Search Results (781)

Postbiotics are an emerging ingredient class which have promising potential to support canine gut function by delivering beneficial microbial compounds directly to the gut. We tested a canine immune health postbiotic (CIHP) in a randomized, double-blind, placebo-controlled study of twenty colony-housed dogs (ten per group) selected for having consistently loose stools but with no diagnosed gastrointestinal disease. After a 5-day wash-in and 5-day baseline, dogs received 12 mg/kg body weight per day of CIHP or a placebo for 28 days mixed with their normal dry diet. The primary outcome was stool consistency (Waltham fecal score), measured on Days 0, 14, and 28; secondary outcomes included fecal gut-health biomarkers and fecal microbiome composition from 16S rRNA sequencing, measured on Days 0 and 28. CIHP improved stool quality (p-value = 0.03), while placebo did not (p-value = 0.5), and CIHP showed a trend toward increasing the odds of individual dogs showing improved fecal scores by Day 28 compared to placebo (p-value = 0.07). Microbiome profiling revealed broader community remodeling with CIHP than the placebo (16 taxa significantly shifted with CIHP vs. 1 with the placebo), consistent with stool quality being impacted by both gastrointestinal and gut microbiome functions. Fecal biomarkers that reflect gut health (pH, dry matter, short-chain fatty acids, dysbiosis index, calprotectin) were within reference ranges at baseline and remained stable in both groups, indicating benefits occurred within a normal physiological window. Together, these findings show that CIHP can improve stool consistency while reshaping the gut microbiome in otherwise healthy dogs prone to loose stools. Future studies in home-environment dogs across breeds, ages, and living conditions are needed to generalize these findings to the broader canine population. Full article

The gut microbiota plays a multifaceted role in calcium homeostasis and bone metabolism —acting through metabolic, immunological, and hormonal pathways that collectively constitute the gut–bone axis. The microbiota influences calcium bioavailability through several overlapping mechanisms that act in the intestine. Moreover, microbial fermentation products may directly impact the osteoblast–osteoclast interplay and, by modulating immune and endocrine functions, are crucial for bone metabolism. A healthy microbiota supports bone formation; however, intestinal dysbiosis may impair bone structure and function. This narrative review aims to present pathways linking the gut microbiota to bone metabolism, both in health and disease. First, we will discuss the influence of gut microbiota on calcium absorption. We will then outline the role that microbial metabolites, such as bile acids and short-chain fatty acids (SCFAs), play in regulating bone structure and function. In the following section, we will discuss the role of the microbiota in the immunological and hormonal modulation of bone metabolism. Finally, we will discuss how dysbiosis affects bone and how therapeutic interventions, such as probiotics, prebiotics, and postbiotics, may influence bone tissue quality. Full article

Ototoxicity is traditionally viewed as a local cochlear adverse effect of indispensable therapies such as cisplatin and aminoglycosides. However, emerging evidence suggests that cochlear vulnerability is shaped by systemic physiology, including inflammatory tone, vascular barrier integrity, and metabolic state. In this Review, we propose a Gut–Mito–Ear axis in which gut ecosystem function influences circulating mediator modules that converge on two cochlear mediator nodes: blood–labyrinth barrier (BLB) gating and mitochondrial stress tolerance. We synthesize evidence showing that gut perturbation can alter cochlear outcomes in vivo, that at least one microbiota-derived metabolite signal can directly protect hearing in experimental settings, and that BLB dysfunction and inflammatory trafficking are mechanistically relevant to cisplatin- and aminoglycoside-induced injury. We further organize the literature using an evidence-weighted framework that distinguishes direct cochlear causality from mechanistic plausibility and explicitly retains negative studies as boundary-setting evidence. Finally, we outline a translational roadmap in which microbiome-targeted prevention is pursued through mediator-anchored, non-interference-aware strategies and evaluated across linked state variables spanning exposure context, gut function, defined mediator modules, BLB gating, mitochondrial stress tolerance, and auditory phenotype. The Gut–Mito–Ear axis is not considered an established mechanism. We present it as a falsifiable systems-biology model that organizes the current evidence. Within this model, we define the minimum and ideal standards for A-tier causal evidence, explicit criteria for interpreting boundary-setting negative (A−) studies, and a set of testable predictions for causal validation. Full article

Although prebiotics and postbiotics support gastrointestinal health, evidence for their combined effects in dogs remains limited. This study evaluated a novel prebiotic and postbiotic supplement in healthy dogs undergoing a dietary transition. Thirty-six healthy adult dogs were randomly assigned to control group (CON, high-protein basal diet with placebo chew) or treatment group (TRT, the same basal diet with chew containing prebiotics [baobab fruit pulp and acacia gum] and postbiotics [inactivated Lactobacillus acidophilus and selected yeast fractions]) for a 28-day formal trial following a 7-day adaptation period. The primary outcomes evaluated included clinical fecal scores, specific biomarkers of intestinal barrier function and inflammation, fecal short-chain fatty acids, and microbiota structure. Following the 7-day adaptation, formal trial baseline, fecal scores were already within the healthy range and remained optimal without differing between groups throughout the study. Compared with CON, the TRT group showed lower fecal calprotectin and serum diamine oxidase levels, and higher fecal butyrate (p < 0.05). Metagenomic analysis revealed increased abundances of Bacteroidota, Oscillospiraceae, Prevotellaceae, and Prevotella in TRT (p < 0.05). Overall, in healthy dogs, this supplementation was associated with favorable microbiota modulation and modulated biomarkers of intestinal barrier and inflammation within normal ranges, without altering clinical fecal endpoints. Full article

Sarcopenia is an age-related skeletal muscle disorder characterized by reduced muscle mass, strength, and physical performance, as well as increased risk of disability, hospitalization, and mortality. Emerging evidence suggests that gut microbiota alterations may contribute to muscle decline via a microbiota–gut–muscle axis, acting as a context-dependent modulator rather than a primary causal driver. This narrative review synthesizes mechanistic, clinical, and translational evidence linking gut dysbiosis to sarcopenia. Preclinical studies show that microbiota modulation (e.g., antibiotics, probiotics, prebiotics, postbiotics, fecal microbiota transplantation) affects muscle mass, strength, and metabolism through pathways including inflammation, mitochondrial dysfunction, altered short-chain fatty acid production, and impaired anabolic signaling. In humans, observational studies associate lower microbial diversity and reduced short-chain fatty acid-producing taxa with poorer muscle outcomes, but findings are heterogeneous and non-causal. Interventional trials remain limited and characterized by small sample sizes, with effects more consistent for functional outcomes than muscle mass. Overall, the gut microbiota represents a modifiable contributor within the complex biology of sarcopenia. Future studies should integrate microbiome profiling and multi-omics approaches within well-designed clinical trials to identify responder phenotypes and define the role of microbiota-targeted strategies within multimodal interventions. Full article

Allergic asthma is a prevalent chronic inflammatory disease of the airways whose pathogenesis has traditionally been attributed to localized immune dysfunction within the lung. However, accumulating evidence from microbiome research supports a broader system-level perspective in which cross-organ interactions contribute to disease susceptibility and progression. In particular, the gut–lung axis has emerged as a key regulatory pathway linking intestinal microbial ecology, immune development, and respiratory health. This review synthesizes current epidemiological, mechanistic, and experimental evidence supporting the role of gut microbiota dysbiosis in allergic asthma. We examine how early-life environmental and nutritional exposures and gut microbiota establishment during critical developmental windows shape long-term immune tolerance and asthma susceptibility. We then summarize characteristic features of asthma-associated gut dysbiosis and discuss how microbial-derived metabolites, including short-chain fatty acids, tryptophan metabolites, pro-allergic lipid mediators such as 12,13-dihydroxy-9Z-octadecenoic acid, and bacterial-derived histamine, modulate distal airway immune responses through epigenetic, receptor-mediated, and immune trafficking mechanisms. Particular emphasis is placed on the role of diet as a key upstream regulator of gut microbiota composition and metabolic function. Finally, we evaluate experimental and translational studies targeting the gut–lung axis, including dietary modulation, microbiome-targeted interventions such as fecal microbiota transplantation, and emerging postbiotic approaches. Collectively, current evidence indicates that gut microbial composition and metabolic function are critical determinants of respiratory immune homeostasis. Targeting the gut–lung axis through nutrition- and microbiome-based strategies offers a promising avenue for the prevention and precision treatment of allergic asthma. Full article

Probiotics, live microorganisms that confer health benefits when administered in adequate amounts, are increasingly recognized as modulators of interconnected microbiome–host networks that extend beyond gastrointestinal function. This review synthesizes evidence on classical probiotic roles in maintaining gut homeostasis, immune regulation, and infection prevention, while integrating emerging systemic effects across the gut–brain, gut–skin, gut–oral, and metabolic axes. Rather than presenting isolated outcomes, we adopt a systems-level framework that links probiotic actions to shared mechanisms, including microbial metabolite signaling (e.g., SCFAs), competitive exclusion of pathobionts, barrier reinforcement, and immune–neuroendocrine pathway modulation. We further discuss translational advances that enable rational probiotic design, including targeted delivery platforms (encapsulation and protective matrices), engineered/next-generation strains, and postbiotic-inspired strategies, alongside sustainability considerations and regulatory/labeling challenges. Finally, we outline future directions emphasizing precision microbiome-centered interventions, synthetic biology, and AI-assisted multi-omics analysis to support strain- and context-specific probiotic strategies. Collectively, this review provides an integrated, systems-oriented synthesis to guide future research and accelerate safe clinical and industrial applications of probiotics. Full article

The gut microbiota is a central regulator of metabolic function, and its disruption by a high-fat diet (HFD) is strongly linked to obesity and metabolic impairment. This study evaluated the potential of heat-killed Lactiplantibacillus plantarum beLP1 (beLP1^®) in alleviating HFD-induced metabolic and microbial imbalances in mice. Male C57BL/6N mice were fed an HFD for 10 weeks, with or without daily oral supplementation of beLP1 (≥3 × 10¹⁰ cells). Compared with untreated HFD mice, beLP1 supplementation reduced serum triglycerides by 35% and lowered liver enzymes AST and ALT by 17% and 36%, respectively. Blood glucose levels remained similar to the HFD group throughout the study period. Shotgun metagenomic analysis revealed that beLP1 restored gut microbial diversity, increased beneficial taxa such as Akkermansia and Faecalibaculum high. and reduced pro-inflammatory species including Streptococcus sp., Mucispirillum schaedleri and Clostridium cocleatum. These microbial changes were associated with partial normalization of the Firmicutes/Bacteroidota ratio and improvements in antibiotic resistance gene (ARG) profiles. Specifically, in silico analysis of the short-chain fatty acid (SCFA) synthesis pathways indicated that the potential for acetate and propionate production was maximized in the beLP1 group, resulting in the highest relative abundance among all groups. This functional enhancement directly correlated with the enrichment of key SCFA-producing taxa, particularly Akkermansia muciniphila, confirming that increased bacterial abundance suggests an enhanced functional potential for SCFA production. Furthermore, beLP1^® induced a selective modulation of gut ARGs, significantly reducing specific subtypes such as tetracycline and multidrug efflux genes, despite a slight increase in vancomycin resistance markers. Overall, our findings suggest that beLP1^® attenuated the rate of body weight gain during the initial weeks of HFD exposure and significantly improved markers of hepatic stress and lipid metabolism. Full article

Enterococci are found not only in warm-blooded animals but also as a resident population of water and an indicator of fecal pollution. The species Enterococcus haemoperoxidus and E. moraviensis are relatively new, having been detected in water. Strains with genes for biofilm formation can serve as reservoirs for gene transfer. The aim and novelty of this study were to determine whether the postbiotic substance (PS) of proteinaceous character (Durancin-like) produced by our strain Enterococcus durans ED26E/7 can inhibit in vitro the growth of biofilm-forming E. haemoperoxidus and E. moraviensis isolated from water sources. E. haemoperoxidus and E. moraviensis lacked the biofilm-forming genes ica, bap, ace, and fsrA. The bopD gene was found only in three strains of E. haemoperoxidus. The srtA gene was present in two strains of E. haemoperoxidus and E. moraviensis. Using the quantitative test, three strains showed low-grade biofilm-forming ability. They exhibited ɤ-hemolysis, and they were mostly susceptible to antibiotics. However, they were susceptible to PS Durancin-like ED26E/7. E. haemoperoxidus, the strains EHae466 and EMo494, showed the highest susceptibility to Durancin-like ED26E/7. Full article

The efficacy of postbiotics varies significantly between different strains and preparation processes. We aimed at evaluating the effect of an innovative postbiotic product (iPB) generated through the sequential fermentation of Lacticaseibacillus rhamnosus GG and Lacticaseibacillus paracasei NPB-01, compared to single-strain postbiotics, on epithelial barrier integrity and innate immunity in human enterocytes using a Caco-2-cell-based experimental model by measuring human enterocyte proliferation and differentiation (lactase expression), tight junction proteins (occludin and zonula occludens 1, ZO-1), and mucus protein Mucin-2 (Muc-2) expression. The modulatory action on the major innate immunity peptide, Human Beta-Defensin 2 (HBD-2), production was also assessed. The iPB exposure resulted in a higher up-regulation of human enterocyte proliferation and differentiation, as suggested by higher lactase expression, and of occludin, ZO-1, and MUC2 expression compared with the single-strain postbiotics, suggesting a beneficial synergistic action in modulating the epithelial gut barrier. Furthermore, iPB induced a higher production of HBD-2, suggesting a synergistic enhancement of innate immune response. Our findings suggested that the sequential fermentation process could act as a biotechnological catalyst, optimizing the gut-barrier-protective properties and the immunomodulatory action of Lacticaseibacillus strains. This study introduces iPB as a high-performance postbiotic candidate for the prevention and management of conditions characterized by alterations in epithelial gut barrier and innate immunity. Full article

Fermented foods and probiotics represent complementary yet distinct components of human nutrition. Fermented foods are shaped by biochemical transformations driven by microbial metabolism, whereas probiotics are live microorganisms that may confer health benefits to the host. In both cases, bacteria, yeasts, and filamentous fungi mediate key metabolic activities that generate bioactive compounds and modulate host–microbiota interactions. During fermentation, microbial communities synthesize organic acids, peptides, exopolysaccharides, vitamins, and other metabolites that enhance food safety, sensory attributes, and potential health-promoting properties. Several microbial products, such as bacteriocins, reuterin, hydroxylated fatty acids, and exopolysaccharides, exhibit antimicrobial, immunomodulatory, antioxidant, and cholesterol-lowering activities. Advancing our understanding of microbial metabolism in fermented foods is essential for developing next-generation functional foods and nutraceuticals that leverage microbial biotransformations to support human health. Nonetheless, multiple challenges limit the translation of these advances into commercial products. Inadequately controlled fermentation may introduce microbiological or chemical hazards, regulatory frameworks governing microbial use in foods remain insufficiently defined, and standardized procedures for microbial strain handling and characterization are still lacking. This narrative review integrates current evidence on the nutraceutical properties of fermented foods and probiotics, while also examining the associated safety considerations and the technological factors that influence fermentation processes. Full article

Atopic dermatitis (AD) is a chronic inflammatory dermatosis driven by skin barrier dysfunction, immune dysregulation, and gut–skin axis imbalance. While probiotics show promise, the therapeutic potential and mechanisms of topical postbiotics in modulating the gut–skin axis remain understudied. Here, we investigated the efficacy of Schleiferilactobacillus harbinensis JNDM-derived cell-free supernatant (CFS) and lysate (ShL) in a DNFB-induced AD mouse model. Topical application of both CFS and ShL significantly attenuated AD-like symptoms, reduced epidermal thickening, and restored the expression of the barrier protein filaggrin. Immunologically, treatment suppressed the Th2-dominant inflammatory cascade (IL-4, IL-5, IL-13, IL-33, TSLP) and reduced serum IgE and IFN-γ levels. Notably, ShL exhibited superior systemic efficacy, significantly inhibiting mast cell infiltration and reducing the spleen index. 16S rRNA sequencing revealed that topical intervention remotely remodeled the gut microbiota, specifically reversing the depletion of the beneficial genus Alistipes and suppressing the compensatory increase in Odoribacter. This microbial restructuring was accompanied by distinct metabolic changes: ShL treatment resulted in an approximately 4-fold elevation in fecal butyrate concentrations compared with the model group. Correlation analysis further validated a strong positive axis linking Alistipes abundance and butyrate levels to skin barrier integrity. Collectively, our findings demonstrate that S. harbinensis postbiotics—particularly the lysate—ameliorate AD through a dual mechanism of local barrier repair and systemic metabolic modulation via the gut–skin axis, presenting a promising non-steroidal therapeutic strategy. Full article

Background: Subclinical psychological symptoms—such as low mood, perceived stress, and poor sleep—affect a large portion of the population and can impair quality of life despite remaining below clinical thresholds. The gut–brain axis has emerged as a promising target for interventions that support emotional and psychological resilience. Probiotics and postbiotics are gaining attention for their potential to modulate mood and stress via microbiome-related mechanisms, but human evidence remains limited, particularly in non-clinical populations. Objectives: We aimed to assess the effects of a two-strain combination of live microorganisms alongside a two-strain combination of heat-treated inactivated microorganisms on outcomes associated with anxiety, mood, perceived stress, and quality of life in healthy adults experiencing mild stress. Methods: This study was conducted in two parts. In Part I, a randomized, double-blind, placebo-controlled study, 100 participants were randomized to receive either a blend of live microorganisms (Bifidobacterium longum CECT 7347 and Lactobacillus rhamnosus CECT 8361) or an identical placebo once daily for 12 weeks. In Part II, a pilot feasibility study, a subset of eight placebo non-responders from Part I received the heat-inactivated preparation of the same bacterial strains in a 6-week trial extension phase. For Parts I and II, the primary outcome was the change in the Hamilton Anxiety Rating Scale (HAM-A). Secondary outcomes included measures of mood (Beck Depression Inventory (BDI); Patient Health Questionnaire-9 (PHQ-9)), stress (state and trait anxiety inventory (STAI); Perceived Stress Scale (PSS)), sleep (Pittsburgh Sleep Quality Index (PSQI)), quality of life (36-item Short Form Survey (SF-36)), gastrointestinal symptoms (Gastrointestinal Symptom Rating Scale (GSRS)), salivary cortisol and microbiome modulation. Results: In Part I, there were no significant effects of the live blend on the HAM-A, indicating that the primary endpoint was not met. In addition, no significant effects were seen on the STAI or PSS scores when compared to the placebo. However, participants consuming the live blend trended toward a reduction in total PHQ-9 scores compared to placebo (p = 0.089), whilst preliminary exploratory analyses suggested an improvement in anhedonia (p = 0.045). Furthermore, there was a significant improvement in the vitality domain of the SF-36 compared to placebo (p = 0.017). On microbiome analysis, it was noted that consumption of the live blend was linked to the preservation of butyrate-producing bacteria, particularly members of the Pseudoflavonifractor genus and the Clostridium SGB6179 species. Furthermore, the abundance of B. longum species was found to be inversely associated with the total PSS Scores. In Part II, supplementation with the inactivated preparation resulted in significant within-group improvements for the vitality (p = 0.006) and social functioning (p = 0.010) domains of the SF-36 and improvements in PSS scores compared to baseline (p = 0.050). Conclusions: Supplementation with either the dual-strain live or inactivated formulations was associated with significant improvements in the vitality domain of the SF-36, whilst participants receiving the inactivated formulation demonstrated lower perceived stress and improved social functioning compared to baseline. Overall, the findings from this pilot study suggest that these two biotic consortia are well-tolerated and may be associated with improvements in measures of vitality in individuals with subclinical psychological symptoms. The subtle observations detected for stress and anhedonia suggest that further well-powered trials are needed to better characterize these findings, potentially in populations with greater baseline symptomatology. Full article

Functional pet food has grown rapidly, in line with the accelerated humanization of pets, growing attention to relations between diet and health, and mounting sustainability awareness. The article provides a critical overview of recent developments and new trends in functional pet food, combining data from published works, patents and market-driven innovative companies. The current trends depict a transition from single-nutrient fortification to integrated nutrition interventions through modulation of gastrointestinal health, immunity, metabolism, cognition and age-associated conditions. Special attention is dedicated to probiotics, prebiotics, postbiotics, polyphenols and novel protein sources, as well as innovations in processing and delivery technologies. The review highlights ongoing issues on the relevance of study design, available long-term safety information and our capacity to mechanistically underpin claims with respect to function. Because this review maps clusters of innovation and clusters of underdeveloped knowledge, it offers a roadmap for the translational pathway from scientific discovery to commercialization. The results highlight a call for harmonized methods, longer duration studies and integrative omics-based approaches in order to improve the evidence basis formulation and responsible marketing of future functional pet food products following credible, safe and sustainable strategies. Full article

The high prevalence of biofilm-associated multidrug-resistant (MDR) Escherichia coli infections in older adults calls for novel control strategies. This study compared fecal E. coli carriage, antimicrobial resistance, and biofilm formation among community-dwelling older adults with different self-reported immune statuses (lower vs. normal), and evaluated the antibiofilm activity of five Lactobacillus cell-free supernatants (CFSs). Fecal samples from 20 older adults were analyzed. E. coli was enumerated, and isolates were characterized for antimicrobial susceptibility and biofilm formation. Five Lactobacillus strains were screened for antibiofilm activity using crystal violet assay, with further evaluation of extracellular polymeric substance (EPS) production and biofilm morphology. After removing the redundant isolates, 70 isolates were reported, with significantly higher counts in the lower-immunity group (7.89 vs. 6.04 log MPN/g). The lower-immunity group had significantly higher antimicrobial resistance (97.3% vs. 60.6%), and higher MDR prevalence (91.7% vs. 24.2%). Biofilm formation was observed in 62.9% of isolates, with significantly higher prevalence among MDR isolates and in the lower-immunity group. L. paracasei L475 CFS showed the strongest antibiofilm activity against a representative MDR isolate (L5-1), with inhibition and eradication rates of 82.9% and 75.0%, respectively. Mechanistically, L475 CFS reduced extracellular polymeric substance components, with a 92.3% reduction in proteins and 41.3% in polysaccharides. Microscopy confirmed disrupted biofilm architecture, membrane damage, and cell lysis. In conclusion, these preliminary findings indicate a potential association between self-reported immune function and E. coli resistance/biofilm formation in older adults. L. paracasei L475 CFS demonstrates promising in vitro antibiofilm activity against an MDR E. coli isolate from this population, supporting its potential as a postbiotic candidate. Full article