Akkermansia muciniphila as a Next-Generation Probiotic in Modulating Human Metabolic Homeostasis and Disease Progression: A Role Mediated by Gut-Liver-Brain Axes?

Beneficial effects of Akkermansia muciniphila on benign prostatic hyperplasia and metabolic syndrome

Benign prostatic hyperplasia (BPH) is a prevalent condition associated with male lower urinary tract symptoms (LUTS) and is influenced by metabolic syndrome (MetS) and gut microbiota. Akkermansia muciniphila (AKK) is a gut commensal that has emerged as a potential modulator of metabolic health and inflammatory conditions. This study investigated the correlation between Akkermansia abundance and BPH severity and metabolic indices in fecal and serum samples from BPH patients and healthy donors using 16S rRNA sequencing and metabolic profiling. A testosterone-induced BPH mouse model was used to evaluate the effects of AKK administration on BPH severity and metabolic indices. Altered gut microbiota diversity was observed in BPH patients, with a significant reduction in Akkermansia abundance. Akkermansia abundance was negatively correlated with BPH symptom score, serum lipopolysaccharides (LPS), body mass index (BMI), blood glucose, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). AKK administration in BPH mice resulted in histopathological improvements, reduced prostate index, and amelioration of glandular hyperplasia. Although changes in blood glucose, TC, and LDL-C levels post-AKK supplementation were not statistically significant, a trend toward improvement was noted. Additionally, AKK administration led to a reduction in systemic inflammation markers and restoration of intestinal barrier integrity. In conclusion, AKK might modulate the gut microbiota-prostate axis and MetS. AKK's influence on systemic inflammation and gut barrier function suggests its therapeutic promise in managing BPH and associated metabolic disorders. These findings pave the way for novel microbiota-targeted therapies in the treatment of BPH and MetS.

Modulatory effects of red seaweeds (Palmaria palmata, Porphyra umbilicalis and Chondrus crispus) on the human gut microbiota via an in vitro model

This work investigated the nutritional and mineral composition of three red seaweed species, Palmaria palmata, Porphyra umbilicalis and Chondrus crispus, and an in vitro assay was performed to determinate the effects of the intake of whole red seaweed on gut microbiota, short chain fatty acids production and metabolic pathways. The results obtained showed that 100 g of seaweeds contained essential minerals such as 28-107 % daily needs of Ca, 183-600 % daily needs of Fe and 18-54 % daily needs of Zn, whereas low content were found for Cu and I. Seaweed digestion fermentation showed beneficial effects of gut microbiota, as increases in beneficial species such as Akkermansia muciniphila, and in some seaweed, Bifidobacterium adoslescentis, Bacteroides ovatus or Lactobacillus ruminis. Metabolic pathways did only found little significant differences with respect to inulin fermentation. In view of the results, red seaweed showed prebiotic effects on human gut microbiota.

Cutting-edge insights into the mechanistic understanding of plant-derived exosome-like nanoparticles: Implications for intestinal homeostasis

Plant-derived exosome-like nanoparticles (PDELNs) are extracted from plants such as ginger, garlic, broccoli, and others, attracting attention for their therapeutic potential due to their availability and capacity for large-scale production. Their unique physicochemical properties position PDELNs as ideal candidates for targeted gut delivery, improving intestinal health by modulating mucosal immunity, gut microbiota, and intestinal barrier integrity, all essential for maintaining intestinal homeostasis. PDELNs regulate intestinal barrier function through their bioactive components (e.g. microRNAs, lipids, and proteins). These vesicles enhance the expression of tight junction proteins and stimulate mucin production. Additionally, they promote intestinal stem cell proliferation and increase the secretion of antimicrobial peptides. PDELNs also modulate inflammatory cytokine levels and immune cell activity, fostering a balanced immune response. Further, they support the growth of beneficial gut microbiota and their metabolites, while suppressing the proliferation of pathogenic bacteria. This review summarizes recent advancements in understanding the roles of PDELNs in regulating intestinal homeostasis, focusing on their impact on mucosal immunity, intestinal barrier function, and gut microbiota composition, along with underlying molecular mechanisms and therapeutic implications. Overall, PDELNs show promise as a novel approach for treating and preventing intestinal diseases, paving the way for effective gut health interventions.

Causal relationship between gut microbiota and ageing: A multi-omics Mendelian randomization study

INTRODUCTION

Observational studies and clinical trials have suggested a connection between gut microbiota and aging. However, the causal relationship between them remains undetermined.

OBJECTIVES

This study aimed to use bidirectional two-sample Mendelian randomization (TSMR) analysis to explore the causal relationship between gut microbiota and aging.

METHODS

Summary statistics from genome-wide association studies (GWAS) on gut microbiota and seven aging-related phenotypes were employed for TSMR analysis. Reverse Mendelian randomization (MR) analysis was performed to assess the potential for reverse causality. Additionally, the relationship between Akkermansia muciniphila and inflammation-related proteins and metabolites was further investigated. The effects of Akkermansia muciniphila on aging were also examined in Caenorhabditis elegans by measuring both lifespan and healthspan.

RESULTS

MR analysis of 207 microbial taxa and seven aging phenotypes revealed 44 causal relationships between the gut microbiota and aging. Akkermansia muciniphila was found to be causally linked to several aging-related traits, including mvAge, appendicular lean mass, and grip strength (P < 0.05). Reverse MR analysis identified 23 causal relationships, but no bidirectional causality was observed. Moreover, Akkermansia muciniphila is causally related to ST1A1, taurine bile acid, and mannose (P < 0.05). In Caenorhabditis elegans, treatment with Akkermansia muciniphila significantly extended lifespan (P < 0.05) and improved mobility in aging nematodes.

CONCLUSION

TSMR analysis uncovers multiple potential causal links between gut microbiota and aging, particularly Akkermansia muciniphila. Experimental results support its role in alleviating aging. This study provides a strong foundation for future research on gut microbiota's role in aging.

Exploring the Probiotic Potential of Bacteroides spp. Within One Health Paradigm

Probiotics are pivotal in maintaining or restoring the balance of human intestinal microbiota, a crucial factor in mitigating diseases and preserving the host's health. Exploration into Bacteroides spp. reveals substantial promise in their development as next-generation probiotics due to their profound interaction with host immune cells and capability to regulate the microbiome's metabolism by significantly impacting metabolite production. These beneficial bacteria exhibit potential in ameliorating various health issues such as intestinal disorders, cardiovascular diseases, behavioral disorders, and even cancer. Though it's important to note that a high percentage of them are as well opportunistic pathogens, posing risks under certain conditions. Studies highlight their role in modifying immune responses and improving health conditions by regulating lymphocytes, controlling metabolism, and preventing inflammation and cancer. The safety and efficacy of Bacteroides strains are currently under scrutiny by the European Commission for authorization in food processing, marking a significant step towards their commercialization. The recent advancements in bacterial isolation and sequencing methodologies, coupled with the integration of Metagenome-Assembled Genomes (MAGs) binning from metagenomics data, continue to unveil the potential of Bacteroides spp., aiding in the broader understanding and application of these novel probiotics in health and disease management.

Gut Microbiota Modulation in IBD: From the Old Paradigm to Revolutionary Tools

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders primarily comprising two main conditions: ulcerative colitis and Crohn's disease. The gut microbiota's role in driving inflammation in IBD has garnered significant attention, yet the precise mechanisms through which the microbiota influences IBD pathogenesis remain largely unclear. Given the limited therapeutic options for IBD, alternative microbiota-targeted therapies-including prebiotics, probiotics, postbiotics, and symbiotics-have been proposed. While these approaches have shown promising results, microbiota modulation is still mainly considered an adjunct therapy to conventional treatments, with a demonstrated impact on patients' quality of life. Fecal microbiota transplantation (FMT), already approved for treating Clostridioides difficile infection, represents the first in a series of innovative microbiota-based therapies under investigation. Microbial biotherapeutics are emerging as personalized and cutting-edge tools for IBD management, encompassing next-generation probiotics, bacterial consortia, bacteriophages, engineered probiotics, direct metabolic pathway modulation, and nanotherapeutics. This review explores microbial modulation as a therapeutic strategy for IBDs, highlighting current approaches and examining promising tools under development to better understand their potential clinical applications in managing intestinal inflammatory disorders.

Pre-Administration of Saccharomyces boulardii-Derived Postbiotics Effectively Prevents Dextran Sulfate Sodium-Induced Colitis in Mice

Ulcerative colitis (UC) is effectively alleviated by Saccharomyces boulardii (S. boulardii), an important probiotic. Postbiotics, defined as beneficial non-viable microorganisms and/or their components, can potentially improve gut health. In this study, we utilized S. boulardii to prepare postbiotics via freeze-drying and spray-drying methods, characterized the resulting postbiotics, and investigated their efficacy and underlying mechanisms in preventing UC. In a mouse model of UC induced by dextran sulfate sodium (DSS), we found that prevention with two forms of S. boulardii postbiotics alleviated colitis symptoms triggered by DSS, mitigated colon tissue damage, maintained the distribution of intestinal occludin and ZO-1 proteins, and suppressed the secretion and expression of TNF-α, IL-1β, and IL-6 in serum and colon tissues. Additionally, S. boulardii postbiotics mitigated dysbiosis by modulating gut microbiota composition, including the balance between Bacteroidota and Firmicutes (F/B), as well as the levels of Akkermansia, Muribaculaceae, Dubosiella, and Turicibacter. In conclusion, as a novel biotherapeutic agent, S. boulardii postbiotics effectively prevent DSS-induced UC in mice. Compared to live S. boulardii, postbiotics may hold greater potential for UC prevention.

Identification and evaluation of active fractions from Radix Hedysari polysaccharides: Their regulatory impacts on intestinal flora and metabolism in mice

Polysaccharides are one of the primary active components of Radix Hedysari, although their regulatory effects on gut microbiota remain poorly understood. In this study, Radix Hedysari polysaccharides (RHPS) were isolated and purified, yielding three fractions: RHPS-1, RHPS-2, and RHPS-4. The yields of these fractions were 51.33 %, 3.15 %, and 2.34 %, respectively, with weight-average molecular weights of 18.781, 25.660, and 100.149 kDa. The three polysaccharides were composed of arabinose, galactose, glucose, glucuronic acid. RHPS-1 exhibits good antioxidant, antibacterial, and immune-enhancing activities. Further purification of RHPS-1 yielded RHPS-1-1, and it was found that RHPS-1-1 enhances the growth of beneficial bacteria while suppressing the growth of harmful bacteria in mice. Additionally, mice treated with RHPS-1-1 were primarily involved in bile acid, short-chain fatty acid, and energy metabolism pathways. Our results represent the first demonstration that RHPS-1-1 exhibits good biological activity and possesses the ability to regulate the gut microbiota and its metabolites in mice.

Total dietary fiber of tartary buckwheat alleviates T2DM through the IRS-1/PI3K/AKT pathway and gut microbiota-bile acids-TGR5/FXR axis in db/db mice

Buckwheat dietary fiber has good hypoglycemic activity, with its water-soluble parts and modification widely studied, however, the specific effects and mechanisms of action regarding buckwheat total dietary fiber (BDF) to improve T2DM need to be further explored. In this study, we investigated the improvement of diabetes-related symptoms in db/db mice by 10 % BDF and explored the possible mechanisms. The results showed that hyperglycemia, hyperlipemia, insulin resistance, elevated body weight, severe inflammatory response and impaired intestinal function were significantly improved after 8 weeks of BDF intervention. Moreover, BDF was able to ameliorate the distribution of gut microbiota, enhance the bacteria associated with T2DM, and improve glucose metabolism by altering the levels of the metabolites of gut microbiota, bile acids (BAs), and their receptors, TGR5 and FXR. In addition, BDF activated the hepatic IRS-1/PI3K/AKT pathway which can reduce hepatic gluconeogenesis and promoted glycogen synthesis. Taken together, our results suggest that BDF can alleviate T2DM symptoms by activating the IRS-1/PI3K/AKT pathway and the gut microbiota-BAs-TGR5/FXR axis. The results of this study deepen the exploration of the active ingredients of cereals and suggesting a scientific basis for the development of glucose-lowering functional foods and nutraceuticals.

Akkermansia muciniphila: promises and pitfallsfor next-generation beneficial microorganisms

Akkermansia muciniphila, a microorganism ubiquitously colonizing the mucosal layer of the human gut, has garnered significant scientific interest as a promising candidate for probiotic therapeutics. Its persistent identification in both laboratory and living organism studies underscores its potential physiological benefits, positioning it as a bacterium of paramount importance in promoting host health. This review examines the diversity and abundance of gut microbiota members, emphasizing the identification of microbial species engaged in cross-feeding networks with A. muciniphila. Insightful exploration into the mechanisms of cross-feeding, including mucin-derived nutrient exchange and metabolite production, unveils the intricate dynamics shaping microbial community stability. Such interactions contribute not only to the availability of essential nutrients within the gut environment but also to the production of metabolites influencing microbial community dynamics and host health. In conclusion, the cumulative evidence from in vitro and in vivo perspectives substantiates the notion that A. muciniphila holds tremendous promise as a next-generation probiotic. By leveraging its unique physiological benefits, particularly in mucosal health and metabolic regulation, A. muciniphila stands poised to revolutionize the landscape of probiotic interventions for enhanced host well-being.

Microbial signatures and therapeutic strategies in neurodegenerative diseases

Neurodegenerative diseases (NDs), including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS), arise from complex interactions between genetic factors, environmental exposures, and aging. Additionally, gut dysbiosis has been linked to systemic inflammation and neurodegeneration. Advances in microbiome and metabolome profiling techniques have provided deeper insights into how alterations in gut microbiota and dietary patterns affect metabolic pathways and contribute to the progression of NDs. This review explores the profiles of gut microbiome and metabolome derived biomarkers and their roles in NDs. Across phyla, families, and genera, we identified 55 microbial alterations in PD, 24 in AD, 4 in ALS, and 17 in MS. Some notable results include an increase in Akkermansia in PD, AD, and MS and a decrease in short-chain fatty acids (SCFAs) in PD and AD. We examined the effects of probiotics, prebiotics, fecal microbiota transplants (FMT), sleep, exercise, and diet on the microbiota, all of which contributed to delayed onset and alleviation of symptoms. Further, artificial intelligence (AI) and machine learning (ML) algorithms applied to omics data have been crucial in identifying novel therapeutic targets, diagnosing and predicting prognosis, and enabling personalized medicine using microbiota-modulating therapies in NDs patients.

Integrated Macrogenomics and Metabolomics Analysis of the Effect of Sea Cucumber Ovum Hydrolysates on Dextran Sodium Sulfate-Induced Colitis

Inflammatory bowel disease remains a significant challenge in clinical settings. This study investigated the therapeutic potential of sea cucumber ovum hydrolysates (SCH) in a dextran sulfate sodium (DSS)-induced colitis mouse model. SCH, defined by its elevated stability and solubility, with a molecular weight below 1000 Da, significantly alleviated DSS-induced colitis, as evidenced by enhanced splenic index, reduced colonic damage, and diminished serum pro-inflammatory cytokines. Furthermore, macrogenomic analysis demonstrated that SCH increased beneficial gut microbes and decreased pro-inflammatory bacteria. Furthermore, metabolomic analysis of colonic tissues identified elevated levels of anti-inflammatory metabolites, such as Phenyllactate, 2-Hydroxyglutarate, and L-Aspartic acid, in colitis mice after oral administration of SCH. In conclusion, SCH represents a promising candidate for the treatment of colitis.

Combined metabolomics and 16S rDNA sequence analyses of the gut microbiome reveal the action mechanism of Fructus Akebiae against hepatic fibrosis

Objectives

To explore the mechanism underlying the effect of Fructus Akebiae (FAE) against hepatic fibrosis in mice through combined network pharmacology, liver metabolomics, and 16S rDNA analyses of the gut microbiota.

Methods

In this study, we randomly divided mice into the control, model, FAE high-dose, FAE medium-dose, and FAE low-dose groups to analyze the pathological changes in the hepatic fibrosis and levels of the α-SMA, collagen 1, Nuclear Factor Kappa B (NF-κ B), Toll Like Receptor 4 (TLR4). The gut microbiota was analyzed through 16S rDNA sequencing analysis of liver metabolites using liquid chromatography-mass spectrometry. Furthermore, network pharmacology was used to determine the specific molecular regulation mechanism of FAE in hepatic fibrosis treatment.

Results

FAE treatment markedly improved the pathological changes in the hepatic fibrosis. Analysis revealed that FAE administration reversed the carbon tetrachloride (CCl4)-induced dysbiosis by increasing the abundance of Akkermansia and reducing that of Cyanobacteria. Additionally, metabolomic analysis showed that FAE treatment reversed the CCl4-induced metabolic disorders by regulating amino and nucleotide sugar metabolism. Furthermore, correlation analysis showed that Akkermansia and Verrucomicobiota were closely related to D-tolasaccharide and maltotetraose saccharide. Moreover, network pharmacology indicated that FAE might regulate the signaling pathway through the JUN/CASP3/NOS3/PTGS2/HSP90AA1 during treatment.

Conclusion

FAE may be a promising treatment for hepatic fibrosis, and its protective effects are associated with improvements in the microbiome and metabolic disorders.

Exploring Extracellular Vesicles: A Novel Approach in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) represents an increasing public health concern. The underlying pathophysiological mechanisms of NAFLD remains unclear, and as a result, there is currently no specific therapy for this condition. However, recent studies focus on extracellular vesicles (EVs) as a novelty in their role in cellular communication. An imbalance in the gut microbiota composition may contribute to the progression of NAFLD, making the gut-liver axis a promising target for therapeutic strategies. This review aims to provide a comprehensive overview of EVs in NAFLD. Additionally, exosome-like nanovesicles derived from plants (PELNs) and probiotics-derived extracellular vesicles (postbiotics) have demonstrated the potential to re-establish intestinal equilibrium and modulate gut microbiota, thus offering the potential to alleviate NAFLD via the gut-liver axis. Further research is needed using multiple omics approaches to comprehensively characterize the cargo including protein, metabolites, genetic material packaged, and biological activities of extracellular vesicles derived from diverse microbes and plants.

WKB ameliorates DSS-induced colitis through inhibiting enteric glial cells activation and altering the intestinal microbiota

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic condition influenced by diet, which affects gut microbiota and immune functions. The rising prevalence of IBD, linked to Western diets in developing countries, highlights the need for dietary interventions. This study aimed to assess the impact of white kidney beans (WKB) on gut inflammation and microbiota changes, focusing on their effects on enteric glial cells (EGCs) and immune activity in colitis.

METHODS

Male C57BL/6 mice were divided into four groups: normal diet (ND), ND with 2.5% dextran sulfate sodium (DSS) for colitis induction, ND with 20% WKB, and WKB with 2.5% DSS. The dietary intervention lasted 17 weeks, with DSS given in the final week. Colonic inflammation was assessed by body weight, disease activity index, and histopathology. Epithelial barrier integrity was evaluated using immunofluorescence, transmission electron microscopy, and permeability assays. EGCs activity was analyzed via immunofluorescence and quantitative real-time PCR. Immune responses were measured using flow cytometry and cytokine profiling, while gut microbiota changes were examined through metagenomic sequencing.

RESULTS

WKB supplementation significantly alleviated DSS-induced colitis in mice, evidenced by reduced weight loss, disease activity, and improved colonic histology. This effect was linked to enhanced mucosal barrier integrity, seen through increased tight junction protein and Muc2 expression, accompanied by favorable ultrastructural changes. WKB modulated EGCs activity via TNF-like cytokine 1 A inhibition, resulting in reduced glial fibrillary acidic protein expression. Immunologically, it downregulated Th1 and Th17 pro-inflammatory cells, increased Treg cells, and altered cytokine profiles (reduced TNF-α, IFN-γ, IL-17; increased IL-10). Metagenomic analysis showed that WKB restored gut microbiota balance, particularly enhancing beneficial bacteria like Akkermansia. KEGG pathway analysis further indicated that WKB supplementation improved key metabolic pathways, notably those related to phenylalanine, tyrosine, and tryptophan biosynthesis, thereby countering DSS-induced metabolic disruptions.

CONCLUSIONS

WKB shows promise for treating IBD by enhancing mucosal barriers, inhibiting EGCs activity, balancing Th1/Th17/Treg cells, and restoring gut microbiota and metabolic homeostasis, thereby alleviating colitis symptoms.

A disturbed communication between hypothalamic-pituitary-ovary axis and gut microbiota in female infertility: is diet to blame?

Female infertility is a multifactorial condition influenced by various genetic, environmental, and lifestyle factors. Recent research has investigated the significant impact of gut microbiome dysbiosis on systemic inflammation, metabolic dysfunction, and hormonal imbalances, which can potentially impair fertility. The gut-brain axis, a bidirectional communication system between the gut and the brain, also plays a significant role in regulating reproductive functions. Emerging evidence suggests that the gut microbiome can influence brain functions and behavior, further emphasizing the importance of the microbiota-gut-brain axis in reproduction. Given their role as a major modulator of the gut microbiome, diet and dietary factors, including dietary patterns and nutrient intake, have been implicated in the development and management of female infertility. Hence, this review aims to highlight the impact of dietary patterns, such as the Western diet (WD) and Mediterranean diet (MD), and to decipher their modulatory action on the microbiota-gut-brain axis in infertile women. By contrasting the detrimental effects of WD with the therapeutic potential of MD, we emphasize the pivotal role of a balanced diet rich in nutrients in promoting a healthy gut microbiome. These insights underscore the potential of targeted dietary interventions and lifestyle modifications as promising strategies to enhance reproductive outcomes in subfertile women.

Protection of Alzheimer's disease progression by a human-origin probiotics cocktail

Microbiome abnormalities (dysbiosis) significantly contribute to the progression of Alzheimer's disease (AD). However, the therapeutic efficacy of microbiome modulators in protecting against these ailments remains poorly studied. Herein, we tested a cocktail of unique probiotics, including 5 Lactobacillus and 5 Enterococcus strains isolated from infant gut with proven microbiome modulating capabilities. We aimed to determine the probiotics cocktail's efficacy in ameliorating AD pathology in a humanized AD mouse model of APP/PS1 strains. Remarkably, feeding mice with 1 × 1011 CFU per day in drinking water for 16 weeks significantly reduced cognitive decline (measured by the Morris Water Maze test) and AD pathology markers, such as Aβ aggregation, microglia activation, neuroinflammation, and preserved blood-brain barrier (BBB) tight junctions. The beneficial effects were linked to a reduced inflammatory microbiome, leading to decreased gut permeability and inflammation in both systemic circulation and the brain. Although both male and female mice showed overall improvements in cognition and biological markers, females did not exhibit improvements in specific markers related to inflammation and barrier permeability, suggesting that the underlying mechanisms may differ depending on sex. In conclusion, our results suggest that this unique probiotics cocktail could serve as a prophylactic agent to reduce the progression of cognitive decline and AD pathology. This is achieved by beneficially modulating the microbiome, improving intestinal tight junction proteins, reducing permeability in both gut and BBB, and decreasing inflammation in the gut, blood circulation, and brain, ultimately mitigating AD pathology and cognitive decline.

Role of Akkermansia muciniphila in insulin resistance

Insulin resistance (IR) is a pathogenic factor in numerous metabolic diseases. The gut microbiota plays a crucial role in maintaining the function of the intestinal barrier and overall human health, thereby influencing IR. Dysbiosis of the gut microbiota can contribute to the development of IR. Therefore, it is essential to maintain a balanced and diverse gut microbiota for optimal health. Akkermansia muciniphila, a widely present microorganism in the human intestine, has been shown to regulate gastrointestinal mucosal barrier integrity, reduce endotoxin penetration, decrease systemic inflammation levels, and improve insulin sensitivity. Reduced abundance of A. muciniphila is associated with an increased risk of IR and other metabolic diseases, highlighting its correlation with IR. Understanding the role and regulatory mechanism of A. muciniphila is crucial for comprehending IR pathogenesis and developing novel strategies for preventing and treating related metabolic disorders. Individual variations may exist in both the gut microbiota composition and its impact on IR among different individuals. Further investigation into individual differences between A. muciniphila and IR will facilitate advancements in personalized medicine by promoting tailored interventions based on the gut microbiota composition, which is a potential future direction that would optimize insulin sensitivity while preventing metabolic disease occurrence. In this review, we describe the physiological characteristics of A. muciniphila, emphasize its roles in underlying mechanisms contributing to IR pathology, and summarize how alterations in its abundance affect IR development, thereby providing valuable insights for further research on A. muciniphila, as well as new drug development targeting diabetes.

The intricate interactions between inflammasomes and bacterial pathogens: Roles, mechanisms, and therapeutic potentials

Inflammasomes are intracellular multiprotein complexes that consist of a sensor, an adaptor, and a caspase enzyme to cleave interleukin (IL)-1β and IL-18 into their mature forms. In addition, caspase-1 and -11 activation results in the cleavage of gasdermin D to form pores, thereby inducing pyroptosis. Activation of the inflammasome and pyroptosis promotes host defense against pathogens, whereas dysregulation of the inflammasome can result in various pathologies. Inflammasomes exhibit versatile microbial signal detection, directly or indirectly, through cellular processes, such as ion fluctuations, reactive oxygen species generation, and the disruption of intracellular organelle function; however, bacteria have adaptive strategies to manipulate the inflammasome by altering microbe-associated molecular patterns, intercepting innate pathways with secreted effectors, and attenuating inflammatory and cell death responses. In this review, we summarize recent advances in the diverse roles of the inflammasome during bacterial infections and discuss how bacteria exploit inflammasome pathways to establish infections or persistence. In addition, we highlight the therapeutic potential of harnessing bacterial immune subversion strategies against acute and chronic bacterial infections. A more comprehensive understanding of the significance of inflammasomes in immunity and their intricate roles in the battle between bacterial pathogens and hosts will lead to the development of innovative strategies to address emerging threats posed by the expansion of drug-resistant bacterial infections.

Can Gut Microbiota Analysis Reveal Clostridioides difficile Infection? Evidence from an Italian Cohort at Disease Onset

A diverse and well-functioning gut microbiota normally serves as a protective shield against the invasion of harmful bacteria or the proliferation of opportunistic pathogens. Clostridioides difficile infection (CDI) is predominantly associated with the overuse of antibiotics, resulting in a significant alteration in the gut's microbial balance. Unfortunately, the lack of global standardization does not allow for the identification of a set of biomarkers associated with the onset and progression of this disease. In this study, we examined the composition of the gut microbiota in patients at the time of the initial detection of CDI compared to a control group of CDI-negative individuals, with a focus on identifying potential CDI biomarkers for diagnosis. While no significant differences in the alpha and beta diversity between CDI-negative and CDI-positive individuals were found, we found that certain genera (such as Clostridium XIVa and Clostridium XVIII) showed different abundance patterns in the two groups, indicating potential differences in gut microbiota balance. In conclusion, am enrichment in Clostridium XI and a decrease in Faecalibacterium emerged in the CDI-positive patients and following antibiotic treatment, indicating that changes in the Clostridium/Faecalibacterium ratio may be a promising biomarker that warrants further investigation for CDI diagnosis.

Dietary fiber pectin alters the gut microbiota and diminishes the inflammatory immune responses in an experimental peach allergy mouse model

Since therapeutic options are limited the utilization of prebiotics is suggested to prevent food allergies (FAs). Using an experimental peach allergy model we explored the effect of dietary fiber pectin, a high-methoxyl heteropolysaccharide, on the manifestation of FA. CBA/J mice were sensitized, subsequently orally boosted and provoked with peach peel extract. For dietary intervention, mice were fed a pectin containing diet before (primary-preventive) or after (secondary-preventive) sensitization. Non-treated allergic and sham-treated mice were fed a diet containing 20% cellulose. Fecal microbiota, humoral and intestinal immune cell responses were analyzed. Pectin remarkably affected the gut microbiota composition and diversity, promoting mainly the growth of Bacteroides. The frequency of mast cells, macrophages, and CD3+T cells in the lamina propria of the small intestine was reduced, whereas the frequency of B cells and CD4+T cell subpopulation was enhanced. Pectin intervention in the primary-preventive stetting significantly triggered serum IgA levels, whereas production of IgE and mMCPT-1 was reduced. Remarkably, in both settings peach allergen-specific IgG1/IgG2a ratio and specific IgE were significantly reduced to baseline. The data suggest, that dietary supplementation of pectin in both intervention approaches can diminish inflammatory responses and signs of allergic immune responses, accompanied by alteration of the gut microbiota composition.

Ameliorative effects of Akkermansia muciniphila on anxiety-like behavior and cognitive deficits in a rat model of Alzheimer's disease

Alzheimer's Disease (AD) is the primary neurodegenerative disorder in the elderly, lacking a definitive treatment. The gut microbiota influences the gut-brain axis by aiding in hypothalamic-pituitary-adrenal (HPA) axis development and neuromodulator production. Research links AD and gut microbiota, suggesting gut microbiota regulation could be a therapeutic approach for AD. This study explores Akkermansia muciniphila's impact on preventing AD. This research investigates the effect of A. muciniphila consumption (1 × 109 CFU) on tau protein-induced AD rats compared to a control group. Rats were divided into four groups: sham, sham + Akk, AD (tau-induced rats), and AD + Akk (tau-induced rats treated with A. muciniphila). A. muciniphila gavage lasted five weeks. Rats underwent qRT-PCR analysis to assess mRNA expression of pro-inflammatory factors (TNF-α, IL-6, IL-1β, IFN-γ) in the hippocampus. Behavioral tests included Morris Water Maze (MWM), Passive Avoidance Memory Test (Shuttle box), Elevated Plus Maze (EPM), and marble burying. After five weeks of A. muciniphila treatment, anxiety-like behavior significantly decreased. The AD group receiving A. muciniphila showed improved spatial and recognition memory compared to the AD group. Pro-inflammatory cytokine levels (TNF-α, IL-1β, IL-6, IFN-γ) decreased. A. muciniphila effectively reduces cognitive impairments and anxiety-related behavior, showing promise as an AD therapeutic by influencing the gut-brain axis.

Host-specific effects of Eubacterium species on Rg3-mediated modulation of osteosarcopenia in a genetically diverse mouse population

BACKGROUND

Osteosarcopenia, characterized by the simultaneous loss of bone and muscle mass, is a serious health problem in the aging population. This study investigated the interplay between host genetics, gut microbiota, and musculoskeletal health in a mouse model of osteosarcopenia, exploring the therapeutic potential of gut microbiota modulation.

METHODS

We examined the effects of Rg3, a phytochemical, on osteosarcopenia and its interactions with host genetics and gut microbiota in six founder strains of the Collaborative Cross (CC) population. Subsequently, we evaluated the therapeutic potential of Eubacterium nodatum (EN) and Eubacterium ventriosum (EV), two gut microbes identified as significant correlates of Rg3-mediated osteosarcopenia improvement, in selected C57BL/6 J (B6) and 129S1/SvImJ (129S1) mouse strains.

RESULTS

Rg3 treatment altered gut microbiota composition aligned with osteosarcopenia phenotypes, which response varied depending on host genetics. This finding enabled the identification of two microbes in the Eubacterium genus, potential mediator of Rg3 effect on osteosarcopenia. Oral administration of EN and EV differentially impacted bone density, muscle mass, exercise performance, and related gene expression in a mouse strain-specific manner. In 129S1 mice, EN and EV significantly improved these parameters, effectively reversing osteosarcopenic phenotypes. Mechanistic investigations revealed that these effects were mediated through the modulation of osteoblast differentiation and protein degradation pathways. In contrast, EN and EV did not significantly improve osteosarcopenic phenotypes in B6 mice, although they did modulate mitochondrial biogenesis and microbial diversity.

CONCLUSIONS

Our findings underscore the complex interplay between host genetics and the gut microbiota in osteosarcopenia and emphasize the need for personalized treatment strategies. EN and EV exhibit strain-specific therapeutic effects, suggesting that tailoring microbial interventions to individual genetic backgrounds may be crucial for optimizing treatment outcomes. Video Abstract.

Understanding the impact of diabetes on bone health: A clinical review

Diabetic bone disease, a form of secondary osteoporosis, is characterized by weakened bones and an increased risk of fractures, especially in patients with type 2 diabetes (T2D). This review explores the key mechanisms driving this condition, including hyperglycemia, insulin resistance, advanced glycation end products (AGEs), and proinflammatory cytokines, all of which disturb normal bone turnover by disrupting the functions of osteoblasts and osteoclasts. We examine the roles of bone turnover and mineralization, as well as how microvascular complications affect bone microarchitecture. Additionally, the influence of gut hormones, such as GLP-1 and GIP, and gut microbiota, particularly species like Akkermansia muciniphila, on the gut-bone axis is discussed, as these factors play a role in regulating bone density and structure. While T2D patients may show normal or even elevated bone mineral density (BMD), the underlying quality of bone is often compromised, leading to increased fragility. This review integrates current knowledge on the molecular, hormonal, and microbial interactions contributing to diabetic bone disease. By highlighting these pathways, we aim to offer insights into potential therapeutic strategies and inform future research aimed at improving the diagnosis, treatment, and overall management of this condition.

Should the Faecal Microbiota Composition Be Determined to Certify a Faecal Donor?

BACKGROUND/OBJECTIVES

Faecal microbiota transplantation (FMT) is considered a safe and effective therapy for recurrent Clostridioides difficile infection. It is the only current clinical indication for this technique, although numerous clinical research studies and trials propose its potential usefulness for treating other pathologies. Donor selection is a very rigorous process, based on a personal lifestyle interview and the absence of known pathogens in faeces and serum, leading to only a few volunteers finally achieving the corresponding certification. However, despite the high amount of data generated from the ongoing research studies relating microbiota and health, there is not yet a consensus defining what is a "healthy" microbiota. To date, knowledge of the composition of the microbiota is not a requirement to be a faecal donor. The aim of this work was to evaluate whether the analysis of the composition of the microbiota by massive sequencing of 16S rDNA could be useful in the selection of the faecal donors.

METHODS

Samples from 10 certified donors from Mikrobiomik Healthcare Company were collected and sequenced using 16S rDNA in a MiSeq (Illumina) platform. Alpha (Chao1 and Shannon indices) and beta diversity (Bray-Curtis) were performed using the bioinformatic web server Microbiome Analyst. The differences in microbial composition at the genera and phyla levels among the donors were evaluated.

RESULTS

The microbial diversity metric by alpha diversity indexes showed that most donors exhibited a similar microbial diversity and richness, whereas beta diversity by 16S rDNA sequencing revealed significant inter-donor differences, with a more stable microbial composition over time in some donors. The phyla Bacillota and Bacteroidota were predominant in all donors, while the density of other phyla, such as Actinomycota and Pseudomonota, varied among individuals. Each donor exhibited a characteristic genera distribution pattern; however, it was possible to define a microbiome core consisting of the genera Agathobacter, Eubacterium, Bacteroides, Clostridia UCG-014 and Akkermansia. Conclusions: The results suggest that donor certification does not need to rely exclusively on their microbiota composition, as it is unique to each donor. While one donor showed greater microbial diversity and richness, clear criteria for microbial normality and health have yet to be established. Therefore, donor certification should focus more on clinical and lifestyle aspects.

Exposure to polystyrene nanoplastics causes immune damage, oxidative stress and intestinal flora disruption in salamander (Andrias davidianus) larvae

The toxic effects of nanoparticles have been increasingly investigated, but there has been limited research on amphibians, especially those of conservation value. This study examined the effects of different concentrations (0, 0.04, 0.2, 1, 5 mg/L) of polystyrene nanoplastics (PS-NPs, 80 nm) on the short-term exposure (7 d) of Andrias davidianus. Results demonstrated the concentration-dependent enrichment of PS-NPs in the intestine. Histological lesions displayed increased hepatic macrophages with cellular rupture, broken intestinal villi, decreased cuprocytes and crypt depression. Antioxidant- and inflammation-related enzyme activities were analysed, and it was found that hepatic and intestinal MDA content and CAT activity were highest in the N-1 group and SOD activity was highest in the N-0.2 group (p < 0.05). AKP activity continued to decline, and iNOS activity was highest in the N-0.2 group (p < 0.05). il-10, tgf-β, bcl-w and txnl1 were significantly downregulated in the N-0.2 group, while il-6 and il-8 were markedly upregulated in the N-0.2 group (p < 0.05). Exposing to PS-NPs decreased probiotic bacteria (Cetobacterium, Akkermansia) and increased pathogenic bacteria (Lachnoclostridium). Our results suggest that NPs exposure can have deleterious effects on salamanders, which predicts that NPs contamination may lead to continued amphibian declines. Therefore, we strongly recommend that attention be paid to amphibians, especially endangered species, in the field of NPs.

Tea (Camellia sinensis L.) flower polysaccharide attenuates metabolic syndrome in high-fat diet induced mice in association with modulation of gut microbiota

There is a growing body of evidence suggesting that dietary polysaccharides play a crucial role in preventing metabolic syndrome (MetS) through their interaction with gut microbes. Tea (Camellia sinensis L.) flower polysacchride (TFPS) is a novel functional compound known for its diverse beneficial effects in both vivo and vitro. To further investigate the effects of TFPS on MetS and gut microbiota, and the possible association between gut microbiota and their activities, this study was carried out on mice that were fed a high-fat diet (HFD) and given oral TFPS at a dose of 400 and 800 mg/kg·body weight (BW)/d, respectively. TFPS treatment significantly mitigated HFD-induced MetS, evidenced by reductions in body weight, fat accumulation, plasma levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and pro-inflammatory cytokines tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and IL-1β, along with an increase in plasma IL-10 levels. Furthermore, TFPS induced alterations in the diversity and composition of HFD-induced gut microbiota. Specifically, TFPS influenced the relative abundance of 11 genera, including Lactobacillus and Lactococcus, which showed strong correlations with metabolic improvements and likely contributed to the amelioration of MetS. In conclusion, TFPS exhibits promising prebiotic properties in preventing MetS and regulating gut microbiota.

A comprehensive update on the immunoregulatory mechanisms of Akkermansia muciniphila: insights into active ingredients, metabolites, and nutrient-driven modulation

Akkermansia muciniphila (A. muciniphila) has gained recognition as a pioneering probiotic, exhibiting considerable potential to enhance immune conditions across both humans and animals. The health benefits of A. muciniphila are attributed to its various components, including outer membrane proteins (PilQ and Amuc_1100), secreted proteins (P9 and AmTARS), extracellular vesicles, and metabolites such as SCFAs, ornithine lipids, γ-aminobutyric acid, cobalamin, and inosine. The dynamic control of the mucus layer by A. muciniphila plays a crucial role in regulating intestinal mucosal immunity. Furthermore, A. muciniphila modulates immune function by interacting with macrophages, dendritic cells, T lymphocytes, and Paneth cells. Increasing the abundance of A. muciniphila in the gut through nutritional strategies represents a safe and effective means to augment immune function. Various polyphenols, oligosaccharides, and polysaccharides have been shown to elevate the levels of this bacterium, thereby contributing to favorable immunoregulatory outcomes. This paper delves into the latest research advancements related to the probiotic mechanisms of A. muciniphila and provides an overview of the current understanding of how its abundance responds to nutrients. These insights offer a theoretical foundation for the utilization of A. muciniphila in immunoregulation.

Atypical gut microbiota composition in a mouse model of developmental stuttering

Developmental stuttering is a complex neurodevelopmental disorder characterized by disfluent speech. It has been associated with mutations in genes involved in lysosomal enzyme trafficking. Mice with mutations in one such gene, Gnptab, exhibit atypical vocalizations analogous to stuttering in humans. This mouse model has enabled the study of various molecular mechanisms related to the disorder. Simultaneously, an increasing number of reports have suggested the role of gut microbiota in altered brain function and development in neurological disorders. In this study, we compared gut microbiota profiles from Gnptab mutant mice to wildtype control mice. Microbiome analysis demonstrated a distinct microbiota profile in Gnptab mutant mice. The most significant alteration was an increased relative abundance of Akkermansia, a genus of mucin degrading bacteria, which has previously been associated with multiple neurological disorders. Moreover, the altered microbiota profile of these mice was predicted to result in differences in abundance of several metabolic pathways, including short chain fatty acid and lipopolysaccharide synthesis. These pathways may play a role in the onset, progression and persistence of developmental stuttering. This is the first study to show a potential link between developmental stuttering and changes in the gut microbiota, laying the groundwork for a new research direction.

Comparative analysis of gut microbiome in Pangasionodon hypopthalmus and Labeo catla during health and disease

The present study was conducted to study the composition of gut microbiome in the advanced fingerling and fingerling stage of striped pangasius catfish and catla during healthy and diseased conditions. Healthy pangasius and catla fishes were obtained from commercial farms and injected with the LD50 dose of A. hydrophila. The intestinal samples from the control and injected group were collected and pooled for 16 s metagenomic analysis. Community analysis was performed by targeting the 16 s rRNA gene to explore and compare the gut microbiota composition of these fishes. The operational taxonomic units (OTUs) consisted of four major phyla: Bacteroidia, Proteobacteria, Firmicutes, and Actinobacteria. Alpha and beta diversity indices were carried out to understand the diversity of microbes within and between a sample. While comparing the advanced fingerling and fingerling stage gut microbiome of Pangasius catfish, the dominance of Proteobacteria was found in fingerlings, whereas Firmicutes and Bacteroides were found in advanced fingerlings. In catla, Proteobacteria and Bacteroides were predominant. Taxonomic abundance of the microbiota in control and diseased Pangasius and catla fishes at phylum, class, order, family, genus, and species levels were also depicted. The present study is the first of its kind, and it will help to identify the diversity of novel potential bacterial species involved in disease protection of fishes. It can lead to the development of sustainable prophylactic measures against (re-)emerging bacterial diseases in aquaculture.

Regulation of Cecal Microbiota and Improvement of Blood Lipids Using Walnut Non-Dairy Creamer in High-Fat Mice: Replacing Traditional Non-Dairy Creamer

Non-dairy creamer is a class of microencapsulated powdered fats and oils that are widely used in the food industry. However, the oils used in it are hydrogenated vegetable oils, which contain large amounts of saturated fatty acids and are extremely harmful to the human body. This study investigated the effects of replacing hydrogenated vegetable oil with walnut oil to prepare walnut non-dairy creamer on lipid levels and intestinal microorganisms in mice. The results show that low-dose walnut non-dairy creamer significantly decreased the contents of TC and TG in serum and increased the content of HDL-C (p < 0.01). The contents of MDA, ALT, and AST were significantly decreased, while the content of SOD was increased (p < 0.01). The abundance of Firmicutes in the walnut non-dairy creamer group decreased, and the abundance of Bacteroidetes/Firmicutes (B/F) increased, which significantly increased the richness of Lactobacillus and Oscillospira (p < 0.01). Allobaculum richness was significantly decreased (p < 0.01). In conclusion, a low dose of walnut non-dairy creamer can effectively promote the metabolism of blood lipids in vivo, alleviate oxidative stress injury and lipid accumulation damage to mouse hepatocytes, and ameliorate the adverse effects of a high-fat diet on the intestinal microbiota of mice. This study provides a theoretical basis for the replacement of traditional non-dairy creamer and the research and development of walnut deep processing.

Role of probiotic extracellular vesicles in inter-kingdom communication and current technical limitations in advancing their therapeutic utility

Diverse functions of probiotic extracellular vesicles (EVs) have been extensively studied over the past decade, proposing their role in inter-kingdom communication. Studies have explored their therapeutic role in pathophysiological processes ranging from cancer, immunoregulation, and ulcerative colitis to stress-induced depression. These studies have highlighted the significant and novel potential of probiotic EVs for therapeutic applications, offering immense promise in addressing several unmet clinical needs. Additionally, probiotic EVs are being explored as vehicles for targeted delivery approaches. However, the realization of clinical utility of probiotic EVs is hindered by several knowledge gaps, pitfalls, limitations, and challenges, which impede their wider acceptance by the scientific community. Among these, limited knowledge of EV biogenesis, markers and regulators in bacteria, variations in cargo due to culture conditions or EV isolation method, and lack of proper understanding of gut uptake and demonstration of in vivo effect are some important issues. This review aims to summarize the diverse roles of probiotic EVs in health and disease conditions. More importantly, it discusses the significant knowledge gaps and limitations that stand in the way of the therapeutic utility of probiotic EVs. Furthermore, the importance of addressing these gaps and limitations with technical advances such as rigorous omics has been discussed.

Marine red yeast supplementation improves laying performance by regulating small intestinal homeostasis in aging chickens

Recent studies have shown that age-related aging evolution is accompanied by imbalances in intestinal homeostasis. Marine red yeast (MRY) is a functional probiotic that has been shown to have antioxidant, immune and other properties. Therefore, we chose 900 healthy Hy-Line Brown hens at 433 d old as the research subjects and evaluated the correlation between intestinal health, laying performance, and egg quality in aged hens through the supplementation of MRY. These laying hens were assigned into 5 groups and received diet supplementation with 0%, 0.5%, 1.0%, 1.5%, and 2% MRY for 12 weeks. The results showed that MRY supplementation increased egg production rate, average egg weight, and egg quality, and decreased feed conversion ratio and daily feed intake (P < 0.05). The MRY supplement improved antioxidant indicators such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), stimulated villus height, and increased the villus height to crypt depth ratio (V/C ratio) in the intestine (P < 0.05). It also regulated the expression of intestinal inflammatory factors (transforming growth factor-β [TGF-β], interleukin [IL]-1β, IL-8, tumor necrosis factor-α [TNF-α]) while increasing serum immunoglobulin G (IgG) levels (P < 0.05). Furthermore, MRY supplementation upregulated the mRNA expression of tight junction proteins (occludin and zonula occludens-1 [ZO-1]), anti-apoptotic gene (Bcl-2), and autophagy-related proteins (beclin-1 and light chain 3I [LC3I]) in the intestine (P < 0.05). The MRY supplement also led to an increase in the concentration of short-chain fatty acids in the cecum, and the relative abundance of the phylum Bacteroidetes, and genera Bacteroides and Rikenellaceae_RC9_gut_group. The LEfSe analysis revealed an enrichment of Sutterella and Akkermansia muciniphila. In conclusion, the results of this experiment indicated that the additional supplementation of MRY can improve the production performance of laying hens and may contribute to the restoration and balance of intestinal homeostasis, which supports the application potential of MRY as a green and efficient feed additive for improving the laying performance in chickens.

Akkermansia muciniphila in patients with metabolic dysfunction-associated steatotic liver disease

Akkermansia muciniphila (AM), one of the many microbial species residing in the human gut, has been particularly highlighted for its potential beneficial impacts on host metabolism and gut barrier function. This study evaluated the association between AM concentration and metabolic markers among patients diagnosed with metabolic dysfunction-associated steatotic liver disease (MASL). The study included a cohort of 122 patients with MASLD, monitored between January 1 and June 30, 2024, at the Venus Vascular Center in Oradea, Romania. Enterotype 2 was predominant in the study population, accounting for over 60% of participants. Correlation analysis revealed no statistically significant association between alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels and AM concentration (ALT: r = -0.147, P = 0.105; AST: r = -0.090, P = 0.325). However, a significant negative linear correlation was determined between gamma-glutamyl transferase (GGT) values and AM concentrations (r = -0.314, P < 0.001) and a moderate, positive correlation between high-density lipoprotein (HDL) values and AM concentration (r = 0.307, P < 0.001). Glycemia showed a weak negative correlation with AM concentration (r = -0.262, P = 0.003). The improvement of liver markers (AST, ALT), even in the absence of correlation with AM concentration, and the negative correlation of GGT, a marker for hepatobiliary diseases and metabolic syndrome, suggest the reduction of oxidative stress in MASLD.

The Role and Mechanism of Probiotics Supplementation in Blood Glucose Regulation: A Review

With economic growth and improved living standards, the incidence of metabolic diseases such as diabetes mellitus caused by over-nutrition has risen sharply worldwide. Elevated blood glucose and complications in patients seriously affect the quality of life and increase the economic burden. There are limitations and side effects of current hypoglycemic drugs, while probiotics, which are safe, economical, and effective, have good application prospects in disease prevention and remodeling of intestinal microecological health and are gradually becoming a research hotspot for diabetes prevention and treatment, capable of lowering blood glucose and alleviating complications, among other things. Probiotic supplementation is a microbiologically based approach to the treatment of type 2 diabetes mellitus (T2DM), which can achieve anti-diabetic efficacy through the regulation of different tissues and metabolic pathways. In this study, we summarize recent findings that probiotic intake can achieve blood glucose regulation by modulating intestinal flora, decreasing chronic low-grade inflammation, modulating glucagon-like peptide-1 (GLP-1), decreasing oxidative stress, ameliorating insulin resistance, and increasing short-chain fatty acids (SCFAs) content. Moreover, the mechanism, application, development prospect, and challenges of probiotics regulating blood glucose were discussed to provide theoretical references and a guiding basis for the development of probiotic preparations and related functional foods regulating blood glucose.

Gut Microbiome in Children with Congenital Heart Disease After Cardiopulmonary Bypass Surgery (GuMiBear Study)

The gut microbiome of infants with congenital heart disease (CHD) undergoing cardiopulmonary bypass surgery (CPB) is at risk of profound alteration. The aim of this study was to examine the gut microbiome pre- and post-bypass surgery to explore potential implications of altered gut biodiversity. A prospective cohort study involving infants with CHD who underwent CPB was performed. Faecal samples were collected from infants alongside the collection of demographic and clinical data in order to examine gut microbiome changes before and after surgery. 16S rRNA sequencing analysis was performed on DNA isolated from stool samples to determine changes in gut microbiome composition. Thirty-three patients were recruited, with samples from thirteen of these available for final analysis. Compared with healthy, matched controls, at a genus level, pre-operative samples for infants with CHD demonstrated a higher relative abundance of Escherichia-Shigella (31% vs 2-6%) and a lower relative abundance of Bifidobacterium (13% vs 40-60%). In post-operative samples, the relative abundance of Escherichia-Shigella (35%), Enterococcus (11%), Akkermansia (6%), and Staphylococcus (5%) were higher than pre-op samples. One infant developed post-operative necrotising-enterocolitis (NEC). They displayed a marked abundance of the Enterococcus (93%) genus pre-operatively. This study demonstrates that infants with CHD have an altered gut microbiome when compared with healthy controls and there might be a possible link between an abundance of virulent species and NEC.

The potential role of Akkermansia muciniphila in liver health

Akkermansia muciniphila (A. muciniphila) is a 'star strain' that has attracted much attention in recent years. A. muciniphila can effectively regulate host metabolism, significantly affect host immune function, and play an important role in balancing host health and disease. As one of the organs most closely related to the gut (the two can communicate through the hepatic portal vein and bile duct system), liver is widely affected by intestinal microorganisms. A growing body of evidence suggests that A. muciniphila may alleviate liver-related diseases by improving the intestinal barrier, energy metabolism and regulating inflammation through its protein components and metabolites. This paper systematically reviews the key roles of A. muciniphila and its derivatives in maintaining liver health and improving liver disease.

The Role of Akkermansia muciniphila on Improving Gut and Metabolic Health Modulation: A Meta-Analysis of Preclinical Mouse Model Studies

Akkermansia muciniphila (A. muciniphila) and its derivatives, including extracellular vesicles (EVs) and outer membrane proteins, are recognized for enhancing intestinal balance and metabolic health. However, the mechanisms of Akkermansia muciniphila's action and its effects on the microbiome are not well understood. In this study, we examined the influence of A. muciniphila and its derivatives on gastrointestinal (GI) and metabolic disorders through a meta-analysis of studies conducted on mouse models. A total of 39 eligible studies were identified through targeted searches on PubMed, Web of Science, Science Direct, and Embase until May 2024. A. muciniphila (alive or heat-killed) and its derivatives positively affected systemic and gut inflammation, liver enzyme level, glycemic response, and lipid profiles. The intervention increased the expression of tight-junction proteins in the gut, improving gut permeability in mouse models of GI and metabolic disorders. Regarding body weight, A. muciniphila and its derivatives prevented weight loss in animals with GI disorders while reducing body weight in mice with metabolic disorders. Sub-group analysis indicated that live bacteria had a more substantial effect on most analyzed biomarkers. Gut microbiome analysis using live A. muciniphila identified a co-occurrence cluster, including Desulfovibrio, Family XIII AD3011 group, and Candidatus Saccharimonas. Thus, enhancing the intestinal abundance of A. muciniphila and its gut microbial clusters may provide more robust health benefits for cardiometabolic, and age-related diseases compared with A. muciniphila alone. The mechanistic insight elucidated here will pave the way for further exploration and potential translational applications in human health.

Gut microbiota changes in patients with Alzheimer's disease spectrum based on 16S rRNA sequencing: a systematic review and meta-analysis

Background

The gut microbiota (GM) is hypothesized to play roles in Alzheimer's disease (AD) pathogenesis. In recent years, many GM composition and abundance investigations in AD patients have been conducted; however, despite this work, some results remain controversial. Therefore, we conducted a systematic review and meta-analysis using 16S ribosomal RNA (16S rRNA) sequencing to explore GM alterations between patients with AD spectrum and healthy controls (HCs).

Methods

A systematic and comprehensive literature search of PubMed, Web of Science, Embase, the Cochrane Library, China National Knowledge Infrastructure, China Biology Medicine disc database, WanFang database and Social Sciences Citation Index databases was conducted from inception to January 2023. Inclusion and exclusion criteria were strictly defined, and two researchers independently screened and extracted information from selected studies. Data quality were evaluated according to the "Cochrane system evaluator manual" and pooled data were comprehensively analyzed using Stata 14 software with standardized mean differences (SMDs) and 95% confidence intervals (95% CIs) used to measure effect sizes. Also, geographical heterogeneity effects (related to cohorts) on GM abundance were examined based on subgroup meta-analyses if sufficient studies reported outcomes. Finally, publication bias was assessed using funnel plots.

Results

Out of 1566 articles, 13 studies involving 581 patients with AD spectrum and 445 HCs were deemed eligible and included in our analysis. In summary, a decreased microbiota alpha diversity and a significantly distinct pattern of clustering with regard to beta diversity were observed in AD spectrum patients when compared with HCs. Comparative analyses revealed a decreased Ruminococcus, Faecalibacterium, Lachnospira, Dialister, Lachnoclostridium, and Roseburia abundance in AD spectrum patients while Phascolarctobacterium, Lactobacillus, and Akkermansia muciniphila were more enriched in patients when compared to HCs. Furthermore, regional variations may have been in play for intestinal microbes such as Bacteroides, Bifidobacterium, and Alistipes.

Conclusion

Our meta-analysis identified alterations in GM abundance in patients with AD spectrum, with 12 genera from four major phyla significantly associated with AD. Moreover, we provided evidence for region-specific alterations in Bacteroides, Bifidobacterium, and Alistipes abundance. These findings may have profound implications for the development of innovative GM-based strategies to prevent and treat AD.

Systematic review registration

https://doi.org/10.37766/inplasy2024.6.0067, identifier INPLASY202460067.

The microbiota: a crucial mediator in gut homeostasis and colonization resistance

The gut microbiota is a complex and diverse community of microorganisms that colonizes the human gastrointestinal tract and influences various aspects of human health. These microbes are closely related to enteric infections. As a foreign entity for the host, commensal microbiota is restricted and regulated by the barrier and immune system in the gut and contributes to gut homeostasis. Commensals also effectively resist the colonization of pathogens and the overgrowth of indigenous pathobionts by utilizing a variety of mechanisms, while pathogens have developed strategies to subvert colonization resistance. Dysbiosis of the microbial community can lead to enteric infections. The microbiota acts as a pivotal mediator in establishing a harmonious mutualistic symbiosis with the host and shielding the host against pathogens. This review aims to provide a comprehensive overview of the mechanisms underlying host-microbiome and microbiome-pathogen interactions, highlighting the multi-faceted roles of the gut microbiota in preventing enteric infections. We also discuss the applications of manipulating the microbiota to treat infectious diseases in the gut.

Research trends of next generation probiotics

Gut represents one of the largest interfaces for the interaction of host factors and the environmental ones. Gut microbiota, largely dominated by bacterial community, plays a significant role in the health status of the host. The healthy gut microbiota fulfills several vital functions such as energy metabolism, disease protection, and immune modulation. Dysbiosis, characterized by microbial imbalance, can contribute to the development of various disorders, including intestinal, systemic, metabolic, and neurodegenerative conditions. Probiotics offer the potential to address dysbiosis and improve overall health. Advancements in high-throughput sequencing, bioinformatics, and omics have enabled mechanistic studies for the development of bespoke probiotics, referred to as next generation probiotics. These tailor-made probiotics have the potential to ameliorate specific disease conditions and thus fulfill the specific consumer needs. This review discusses recent updates on the most promising next generation probiotics, along with the challenges that must be addressed to translate this concept into reality.

Elucidation of the beneficial role of co-fermented whole grain quinoa and black barley with Lactobacillus on rats fed a western-style diet via a multi-omics approach

Long-term consumption of Western-style diet (WSD) can lead to metabolic disorders and dysbiosis of gut microbiota, presenting a critical risk factor for various chronic conditions such as fatty liver disease. In the present study, we investigated the beneficial role of co-fermented whole grain quinoa and black barley with Lactobacillus kisonensis on rats fed a WSD. Male Sprague-Dawley (SD) rats, aged six weeks and weighing 180 ± 10 g, were randomly assigned to one of three groups: the normal control group (NC, n = 7), the WSD group (HF, n = 7), and the WSD supplemented with a co-fermented whole grain quinoa with black barley (FQB) intervention group (HFF, n = 7). The findings indicated that FQB was effective in suppressing body weight gain, mitigating hepatic steatosis, reducing perirenal fat accumulation, and ameliorating pathological damage in the livers and testicular tissues of rats. Additionally, FQB intervention led to decreased levels of serum uric acid (UA), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). These advantageous effects can be ascribed to the regulation of FQB on gut microbiota dysbiosis, which includes the restoration of intestinal flora diversity, reduction of the F/B ratio, and promotion of probiotics abundance, such as Akkermansia and [Ruminococcus] at the genus level. The study employed the UPLC-Q-TOF-MSE technique to analyze metabolites in fecal and hepatic samples. The findings revealed that FQB intervention led to a regression in the levels of specific metabolites in feces, including oxoadipic acid and 20a, 22b-dihydroxycholesterol, as well as in the liver, such as pyridoxamine, xanthine and xanthosine. The transcriptome sequencing of liver tissues revealed that FQB intervention modulated the mRNA expression of specific genes, including Cxcl12, Cidea, and Gck, known for their roles in anti-inflammatory and anti-insulin resistance mechanisms in the context of WSD. Our findings indicate that co-fermented whole-grain quinoa with black barley has the potential to alleviate metabolic disorders and chronic inflammation resulting from the consumption of WSD.

Amelioration of walnut, peony seed and camellia seed oils against D-galactose-induced cognitive impairment in mice by regulating gut microbiota

Diet adjustment will affect the health of gut microbiota, which in turn influences the development and function of the organism's brain through the gut-brain axis. Walnut oil (WO), peony seed oil (PSO) and camellia seed oil (CSO), as typical representatives of woody plant oils, have been shown to have the potential to improve cognitive impairment in mice, but the function mechanisms are not clear. In this study, we comparatively investigated the neuroprotective effects of these three oils on D-galactose (D-gal)-induced cognitive impairment in mice, and found that the ameliorative effect of WO was more prominent. During the behavioral experiments, supplementation with all three oils would improve spatial learning and memory functions in D-gal mice, with a significant reduction in the error times (p < 0.001) and a significant increase in step-down latency (p < 0.001); walnut oil supplementation also significantly increased the number of hidden platform traversals, the target quadrant spent times and percentage of distance (p < 0.05). The results of biomarker analysis showed that WO, in addition to significantly inhibiting D-gal-induced oxidative stress and neuroinflammation as did PSO, significantly increased the ACh content in the mouse brain (p < 0.05) and modulated neurotransmitter levels. The results of further microbiota diversity sequencing experiments also confirmed that dietary supplementation with all three oils affected the diversity and composition of the gut microbiota in mice. Among them, WO significantly restored the balance of the mouse gut microbiota by increasing the abundance of beneficial bacteria (Bacteroidetes, Actinobacteria, Firmicutes) and decreasing the abundance of harmful bacteria (Clostridium, Shigella, Serratia), which was consistent with the results of behavioral experiments and biomarker analyses. Based on the analysis of the fatty acid composition of the three oils and changes in the gut microbiota, it is hypothesized that there is a correlation between the fatty acid composition of the dietary supplement oils and neuroprotective effects. The superiority of WO over PSO and CSO in improving cognitive impairment is mainly attributed to its balanced composition of omega-6 and omega-3 fatty acids.

NAFLD/MASLD and the Gut-Liver Axis: From Pathogenesis to Treatment Options

Nonalcoholic fatty liver disease (NAFLD) poses an emerging threat topublic health. Nonalcoholic steatohepatitis (NASH) is reported to be the most rapidly rising cause of hepatocellular carcinoma in the western world. Recently, a new term has been proposed: metabolic dysfunction-associated steatotic liver disease (MASLD). The introduction of this new terminology has sparked a debate about the interchangeability of these terms. The pathogenesis of NAFLD/MASLD is thought to be multifactorial, involving both genetic and environmental factors. Among these factors, alterations in gut microbiota and gut dysbiosis have recently garnered significant attention. In this context, this review will further discuss the gut-liver axis, which refers to the bidirectional interaction between the human gut microbiota and the liver. Additionally, the therapeutic potential of probiotics, particularly next-generation probiotics and genetically engineered bacteria, will be explored. Moreover, the role of prebiotics, synbiotics, postbiotics, and phages as well as fecal microbiota transplantation will be analyzed. Particularly for lean patients with NAFLD/MASLD, who have limited treatment options, approaches that modify the diversity and composition of the gut microbiota may hold promise. However, due to ongoing safety concerns with approaches that modulate gut microbiota, further large-scale studies are necessary to better assess their efficacy and safety in treating NAFLD/MASLD.

The Effect of the Lacticaseibacillus paracasei BEPC22 and Lactiplantibacillus plantarum BELP53 Combination (BN-202M) on Body Fat Percentage Loss in Overweight Individuals: A Randomized, Double-Blind, Placebo-Controlled Study

BN-202M is derived from humans and consists of two strains, Lacticaseibacillus paracasei BEPC22 and Lactiplantibacillus plantarum BELP53. Body fat reduction effect and safety of BN-202M were assessed in overweight participants. A total of 150 participants were randomly assigned to the BN-202M and placebo groups at a 1:1 ratio. Dual-energy X-ray absorptiometry was used to objectively measure body fat. After 12 weeks of oral administration, the body fat percentage (-0.10 ± 1.32% vs. 0.48 ± 1.10%; p = 0.009) and body fat mass (-0.24 ± 1.19 kg vs. 0.23 ± 1.05 kg; p = 0.023) of the BN-202M group decreased significantly compared to those of the placebo group. The body weight (-0.58 kg, p = 0.004) and body mass index (BMI; -0.23, p = 0.003) was found to decrease significantly at 12 weeks in the BN-202M group, but not in the placebo group. Metabolome analysis revealed that β-alanine, 3-aminoisobutyric acid, glutamic acid, and octopamine decreased in the weight-decreased BN-202M post-intake group. In the gut microbiota analysis, Akkermansia showed a statistically significant increase in the BN-202M group post-intake compared to the placebo group. No serious adverse events were observed in either group. These results suggest that BN-202M is safe and effective for reducing body fat and weight.

A Narrative Review of Intestinal Microbiota's Impact on Migraine with Psychopathologies

Migraine is a common and debilitating neurological disorder characterized by the recurrent attack of pulsating headaches typically localized on one side of the head associated with other disabling symptoms, such as nausea, increased sensitivity to light, sound and smell and mood changes. Various clinical factors, including the excessive use of migraine medication, inadequate acute treatment and stressful events, can contribute to the worsening of the condition, which may evolve to chronic migraine, that is, a headache present on >15 days/month for at least 3 months. Chronic migraine is frequently associated with various comorbidities, including anxiety and mood disorders, particularly depression, which complicate the prognosis, response to treatment and overall clinical outcomes. Emerging research indicates a connection between alterations in the composition of the gut microbiota and mental health conditions, particularly anxiety and depression, which are considered disorders of the gut-brain axis. This underscores the potential of modulating the gut microbiota as a new avenue for managing these conditions. In this context, it is interesting to investigate whether migraine, particularly in its chronic form, exhibits a dysbiosis profile similar to that observed in individuals with anxiety and depression. This could pave the way for interventions aimed at modulating the gut microbiota for treating difficult-to-manage migraines.

Polygonatum cyrtonema polysaccharides reshape the gut microbiota to ameliorate dextran sodium sulfate-induced ulcerative colitis in mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized inflammatory imbalance, intestinal epithelial mucosal damage, and dysbiosis of the gut microbiota. Polygonatum cyrtonema polysaccharides (PCPs) can regulate gut microbiota and inflammation. Here, the different doses of PCPs were administered to dextran sodium sulfate-induced UC mice, and the effects of the whole PCPs were compared with those of the fractionated fractions PCP-1 (19.9 kDa) and PCP-2 (71.6 and 4.2 kDa). Additionally, an antibiotic cocktail was administered to UC mice to deplete the gut microbiota, and PCPs were subsequently administered to elucidate the potential role of the gut microbiota in these mice. The results revealed that PCP treatment significantly optimized the lost weight and shortened colon, restored the balance of inflammation, mitigated oxidative stress, and restored intestinal epithelial mucosal damage. And, the PCPs exhibited superior efficacy in ameliorating these symptoms compared with PCP-1 and PCP-2. However, depletion of the gut microbiota diminished the therapeutic effects of PCPs in UC mice. Furthermore, fecal transplantation from PCP-treated UC mice to new UC-afflicted mice produced therapeutic effects similar to PCP treatment. So, PCPs significantly ameliorated the symptoms, inflammation, oxidative stress, and intestinal mucosal damage in UC mice, and gut microbiota partially mediated these effects.

Akkermansia muciniphila extracellular vesicles have a protective effect against hypertension

Akkermansia muciniphila (Am) shows a beneficial role as a probiotic in the treatment of metabolic syndrome. However, the mechanism remains to be elucidated. We tested the hypothesis that Am extracellular vesicles (AmEVs) have a protective effect against hypertension. Extracellular vesicles purified from anaerobically cultured Am were characterized by nanoparticle tracking analysis, transmission electron microscopy, and silver stain after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). AmEVs (1.0 × 1010 log particles/L) or vehicles were added into organ baths to induce vasorelaxation. In addition, AmEVs (1.0 × 108 or 1.0 × 109 particles/kg) or vehicles were injected into the tail veins of Wistar-Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) weekly for 4 weeks. Peripheral blood mononuclear cells (PBMCs) and splenocytes isolated from both rat strains were analyzed by flow cytometry, RT-qPCR, and western blot. AmEVs affected neither vascular contraction nor endothelial relaxation in thoracic aortas. Moreover, AmEVs protected against the development of hypertension in SHRs without a serious adverse reaction. Additionally, AmEVs increased the population of T regulatory (Treg) cells and tended to reduce proinflammatory cytokines. These results indicate that AmEVs have a protective effect against hypertension without a serious adverse reaction. Therefore, it is foreseen that AmEVs may be utilized as a novel therapeutic for the treatment of hypertension.

Long-term use of etomidate disrupts the intestinal homeostasis and nervous system in mice

Etomidate (ETO) is used as an anesthetic in surgery, but it is being abused in some populations. The damage caused by long-term intake of ETO to intestinal and brain functions is not yet clear, and it remains to be determined whether the drug affects the central nervous system through the gut-brain axis. This study aimed to investigate the neurotoxic and gastrointestinal effects of ETO at doses of 1 mg/kg and 3 mg/kg in mice over 14 consecutive days. The results showed that long-term injection of ETO led to drug resistance in mice, affecting their innate preference for darkness and possibly inducing dependence on ETO. The levels of 5-hydroxytryptamine in the brain, serum, and colon decreased by 37%, 51%, and 42% respectively, while the levels of γ-aminobutyric acid reduced by 38%, 52%, and 41% respectively. H&E staining revealed that ETO reduced goblet cells in the colon and damaged the intestinal barrier. The expression of tight junction-related genes Claudin4 and ZO-1 was downregulated. The intestinal flora changed, the abundance of Akkermansia and Lactobacillus decreased by 33% and 14%, respectively, while Klebsiella increased by 18%. TUNEL results showed that high-dose ETO increased apoptotic cells in the brain. The expression of Claudin1 in the brain was downregulated. Untargeted metabolomics analysis of the colon and brain indicated that ETO caused abnormalities in glycerophospholipid metabolism. Abnormal lipid metabolism might lead to the production or accumulation of lipotoxic metabolites, causing central nervous system diseases. ETO induced changes in the intestinal flora and metabolism, further affecting the central nervous system through the gut-brain axis. The study unveiled the detrimental effects on the brain and gastrointestinal system resulting from long-term intake of ETO, which holds significant implications for comprehending the adverse impact of ETO abuse on human health.

Carrageenan as a Potential Factor of Inflammatory Bowel Diseases

Carrageenan is a widely used food additive and is seen as a potential candidate in the pharmaceutical industry. However, there are two faces to carrageenan that allows it to be used positively for therapeutic purposes. Carrageenan can be used to create edible films and for encapsulating drugs, and there is also interest in the use of carrageenan for food printing. Carrageenan is a naturally occurring polysaccharide gum. Depending on the type of carrageenan, it is used in regulating the composition of intestinal microflora, including the increase in the population of Bifidobacterium bacteria. On the other hand, the studies have demonstrated the harmfulness of carrageenan in animal and human models, indicating a direct link between diet and intestinal inflammatory states. Carrageenan changes the intestinal microflora, especially Akkermansia muciniphilia, degrades the mucous barrier and breaks down the mucous barrier, causing an inflammatory reaction. It directly affects epithelial cells by activating the pro-inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) pathway. The mechanism is based on activation of the TLR4 receptor, alterations in macrophage activity, production of proinflammatory cytokines and activation of innate immune pathways. Carrageenan increases the content of Bacteroidetes bacteria, also causing a reduction in the number of short chain fatty acid (SCFA)-producing bacteria. The result is damage to the integrity of the intestinal membrane and reduction of the mucin layer. The group most exposed to the harmful effects of carrageenan are people suffering from intestinal inflammation, including Crohn disease (CD) and ulcerative colitis (UC).