBI, using inverse variance weighting as the main method to analyse causality in the TSMR causality analysis. To check the stability of the TSMR results, we performed several sensitivity analyses and assessed the presence of reverse causality through a reverse TSMR analysis. We calculated the degree of sample overlap where applicable. The current TSMR analyses identified four bacterial taxa associated with JIA. Specifically, two bacteria, Catenibacterium (p = 2 × 10-2) and Holdemania (p = 4 × 10-2), were negatively associated with the risk of developing JIA, suggesting a protective effect, while Olsenella (p = 1 × 10-2) and Rikenellaceae (RC9gutgroup) (p = 1 × 10-2) were positively associated with the risk of JIA, suggesting that these two bacteria may be risk factors for JIA. However, the results for Catenibacterium and Holdemania should be interpreted with caution due to instability observed in 'leave-one-out' sensitivity analyses. Reverse TSMR analyses found no evidence of reverse causality between JIA and gut flora. Our confirmation of a causal relationship between gut flora and JIA provides an innovative perspective for the study of JIA: targeting and modulating dysregulation of specific bacterial taxa to prevent and treat JIA.

The role of gut-derived short-chain fatty acids in Parkinson's disease

The emerging function of short-chain fatty acids (SCFAs) in Parkinson's disease (PD) has been investigated in this article. SCFAs, which are generated via the fermentation of dietary fiber by gut microbiota, have been associated with dysfunction of the gut-brain axis and, neuroinflammation. These processes are integral to the development of PD. This article examines the potential therapeutic implications of SCFAs in the management of PD, encompassing their capacity to modulate gastrointestinal permeability, neuroinflammation, and neuronal survival, by conducting an extensive literature review. As a whole, this article emphasizes the potential therapeutic utility of SCFAs as targets for the management and treatment of PD.

New findings in the metabolism of the saffron apocarotenoids, crocins and crocetin, by the human gut microbiota

The main constituents of saffron are the apocarotenoids crocins and crocetin, present in the stigmas. Numerous healthy properties, especially those related to the effects on the central nervous system, have been attributed to these compounds but the metabolites responsible for these effects are still unknown. Previous evidences in animal models suggest a role for the gut microbiota in the pharmacokinetics and the neuroprotective effects of these compounds. However, the interaction between these apocarotenoids and the gut microbiota has been poorly studied. In this article, we have thoroughly investigated the batch fermentation of crocin-1 and crocetin (10 μM) with human fecal samples of two donors at different incubation times (0-240 h) using a metabolomic approach. We corroborated a rapid transformation of crocin-1 which looses the glucose molecules through de-glycosylation reactions until its complete transformation into crocetin in 6 hours. A group of intermediate crocins with different degrees of glycosylation were detected in a very short time. Crocetin was further metabolized and new microbial metabolites produced by double-bond reduction and demethylation reactions were identified for the first time: dihydro and tetrahydro crocetins and di-demethyl crocetin. In addition, we detected changes in the levels of the short chain fatty acids valeric acid and hexanoic acid suggesting further structural modifications of crocetin or changes in the catabolic production of these compounds. This research is a pioneering study of the action of the human gut microbiota on the saffron apocarotenoids and goes one step further towards the discovery of metabolites potentially involved in the benefits of saffron.

Methionine-choline deficient diet deteriorates DSS-induced murine colitis through disturbance of gut microbes and infiltration of macrophages

Ulcerative colitis (UC) is associated with changed dietary habits and mainly linked with the gut microbiota dysbiosis, necroptosis of epithelial cells, and mucosal ulcerations. Liver dysfunction and abnormal level of liver metabolism indices were identified in UC patients, suggesting a close interaction between gut and liver disorders. Methionine-choline deficient diet (MCD) has been shown to induce persistent alterations of gut microbiota and metabolome during hepatitis. In this study we further explored the disease phenotypes in UC patients and investigated whether MCD functioned as a trigger for UC susceptibility. After assessing 88 serum specimens from UC patients, we found significant liver dysfunction and dyslipidemia including abnormal ALT, AST, TG, TC, LDL-c and HDL-c. Liver dysfunction and dyslipidemia were confirmed in DSS-induced colitis mice. We fed mice with MCD for 14 days to cause mild liver damage, and then treated with DSS for 7 days. We found that MCD intake significantly exacerbated the pathogenesis of mucosal inflammation in DSS-induced acute, progressive, and chronic colitis, referring to promotion of mucosal ulcers, colon shortening, diarrhea, inflammatory immune cell infiltration, cytokines release, and abnormal activation of inflammatory macrophages in colon and liver specimens. Intraperitoneal injection of clodronate liposomes to globally delete macrophages dramatically compromised the pathogenesis of MCD-triggering colitis. In addition, MCD intake markedly changed the production pattern of short-chain fatty acids (SCFAs) in murine stools, colons, and livers. We demonstrated that MCD-induced colitis pathogenesis largely depended on the gut microbes and the disease phenotypes could be transmissible through fecal microbiota transplantation (FMT). In conclusion, this study supports the concept that intake of MCD predisposes to experimental colitis and enhances its pathogenesis via modulating gut microbes and macrophages in mice.

Interactions between Gut Microbiota and Natural Bioactive Polysaccharides in Metabolic Diseases: Review

The gut microbiota constitutes a complex ecosystem, comprising trillions of microbes that have co-evolved with their host over hundreds of millions of years. Over the past decade, a growing body of knowledge has underscored the intricate connections among diet, gut microbiota, and human health. Bioactive polysaccharides (BPs) from natural sources like medicinal plants, seaweeds, and fungi have diverse biological functions including antioxidant, immunoregulatory, and metabolic activities. Their effects are closely tied to the gut microbiota, which metabolizes BPs into health-influencing compounds. Understanding how BPs and gut microbiota interact is critical for harnessing their potential health benefits. This review provides an overview of the human gut microbiota, focusing on its role in metabolic diseases like obesity, type II diabetes mellitus, non-alcoholic fatty liver disease, and cardiovascular diseases. It explores the basic characteristics of several BPs and their impact on gut microbiota. Given their significance for human health, we summarize the biological functions of these BPs, particularly in terms of immunoregulatory activities, blood sugar, and hypolipidemic effect, thus providing a valuable reference for understanding the potential benefits of natural BPs in treating metabolic diseases. These properties make BPs promising agents for preventing and treating metabolic diseases. The comprehensive understanding of the mechanisms by which BPs exert their effects through gut microbiota opens new avenues for developing targeted therapies to improve metabolic health.

The signature of the gut microbiota associated with psoriatic arthritis revealed by metagenomics

Background

Gut microbiota is involved in the development of psoriatic arthritis (PsA), but until now, there has been a lack of understanding of the PsA host-bacteria interaction.

Objectives

To reveal the labels of gut microbiota in PsA patients and the species and functions related to disease activity.

Design

Observational research (cross-sectional) with an exploratory nature.

Methods

Metagenomics sequencing was used to analyze stool samples from 20 treatment-naïve PsA patients and 10 age-matched healthy individuals. All samples were qualified for subsequent analysis.

Results

Compared with the healthy group, α-diversity was reduced in the PsA group, and β-diversity could distinguish the two groups. Two bacteria with high abundance and correlation with PsA disease activity were identified, Bacteroides sp. 3_1_19 and Blautia AF 14-40. In different functions, K07114 (calcium-activated chloride channel (CaCC) homolog) showed a positive correlation with PsA disease activity (disease activity in psoriatic arthritis, DAPSA) and Tet32 (an antibiotic-resistant gene), and carbohydrate-binding module family 50 was negatively correlated with erythrocyte sedimentation rate. A bacterial co-expression network associated with DAPSA was constructed. The network was centered on the bacteria in the Bacteroides genus, which formed a closely related network and were positively correlated with DAPSA. As another core of the network, K07114 was closely related to multiple bacteria in the Bacteroides genus and is also positively correlated with disease activity.

Conclusion

The network composed of Bacteroides is associated with PsA disease activity, and its therapeutic value needs to be further explored. CaCCs may be a key channel for the interaction between Bacteroides and PsA-host.

Just scratching the surface: novel treatment approaches for multiple myeloma targeting cell membrane proteins

A better understanding of the roles of the adaptive and innate immune systems in the oncogenesis of cancers including multiple myeloma (MM) has led to the development of novel immune-based therapies. B cell maturation antigen (BCMA), G protein-coupled receptor family C group 5 member D (GPRC5D) and Fc receptor-like protein 5 (FcRL5, also known as FcRH5) are cell-surface transmembrane proteins expressed by plasma cells, and have been identified as prominent immunotherapeutic targets in MM, with promising activity demonstrated in patients with heavily pretreated relapsed and/or refractory disease. Indeed, since 2020, antibody-drug conjugates, bispecific T cell engagers and autologous chimeric antigen receptor T cells targeting BCMA or GPRC5D have been approved for the treatment of relapsed and/or refractory MM. However, responses to these therapies are not universal, and acquired resistance invariably occurs. In this Review, we discuss the various immunotherapeutic approaches targeting BCMA, GPRC5D and FcRL5 that are currently either available or in clinical development for patients with MM. We also review the mechanisms underlying resistance to such therapies, and discuss potential strategies to overcome these mechanisms and improve patient outcomes.

Guizhi Shaoyao Zhimu Decoction ameliorates gouty arthritis in rats via altering gut microbiota and improving metabolic profile

BACKGROUND

The incidence of gouty arthritis (GA) has gradually increased, and modern drug therapies have obvious side effects. Guizhi Shaoyao Zhimu Decoction (GSZD), a classic prescription in Traditional Chinese Medicine for treating various osteoarthritis, has shown significant advantages in curing GA.

PURPOSE

To verify the therapeutic effect of GSZD on GA and investigate its potential pharmacological mechanism via integrated analysis of the gut microbiota and serum metabolites for the first time.

METHODS

The chemical composition of GSZD was determined using UPLC-MS. The GA rat model was established by the induction of a high-purine diet combined with local injection. We examined the effects and mechanisms of GSZD after 21 d using enzyme-linked immunosorbent assays, 16S rRNA, and non-targeted metabolomics. Finally, correlation analysis and validation experiment were performed to explore the association among the gut microbiota, serum metabolites, and GA-related clinical indices.

RESULTS

In total, 19 compounds were identified as GSZD. High-purine feedstuff with local injection-induced arthroceles were significantly attenuated after GSZD treatment. GSZD improved bone erosion and reduced the serum levels of inflammatory factors (lipopolysaccharide, tumor cell necrosis factor-α, and interleukin) and key indicators of GA (uric acid). 16S rRNA analysis indicated that GSZD-treated GA rats exhibited differences in the composition of the gut microbiota. The abundance of flora involved in uric acid transport, including Lactobacillus, Ruminococcaceae, and Turicibacter, was elevated to various degrees, whereas the abundance of bacteria involved in inflammatory responses, such as Blautia, was markedly reduced after treatment. Moreover, serum metabolite profiles revealed 27 different metabolites associated with the amelioration of GA, which primarily included fatty acids, glycerophospholipids, purine metabolism, amino acids, and bile acids, as well as primary metabolic pathways, such as glycerophospholipid metabolism and alanine. Finally, correlation analysis of the heat maps and validation experiment demonstrated a close relationship among inflammatory cytokines, gut microbial phylotypes, and metabolic parameters.

CONCLUSION

This study demonstrated that GSZD could modulate the gut microbiota and serum metabolic homeostasis to treat GA. In addition, the application of gut microbiota and serum metabolomics correlation analyses sheds light on the mechanism of Traditional Chinese Medicine compounds in the treatment of bone diseases.