Search Results (1,471)

The oral–gut microbiota axis is a relatively new field of research. Although most studies have focused separately on the oral and gut microbiota, emerging evidence has highlighted that the two microbiota are interconnected and may influence each other through various mechanisms shaping systemic health. The aim of this review is therefore to provide an overview of the interactions between oral and gut microbiota, and the influence of diet and related metabolites on this axis. Pathogenic oral bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, can migrate to the gut through the enteral route, particularly in individuals with weakened gastrointestinal defenses or conditions like gastroesophageal reflux disease, contributing to disorders like inflammatory bowel disease and colorectal cancer. Bile acids, altered by gut microbes, also play a significant role in modulating these microbiota interactions and inflammatory responses. Oral bacteria can also spread via the bloodstream, promoting systemic inflammation and worsening some conditions like cardiovascular disease. Translocation of microorganisms can also take place from the gut to the oral cavity through fecal–oral transmission, especially within poor sanitary conditions. Some metabolites including short-chain fatty acids, trimethylamine N-oxide, indole and its derivatives, bile acids, and lipopolysaccharides produced by both oral and gut microbes seem to play central roles in mediating oral–gut interactions. The complex interplay between oral and gut microbiota underscores their crucial role in maintaining systemic health and highlights the potential consequences of dysbiosis at both the oral and gastrointestinal level. Some dietary patterns and nutritional compounds including probiotics and prebiotics seem to exert beneficial effects both on oral and gut microbiota eubiosis. A better understanding of these microbial interactions could therefore pave the way for the prevention and management of systemic conditions, improving overall health outcomes. Full article

Background: Ulcerative colitis (UC), characterized by chronic intestinal inflammation, epithelial barrier dysfunction, and immune imbalance demands novel ameliorative strategies beyond conventional approaches. Methods: In this study, the probiotic properties of Lactobacillus paracasei L21 (L. paracasei L21) and its ability to ameliorate colitis were evaluated using an in vitro lipopolysaccharide (LPS)-induced intestinal crypt epithelial cell (IEC-6) model and an in vivo dextran sulfate sodium (DSS)-induced UC mouse model. Results: In vitro, L. paracasei L21 decreased levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-8) while increasing anti-inflammatory IL-10 levels (p < 0.05) in LPS-induced IEC-6 cells, significantly enhancing the expression of tight junction proteins (ZO-1, occludin, claudin-1), thereby restoring the intestinal barrier. In vivo, both viable L. paracasei L21 and its heat-inactivated postbiotic (H-L21) mitigated weight loss, colon shortening, and disease activity indices, concurrently reducing serum LPS and proinflammatory mediators. Interventions inhibited NF-κB signaling while activating HIF1α/AhR pathways, increasing IL-22 and mucin MUC2 to restore goblet cell populations. Gut microbiota analysis showed that both interventions increased the abundance of beneficial gut bacteria (Lactobacillus, Dubococcus, and Akkermansia) and improved faecal propanoic acid and butyric acid levels. H-L21 uniquely exerted an anti-inflammatory effect, marked by the regulation of Dubosiella, while L. paracasei L21 marked by the Akkermansia. Conclusions: These results highlight the potential of L. paracasei L21 as a candidate for the development of both probiotic and postbiotic formulations. It is expected to provide a theoretical basis for the management of UC and to drive the development of the next generation of UC therapies. Full article

Gut microbiota-derived trimethylamine N-oxide (TMAO) has been implicated in both intestinal and renal diseases; however, its specific role in modulating gut–kidney interactions remains unclear. This study aimed to investigate the effects of TMAO on gut–kidney crosstalk using a mouse model of diarrhea. Mice were divided into four groups: normal, model, TMAO, and TMAO + model. The normal group received sterile water, while the other groups were administered adenine + Folium sennae, TMAO, or a combination of TMAO and adenine + Folium sennae. Samples were collected to assess morphological changes in the colon and kidney, evaluate the colonic mucosal barrier and renal function, and measure NLRP3 inflammasome activity and inflammatory cytokine levels in colonic and renal tissues. TMAO levels and the gut microbiota composition were analyzed using 16S rRNA sequencing. The model group exhibited altered stool morphology, which was further aggravated by TMAO intervention. Both the model and TMAO + model groups exhibited significant damage to intestinal and renal tissues, along with compromised intestinal mucosal barriers and impaired renal function compared to controls. Inflammatory markers were elevated in these groups, with the TMAO + model group showing the most pronounced increases. Correlation analysis indicated significant relationships among TMAO levels, inflammasome activation, and inflammatory cytokines. The genera Mucispirillum and Anaerotruncus negatively correlated with TMAO, whereas Parabacteroides and Parasutterella genera positively correlated with TMAO. In conclusion, TMAO plays a critical role in modulating gut–kidney crosstalk by promoting inflammation, disrupting mucosal and renal integrity, and altering the gut microbial ecosystem. Full article

Faecal microbiota transplantation (FMT) is an emerging therapy for gastrointestinal and neurological disorders, acting via the microbiota–gut–brain axis. Altering gut microbial composition may influence cognitive function, but this has not been tested in cognitively healthy adults. This randomised, double-blinded, placebo-controlled pilot trial investigates whether FMT is feasible and improves cognition in adults with irritable bowel syndrome (IBS). Participants receive a single dose of FMT or placebo via rectal retention enema. Cognitive performance is the primary outcome, assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). Secondary outcomes include IBS symptom severity and mood. Tertiary outcomes include microbiome composition and plasma biomarkers related to inflammation, short-chain fatty acids, and tryptophan metabolism. Outcomes are assessed at baseline and at one, three, six, and twelve months following treatment. We hypothesise that FMT will lead to greater improvements in cognitive performance than placebo, with benefits extending beyond practice effects, emerging at one month and persisting in the long term. The findings will contribute to evaluating the safety and efficacy of FMT and enhance our understanding of gut–brain interactions. Full article

Among the numerous compounds released as a result of human activities, endocrine-disrupting chemicals (EDCs) have attracted particular attention due to their widespread detection in human biological samples and their accumulation across various ecosystems. While early research primarily focused on their effects on reproductive health, it is now evident that EDCs may impact neurodevelopment, altering the integrity of neural circuits essential for cognitive abilities, emotional regulation, and social behaviors. These compounds may elicit epigenetic modifications, such as DNA methylation and histone acetylation, that result in altered expression patterns, potentially affecting multiple generations and contribute to long-term behavioral phenotypes. The effects of EDCs may occur though both direct and indirect mechanisms, ultimately converging on neurodevelopmental vulnerability. In particular, the gut–brain axis has emerged as a critical interface targeted by EDCs. This bidirectional communication network integrates the nervous, immune, and endocrine systems. By altering the microbiota composition, modulating immune responses, and triggering epigenetic mechanisms, EDCs can act on multiple and interconnected pathways. In this context, elucidating the impact of EDCs on neurodevelopmental processes is crucial for advancing our understanding of their contribution to neurological and behavioral health risks. Full article

Zearalenone (ZEN), a mycotoxin commonly found in cereal crops and foods, induces testicular damage and disrupts gut microbial composition. Curcumin (CUR), a bioactive compound derived from turmeric, is known to enhance intestinal microbial balance and exhibit anti-inflammatory properties. This study aimed to investigate the mechanism by which CUR alleviates ZEN-induced reductions in sperm quality through the modulation of the gut microbiota–testis axis. Forty-eight 6-week-old Balb/c male mice were randomly assigned to four treatment groups: control (CON), CUR (200 mg/kg body weight CUR), ZEN (40 mg/kg body weight ZEN), and ZEN + CUR (200 mg/kg CUR + 40 mg/kg ZEN). The degree of sperm damage was quantified by assessing both the survival rate and the morphological integrity of the spermatozoa. CUR was found to mitigate ZEN-induced reductions in the testosterone levels, testicular structural damage, and disrupted spermatogenesis. Exposure to ZEN markedly perturbed the gut microbiota, characterized by increased relative abundances of Prevotella and Bacteroides and a concomitant reduction in Lactobacillus. These alterations were accompanied by pronounced activation of the IL-17A–TNF-α signaling axis, as demonstrated by elevated transcriptional and translational expression of pathway-associated genes and proteins. Co-administration of CUR effectively reinstated microbial homeostasis and mitigated ZEN-induced IL-17A pathway activation. In conclusion, ZEN induces testicular inflammation and reduced sperm quality by lowering testosterone levels and disrupting gut microbial balance, which drives the testicular IL-17A signaling pathway. CUR alleviates ZEN-induced testicular inflammation and sperm quality reduction by restoring beneficial gut microbes and testosterone levels. Full article

Background/Objectives: Hepatic cancers, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), are major global health concerns due to rising incidence and limited therapeutic success. While traditional risk factors include chronic liver disease and environmental exposures, recent evidence underscores the significance of genetic alterations and gut microbiota in liver cancer development and progression. This review aims to integrate emerging knowledge on the interplay between host genomic changes and gut microbial dynamics in the pathogenesis and treatment of hepatic cancers. Methods: We conducted a comprehensive review of current literature on genetic and epigenetic drivers of HCC and CCA, focusing on commonly mutated genes such as TP53, CTNNB1, TERT, IDH1/2, and FGFR2. In parallel, we evaluated studies addressing the gut–liver axis, including the roles of dysbiosis, microbial metabolites, and immune modulation. Key clinical and preclinical findings were synthesized to explore how host–microbe interactions influence tumorigenesis and therapeutic response. Results: HCC and CCA exhibit distinct but overlapping genomic landscapes marked by recurrent mutations and epigenetic reprogramming. Alterations in the gut microbiota contribute to hepatic inflammation, genomic instability, and immune evasion, potentially enhancing oncogenic signaling pathways. Furthermore, microbiota composition appears to affect responses to immune checkpoint inhibitors. Emerging therapeutic strategies such as probiotics, fecal microbiota transplantation, and precision oncology based on mutational profiling demonstrate potential for personalized interventions. Conclusions: The integration of host genomics with microbial ecology provides a promising paradigm for advancing diagnostics and therapies in liver cancer. Targeting the gut–liver axis may complement genome-informed strategies to improve outcomes for patients with HCC and CCA. Full article

Background/Objectives: Endometriosis is a chronic, estrogen-driven gynecological disorder affecting approximately 10% of reproductive-aged women worldwide, with significant physical, psychosocial, and socioeconomic impacts. Recent research suggests a possible involvement of the gut microbiome in endometriosis disease mechanisms through immune manipulation, estrogen metabolism, and inflammatory networks. This narrative review aims to summarize current evidence on gut microbiota changes in endometriosis patients, explore the mechanisms by which gut dysbiosis contributes to disease progression, and examine epidemiological links between gastrointestinal health and endometriosis risk. Methods: A narrative review was conducted to synthesize available literature on the compositional changes in gut microbiota associated with endometriosis. The review also evaluated studies investigating potential mechanisms and epidemiological patterns connecting gut health with endometriosis development and severity. Results: Alterations in gut microbiota composition were observed in endometriosis patients, suggesting roles in immune dysregulation, estrogen metabolism, and inflammation. Potential gut-oriented interventions, including dietary changes, probiotics, and lifestyle modifications, emerged as promising management options. However, methodological variability and research gaps remain barriers to clinical translation. Conclusions: Integrating gut microbiome research into endometriosis management holds potential for improving early diagnosis, patient outcomes, and healthcare system sustainability. The study emphasizes the need for further research to address existing challenges and to develop public health strategies that incorporate microbiome-based interventions in population-level endometriosis care. Full article

Irritable bowel syndrome (IBS) is a gut–brain axis chronic disorder, characterized by recurrent abdominal pain and altered bowel habits in the absence of organic pathology. Nutrition plays a central role in symptom management, yet no single dietary strategy has demonstrated universal effectiveness. This narrative review critically evaluates current nutritional approaches to IBS. The low-Fermentable Oligo-, Di-, Mono-saccharides and Polyols (FODMAP) diet is the most extensively studied and provides short-term symptom relief, but its long-term effects on microbiota diversity remain concerning. The Mediterranean diet, due to its anti-inflammatory and prebiotic properties, offers a sustainable, microbiota-friendly option; however, it has specific limitations in the context of IBS, particularly due to the adverse effects of certain FODMAP-rich foods. A gluten-free diet may benefit individuals with suspected non-celiac gluten sensitivity, although improvements are often attributed to fructan restriction and placebo and nocebo effects. Lactose-free diets are effective in patients with documented lactose intolerance, while a high-soluble-fiber diet is beneficial for constipation-predominant IBS. IgG-based elimination diets are emerging but remain controversial and require further validation. In this review, we present the 10 dietary commandments for IBS, pragmatic and easily retained recommendations. It advocates a personalized, flexible, and multidisciplinary management approach, avoiding rigidity and standardized protocols, with the aim of optimizing adherence, symptom mitigation, and health-related quality of life. Future research should aim to evaluate, in real-world clinical settings, the impact and applicability of the 10 dietary commandments for IBS in terms of symptom improvement and quality of life Full article

Recent findings highlight that Reelin, a glycoprotein involved in neural development, synaptic plasticity, and neuroinflammation, plays some specific roles in neurodegenerative disorders associated with aging, such as age-related macular degeneration (AMD) and Alzheimer’s disease (AD). Reelin modulates synaptic function and guarantees homeostasis in neuronal-associated organs/tissues (brain and retina). The expression of Reelin is dysregulated in these neurological disorders, showing common pathways depending on chronic neurogenic inflammation and/or dysregulation of the extracellular matrix in which Reelin plays outstanding roles. Recently, the relationship between AMD and AD has gained increasing attention as they share many common risk factors (aging, genetic/epigenetic background, smoking, and malnutrition) and histopathological lesions, supporting certain pathophysiological crosstalk between these two diseases, especially regarding neuroinflammation, oxidative stress, and vascular complications. Outside the nervous system, Reelin is largely produced at the gastrointestinal epithelial level, in close association with innervated regions. The expression of Reelin receptors inside the gut suggests interesting aspects in the field of the gut–brain–eye axis, as dysregulation of the intestinal microbiota has been frequently described in neurodegenerative and behavioral disorders (AD, autism, and anxiety and/or depression), most probably linked to inflammatory, neurogenic mediators, including Reelin. Herein we examined previous and recent findings on Reelin and neurodegenerative disorders, offering findings on Reelin’s potential relation with the gut–brain and gut–brain–eye axes and providing novel attractive hypotheses on the gut–brain–eye link through neuromodulator and microbiota interplay. Neurodegenerative disorders will represent the ground for a future starting point for linking the common neurodegenerative biomarkers (β-amyloid and tau) and the new proteins probably engaged in counteracting neurodegeneration and synaptic loss. Full article

Background/Objectives: Selective serotonin reuptake inhibitors (SSRIs), widely prescribed for anxiety disorders, may negatively impact the gut microbiota, contributing to dysbiosis. Considering the gut–brain axis’s importance in mental health, probiotics could represent an effective adjunctive strategy. This study evaluated the effects of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on microbiota composition, metabolic activity, and immune markers in fecal samples from patients with anxiety on SSRIs, using the SHIME^® (Simulator of the Human Intestinal Microbial Ecosystem) model. Methods: The fecal microbiotas of four patients using sertraline or escitalopram were inoculated in SHIME^® reactors simulating the ascending colon. After stabilization, a 14-day probiotic intervention was performed. Microbial composition was assessed by 16S rRNA sequencing. Short-chain fatty acids (SCFAs), ammonia, and GABA were measured, along with the prebiotic index (PI). Intestinal barrier integrity was evaluated via transepithelial electrical resistance (TEER), and cytokine levels (IL-6, IL-8, IL-10, TNF-α) were analyzed using a Caco-2/THP-1 co-culture system. The statistical design employed in this study for the analysis of prebiotic index, metabolites, intestinal barrier integrity and cytokines levels was a repeated measures ANOVA, complemented by post hoc Tukey’s tests to assess differences across treatment groups. For the 16S rRNA sequencing data, alpha diversity was assessed using multiple metrics, including the Shannon, Simpson, and Fisher indices to evaluate species diversity, and the Chao1 and ACE indices to estimate species richness. Beta diversity, which measures microbiota similarity across groups, was analyzed using weighted and unweighted UniFrac distances. To assess significant differences in beta diversity between groups, a permutational multivariate analysis of variance (PERMANOVA) was performed using the Adonis test. Results: Probiotic supplementation increased Bifidobacterium and Lactobacillus, and decreased Klebsiella and Bacteroides. Beta diversity was significantly altered, while alpha diversity remained unchanged. SCFA levels increased after 7 days. Ammonia levels dropped, and PI values rose. TEER values indicated enhanced barrier integrity. IL-8 and TNF-α decreased, while IL-6 increased. GABA levels remained unchanged. Conclusions: The probiotic combination of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 modulated gut microbiota composition, metabolic activity, and inflammatory responses in samples from individuals with anxiety on SSRIs, supporting its potential as an adjunctive strategy to mitigate antidepressant-associated dysbiosis. However, limitations—including the small pooled-donor sample, the absence of a healthy control group, and a lack of significant GABA modulation—should be considered when interpreting the findings. Although the SHIME^® model is considered a gold standard for microbiota studies, further clinical trials are necessary to confirm these promising results. Full article

Background/Objectives: Autism spectrum disorder (ASD) encompasses several neurodevelopmental disorders, whose onset is correlated to genetic and environmental factors. Although the etiopathogenesis is not entirely clear, the involvement of inflammatory processes, the endocannabinoid system, and alterations in the permeability and composition of the intestinal microbiota are known to occur. Methods: This review systematically explores the literature available to date on the most widely used murine models for the study of ASD, the main biomarkers investigated for the diagnosis of ASD, and the therapeutic potential of probiotics, with a particular focus on the use of strains of Lactiplantibacillus (Lpb.) plantarum in in vivo models and clinical trials for ASD. Results: Several studies have demonstrated that targeting multifactorial biomarkers in animal models and patients contributes to a more comprehensive understanding of the complex mechanisms underlying ASD. Moreover, accumulating evidence supports the beneficial effect of probiotics, including Lpb. plantarum, as a promising alternative therapeutic strategy, capable of modulating gut–brain axis communication. Conclusions: Probiotic supplementation, particularly with selected Lpb. plantarum strains, is emerging as a potential complementary approach for ameliorating ASD-related gastrointestinal and behavioral symptoms. However, further large-scale clinical studies are essential to validate their efficacy and determine optimal treatment protocols and dietary strategies. Full article

The global obesity epidemic and associated metabolic disorders present urgent public health challenges. This study employed a multi-omics approach (lipidomics, metabolomics, and gut microbiome analysis) to investigate how Bletilla striata polysaccharides (BSPs) and composite polysaccharides modulate liver lipid metabolism and gut microbiota in high-fat diet (HFD)-induced obese mice. HFD elevated hepatic phosphatidylcholines, cholesteryl esters (CEs), and acylcarnitines (CARs), alongside increased cecal choline and trimethylamine. BSP interventions reduced hepatic CEs, free fatty acids (FAs), CARs, and cecal sarcosine while restoring gut microbial diversity. Notably, BSP enriched beneficial genera, including Jeotgalicoccus and Atopostipes, and the network analysis revealed negative correlations between these genera and hepatic triglycerides (TGs), implicating the gut–liver axis in lipid metabolism regulation. These findings elucidate the anti-obesity mechanisms of polysaccharides through gut microbiota remodeling and cross-tissue metabolic interactions, providing a foundation for leveraging plant polysaccharides in developing safer, effective obesity therapies. 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

Background: Myeloproliferative neoplasms (MPN), a group of chronic hematologic neoplasms, are driven by inflammatory mechanisms that influence disease initiation and progression. Emerging evidence highlights the gut microbiome and plasma metabolome as pivotal immunomodulators, yet their causal roles in MPN pathogenesis remain uncharacterized. Methods: We conducted a two-sample Mendelian randomization (MR) analysis to systematically evaluate causal relationships between 196 gut microbial taxa, 526 plasma metabolites, and MPN risk. Instrumental variables were derived from genome-wide association studies (GWASs) of microbial/metabolite traits. Validation utilized 16S rRNA sequencing data from NCBI Bioproject PRJNA376506. Mediation and multivariable MR analyses elucidated metabolite-mediated pathways linking microbial taxa to MPN. Results: Our MR analysis revealed that 7 intestinal taxa and 17 plasma metabolites are causally linked to MPN. External validation confirmed the three taxa’s differential abundance in MPN cohorts. Mediation analysis revealed two mediated relationships, of which succinylcarnitine mediated 14.5% of the effect, and lysine 27.9%, linking the Eubacterium xylanophilum group to MPN. Multivariate MR analysis showed that both succinylcarnitine (p = 0.004) and lysine (p = 0.040) had a significant causal effect on MPN. Conclusions: This study identifies novel gut microbiota–metabolite axes driving MPN pathogenesis through immunometabolic mechanisms. The validated biomarkers provide potential therapeutic targets for modulating inflammation in myeloproliferative disorders. Full article