Akkermansia muciniphila secretes a glucagon-like peptide-1-inducing protein that improves glucose homeostasis and ameliorates metabolic disease in mice

Gut dysbiosis was inevitable, but tolerance was not: temporal responses of the murine microbiota that maintain its capacity for butyrate production correlate with sustained antinociception to chronic morphine

The therapeutic benefits of opioids are compromised by the development of analgesic tolerance, which necessitates higher dosing for pain management thereby increasing the liability for drug dependence and addiction. Rodent models indicate opposing roles of the gut microbiota in tolerance: morphine-induced gut dysbiosis exacerbates tolerance, whereas probiotics ameliorate tolerance. Not all individuals develop tolerance, which could be influenced by differences in microbiota, and yet no study design has capitalized upon this natural variation. We leveraged natural behavioral variation in a murine model of voluntary oral morphine self-administration to elucidate the mechanisms by which microbiota influences tolerance. Although all mice shared similar morphine-driven microbiota changes that largely masked informative associations with variability in tolerance, our high-resolution temporal analyses revealed a divergence in the progression of dysbiosis that best explained sustained antinociception. Mice that did not develop tolerance maintained a higher capacity for production of the short-chain fatty acid (SCFA) butyrate known to bolster intestinal barriers and promote neuronal homeostasis. Both fecal microbial transplantation (FMT) from donor mice that did not develop tolerance and dietary butyrate supplementation significantly reduced the development of tolerance independently of suppression of systemic inflammation. These findings could inform immediate therapies to extend the analgesic efficacy of opioids.

Interkingdom signaling between gastrointestinal hormones and the gut microbiome

The interplay between the gut microbiota and gastrointestinal hormones plays a pivotal role in the health of the host and the development of diseases. As a vital component of the intestinal microecosystem, the gut microbiota influences the synthesis and release of many gastrointestinal hormones through mechanisms such as modulating the intestinal environment, producing metabolites, impacting mucosal barriers, generating immune and inflammatory responses, and releasing neurotransmitters. Conversely, gastrointestinal hormones exert feedback regulation on the gut microbiota by modulating the intestinal environment, nutrient absorption and utilization, and the bacterial biological behavior and composition. The distributions of the gut microbiota and gastrointestinal hormones are anatomically intertwined, and close interactions between the gut microbiota and gastrointestinal hormones are crucial for maintaining gastrointestinal homeostasis. Interventions leveraging the interplay between the gut microbiota and gastrointestinal hormones have been employed in the clinical management of metabolic diseases and inflammatory bowel diseases, such as bariatric surgery and fecal microbiota transplantation, offering promising targets for the treatment of dysbiosis-related diseases.

Akkermansia muciniphila Alleviates Porphyromonas gingivalis-induced Periodontal Disease by Enhancing Bacterial Clearance

This study is to investigate the role of Akkermansia muciniphila (Am) in enhancing immune defense against Porphyromonas gingivalis (Pg)-induced periodontal disease. Twenty C57BL/6 J mice received 50 µL of Pg suspension (1.5 × 109 CFU/mL) with or without 50 µL of Am suspension (1.5 × 109 CFU/mL) orally every 2 days for a total of 18 administrations to assess bone resorption and inflammation. Gingival cervical fluid and periodontal plaques were collected for microbiota analysis using 16S sequencing. THP-1 (a human leukemia monocytic cell line) differentiated macrophages were used to explore the underlying beneficial mechanisms of Am by evaluating gene expression, cytokine production, and phagocytosis activity. Am administration attenuated alveolar bone loss and reduced inflammation in Pg-induced periodontitis in mice. Microbiota analysis revealed that Am reduced bacterial load and modified the composition of periodontal microbiota. In THP-1 macrophages, Am enhanced the phagocytosis of Pg by restoring MyD88 protein levels. RNA sequencing and western blotting results showed that Am upregulated TLR2 and MyD88 expression while downregulating C5aR, indicating interference with the TLR2-C5aR-MyD88 interplay. Am enhances immune defense against Pg-induced periodontal disease by modulating the TLR2-C5aR-MyD88 signaling pathway. These findings suggest that Am could be a promising therapeutic option for managing periodontal disease.

Structural characterization and alleviative effects of novel polysaccharides from Artemisia sphaerocephala Krasch seed on obese mice by regulating gut microbiota

This study aimed to investigate the efficacy of polysaccharides from Artemisia sphaerocephala Krasch (ASK) seed in alleviating high fat diet (HFD) caused obesity. Here, three polysaccharide fractions (ASKP1, ASKP2 and ASKP3) were purified from ASK seed. Chemical characteristic analysis revealed that ASKP1 is a neutral heteropolysaccharide with the average molecular weight of 9.08 × 105 Da, while ASKP2 and ASKP3 are acidic heteropolysaccharides with the molecular weight of 9.39 × 105 and 8.41 × 105 Da, respectively. Animal experiment found that three ASKP fractions obviously relieved obesity and related metabolic disorders induced by HFD, while ASKP1 was more effective in reducing the blood glucose and serum LDL levels. 16S rDNA sequencing showed that ASKP fractions improved the gut microbiota imbalance of obese mice, and ASKP1 promoted the proliferation of beneficial bacterium Akkermansia more effectively than ASKP2 and ASKP3. Furthermore, ASKP fractions facilitated thermogenesis of brown adipose tissue (BAT) of obese mice, as evidenced by increased expression of thermogenic marker genes UCP1 in BAT, and the thermogenesis effect of ASKP1 was the most obvious. Taken together, our results show that ASKP1 is a novel prebiotic that may be used to treat obesity and its related abnormal metabolism.

Recent advances in therapeutic probiotics: insights from human trials

SUMMARYRecent advances in therapeutic probiotics have shown promising results across various health conditions, reflecting a growing understanding of the human microbiome's role in health and disease. However, comprehensive reviews integrating the diverse therapeutic effects of probiotics in human subjects have been limited. By analyzing randomized controlled trials (RCTs) and meta-analyses, this review provides a comprehensive overview of key developments in probiotic interventions targeting gut, liver, skin, vaginal, mental, and oral health. Emerging evidence supports the efficacy of specific probiotic strains and combinations in treating a wide range of disorders, from gastrointestinal (GI) and liver diseases to dermatological conditions, bacterial vaginosis, mental disorders, and oral diseases. We discuss the expanding understanding of microbiome-organ connections underlying probiotic mechanisms of action. While many clinical trials demonstrate significant benefits, we acknowledge areas requiring further large-scale studies to establish definitive efficacy and optimal treatment protocols. The review addresses challenges in standardizing probiotic research methodologies and emphasizes the importance of considering individual variations in microbiome composition and host genetics. Additionally, we explore emerging concepts such as the oral-gut-brain axis and future directions, including high-resolution microbiome profiling, host-microbe interaction studies, organoid models, and artificial intelligence applications in probiotic research. Overall, this review offers a comprehensive update on the current state of therapeutic probiotics across multiple domains of human health, providing insights into future directions and the potential for probiotics to revolutionize preventive and therapeutic medicine.

Inulin Diet Alleviates Abdominal Aortic Aneurysm by Increasing Akkermansia and Improving Intestinal Barrier

Background/Objectives: Previous studies have shown varying efficacy of high-fiber diets containing different ingredients in abdominal aortic aneurysms (AAAs). This study aimed to identify which high-fiber diet protects against AAA in mice and elucidate the underlying mechanisms. Methods: This study compared inulin, cellulose, and chow diets in terms of their impact on aneurysm enlargement, elastin degradation, matrix metalloproteinase 2 and 9 expressions, CD3+ T cell and CD68+ macrophage infiltration, and macrophage differentiation. It also examined gut microbiota composition, focusing on Akkermansia, and evaluated intestinal barrier function and systemic inflammatory response. Results: The inulin diet, but not the cellulose diet, compared with the chow diet, reduced aneurysm enlargement, elastin degradation, matrix metalloproteinase 2 and 9 expressions, CD3+ T cell and CD68+ macrophage infiltration, and skewed macrophage towards M2 differentiation. The inulin diet enriched Akkermansia in both the small and large intestine. The inulin diet also enhanced the intestinal barrier by augmenting goblet cells, upregulating the gene related to the epithelial barrier and antibacterial peptides in the small intestine, and reducing circulating lipopolysaccharide and interleukin-1β levels. The inulin diet lowered the proportion of Ly6Chi monocytes and C-C chemokine receptor 2 expression on these cells in the bone marrow, reducing aneurysm infiltration. Administering Akkermansia to AAA mice decreased intestinal permeability and mitigated AAA. Conclusions: A diet rich in fermentable fiber inulin, as opposed to cellulose, alleviates AAA in mice. This beneficial effect is attributed to the enhanced presence of Akkermansia bacteria and improvement of the intestinal barrier.

Akkermansia muciniphila restrains type 1 diabetes onset by eliciting cDC2 and Treg cell differentiation in NOD and STZ-induced experimental models

AIMS

Akkermansia muciniphila (A. muciniphila), a Gram-negative anaerobic mucus-layer-degrading bacterium found in the intestinal mucosa, exhibits potential as a probiotic, showing promise in mitigating autoimmune and chronic inflammatory diseases. This study aims to investigate whether A. muciniphila supplementation might confer protection against type 1 diabetes (T1D) and to elucidate the immunological pathways through which it exerts its beneficial effects.

MATERIALS AND METHODS

Non-obese diabetic (NOD) mice and streptozotocin (STZ)-induced type 1 diabetes (T1D) models were used to evaluate the protective effects of A. muciniphila during T1D course. Body weight, blood glucose levels, and T1D incidence were monitored. Immune responses in the pancreas, pancreatic (PLN) and cecal lymph nodes (CLN) and bone marrow-derived dendritic cells (BMDC) were evaluated by flow cytometry and ELISA.

KEY FINDINGS

Viable A. muciniphila supplementation conferred protection against T1D onset in STZ-induced T1D and NOD mouse models. T1D modulation by A. muciniphila in the STZ model was independent of the gut microbiota, and it was associated with increased tolerogenic type-2 dendritic cells (SIRP-α+CD11b+CD103+) and regulatory T (Treg) cells in PLN and pancreas. BMDC differentiated in the presence of A. muciniphila exhibited a tolerogenic profile and induced Treg cell generation in vitro. A. muciniphila-induced protection in T1D outcome was abrogated in FOXP3-DTR mice depleted of Treg cells, indicating that its mechanism of action is dependent on the CD4+Foxp3+ Treg cells.

SIGNIFICANCE

A. muciniphila supplementation attenuates T1D development in mice by modulating the tolerogenic immune response and is a promising new therapeutic tool for this autoimmune disease.

Akkermansia muciniphila inhibits jejunal lipid absorption and regulates jejunal core bacteria

Insufficiency of Akkermansia muciniphila (Akk) has been implicated in the pathogenesis of metabolic diseases, and administration or restoration of Akk has ameliorated these disorders. Recently, Pasteurized Akk (PA-Akk) has been approved as a functional food. However, the impact of Akk on lipid absorption in the proximal intestine, which is directly exposed to orally administered Akk, remains largely unexplored. In this study, we orally administered Akk and PA-Akk to mice and investigated the subsequent lipid absorption. Long-term administration of Akk resulted in reduced lipid deposits in the liver and adipocytes, along with improved glucose metabolism. This was primarily attributed to a reduction in lipid absorption by epithelial cells in the proximal jejunum. Mechanistically, Akk activated AMP-activated protein kinase (AMPK) and directly inhibit lipids absorption in both mouse and human jejunal epithelial cells. Furthermore, we demonstrated that Akk treatment, but not PA-Akk treatment, promotes the abundance of genera that are highly abundant in the normal jejunum and belong to the phylum Firmicutes. Thus, our study concludes that oral administration of Akk provides beneficial effects on metabolism, partially through inhibiting jejunal lipid absorption and promoting the abundance of core jejunal microbes.

Investigating Polyreactivity of CD4+ T Cells to the Intestinal Microbiota

Antigen-specific recognition of microbiota by T cells enforces tolerance at homeostasis. Conversely, dysbiosis leads to imbalanced T-cell responses, triggering inflammatory and autoimmune diseases. Despite their significance, the identities of immunogenic microbial antigens remain largely enigmatic. Here, we leveraged a sensitive, unbiased, genome-wide screening platform to identify peptides from Akkermansia muciniphila (AKK) and Bacteroides thetaiotaomicron (BT) recognized by CD4+ T cells. The platform is based on screening peptide libraries using an NFAT-fluorescence reporter cell line transduced with a retrovirus encoding an MHC-TCR (MCR) hybrid molecule. We discovered several novel epitopes from AKK and BT. T-cell hybridomas reactive to AKK and BT bacteria demonstrated polyreactivity to microbiota-derived peptides in co-cultures with MCR reporter cells. Steady-state T cells recognized these epitopes in an MHC-restricted fashion. Intriguingly, most of the identified epitopes are broadly conserved within the given phylum and originate from membrane and intracellular proteins. Ex vivo stimulation of CD4+ T cells from mice vaccinated with the identified peptides revealed mono-specific IFN-γ and IL-17 responses. Our work showcases the potential of the MCR system for identifying immunogenic microbial epitopes, providing a valuable resource. Our study facilitates decoding antigen specificity in immune system-bacterial interactions, with applications in understanding microbiome and pathogenic bacterial immunity.

Discussion on the treatment of diabetic kidney disease based on the "gut-fat-kidney" axis

Diabetic kidney disease is the main cause of end-stage renal disease, and its prevention and treatment are still a major clinical problem. The human intestine has a complex flora of hundreds of millions of microorganisms, and intestinal microorganisms, and their derivatives are closely related to renal inflammatory response, immune response, and material metabolism. Brown adipose tissue is the main part of adaptive thermogenesis. Recent studies have shown that activating brown fat by regulating intestinal flora has good curative effects in diabetic kidney disease-related diseases. As an emerging medical concept, the "gut-fat-kidney" axis has received increasing attention in diabetic kidney disease and related diseases. However, the specific mechanism involved needs further study. A new theoretical basis for the prevention and treatment of diabetic kidney disease is presented in this article, based on the "gut-fat-kidney" axis.

Neurobiological and Microbiota Alterations After Bariatric Surgery: Implications for Hunger, Appetite, Taste, and Long-Term Metabolic Health

Bariatric surgery (BS) is an effective intervention for obesity, inducing significant neurobiological and gut microbiota changes that influence hunger, appetite, taste perception, and long-term metabolic health. This narrative review examines these alterations by analyzing recent findings from clinical and preclinical studies, including neuroimaging, microbiome sequencing, and hormonal assessments. BS modulates appetite-regulating hormones, reducing ghrelin while increasing glucagon-like peptide-1 (GLP-1) and peptide tyrosine-tyrosine (PYY), leading to enhanced satiety and decreased caloric intake. Neuroimaging studies reveal structural and functional changes in brain regions involved in reward processing and cognitive control, contributing to reduced cravings and altered food choices. Additionally, BS reshapes the gut microbiota, increasing beneficial species such as Akkermansia muciniphila, which influence metabolic pathways through short-chain fatty acid production and bile acid metabolism. These findings highlight the complex interplay between the gut and the brain in post-surgical metabolic regulation. Understanding these mechanisms is essential for optimizing post-operative care, including nutritional strategies and behavioral interventions. Future research should explore how these changes impact long-term outcomes, guiding the development of targeted therapies to enhance the recovery and quality of life for BS patients.

Function and therapeutic potential of Amuc_1100, an outer membrane protein of Akkermansia muciniphila: A review

The gut microbiota-derived protein Amuc_1100, a key outer membrane component of Akkermansia muciniphila, has emerged as a groundbreaking therapeutic agent with unique structural and functional properties. Amuc_1100 exerts multifaceted immune-metabolic effects through novel mechanisms, including modulation of TLR2/4 and JAK/STAT pathways. This review highlights its unique multi-component structure that enables synergistic biological activity, and its pharmacological properties, which underlies its ability to enhance intestinal barrier integrity, restore microbiota balance, and suppress systemic inflammation. Crucially, Amuc_1100 demonstrates unprecedented therapeutic versatility across both intestinal disorders (e.g., inflammatory bowel disease, antibiotic-associated diarrhea) and extraintestinal conditions-notably improving neuropsychiatric symptoms via gut-serotonin axis regulation, combating cancer through CD8+ T cell activation, and mitigating cardiotoxicity via gut-heart immune crosstalk. Emerging innovations in targeted delivery systems, including gut-retentive nano-formulations and engineered probiotic vectors, further amplify its clinical potential. We critically evaluate recent advances distinguishing Amuc_1100's mechanisms from live bacterial interventions. By synthesizing evidence from preclinical models, this work positions Amuc_1100 as a prototype for next-generation microbiome-derived therapeutics, bridging microbial ecology with precision medicine.

Epigenetic phase variation in the gut microbiome enhances bacterial adaptation

The human gut microbiome within the gastrointestinal tract continuously adapts to variations in diet, medications, and host physiology. A strategy for bacterial genetic adaptation is epigenetic phase variation (ePV) mediated by bacterial DNA methylation, which can regulate gene expression, enhance clonal heterogeneity, and enable a single bacterial strain to exhibit variable phenotypic states. Genome-wide and site-specific ePVs have been characterized in human pathogens' antigenic variation and virulence factor production. However, the role of ePV in facilitating adaptation within the human microbiome remains poorly understood. Here, we comprehensively cataloged genome-wide and site-specific ePV in human infant and adult gut microbiomes. First, using long-read metagenomic sequencing, we detected genome-wide ePV mediated by complex structural variations of DNA methyltransferases, highlighting those associated with antibiotics or fecal microbiota transplantation. Second, we analyzed a collection of public short-read metagenomic sequencing datasets, uncovering a great prevalence of genome-wide ePV in the human gut microbiome. Third, we quantitatively detected site-specific ePVs using single-molecule methylation analysis to identify dynamic variation associated with antibiotic treatment or probiotic engraftment. Finally, we performed an in-depth assessment of an Akkermansia muciniphila isolate from an infant, highlighting that ePVs can regulate gene expression and enhance the bacterial adaptive capacity by employing a bet-hedging strategy to increase tolerance to differing antibiotics. Our findings indicate that epigenetic modifications are a common strategy used by gut bacteria to adapt to the fluctuating environment.

Clade-specific extracellular vesicles from Akkermansia muciniphila mediate competitive colonization via direct inhibition and immune stimulation

Akkermansia muciniphila, a promising candidate for next-generation probiotics, exhibits significant genomic diversity, classified into several distinct clades (AmI to AmIV). Notably, a single Akkermansia clade tends to predominate within individual hosts, with co-occurrence of different clades being rare. The mechanisms driving such clade-specific exclusion remain unclear. Here, we show that extracellular vesicles (EVs) derived from AmII clade inhibit the growth of clade I (AmI), conferring a competitive advantage to AmII. Moreover, we observe clade-specific immunoglobulin A (IgA) responses, where AmII clade-specific IgAs, induced by EVs from AmII, facilitate niche occupancy and competitive exclusion of AmI. These findings provide insights into the competitive dynamics of A. muciniphila clades and suggest that future personalized microbiome interventions could be optimized by considering the clade composition of A. muciniphila in individual hosts.

Live Biotherapeutic Products for Metabolic Diseases: Development Strategies, Challenges, and Future Directions

Metabolic diseases, such as obesity, type 2 diabetes, and non-alcoholic fatty liver disease, have emerged as major global health challenges. Recent research has revealed that the gut microbiome is closely associated with the development of these conditions. The Food and Drug Administration has recognized certain probiotic strains with therapeutic potential, classifying them as live biotherapeutic products (LBPs). LBPs, which are derived from naturally occurring microorganisms, may present an effective strategy for treating metabolic diseases by restoring gut microbiota balance and regulating metabolic functions. This review explores the development of LBPs specifically for metabolic disease treatments, covering every phase from strain identification, non-clinical and clinical trials, manufacturing and formulation to regulatory approval. Furthermore, it addresses the challenges involved in the commercialization of these therapies. By offering critical insights into the research and development of LBPs for metabolic disease treatment, this review aims to contribute to the progress of these promising therapies.

Gut microbiota: an emerging target connecting polycystic ovarian syndrome and insulin resistance

Polycystic ovary syndrome (PCOS) is a highly heterogeneous metabolic disorder, with oligomenorrhea and hirsutism as patients' primary complaints. Hyperinsulinemia is a crucial pathophysiological mechanism in the development of PCOS, with 50-70% of patients exhibiting insulin resistance (IR). This condition not only exacerbates ovulatory dysfunction but also leads to various adverse metabolic outcomes, such as dyslipidemia and diabetes, and increases the risk of cardiovascular events both before and after menopause. Gut microbiota is a microbial community within the host that possesses significant metabolic potential and is shaped by external environmental factors, the neuro-immune network, and metabolism. Recent studies have shown that gut microbiota dysbiosis is closely related to the development and progression of PCOS. Despite the growing recognition of the potential role of gut microbiota in the pathogenesis and treatment of PCOS, its clinical application remains in its infancy. Currently, most clinical guidelines and expert consensus still emphasize traditional therapeutic approaches, such as hormonal treatments, lifestyle modifications, and insulin sensitizers. However, accumulating evidence suggests that gut microbiota may influence the metabolic and reproductive health of PCOS patients through various mechanisms. Therefore, understanding the role of gut microbiota between PCOS and IR is essential. This review describes the changes in the gut microbiota of IR-PCOS patients, examines the potential mechanisms by which the gut microbiota contributes to IR in PCOS patients, and updates the evidence supporting the gut microbiota as a potential metabolic regulatory target in IR-PCOS. In summary, gut microbiota dysbiosis may be involved in the development and progression of IR in PCOS patients, and improving gut microbiota may offer metabolic stability benefits.

Akkermansia muciniphila-derived extracellular vesicles mitigate smoking-induced prostate inflammation and fibrosis

BACKGROUND

Cigarette smoking (CS) is a well-known risk factor for inducing prostate inflammation and fibrosis, presenting significant threats to male reproductive health. Recent research has highlighted the significant role of gut microbiota (GM) in regulating extra-intestinal organs. This study aimed to investigate the effects of Akk and its extracellular vesicles (EVs) on CS-induced prostate inflammation and fibrosis.

METHODS

This study utilized a mouse model of mainstream smoke exposure to investigate the effects of Akkermansia muciniphila (Akk) and its EVs on prostate tissue affected by CS. Prostate inflammation and fibrosis was assessed through HE staining, qRT-PCR, IHC staining, and immunofluorescence staining. Functional protein P9 enriched in Akk-EVs was used to intervene cigarette smoke extract (CSE)-exposed BPH-1 cells in vitro to validate the anti-inflammatory and anti-fibrotic effects.

RESULTS

The results revealed that CS exposure leads or led to pronounced prostatic inflammation and fibrosis, accompanied by a notable decrease in intestinal levels of Akk. Supplementation with Akk was found to effectively mitigate prostate lesions caused by CS, with the therapeutic effects primarily attributed to the Akk-derived extracellular vesicles (Akk-EVs). The transport kinetics of Akk-EVs to prostate tissue and cells were elucidated, providing insights into their mechanism of action. Both in vitro and in vivo experiments demonstrated that Akk-EVs and their enriched P9 protein effectively ameliorated CS-induced pro-inflammatory cytokine expression and collagen deposition in the prostate.

CONCLUSIONS

These findings highlight the anti-inflammatory and anti-fibrotic properties of Akk-EVs and P9 protein, suggesting their potential as therapeutic agents for CS-induced prostate lesions.

The worldview of Akkermansia muciniphila, a bibliometric analysis

Akkermansia muciniphila (A. muciniphila), a critical bacterium within the gut microbiota, plays a key role in human health and immunomodulation. Since its identification in 2004, A. muciniphila has emerged as a significant agent in treating metabolic diseases, gastroenterological diseases, and tumor immunotherapy. Its rapid ascent in scientific translation underscores its importance in gut microbiome research. However, there has been a lack of visualization and analysis of the rapidly occurring commercialization in this field, which has critically hindered insights into the current knowledge structure and understanding of the cutting-edge of the discipline. This study employs the Web of Science Core Collection (WOSCC) and Innography platforms to provide the first comprehensive analysis of A. muciniphila's academic progresses and commercialization over the past two decades, highlighting its growing prominence in global health research. Our analysis delineates that, following the academic trajectory, the evolution of A. muciniphila patents from foundational research through to application development and maturity, with particular emphasis on its expansive potential in emerging fields, including gastroenterological disorders, non-alcoholic fatty liver disease, cancer immunotherapy, stress management, and neurodegenerative disease treatment. Concluding, A. muciniphila presents as a next-generation probiotic with vast implications for human health. Our findings provide essential insights for future research and product development, contributing to the advancement of this burgeoning field.

Akkermansia muciniphila supplementation in patients with overweight/obese type 2 diabetes: Efficacy depends on its baseline levels in the gut

Akkermansia muciniphila is a promising target for managing obesity and type 2 diabetes (T2D), but human studies are limited. We conducted a 12-week randomized, double-blind, placebo-controlled trial involving 58 participants with overweight or obese T2D, who received A. muciniphila (AKK-WST01) or placebo, along with routine lifestyle guidance. Both groups showed decreases in body weight and glycated hemoglobin (HbA1c), without significant between-group differences. In participants with low baseline A. muciniphila, AKK-WST01 supplementation showed high colonization efficiency and significant reductions in body weight, fat mass, and HbA1c, which were not found in the placebo group. However, AKK-WST01 supplementation showed poor colonization and no significant clinical improvements in participants with high baseline A. muciniphila. These findings were verified in germ-free mice receiving feces with low or high A. muciniphila. Our study indicates that metabolic benefits of A. muciniphila supplementation could depend on its baseline intestinal levels, supporting the potential for gut microbiota-guided probiotic supplementation. (ClinicalTrials.gov number, NCT04797442).

Targeted gut microbiome therapy: Applications and prospects of probiotics, fecal microbiota transplantation and natural products in the management of type 2 diabetes

Type 2 diabetes mellitus (T2DM) is considered as one of the most pressing public health challenges worldwide. Studies have shown significant differences in the gut microbiota between healthy individuals and T2DM patients, suggesting that gut microorganisms may play a key role in the onset and progression of T2DM. This review systematically summarizes the relationship between gut microbiota and T2DM, and explores the mechanisms through which gut microorganisms may alleviate T2DM. Additionally, it evaluates the potential of probiotics, fecal microbiota transplantation (FMT)/virome transplantation (FVT), and natural products in modulating gut microbiota to treat T2DM. Although existing studies have suggested that these interventions may delay or even halt the progression of T2DM, most research remained limited to animal models and observational clinical studies, with a lack of high-quality clinical data. This has led to an imbalance between theoretical research and clinical application. Although some studies have explored the regulatory role of the gut virome on the gut microbiota, research in this area remains in its early stages. Based on these current studies, future research should be focused on large-scale, long-term clinical studies and further investigation on the potential role of the gut virome in T2DM. In conclusion, this review aims to summarize the current evidence and explore the applications of gut microbiota in T2DM treatment, as well as providing recommendations for further investigation in this field.

Akkermansia muciniphila: biology, microbial ecology, host interactions and therapeutic potential

Akkermansia muciniphila is a gut bacterium that colonizes the gut mucosa, has a role in maintaining gut health and shows promise for potential therapeutic applications. The discovery of A. muciniphila as an important member of our gut microbiome, occupying an extraordinary niche in the human gut, has led to new hypotheses on gut health, beneficial microorganisms and host-microbiota interactions. This microorganism has established a unique position in human microbiome research, similar to its role in the gut ecosystem. Its unique traits in using mucin sugars and mechanisms of action that can modify host health have made A. muciniphila a subject of enormous attention from multiple research fields. A. muciniphila is becoming a model organism studied for its ability to modulate human health and gut microbiome structure, leading to commercial products, a genetic model and possible probiotic formulations. This Review provides an overview of A. muciniphila and Akkermansia genus phylogeny, ecophysiology and diversity. Furthermore, the Review discusses perspectives on ecology, strategies for harnessing beneficial effects of A. muciniphila for human mucosal metabolic and gut health, and its potential as a biomarker for diagnostics and prognostics.

Harnessing Akkermansia muciniphila Membrane Coating for Probiotic Therapy in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are characterized by dysregulated inflammatory responses, increased reactive oxygen species (ROS), and compromised intestinal barrier function. Current clinical treatments often yield suboptimal responses and significant side effects. Given the great potential of Akkermansia muciniphila (AKK) bacterial membrane components in IBD treatment and the possible pathogenicity of live bacteria, to essentially address these challenges, we develop a natural membrane-based single-cell coating, incorporating a self-assembled AKK bacterial membrane (AKM) and astaxanthin (AST), forming a protective biological barrier on probiotics. Utilizing Escherichia coli Nissle 1917 (EcN) for the oral delivery system, we engineer AKM-AST@EcN nanocoated probiotics, demonstrating exceptional gastrointestinal (GI) tract tolerance and robust bioactivity. Critically, our findings highlight the potential of AKM-AST@EcN as a promising therapeutic approach for IBD treatment while also presenting a distinctive strategy for probiotic oral delivery systems.

Holobiome Harmony: Linking Environmental Sustainability, Agriculture, and Human Health for a Thriving Planet and One Health

The holobiome is an interconnected network of microbial ecosystems spanning soil, plants, animals, humans, and the environment. Microbial interactions drive nutrient cycling, pathogen suppression, and climate regulation. Soil microbiomes facilitate carbon sequestration and enhance soil fertility, while marine microbiomes contribute to carbon capture and climate stability. However, industrial agriculture, extensive herbicide use, antibiotic overuse, and climate change threaten microbial diversity, leading to ecosystem and health disruptions. Probiotic interventions help to restore microbial balance. In human health, probiotics support gut microbiota diversity, reduce inflammation, and regulate metabolism. In agriculture, soil probiotics enhance microbial diversity, improve nutrient cycling, and degrade contaminants, increasing crop yields and soil health. Case studies show that microbial inoculants effectively remediate degraded soils and enhance nutrient uptake. Artificial intelligence is transforming microbiome research by enabling predictive modeling, precision probiotic design, and microbial consortia optimization. Interdisciplinary collaboration and supportive policies are essential for restoring microbial equilibria, ensuring ecosystem resilience, and promoting long-term sustainability. The integration of artificial intelligence, clinical research, and sustainable practices is crucial for advancing holobiome science. The holobiome framework underscores the need for interdisciplinary collaboration to address global challenges, bridging environmental sustainability, agriculture, and public health for a resilient future.

Effects of hawthorn pectin and its oligomers on gut microbiota and metabolites in high-fat diet mice

Pectin is an acidic heteropolysaccharide with natural, green, and inexpensive characteristics. Compared to polysaccharides, oligosaccharides are more easily utilized by the body, and the physiological function of hawthorn pectin oligosaccharides (POS) may vary depending on their degree of polymerization (DP). Therefore, we mainly studied the effects of hawthorn pectin (HP) and POS with different DP on gut microbiota disorders induced by high-fat diet (HFD). HP and POS both improved weight gain, dyslipidemia, and glucose homeostasis caused by HFD, and increased serum GLP-1 levels. Meanwhile, the increased expression of Gcg and Pcsk1 genes in the ileum of the treatment group further confirmed this result. In addition, HP and POS reduced certain opportunistic pathogens, while restoring the richness and diversity of the gut microbiota. Meanwhile, HP and POS can improve intestinal barrier dysfunction by increasing the claudin-1, occludin, ZO-1, and MUC2 genes. Furthermore, fecal metabolomics suggests that POS may enhance linoleic acid synthesis and improve lipid metabolism by upregulating 9,10-DHOME ((12Z)-9,10-dihydroxyoctadec-12-enoic acid), while HP cannot. Overall, the research results indicate that both HP and POS can improve the weight phenotype changes, gut microbiota disruption, and metabolites changes caused by HFD. Particularly, POS has a better effect than HP, and there are differences in the improvement effect of POS with different DP, among which POS with DP 5 has the most significant improvement effect. This discovery enhances a deeper comprehension of the biological activity of different POS, providing an important basis for further optimizing the application of POS as a functional food.

GLP-1-based therapies for type 2 diabetes: from single, dual and triple agonists to endogenous GLP-1 production and L-cell differentiation

Glucagon-like peptide-1 (GLP-1) is an incretin peptide hormone mainly secreted by enteroendocrine intestinal L-cells. GLP-1 is also secreted by α-cells of the pancreas and the central nervous system (CNS). GLP-1 secretion is stimulated by nutrient intake and exerts its effects on glucose homeostasis by stimulating insulin secretion, gastric emptying confiding the food intake, and β-cell proliferation. The insulinotropic effects of GLP-1, and the reduction of its effects in type 2 diabetes mellitus (T2DM), have made GLP-1 an attractive option for the treatment of T2DM. Furthermore, GLP-1-based medications such as GLP-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, have been shown to improve diabetes control in preclinical and clinical trials with human subjects. Importantly, increasing the endogenous production of GLP-1 by different mechanisms or by increasing the number of intestinal L-cells that tend to produce this hormone may be another effective therapeutic approach to managing T2DM. Herein, we briefly describe therapeutic agents/compounds that enhance GLP-1 function. Then, we will discuss the approaches that can increase the endogenous production of GLP-1 through various stimuli. Finally, we introduce the potential of L-cell differentiation as an attractive future therapeutic approach to increase GLP-1 production as an attractive therapeutic alternative for T2DM.

Big lessons from the little Akkermansia muciniphila in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most frequently occurring type of liver tumor and is considered one of the most common primary malignant neoplasms. The prognosis for HCC is dismal because of its complicated etiology and high level of medication resistance. Immunotherapy is presently regarded as one of the most effective therapeutic options for HCC; nevertheless, because of the disturbance of intestinal flora, immunotherapy shows low antitumor efficacy. An increasing body of research indicates that intestinal flora, particularly Akkermansia muciniphila (A. muciniphila), is vital for the treatment of tumors. Studies have demonstrated that the diminished effectiveness of immunotherapy in cancer patients is associated with a reduction in A. muciniphila levels, suggesting that increasing A. muciniphila levels significantly enhance the efficacy of immunotherapy. A. muciniphila functions as a gut probiotic and can treat and prevent a wide range of illnesses, including cancer. Consequently, preserving A. muciniphila abundance is enough to prevent and lower the danger of developing cancer disorders. In this review, we critically evaluate the current body of research on A. muciniphila, with a primary focus on its biological properties and functions. The different illnesses that A. muciniphila treats were then discussed, particularly the way it works with liver cancer. This review aims to give a novel treatment plan for patients with HCC as well as a theoretical foundation for improving HCC immunotherapy.

Effects of Monascus pilosus SWM 008-Fermented Red Mold Rice and Its Functional Components on Gut Microbiota and Metabolic Health in Rats

Red mold rice, fermented by Monascus spp., has been reported to modulate gut microbiota composition and improve metabolic health. Previous studies indicate that red mold rice can reduce cholesterol, inhibit hepatic lipid accumulation, and enhance bile acid excretion, while also altering gut microbiota under high-fat dietary conditions. However, it remains unclear whether these effects are directly due to Monascus-derived products modulating gut microbiota or are a consequence of improved metabolic health conditions, which indirectly influence gut microbiota. This study aimed to evaluate the effects of Monascus pilosus SWM 008 fermented red mold rice and its components-monascin, monascinol, ankaflavin, and polysaccharides-on gut microbiota and metabolic health in rats fed a normal diet. Over eight weeks, physiological, biochemical, and gut microbiota parameters were assessed. Results showed no significant changes in body weight or liver/kidney function, confirming safety. Gut microbiota analysis revealed that red mold rice, monascin, monascinol, and polysaccharides significantly altered gut microbiota composition by increasing the relative abundance of beneficial bacteria, such as Akkermansia muciniphila, Ligilactobacillus murinus, and Duncaniella dubosii. Functional predictions indicated enhanced vitamin K2 biosynthesis, nucleotide metabolism, and other metabolic pathways linked to improved gut health. In conclusion, Monascus pilosus SWM 008 fermented red mold rice demonstrated safety and beneficial effects, suggesting its potential as a functional food to maintain gut microbiota balance under normal dietary conditions.

Antibiotic-associated changes in Akkermansia muciniphila alter its effects on host metabolic health

BACKGROUND

Altered gut microbiota has emerged as a major contributing factor to the etiology of chronic conditions in humans. Antibiotic exposure, historically dating back to the mass production of penicillin in the early 1940s, has been proposed as a primary contributor to the cumulative alteration of microbiota over generations. However, the mechanistic link between the antibiotics-altered microbiota and chronic conditions remains unclear.

RESULTS

In this study, we discovered that variants of the key beneficial gut microbe, Akkermansia muciniphila, were selected upon exposure to penicillin. These variants had mutations in the promoter of a TEM-type β-lactamase gene or pur genes encoding the de novo purine biosynthesis pathway, and they exhibited compromised abilities to mitigate host obesity in a murine model. Notably, variants of A. muciniphila are prevalent in the human microbiome worldwide.

CONCLUSIONS

These findings highlight a previously unknown mechanism through which antibiotics influence host health by affecting the beneficial capacities of the key gut microbes. Furthermore, the global prevalence of A. muciniphila variants raises the possibility that these variants contribute to global epidemics of chronic conditions, warranting further investigations in human populations. Video Abstract.

Effects of exopolysaccharides form Lactobacillus plantarum KX041 on high fat diet-induced gut microbiota and inflammatory obesity

Lactobacillus plantarum KX041 is a probiotics obtained from early screening, which can relieve inflammation and enrich the anti-obesity intestinal flora, and produce high yield of exopolysaccharides (EPS). The extraction, structure and physicochemical properties of EPS have been completed earlier. However, whether the functional activity of L. plantarum KX041 is related to the EPS is still unclear. In this study, combined in vivo and in vitro tests explored the effects of EPS on inflammatory obesity. In vitro tests, EPS relieased inflammation by inhibiting TLR4/p-NFκB, and inhibited adipocyte differentiation and reduced the transcriptional level of inflammation and lipid-synthesis genes (especially CD36 and peroxisome proliferators-activated receptors-γ PPARγ). In vivo tests demonstrated that EPS could alleviate weight gain, white adipocyte expansion, organ damage, insulin resistance, hyperlipidemia, and inflammatory response caused by high fat diet. Combined with in vitro tests, the transcription level of inflammation and lipid-synthesis genes in adipose tissue identified that IL-1β and PPARγ were the key genes for the effect of EPS on inflammatory obesity. Moreover, EPS increased the abundance of Akkermansia and Lachnospiraceae_NK4A136_group, and intestinal levels of isobutyrate, which is one of the key factors in alleviating inflammatory obesity. These insights may inform the development of functionalized dietary interventions in obesity.

Biomimetic nanoplatform with microbiome modulation and antioxidant functions ameliorating insulin resistance and pancreatic β-cell dysfunction for T2DM management

Insulin resistance and pancreatic β-cell dysfunction are the main pathogenesis of type 2 diabetes mellitus (T2DM). However, insulin therapy and diabetes medications do not effectively solve the two problems simultaneously. In this study, a biomimetic oral hydrogen nanogenerator that leverages the benefits of edible plant-derived exosomes and hydrogen therapy was constructed to overcome this dilemma by modulating gut microbiota and ameliorating oxidative stress and inflammatory responses. Hollow mesoporous silica (HMS) nanoparticles encapsulating ammonia borane (A) were used to overcome the inefficiency of H2 delivery in traditional hydrogen therapy, and exosomes originating from ginger (GE) were employed to enhance biocompatibility and regulate intestinal flora. Our study showed that HMS/A@GE not only considerably ameliorated insulin resistance and liver steatosis, but inhibited the dedifferentiation of islet β-cell and enhanced pancreatic β-cell proportion in T2DM model mice. In addition to its antioxidant and anti-inflammatory effects, HMS/A@GE augmented the abundance of Lactobacilli spp. and tryptophan metabolites, such as indole and indole acetic acid, which further activated the AhR/IL-22 pathway to improve intestinal-barrier function and metabolic impairments. This study offers a potentially viable strategy for addressing the current limitations of diabetes treatment by integrating gut-microbiota remodelling with antioxidant therapies.

Xylooligosaccharide and Akkermansia muciniphila synergistically ameliorate insulin resistance by reshaping gut microbiota, improving intestinal barrier and regulating NKG2D/NKG2DL signaling in gestational diabetes mellitus mice

Xylooligosaccharides (XOS) ameliorate insulin resistance (IR) in gestational diabetes mellitus (GDM) probably by propagating Akkermansia muciniphila (Akk). This study aimed to investigate the effects and mechanisms of XOS, Akk and combination on IR in GDM mice/pseudo-germ-free (PGF) mice. Female mice were fed with AIN-93 (n = 19) and high fat diet (HFD) (n = 206). After 4 weeks, HFD-fed mice were further allotted to HFD, GDM, GDM + XOS, GDM + Akk, GDM + XOS + Akk, GDM + PGF, GDM + PGF + XOS, GDM + PGF + Akk, and GDM + PGF + XOS + Akk groups (n ≥ 19). GDM was induced by intraperitoneally injecting streptozotocin and PGF was established by intragastrically administrating antibiotic cocktails. XOS (500 mg/kg·BW) or/and Akk (4 × 108 CFU) were gavaged once a day for 10 days. Fasting blood glucose (FBG), insulin, oral glucose tolerance test (OGTT) and insulin signaling pathway were determined. Gut microbiota were detected by 16S rRNA sequencing and absolute quantities of Akk by qRT-PCR. Intestinal tissues were stained by Hematoxylin-Eosin and Periodic acid-Schiff-Alcian blue staining. Occludin and Zonula occludens-1 (ZO-1) in intestine, Natural killer group 2 member D (NKG2D) on intestinal epithelial lymphocytes (IELs) and NKG2D ligands (NKG2DL) on intestinal epithelial cells (IECs) were detected by Western blotting. In GDM mice, XOS, Akk and XOS + Akk reduced (p < 0.05) the area under the curve of OGTT (AUC), insulin and homeostasis model assessment of insulin resistance (HOMA-IR), and increased (p < 0.05) protein kinase B (Akt) phosphorylation in liver and insulin receptor substrate 1 (IRS-1) phosphorylation in muscle. Furthermore, XOS + Akk reduced (p < 0.05) FBG and increased (p < 0.05) Akt phosphorylation in muscle and IRS-1 phosphorylation in liver. XOS, Akk and XOS + Akk reshaped gut microbiota with XOS + Akk exhibiting the greatest effectiveness. XOS increased (p < 0.05) Akk and clearance of gut microbiota abolished such effect. XOS, Akk and XOS + Akk reduced (p < 0.05) the small intestine Chiu's score and the colon Dieleman's scores, increased (p < 0.05) ZO-1 and Occludin, and reduced (p < 0.05) NKG2D on IELs and NKG2DLs (H60, MULT-1, Rae-1ε) on IECs. Moreover, XOS + Akk reduced (p < 0.05) MULT-1 in duodenum. Collectively, XOS and Akk synergistically ameliorate IR by reshaping gut microbiota, improving intestinal barrier and regulating NKG2D/NKG2DL signaling in GDM mice.

Health Effects and Therapeutic Potential of the Gut Microbe Akkermansia muciniphila

Akkermansia muciniphila is a bacterium commonly found in the human gastrointestinal tract that has received considerable interest as a potential probiotic for the improvement of gut health and overall metabolic function. A. muciniphila is enriched in the mucus layer of the intestinal lining, where it degrades mucin and plays a significant role in gut barrier maintenance and immune regulation. A higher abundance of A. muciniphila has been observed in the gut of healthy individuals relative to those with metabolic disorders, and multiple metabolic benefits, including improved glucose management, reduced body fat, and reduced inflammation have been linked to A. muciniphila. Current research on A. muciniphila primarily relies on mouse models, with limited human interventional studies available. While these animal studies offer valuable insights into the potential roles of A. muciniphila in health and disease, further clinical investigations in humans are needed to fully understand its impact. Here, we explore the current scope of A. muciniphila research and its potential as a therapeutic agent to improve gut and metabolic health while also emphasizing the need to optimize techniques to further improve studies of this organism.

Simiao Wan attenuates high-fat diet-induced hyperlipidemia in mice by modulating the gut microbiota-bile acid axis

ETHNOPHARMACOLOGICAL RELEVANCE

Hyperlipidemia is a lipid metabolism disorder and a risk factor for obesity, diabetes, and coronary heart disease. It occurs mostly in the old adults; however, its incidence rate is increasing annually and there is a trend towards younger adults. Current clinical drugs for treating hyperlipidemia have multiple side effects. Therefore, it is necessary to develop safe and effective drugs from natural products to prevent and treat hyperlipidemia. Simiao Wan (SMW) is a classic Chinese medicine prescription first recorded in the Cheng Fang Bian Du of the Qing Dynasty. Studies have shown that SMW has excellent efficacy in metabolic diseases, which can effectively improve hyperlipidemia combined with other metabolic diseases. However, its underlying mechanism in hyperlipidemia treatment is yet to be clarified.

AIM OF THE STUDY

To investigate the hypolipidemic effect of SMW on hyperlipidemic mice and explore whether the gut microbiota-bile acid (BA) axis is the potential mechanism.

MATERIALS AND METHODS

A hyperlipidemic mouse model was established using a high-fat diet (HFD), and the hypolipidemic effect of SMW was detected in vivo. We performed 16S ribosomal RNA sequencing and BA metabolism analysis to explore the hypolipidemic mechanisms of SMW. Western blotting was conducted to detect the expression of proteins involved in the gut microbiota-BA axis to determine the potential lipid-lowering pathway.

RESULTS

Excessive obesity in hyperlipidemic mice was alleviated after 8 weeks of SMW treatment. The total cholesterol and low-density lipoprotein cholesterol levels decreased significantly, whereas high-density lipoprotein cholesterol levels increased. SMW also reduced hepatic lipid and inguinal white adipose tissue accumulation in HFD-induced hyperlipidemic mice. Furthermore, intestinal bile saline hydrolase (BSH) level, associated with BA excretion, decreased. Meanwhile, SMW decreased the abundance of BSH-enriched microbes in hyperlipidemic mice. SMW increased the intestinal conjugated-BAs contents in hyperlipidemic mice, especially tauro-β-muricholic acid and tauro-ursodeoxycholic acid, which are ileac farnesoid X receptor (FXR) antagonists. Inhibited intestinal FXR signaling with SMW was accompanied by a decreased expression of intestinal fibroblast growth factor 15 and the activation of hepatic FXR, which promoted hepatic cholesterol conversion to BA.

CONCLUSION

SMW indirectly attenuated HFD-induced hyperlipidemia in mice by regulating the gut microbiota-BA axis. Our results provide a pharmacological basis for SMW treating hyperlipidemia and suggest a new idea for developing lipid-lowering drugs.

Randomised double-blind placebo-controlled trial protocol to evaluate the therapeutic efficacy of lyophilised faecal microbiota capsules amended with next-generation beneficial bacteria in individuals with metabolic dysfunction-associated steatohepatitis

BACKGROUND

The spectrum of metabolic dysfunction-associated steatotic liver disease (MASLD) is highly prevalent, affecting 30% of the world's population, with a significant risk of hepatic and cardiometabolic complications. Different stages of MASLD are accompanied by distinct gut microbial profiles, and several microbial components have been implicated in MASLD pathophysiology. Indeed, earlier studies demonstrated that hepatic necroinflammation was reduced in individuals with MASLD after allogenic faecal microbiota transplantation (FMT) from healthy donors on a vegan diet. Here, we further investigate the therapeutic potential of gut microbiome modulation using a syntrophic combination of next-generation beneficial bacteria with FMT in individuals with advanced MASLD.

METHODS AND ANALYSIS

This trial is a randomised, double-blind, placebo-controlled study investigating the therapeutic potential of lyophilised faecal microbiota capsules (LFMCs) in individuals with metabolic dysfunction-associated steatohepatitis. In this study, 48 participants will be randomised 1:1 to receive either healthy vegan donor LFMCs or placebo for 24 weeks. In addition, all participants will be supplemented with a set of next-generation beneficial bacteria, including Anaerobutyricum soehngenii, pasteurised Akkermansia muciniphila and Bifidobacterium animalis subsp. lactis, as well as fructo-oligosaccharides. A liver biopsy will be performed at baseline and at the end of the trial. In addition, participants will be assessed through MRI, FibroScan, blood tests, faecal samples and continuous glucose monitoring. The first participant was enrolled on 25 April 2023.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Medical Ethics Committee of the University Medical Centre of Amsterdam. The results of this study will be disseminated through peer-reviewed journals.

TRIAL REGISTRATION NUMBER

The trial is registered on clinicaltrials.gov (NCT05821010).

Update on Hypothalamic Inflammation and Gliosis: Expanding Evidence of Relevance Beyond Obesity

PURPOSE OF REVIEW

To evaluate the role of hypothalamic inflammation and gliosis in human obesity pathogenesis and other disease processes influenced by obesity.

RECENT FINDINGS

Recent studies using established and novel magnetic resonance imaging (MRI) techniques to assess alterations in hypothalamic microarchitecture in humans support the presence of hypothalamic inflammation and gliosis in adults and children with obesity. Studies also identify prenatal exposure to maternal obesity or diabetes as a risk factor for hypothalamic inflammation and gliosis and increased obesity risk in offspring. Hypothalamic inflammation and gliosis have been further implicated in reproductive dysfunction (specifically polycystic ovarian syndrome and male hypogonadism), cardiovascular disease namely hypertension, and alterations in the gut microbiome, and may also accelerate neurocognitive aging. The most recent translational studies support the link between hypothalamic inflammation and gliosis and obesity pathogenesis in humans and expand our understanding of its influence on broader aspects of human health.

Lactobacillus reuteri-Enriched Eicosatrienoic Acid Regulates Glucose Homeostasis by Promoting GLP-1 Secretion to Protect Intestinal Barrier Integrity

Lactobacillus reuteri is a well-known probiotic with beneficial effects, such as anti-insulin resistance, anti-inflammatory, and improvement of the intestinal barrier. However, the underlying mechanisms remain unclear. Here, we found that gavage of L. reuteri improved the intestinal barrier and glucose homeostasis in HFD-fed mice. Analysis of lipid metabolomics reveals a significant increase in eicosatrienoic acid (ETA) levels in mouse feces after L. reuteri gavage. We found that ETA maintain intestinal barrier integrity and improve glucose homeostasis by promoting GLP-1 secretion. Mechanistically, by using CD36 inhibitor in vivo and CD36 knockdown STC-1 cells in vitro, we elucidate that ETA activates intestinal CD36-activated PLC/IP3R/Ca2+ signaling to promote GLP-1 secretion. In vivo administration of GLP-1R inhibitor and in vitro intestinal organoid experiments demonstrate that GLP-1 upregulates the PI3K/AKT/HIF-1α pathway by GLP-1R and increases intestinal tight junction protein expressions, which in turn enhance the intestinal barrier integrity, reduce serum LPS level, attenuate inflammation in white adipose tissue (WAT), and ultimately improve glucose homeostasis in HFD and db/db mice. Our study elucidates for the first time the mechanism by which L. reuteri and its enriched metabolite ETA inhibit WAT inflammation by ameliorating the intestinal barrier, ultimately improving glucose homeostasis, and provides a new treatment strategy for T2D.

Microbiome and metabolomics reveal the effect of gut microbiota on liver regeneration of fatty liver disease

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is associated with impaired regenerative capacity and poor postoperative prognosis following hepatectomy. Previous research has highlighted the importance of the gut-liver axis in the physiological and pathological processes of the liver. However, the contribution of gut bacteria to the regeneration of livers with MAFLD and its metabolic regulatory mechanisms remain elusive.

METHODS

Partial hepatectomy (PHx) was performed on C57Bl/6J mice fed with high-fat diet (HFD) for 12 weeks. Pathological examination, immunohistochemistry, and qRT-PCR analysis were performed to assess the severity of steatosis and proliferative potential. The gut microbiome was examined by 16S rRNA gene sequencing and shotgun metagenomics, whereas liver metabolomics was analysed via untargeted and targeted metabolomics using liquid chromatography-tandem mass spectrometry (LC-MS).

FINDINGS

HFD-induced hepatic steatosis in mice led to impaired liver regeneration following PHx. The gut microbiota and liver metabolites were altered along with the liver regeneration process. Longitudinal time-series analysis revealed dynamic alterations in these data, whereas correlation analysis screened out bacterial candidates that potentially influence liver regeneration in MAFLD by modulating metabolic pathways. Among these bacteria, the dominant bacterium Akkermansia was selected for subsequent investigation. MAFLD mice gavaged with Akkermansia muciniphila (A. muciniphila) exhibited reduced liver lipid accumulation and accelerated liver regeneration, possibly through the regulation of the tricarboxylic acid (TCA) cycle.

INTERPRETATION

These data demonstrated the interplay between the gut microbiome, liver metabolomics, and liver regeneration in mice with MAFLD. A. muciniphila has the potential to serve as a clinical intervention agent to accelerate postoperative recovery in MAFLD.

FUNDING

This work was supported by the Research Project of Jinan Microecological Biomedicine Shandong Laboratory [JNL-2022008B]; the Zhejiang Provincial Natural Science Foundation of China [LZ21H180001]; the Fundamental Research Funds for the Central Universities [No. 2022ZFJH003].

Live Akkermansia muciniphila boosts dendritic cell retinoic acid synthesis to modulate IL-22 activity and mitigate colitis in mice

BACKGROUND

The interplay between gut microbiota and immune responses is crucial in ulcerative colitis (UC). Though Akkermansia muciniphila (Akk) shows therapeutic potential, the mechanisms remain unclear. This study sought to investigate differences in therapeutic efficacy among different forms or strains of Akk and elucidate the underlying mechanisms.

RESULTS

Employing a dextran sulfate sodium (DSS)-induced colitis mouse model, we assessed Akk's impact on colitis using cellular cytokine analysis, immune phenotyping, proteomics, and biochemical methods. Our results suggest that treatment with live Akk effectively reduced colitis in the DSS-induced model, whereas heat-inactivated Akk did not yield the same results. Notably, Akk exhibited protective properties by promoting the secretion of IL-22 by Group 3 innate lymphoid cells (ILC3s), as evidenced by the absence of protection in IL-22 knockout mice. Additionally, Akk augmented the population of CD103+CD11b- dendritic cells (DCs) and enhanced their retinoic acid (RA) synthesis through the modulation of RALDH2, a crucial enzyme in RA metabolism. The depletion of RALDH2 in DCs diminished Akk's protective properties and impaired IL-22-mediated mucosal healing. Mechanistically, Akk activated RA production in DCs by enhancing the JAK2-STAT3 signaling pathway. Additionally, various strains of Akk may exhibit differing abilities to alleviate colitis, with the novel strain Am06 derived from breast milk showing consistent efficacy similar to the reference strain.

CONCLUSIONS

In summary, our findings indicate that certain strains of Akk may mitigate colitis through the promotion of RA synthesis and IL-22 secretion, underscoring the potential efficacy of Akk as a therapeutic intervention for the management of UC. Video Abstract.

Akkermansia muciniphila: A Potential Target for the Prevention of Diabetes

Akkermansia muciniphila, a Gram-negative anaerobic bacterium colonizing the intestinal mucus layer, is regarded as a promising "next-generation probiotic". There is mounting evidence that diabetes and its complications are associated with disorders of A. muciniphila abundance. Thus, A. muciniphil and its components, including the outer membrane protein Amuc_1100, A. muciniphila-derived extracellular vesicles (AmEVs), and the secreted proteins P9 and Amuc_1409, are systematically summarized with respect to mechanisms of action in diabetes mellitus. Diabetes treatments that rely on altering changes in A. muciniphila abundance are also reviewed, including the identification of A. muciniphila active ingredients, and dietary and pharmacological interventions for A. mucinihila abundance. The potential and challenges of using A. muciniphila are also highlighted, and it is anticipated that this work will serve as a reference for more in-depth studies on A. muciniphila and diabetes development, as well as the creation of new therapeutic targets by colleagues domestically and internationally.

The Effects of Novel Co-Amorphous Naringenin and Fisetin Compounds on a Diet-Induced Obesity Murine Model

BACKGROUND/OBJECTIVE

In recent studies, it has been shown that dietary bioactive compounds can produce health benefits; however, it is not known whether an improvement in solubility can enhance their biological effects. Thus, the aim of this work was to study whether co-amorphous (CoA) naringenin or fisetin with enhanced solubility modify glucose and lipid metabolism, thermogenic capacity and gut microbiota in mice fed a high-fat, high-sucrose (HFSD) diet.

METHODS

Mice were fed with an HFSD with or without CoA-naringenin or CoA-fisetin for 3 months. Body weight, food intake, body composition, glucose tolerance, hepatic lipid composition and gut microbiota were assessed.

RESULTS

CoA-naringenin demonstrated significant reductions in fat-mass gain, improved cholesterol metabolism, and enhanced glucose tolerance. Mice treated with CoA-naringenin gained 45% less fat mass and exhibited improved hepatic lipid profiles, with significant reductions seen in liver triglycerides and cholesterol. Additionally, both CoA-flavonoids increased oxygen consumption (VO2), contributing to enhanced energy expenditure and improved metabolic flexibility. Thermogenic activation, indicated by increased UCP1 and PGC-1α levels, was observed with CoA-fisetin, supporting its role in fat oxidation and adipocyte size reduction. Further, both CoA-flavonoids modulated gut microbiota, restoring diversity and promoting beneficial bacteria, such as Akkermansia muciniphila, which has been linked to improved metabolic health.

CONCLUSIONS

These findings suggest that co-amorphous naringenin or fisetin offers promising applications in improving solubility, metabolic health, and thermogenesis, highlighting the potential of both as therapeutic agents against obesity and related disorders.

Early-life exposure to polystyrene micro- and nanoplastics disrupts metabolic homeostasis and gut microbiota in juvenile mice with a size-dependent manner

Early-life exposure to different sizes of micro- and nanoplastics (MNPs) affects biotoxicity, which is related not only to the dose but also directly to particle size. In this study, pregnant ICR mice received drinking water containing 5 μm polystyrene microplastics (5 μm PS-MPs) or 0.05 μm polystyrene nanoplastics (0.05 μm PS-NPs) from pregnancy to the end of lactation. Histopathological and molecular biological detection, 16s rRNA sequencing for intestinal flora analysis, and targeted metabolomics analysis were used to look into how early-life exposure to MNPs of various sizes affects young mice's growth and development, gut flora, and metabolism. The outcomes showed that 0.05 μm and 5 μm PS-MNPs can pass through the placental and mammary barriers, and MNPs accumulating in various organs were size-dependent: the greater the accumulation in organs, the smaller the particle size. Further studies found that the larger 5 μm PS-MPs caused only small accumulation in organs, with the main health hazard being the disruption of intestinal barrier and liver function, indirectly causing gut dysbiosis and metabolic disorders. In contrast, the smaller 0.05 μm PS-NPs caused excessive accumulation in organs, not only impaired the function of the intestine and liver, but also caused direct mechanical damage to physical tissues, and ultimately resulted in more severe intestinal and metabolic disorders. Our findings underline the size-dependent risks associated with micro- and nanoplastics exposure early in life and highlight the necessity for tailored approaches to address health damages from early MNPs exposure.

Bioactive compounds regulate appetite through the melanocortin system: a review

Obesity, a significant health crisis, arises from an imbalance between energy intake and expenditure. Enhancing appetite regulation has garnered substantial attention from researchers as a novel and effective strategy for weight management. The melanocortin system, situated in the hypothalamus, is recognized as a critical node in the regulation of appetite. It integrates long-term and short-term hormone signals from the periphery as well as nutrients, forming a complex network of interacting feedback mechanisms with the gut-brain axis, significantly contributing to the regulation of energy homeostasis. Appetite regulation by bioactive compounds has been a focus of intensive research due to their favorable safety profiles and easy accessibility. These bioactive compounds, derived from a variety of plant and animal sources, modulate the melanocortin system and influence appetite and energy homeostasis through multiple pathways: central nervous system, peripheral hormones, and intestinal microbiota. Here, we review the anatomy, function, and receptors of the melanocortin system, outline the long-term and short-term regulatory hormones that act on the melanocortin system, and discuss the bioactive compounds and their mechanisms of action that exert a regulatory effect on appetite by targeting the melanocortin system. This review contributes to a better understanding of how bioactive compounds regulate appetite via the melanocortin system, thereby providing nutritional references for citizens' dietary preferences.

Lack of genotoxicity and subchronic toxicity in safety assessment studies of Akkermansia muciniphila formulation

A powder formulation of viable Akkermansia muciniphila bacteria (AMUC) was evaluated in a 90-day repeated-dose toxicity study in rats and a battery of genotoxicity studies to evaluate AMUC as a food ingredient. All studies followed Organisation for Economic Co-operation and Development protocols (OECD TG 408, 471 473, 474). AMUC was administered to rats via gavage at 0, 500, 1000, and 2000 mg/kg body weight/day (equivalent to 0, 4.1 × 1010, 9.2 × 1010, and 1.64 × 1011 CFU/kg body weight/day). No mortality or treatment-related adverse effects were reported in any endpoints that were attributed to AMUC consumption. No bacterial translocation of viable A. muciniphila from the intestinal tract was found to the liver, mesenteric lymph nodes, or blood. The no-observed-adverse-effect level was concluded to be the highest dose tested (2000 mg/kg body weight/day), approximately 1.64 × 1011 CFU/kg body weight/day. AMUC (nonviable) was not mutagenic when examined in an in vitro bacterial reverse mutation assay and not clastogenic in an in vitro mammalian chromosomal aberration test. Viable AMUC was not genotoxic when evaluated in an in vivo mammalian cell micronucleus assay when administered at up to 1.64 ×1011 CFU/kg body weight/day. These results confirm that AMUC is not toxic under the conditions of these studies.

Akkermansia Muciniphila supplementation improves hyperlipidemia, cardiac function, and gut microbiota in high fat fed apolipoprotein E-deficient mice

Hyperlipidemia, obesity and gut dysbiosis are pivotal risk factors for atherosclerotic cardiovascular disease (ACVD). Supplementation of Akkermansia muciniphila (AKK) has also been proven to be effective in the prevention and treatment of obesity and other metabolic disorders. Here we found that AKK was more abundant in healthy control than ACVD patients via metagenomic sequencing on fecal samples. Subsequently, we investigated the role and underlying mechanism of AKK on obesity-associated atherosclerosis. AKK intervention partially reversed the exacerbation of atherosclerotic lesion formation in ApoE-/- mice by improving dyslipidemia. Interestingly, replenishment with AKK significantly enhanced cardiac function and reduced the body weight. It also reduced pro-inflammatory cytokine IL-6 and increased anti-inflammatory IL-10 in the circulation. Additionally, AKK colonization dramatically regulated gut microbiota and increased the abundance of Lactobacillaceae. Our findings have provided novel insights into the therapeutic potential of AKK as a beneficial microbe for treating atherosclerotic-associated cardiovascular diseases.

The Gut Microbiome's Influence on Incretins and Impact on Blood Glucose Control

Obesity and type 2 diabetes mellitus (T2DM) have been increasing in prevalence, causing complications and strain on our healthcare systems. Notably, gut dysbiosis is implicated as a contributing factor in obesity, T2DM, and chronic inflammatory diseases. A pharmacology exists which modulates the incretin pathway to improve glucose control; this has proven to be beneficial in patients with obesity and T2DM. However, it is unclear how the gut microbiome may regulate insulin resistance, glucose control, and metabolic health. In this narrative review, we aim to discuss how the gut microbiome can modulate incretin pathways and related mechanisms to control glucose. To investigate this, Google Scholar and PubMed databases were searched using key terms and phrases related to the microbiome and its effects on insulin and glucose control. Emerging research has shown that several bacteria, such as Akkermansia and MN-Gup, have GLP-1-agonistic properties capable of reducing hyperglycemia. While more human research is needed to prove clinical benefit and identify long-term implications on health, the usage of pre-, pro-, and postbiotics has the potential to improve glucose control.

Limosilactobacillus fermentum KBL674 Alleviates Vaginal Candidiasis

Candida albicans (C. albicans) is the primary etiologic agent of vaginal candidiasis. Lactobacillus species are predominant in the vaginal microbiome; they inhibit the development of vaginal candidiasis by producing antimicrobial agents, such as lactic acid and hydrogen peroxide. In this study, we investigated the effects of Limosilactobacillus fermentum (L. fermentum) KBL674 in a mouse model of vaginal candidiasis. L. fermentum KBL674 inhibited C. albicans hyphal growth. Moreover, oral administration of L. fermentum KBL674 significantly suppressed vaginal C. albicans infection and associated symptoms, including tissue thickness and immune cell infiltration. A substantial quantity of L. fermentum KBL674 was excreted by the mice within 6 h after oral administration, indicating that most L. fermentum KBL674 did not settle within the gastrointestinal tract. L. fermentum KBL674 modulated gut microbiome diversity, increasing abundances of the genera Akkermansia, Eubacterium, and Faecalibaculum and family Muribaculaceae. Abundances of these bacteria showed negative correlations with the vaginal C. albicans burden in the mouse model, suggesting links between the gut microbiome composition and the vaginal C. albicans burden. Therefore, L. fermentum KBL674 can reduce the vaginal C. albicans burden via direct or indirect inhibition and modulation of the gut microbiome composition preventively.

Akkermansia muciniphila: new insights into resistance to gastrointestinal stress, adhesion, and protein interaction with human mucins through optimised in vitro trials and bioinformatics tools

According to the FAO/WHO guidelines, selection of probiotics requires the assessment of survival under gastrointestinal stress and adhesion to human epithelial cells. These attributes were evaluated on Akkermansia muciniphila ATCC BAA-835 simulating the gastrointestinal transit (GIT) immediately followed by adhesion to human intestinal cell lines (CaCo2, HT-29, and HT-29-MTX) as an alternative approach to in vitro methods performed with fresh cells in each trial. The survival rate after GIT, as determined by plate counts and fluorescent probes, was significantly higher for A. muciniphila (about 8 Log CFU/mL) than for the probiotic Lacticaseibacillus rhamnosus GG ATCC 53103 (about 3 Log CFU/mL). The use of Live/Dead assay highlighted that A. muciniphila forms cell aggregates in the gastric phase as protective mechanism, explaining its high viability in the intestine. The rate of adhesion to human cell lines was always lower for strains tested after simulated GIT than for strains that did not undergo simulated GIT. Akkermansia muciniphila exhibited significantly higher adhesion than Lbs. rhamnosus GG, particularly to the mucus-secreting HT-29-MTX cells across a range of concentrations (2-8 Log CFU/mL). Finally, the bioinformatic analysis of A. muciniphila proteome confirmed the Amuc_1434 as a potential factor in binding to the human MUC2 protein.

The emerging role of gut hormones

The gut is traditionally recognized as the central organ for the digestion and absorption of nutrients, however, it also functions as a significant endocrine organ, secreting a variety of hormones such as glucagon-like peptide 1, serotonin, somatostatin, and glucocorticoids. These gut hormones, produced by specialized intestinal epithelial cells, are crucial not only for digestive processes but also for the regulation of a wide range of physiological functions, including appetite, metabolism, and immune responses. While gut hormones can exert systemic effects, they also play a pivotal role in maintaining local homeostasis within the gut. This review discusses the role of the gut as an endocrine organ, emphasizing the stimuli, the newly discovered functions, and the clinical significance of gut-secreted hormones. Deciphering the emerging role of gut hormones will lead to a better understanding of gut homeostasis, innovative treatments for disorders in the gut, as well as systemic diseases.

The role of intestinal microbiota in physiologic and body compositional changes that accompany CLA-mediated weight loss in obese mice

OBJECTIVE

Obesity continues to be a major problem, despite known treatment strategies such as lifestyle modifications, pharmaceuticals, and surgical options, necessitating the development of novel weight loss approaches. The naturally occurring fatty acid, 10,12 conjugated linoleic acid (10,12 CLA), promotes weight loss by increasing fat oxidation and browning of white adipose tissue, leading to increased energy expenditure in obese mice. Coincident with weight loss, 10,12 CLA also alters the murine gut microbiota by enriching for microbes that produce short chain fatty acids (SCFAs), with concurrent elevations in fecal butyrate and plasma acetate.

METHODS

To determine if the observed microbiota changes are required for 10,12 CLA-mediated weight loss, adult male mice with diet-induced obesity were given broad-spectrum antibiotics (ABX) to perturb the microbiota prior to and during 10,12 CLA-mediated weight loss. Conversely, to determine whether gut microbes were sufficient to induce weight loss, conventionally-raised and germ-free mice were transplanted with cecal contents from mice that had undergone weight loss by 10,12 CLA supplementation.

RESULTS

While body weight was minimally modulated by ABX-mediated perturbation of gut bacterial populations, adult male mice given ABX were more resistant to the increased energy expenditure and fat loss that are induced by 10,12 CLA supplementation. Transplanting cecal contents from donor mice losing weight due to oral 10,12 CLA consumption into conventional or germ-free mice led to improved glucose metabolism with increased butyrate production.

CONCLUSIONS

These data suggest a critical role for the microbiota in diet-modulated changes in energy balance and glucose metabolism, and distinguish the metabolic effects of orally delivered 10,12 CLA from cecal transplantation of the resulting microbiota.