Search Results (246)

The gut–brain axis refers to the bidirectional communication network linking the gut microbiota and the central nervous system (CNS). Recent research has highlighted the critical role of gut microbiota in influencing brain health, neurogenesis, and neuroinflammation. In the context of brain tumors, especially gliomas, the gut–brain axis plays a significant role in tumor development, progression, and response to therapy. Gut dysbiosis, characterized by an imbalance in microbiota composition, has been linked to chronic inflammation, immune suppression, and altered blood–brain barrier (BBB) permeability, key factors in glioma pathogenesis. Gut-derived metabolites such as short-chain fatty acids (SCFAs) and neurotransmitters can either promote or inhibit tumor growth, impacting the tumor microenvironment (TME) and immune responses. Emerging evidence suggests that microbiome modulation, through strategies such as probiotics, prebiotics, and dietary interventions, may enhance anti-tumor immunity and improve the efficacy of conventional treatments like chemotherapy, radiotherapy, and immunotherapy. This review examines the interactions between gut microbiota and brain tumors, focusing on how microbiota alterations may influence tumor biology and therapeutic outcomes. Understanding the mechanisms of the gut–brain axis could lead to novel adjunctive therapies in neuro-oncology, offering new prospects for personalized treatment strategies in brain tumor management. Full article

Cerebral cavernous malformation (CCM) is a cluster of abnormal blood vessels in the brain that leads to severe neurological deficits, seizures, and fatal hemorrhagic stroke. Currently, there is no available drug treatment for CCM. Most CCMs are conservatively managed by observing change in appearance (MRI), recent hemorrhage, or any clinical symptoms. Neurosurgery is the only current treatment option, but it is only effective in a few cases. Since most CCM lesions are surgically inaccessible, when left untreated they lead to severe neurological deficits, seizures, and fatal hemorrhagic stroke. Hence, new non-invasive, safe, and effective treatment strategies are urgently needed. Recent research has identified gut microbiome dysbiosis and its innate immune response as the critical stimulus in experimental CCM pathogenesis, demonstrating the importance of the gut–brain axis in CCM. Importantly, CCM patients also manifest gut microbiome dysbiosis and gut barrier health can impact CCM disease course. This review highlights the emerging involvement of the gut microbiome in CCM pathogenesis and its potential as a therapeutic target. While preclinical data suggest mechanistic links, the lack of clinical intervention studies limits current applicability and underscores the need for translational research. Full article

Background: Influenza, a primarily respiratory illness, frequently manifests with gastrointestinal (GI) symptoms including nausea, vomiting, diarrhea, and abdominal pain. In this review, we analyze mechanisms describing GI infiltration and subsequent involvement of the GI system during influenza infection. Direct mechanisms involve the presence of viral particles in the GI tract and binding to sialic acid receptor, α2,3 and α2,6 linkages. The influenza virus may gain access to gut tissue via swallowing of respiratory secretions, hematogenous spread, or lymphocytic migration via the lung–gut axis. Indirect mechanisms involve immune system dysregulation via cytokine, interferon, and leukotriene flux, upregulation of consequential apoptotic pathways, or gut microbiome dysbiosis. Together, they promote secondary GI opportunistic infections. These findings improve our knowledge of GI infiltration during influenza infection which may aid in effective clinical diagnosis and treatment, ultimately improving patient outcomes. Full article

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive loss of motor neurons. Although genetic and environmental factors are established contributors, recent research has highlighted the critical role of the gut–brain axis (GBA) in ALS pathogenesis. The GBA is a bidirectional communication network involving neural, immune, and endocrine pathways that connect the gut microbiota with the central nervous system. Dysbiosis in ALS disrupts this axis, leading to increased intestinal permeability, neuroinflammation, and excitotoxicity. Notably, reductions in butyrate-producing bacteria, alterations in microbial metabolites, and enhanced NLRP3 inflammasome activation have been observed in patients with ALS. These changes may precede motor symptoms, suggesting a potential causative role. Interventions targeting the microbiome, such as dietary modulation, have shown promise in delaying disease onset and reducing inflammation. However, the clinical evidence remains limited. Given that gut dysbiosis may precede neurological symptoms, microbiota-targeted therapies offer a novel and potentially modifiable approach to ALS treatment. Understanding the role of GBA in ALS will open new avenues for early diagnosis and intervention. Further clinical trials are required to clarify the causal links and evaluate the efficacy of microbiome-based interventions. Understanding the brain–gut–microbiota axis in ALS could lead to new diagnostic biomarkers and therapeutic strategies. Full article

Recent studies increasingly highlight the complex interaction between gut microbiota and mental health, drawing attention to the role of the microbiota–gut–brain axis (MGBA) in the pathophysiology of mental and neurodevelopmental disorders. Changes in the composition of the gut microbiota—dysbiosis—are associated with conditions such as depression, schizophrenia, bipolar disorder (BD), autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), and neurodegenerative diseases such as Parkinson’s and Alzheimer’s. These microbial imbalances can affect brain function through a variety of mechanisms, including activation of the immune system, alteration of intestinal permeability, modulation of the digestive and central nervous systems, and changes in the production of neuroactive metabolites such as short-chain fatty acids, serotonin, and tryptophan derivatives. The aim of this paper is to review the current state of knowledge on therapeutic strategies targeting the gut microbiome—including probiotics, prebiotics, synbiotics, personalized dietary interventions, and fecal microbiota transplantation (FMT)—which are becoming promising adjuncts or alternatives to conventional psychopharmacology, offering a forward-looking and individualized approach to mental health treatment. Understanding the bidirectional and multifactorial nature of MGBA may pave the way for new, integrative treatment paradigms in psychiatry and neurology, requiring further research and exploration of their scope of application. Full article

In humans, the bioactivity of polyphenols is highly dependent on dose intake and their interactions with the gastrointestinal tract and gut microbiota, which metabolize polyphenols into bioactive or inactive derivatives. Polyphenols are only partially absorbed in the small intestine, where enzymatic hydrolysis releases aglycone forms that may cross the gut barrier. A significant proportion of polyphenols escapes absorption and reaches the colon, where resident microbes convert them into simpler phenolic metabolites. Such molecules are often more bioavailable than the parent compounds and can enter systemic circulation, leading to distant effects. Although higher polyphenol consumption has been associated with preventive and therapeutic outcomes, even low intake or poor intestinal absorption may still confer benefits, as polyphenols in the colon can positively modulate gut microbiota composition and function, contributing to favorable shifts in the microbial metabolome. These interactions can influence host metabolic, immune, and neurological pathways, particularly through the gut–liver–brain axis. To provide a comprehensive understanding of these relationships, this review examines the dose-related activity of polyphenols, their microbiota-mediated biotransformation, their bioavailability, and the health effects of their metabolites, while also presenting a comparative overview of key studies in the field. We underscore the importance of integrating microbiome and polyphenol research to recapitulate and contextualize the health benefits of dietary polyphenols. Full article

Background: Breast cancer is the most common malignancy affecting women worldwide and continues to pose significant challenges despite progress in early detection and personalized therapies. While its pathogenesis has traditionally been associated with genetic, hormonal, and environmental factors, recent studies have highlighted the potential role of dysbiosis—an imbalance in gut and systemic microbiota—in breast cancer development and progression. This article aims to examine the mechanisms through which systemic dysbiosis may contribute to breast cancer risk and explore its therapeutic implications. Methods: This study seeks to analyze and compare the fecal microbiota profiles of breast cancer patients and healthy individuals from a single center in Craiova, Romania, in order to identify microbial signatures linked to breast cancer and BRCA mutation status. Special attention is given to the gut–liver axis and its influence on estrogen circulation, a key factor in hormone-sensitive breast cancers. Results: Evidence suggests that dysbiosis can influence breast cancer progression by promoting chronic inflammation, impairing immune regulation, and altering estrogen metabolism through the gut–liver axis. These effects may contribute to tumor development, immune evasion, and therapeutic resistance. Interventions aimed at restoring microbial balance show promise in preclinical studies for mitigating these effects. Conclusions: Systemic dysbiosis represents a potentially modifiable risk factor in breast cancer. Microbiota profiling may serve as a useful biomarker for risk stratification and therapeutic response. Future research into microbiome-based interventions could offer novel approaches for prevention and treatment in breast cancer care. Full article

Rosacea is a chronic inflammatory skin disorder with multifactorial pathogenesis involving immune dysregulation and microbial alterations. This study compared the mycobiomes of skin, blood, and stool samples in rosacea patients and healthy controls to assess fungal diversity, abundance, and possible translocation, as well as associations with bacterial microbiomes. Internal transcribed spacer (ITS) region sequencing was performed on samples from 14 rosacea patients and 8 controls. While distinct fungal community compositions were observed across sample types, no significant differences in fungal diversity or genus abundance were found between the patient and control groups in any compartment. Malassezia dominated the skin mycobiome, while stool samples showed higher abundances of Candida and Saccharomyces, which were inversely correlated. Patients with high skin and blood Malassezia also exhibited increased Cutibacterium abundance, suggesting a potential role in impaired skin barrier integrity. Stool samples with elevated Saccharomyces correlated with higher levels of anti-inflammatory bacteria Prevotella and Agathobacter, whereas Candida dominance showed the opposite. These findings suggest that fungal dysbiosis, in the interplay with bacterial communities, may influence rosacea pathogenesis through the gut–skin axis. This work underscores the significance of integrated microbiome research across multiple biological compartments in order to enhance our understanding and potential targeting of microbial factors in rosacea. Full article

Type 2 diabetes (T2D) is a complex metabolic disease characterized by chronic hyperglycemia due to insulin resistance and inadequate insulin secretion. Beyond the classically implicated organs, emerging evidence highlights the gut as a central player in T2D pathophysiology through its interactions with metabolic organs. The gut hosts trillions of microbes and enteroendocrine cells that influence inflammation, energy homeostasis, and hormone regulation. Disruptions in gut homeostasis (dysbiosis and increased permeability) have been linked to obesity, insulin resistance, and β-cell dysfunction, suggesting multifaceted “Gut-X axes” contribute to T2D development. We aimed to comprehensively review the evidence for gut-mediated crosstalk with the pancreas, endocrine system, liver, and kidneys in T2D. Key molecular mechanisms (incretins, bile acids, short-chain fatty acids, endotoxins, etc.) were examined to construct an integrated model of how gut-derived signals modulate metabolic and inflammatory pathways across organs. We also discuss clinical implications of targeting Gut-X axes and identify knowledge gaps and future research directions. A literature search (2015–2025) was conducted in PubMed, Scopus, and Web of Science, following PRISMA guidelines (Preferred Reporting Items for Systematic Reviews). Over 150 high-impact publications (original research and review articles from Nature, Cell, Gut, Diabetologia, Lancet Diabetes & Endocrinology, etc.) were screened. Data on gut microbiota, enteroendocrine hormones, inflammatory mediators, and organ-specific outcomes in T2D were extracted. The GRADE framework was used informally to prioritize high-quality evidence (e.g., human trials and meta-analyses) in formulating conclusions. T2D involves perturbations in multiple Gut-X axes. This review first outlines gut homeostasis and T2D pathogenesis, then dissects each axis: (1) Gut–Pancreas Axis: how incretin hormones (GLP-1 and GIP) and microbial metabolites affect insulin/glucagon secretion and β-cell health; (2) Gut–Endocrine Axis: enteroendocrine signals (e.g., PYY and ghrelin) and neural pathways that link the gut with appetite regulation, adipose tissue, and systemic metabolism; (3) Gut–Liver Axis: the role of microbiota-modified bile acids (FXR/TGR5 pathways) and bacterial endotoxins in non-alcoholic fatty liver disease (NAFLD) and hepatic insulin resistance; (4) Gut–Kidney Axis: how gut-derived toxins and nutrient handling intersect with diabetic kidney disease and how incretin-based and SGLT2 inhibitor therapies leverage gut–kidney communication. Shared mechanisms (microbial SCFAs improving insulin sensitivity, LPS driving inflammation via TLR4, and aryl hydrocarbon receptor ligands modulating immunity) are synthesized into a unified model. An integrated understanding of Gut-X axes reveals new opportunities for treating and preventing T2D. Modulating the gut microbiome and its metabolites (through diet, pharmaceuticals, or microbiota therapies) can improve glycemic control and ameliorate complications by simultaneously influencing pancreatic islet function, hepatic metabolism, and systemic inflammation. However, translating these insights into clinical practice requires addressing gaps with robust human studies. This review provides a state-of-the-art synthesis for researchers and clinicians, underlining the gut as a nexus for multi-organ metabolic regulation in T2D and a fertile target for next-generation therapies. Full article

The kynurenine (KYN) metabolic pathway sits at the crossroads of immunity, metabolism, and neurobiology, yet its clinical translation remains fragmented. Emerging spatial omics, wearable chronobiology, and synthetic microbiota studies reveal that tryptophan (Trp) metabolism is regulated by distinct cellular “checkpoints” along the gut–brain axis, finely modulated by sex differences, circadian rhythms, and microbiome composition. However, current interventions tackle single levers in isolation, leaving a key gap in the precision control of Trp’s fate. To address this, we drew upon an extensive body of the primary literature and databases, mapping enzyme expression across tissues at single-cell resolution and linking these profiles to clinical trials investigating dual indoleamine 2,3-dioxygenase 1 (IDO1)/tryptophan 2,3-dioxygenase (TDO) inhibitors, engineered probiotics, and chrono-modulated dosing strategies. We then developed decision-tree algorithms that rank therapeutic combinations against biomarker feedback loops derived from real-time saliva, plasma, and stool metabolomics. This synthesis pinpoints microglial and endothelial KYN hotspots, quantifies sex-specific chronotherapeutic windows, and identifies engineered Bifidobacterium consortia and dual inhibitors as synergistic nodes capable of reducing immunosuppressive KYN while preserving neuroprotective kynurenic acid. Here, we highlight a framework that couples lifestyle levers, bio-engineered microbes, and adaptive pharmaco-regimens into closed-loop “smart protocols.” By charting these intersections, this study offers a roadmap for biomarker-guided, multidisciplinary interventions that could recalibrate KYN metabolic activity across cancer, mood, neurodegeneration, and metabolic disorders, appealing to clinicians, bioengineers, and systems biologists alike. Full article

Emerging evidence suggests a critical role of the gut microbiome in modulating systemic immune responses, with increasing relevance in dermatological diseases. Chronic spontaneous urticaria (CSU), traditionally viewed as an isolated cutaneous disorder, is now recognized as a systemic immune condition involving complex interactions between innate and adaptive immunity, mast cell dysregulation, and non-IgE-mediated pathways. This review explores the gut–skin axis as a unifying concept linking intestinal dysbiosis to inflammatory skin diseases, including atopic dermatitis, psoriasis, rosacea, and acne. Special emphasis is placed on CSU, where altered gut microbial composition, characterized by reduced diversity, depletion of short-chain fatty acid-producing bacteria, and expansion of Proteobacteria, may contribute to increased intestinal permeability, systemic immune activation via toll-like receptors, and heightened mast cell sensitivity. We discuss findings from animal models demonstrating that gut microbiota modulation can attenuate mast cell hyperreactivity and reduce urticarial symptoms. In parallel, we examine clinical evidence supporting the potential role of probiotics, prebiotics, dietary interventions, and fecal microbiota transplantation as adjunctive strategies in CSU management. Despite promising findings, challenges remain in translating microbiome research into effective therapies due to interindividual variability, the complexity of host–microbiome interactions, and a lack of standardized protocols. Future research should focus on identifying predictive microbial patterns and developing personalized microbiome-targeted interventions. Understanding the bidirectional gut–skin relationship may open new therapeutic avenues beyond symptomatic treatment, positioning the microbiome as a novel target in CSU and related inflammatory dermatoses. Full article

Background: Obesity and periodontitis are two chronic inflammatory diseases with a bidirectional relationship possibly mediated by microbial and immunologic signaling pathways. This narrative review aims to investigate how microbial dysbiosis and inflammation link these diseases, focusing on the interactions between the oral and gut microbiomes. Materials and methods: Peer-reviewed studies (2015–2024) from PubMed, MEDLINE, Ovid and Google Scholar were selected for their relevance to microbial dysbiosis and inflammation, prioritizing clear methodology. Non-peer-reviewed sources or studies lacking microbial/inflammatory data were excluded. Conflicting results and methodological differences, including sampling and study design, were assessed qualitatively on the basis of coherence and methodological rigor. Results: Obesity has been shown to significantly alter the composition of the oral microbiome, characterized by reduced diversity and an increased Firmicutes/Bacteroidetes ratio. At the same time, periodontal pathogens such as Porphyromonas gingivalis can invade the gut, impair barrier function and promote systemic inflammation. Both diseases share common inflammatory pathways involving adipokines and immune-system dysregulation, creating a feedback loop that exacerbates disease progression in both conditions. Obesity also appears to impair the effectiveness of conventional periodontal treatments. Conclusions: The microbial axis between the oral cavity and the gut represents a central pathway in the complex interactions between obesity and periodontitis. This relationship involves microbial dysbiosis, bacterial translocation and shared inflammatory mechanisms that collectively contribute to disease progression. Clinical relevance: A better understanding of the relationship between obesity and periodontitis supports the development of customized treatment strategies for obese patients with periodontal disease. Future research should focus on developing targeted interventions that address both conditions simultaneously to improve patient outcomes and develop more effective prevention and treatment strategies. Full article

Longevity and healthy aging result from the complex interaction of genetic, epigenetic, microbial, behavioral, and environmental factors. The central nervous system—particularly the cerebral cortex—and the autonomic nervous system (ANS) play key roles in integrating external and internal signals, shaping energy metabolism, immune tone, and emotional regulation. This narrative review examines how the brain–ANS axis interacts with epigenetic regulation, telomere dynamics, the gut microbiome, and the exposome to influence biological aging and resilience. Relevant literature published between 2010 and 2025 was selected through comprehensive database searches (PubMed, Scopus, Google Scholar), with a focus on studies addressing the multisystemic determinants of aging. Emphasis is placed on lifestyle-related exposures, such as diet, physical activity, psychosocial support, and environmental quality, that modulate systemic physiology through neurovisceral pathways. Drawing on empirical findings from classical Blue Zones and recent observational research in the Cilento region of southern Italy, this review highlights how context-specific factors—such as clean air, mineral-rich water, Mediterranean dietary patterns, and strong social cohesion—may foster bioelectric, metabolic, and neuroimmune homeostasis. By integrating data from neuroscience, systems biology, and environmental epidemiology, the review proposes a comprehensive model for understanding healthy longevity and supports the development of personalized, context-sensitive strategies in geroscience and preventive medicine. Full article

The complex interrelationship between the gut microbiota and the skin, commonly known as the “gut–skin axis” has become a crucial field of study for comprehending skin health and illness. Systemic immunity, inflammation, and metabolism are all modulated by this two-way communication mechanism, which ultimately affects skin homeostasis. Numerous dermatological disorders, such as rosacea, psoriasis, atopic dermatitis, and acne vulgaris, have been linked to dysbiosis in the gut microbiota. On the other hand, the composition of the gut microbiome may be impacted by skin disorders. Highlighting the important microbial metabolites and immunological processes involved in this interaction, this abstract examines the current understanding of the gut–skin axis. It also talks about the possible therapeutic benefits of using probiotics, synbiotics, and prebiotics to target the gut microbiota to treat and prevent skin conditions. Gaining insight into this intricate interaction opens up exciting possibilities for creating innovative, all-encompassing dermatological treatment strategies. Full article

Respiratory microbiota and lipids are closely associated with airway inflammation. This study aimed to analyze the correlations among the respiratory microbiome, the airway glycerophospholipid–sphingolipid profiles, and airway inflammation in patients with asthma. We conducted a cross-sectional study involving 61 patients with asthma and 17 healthy controls. Targeted phospholipidomics was performed on exhaled breath condensate (EBC) samples, and microbial composition was analyzed via the 16S rDNA sequencing of induced sputum. Asthma patients exhibited significant alterations in the EBC lipid profiles, with reduced levels of multiple ceramides (Cer) and glycerophospholipids, including phosphatidylethanolamine (PE) and phosphatidylcholine (PC), compared with healthy controls. These lipids were inversely correlated with the sputum interleukin-4 (IL-4) levels. Microbiome analysis revealed an increased abundance of Leptotrichia and Parasutterella in asthma patients, both positively associated with IL-4. Correlation analysis highlighted a potential interaction network involving PA, PE, ceramides, Streptococcus, Corynebacterium, Parasutterella, and Leptotrichia. Specific alterations in airway microbiota and phospholipid metabolism are associated with asthma-related inflammation, supporting the concept of a microbiota–phospholipid–immune axis and providing potential targets for future mechanistic and therapeutic studies. Full article