Search Results (337)

In the post-antibiotic era, the Bacillus-based direct-fed beneficial microorganisms are emerging as a cornerstone for sustainable animal farming. This study aimed to screen and evaluate Bacillus strains with probiotic potential for use as feed additives. A total of 394 Bacillus strains were initially screened based on their extracellular enzyme production (cellulase, protease, and amylase) and antibacterial activities against Escherichia coli, Staphylococcus aureus, and Salmonella enterica. Two strains, Bacillus velezensis FJAT-10508 and FJAT-13563, were selected and subsequently subjected to in vitro probiotic characterization, safety assessment, and whole-genome analysis. The results demonstrated that both strains exhibited α-hemolysis, acceptable antibiotic susceptibility profiles, absence of invasion and cytotoxicity effect on the Caco-2 cells, and no mobile virulence or antibiotic resistance genes, indicating their safety as probiotic candidates. High endospore-forming efficiencies (72.4–90.8%), strong auto-aggregation (74–85%) and co-aggregation abilities (52–82%) were observed. In addition, both strains showed considerable tolerance to simulated gastrointestinal conditions, with vegetative cell and endospore survival rates of 28.33–38.33% and 85–89.67% at pH 2.0, and 38.33–43.33% and 90.33–96.33% in 0.3% bile salts, respectively. Overall, B. velezensis FJAT-10508 and FJAT-13563 demonstrated robust in vitro probiotic properties, supporting their potential application as reliable Bacillus-based feed additives. Full article

The female immune system operates within an evolutionary stability-plasticity trade-off, where the physiological demands of pregnancy necessitate a considerable degree of regulatory T cell (Treg) plasticity. This essential flexibility, however, inherently lowers the threshold for autoimmune dysregulation. Recent mechanistic evidence has identified Xist ribonucleoprotein complexes as female-specific autoantigens that constitutively sensitize innate sensors, thereby establishing an intrinsic state of autoimmune priming. This review introduces the Metabolic Calibration Hypothesis, proposing that commensal microbiota-derived metabolites function as essential extrinsic stabilizers specifically required to maintain female immune homeostasis. Beyond canonical short-chain fatty acid signaling, we synthesize emerging evidence regarding host-microbiota metabolic integration, emphasizing the roles of histone lactylation in the reproductive tract and the ligand-specific activation of nuclear receptors by secondary bile acids in orchestrating Treg fate. We posit that female immune pathologies, ranging from systemic autoimmunity to gynecologic malignancies, represent a context-dependent dysregulation or co-option of this metabolic calibration. Ultimately, we discuss the clinical necessity of transitioning from generic biotic interventions toward Sexual Dimorphic Metabotyping, providing a precision framework to restore physiological tolerance and manage sex-biased immune pathologies. Full article

Background/Objectives: Severe and recurrent infections due to multidrug-resistant (MDR) Pseudomonas aeruginosa necessitate alternative antimicrobial strategies. Fermented cacao beans represent a niche microbial ecosystem with the potential to harbor beneficial lactic acid bacteria (LAB). This study aimed to isolate and characterize LAB strains from fermented cacao beans in southern Thailand and to evaluate their probiotic potential and antimicrobial activity against MDR P. aeruginosa. Methods and Results: Five Lactiplantibacillus plantarum isolates were identified via MALDI-TOF MS and whole-genome sequencing (WGS). All strains demonstrated antimicrobial activity against 17 clinical MDR P. aeruginosa isolates and CR14 exhibited the largest inhibition zone. The isolates displayed robust probiotic traits, including survival under simulated gastrointestinal conditions. Acid tolerance (pH 2.0) reached 61.15 ± 7.75%, while resistance to pepsin, pancreatin, and bile salts exceeded 88%, 91%, and 92%, respectively. Strong adhesion was confirmed via auto-aggregation (55.02 ± 1.75%), hydrophobicity (45.58 ± 0.96%) and Caco-2 cell attachment (up to 98.11 ± 3.28%). WGS revealed multiple plantaricin-encoding clusters. Coarse-grained molecular dynamic simulations showed that two-peptide plantaricins (plnJ/K and plnNC8-αβ) self-assembled and formed stable pores in bacterial membrane models, confirming a pore-forming antimicrobial mechanism. The strains lacked acquired resistance genes and virulence factors, confirmed by in silico safety assessments. Conclusions: Thus, these L. plantarum strains are promising probiotics for managing MDR P. aeruginosa via functional foods or adjunct therapies. Full article

Early life represents a critical developmental programming window during which nutrition and microbial exposures shape long-term physiological function. Feeding mode is a major determinant of infant gut microbiota assembly and metabolic activity. This narrative review synthesizes current evidence comparing breastfeeding (BF) and formula feeding in relation to microbial composition, functional capacity, and immune programming during the preweaning and early postweaning periods. BF may support a relatively stable, bifidobacteria-dominated microbiota enriched in pathways involved in carbohydrate utilization, vitamin biosynthesis, and immune modulation. Human milk oligosaccharides, secretory IgA, lactoferrin, and milk-associated microbes collectively guide microbial succession, enhance barrier integrity, and support immune tolerance. In contrast, formula-fed infants typically exhibit greater microbial diversity, earlier transition toward adult-like profiles, and increased abundance of facultative anaerobes, alongside the enrichment of pathways related to bile acid and amino acid metabolism. Microbiota patterns in formula-fed infants are further influenced by formula composition, including protein load, lipid structure, and supplementation with prebiotics, probiotics, and human milk oligosaccharide analogues. Although advances in formula design have reduced compositional gaps, functional differences in microbial stability and immune programming persist. Recognizing early infancy as a sensitive programming window underscores the need for microbiome-informed nutritional strategies and longitudinal, multi-omics research to clarify causal mechanisms and optimize early-life interventions. Full article

Bacillus coagulans has attracted widespread attention in the treatment of irritable bowel syndrome due to its multiple probiotic functions, yet its specific molecular mechanisms remain unclear, and the efficacy of probiotics exhibits significant strain specificity, posing a key bottleneck for practical application. To address this, this study obtained a bile salt-tolerant B. coaguans idrc019 through in vitro screening. This strain demonstrated strong survival and germination in simulated gut conditions, supporting effective intestinal colonization. Further evaluation in an IBS animal model revealed that idrc019 alleviated visceral hypersensitivity and colonic inflammation in a dose-dependent manner. Through enhanced intestinal barrier integrity, microbiota modulation (e.g., Actinobacteria restoration), and elevated metabolites (e.g., kynurenine), the strain exerted IBS-alleviating effects via synchronized immune, microbial, and metabolic regulation. Our findings offer a mechanistically grounded probiotic candidate, underscore functional screening as a critical strategy, and pave the way for clinical application. Full article

The wine ecosystem constitutes a highly selective ecological niche characterized by low pH, high ethanol levels, sulfur dioxide, polyphenols, and nutrient limitation. During malolactic fermentation, this environment becomes dominated by specialized lactic acid bacteria (LAB), particularly Lactiplantibacillus plantarum and Oenococcus oeni, whose persistence under such stressors suggests the presence of adaptive traits relevant to probiotic development. In this study, twenty-three LAB isolates obtained from the spontaneous wine ecosystem were systematically evaluated through a multi-stage screening strategy. Primary single-factor assays revealed pronounced inter- and intraspecies variability in tolerance to acid, lysozyme, and bile salts. As a result, all O. oeni isolates and eight L. plantarum strains were excluded from further consideration. The four selected L. plantarum isolates (M-1, SY-2, XJA2, and XJ14) were subsequently subjected to simulated gastrointestinal challenges. Strains M-1 and XJ14 maintained high viability across both gastric and intestinal phases. In contrast, SY-2 and XJA2 exhibited pronounced gastric sensitivity but demonstrated strong survival in the intestinal phase. Functional characterization further distinguished the isolates: M-1 and XJ14 displayed balanced probiotic profiles, whereas XJA2 exhibited exceptional auto-aggregation and efficient metabolic capacity, suggesting specific colonization potential despite its gastric vulnerability. Comprehensive safety assessments confirmed the absence of hemolytic activity, biogenic amine production, and acquired antibiotic resistance in the tested isolates. Collectively, these findings identify M-1 and XJ14 as promising candidates for direct probiotic application, and XJA2 as a promising functional strain for encapsulation-based delivery. This study highlights the wine ecosystem as a valuable reservoir for novel probiotic development. Full article

Termite guts represent a unique microbial habitat harboring bacteria with potential probiotic properties, owing to their ability to inhibit pathogenic microorganisms. This study investigated the probiotic characteristics of lactic acid bacteria newly isolated from the guts of the termite Termes propinquus, aiming to enhance growth performance and reduce the incidence of foodborne pathogen contamination in the commonly consumed edible two-spotted crickets (Gryllus bimaculatus). In this study, five morphologically different bacteria (TPL-1 to TPL-5) were isolated and respectively identified as Levilactobacillus brevis, Lactiplantibacillus plantarum, Streptococcus anginosus, Companilactobacillus alimentarius, and Aerococcus viridans based on 16S rRNA gene sequences and MALDI-TOF MS. All isolates were evaluated for tolerance to stressful conditions (pH 2.5 and 0.3% bile salts), cell surface properties, antioxidant activity, antimicrobial activity against foodborne pathogens, safety profiles, and adhesion to human colon adenocarcinoma cells (Caco-2 and HT-29). Among them, Lactiplantibacillus plantarum TPL-2 demonstrated the strongest probiotic attributes and was further assessed for anti-adhesion activity against foodborne pathogens and in vivo effects on the crickets. Dietary supplementation with Lb. plantarum TPL-2 significantly improved cricket growth, survival, and gut microbiota homeostasis. These findings point to the prospect of termite-derived lactic acid bacteria as beneficial probiotics for use in biotechnological applications and edible insect farming. Full article

Primary Biliary Cholangitis (PBC) is a chronic, immune-mediated cholestatic liver disease characterized by progressive intrahepatic bile duct destruction, leading to pruritus, fatigue, cirrhosis, and eventually hepatocellular carcinoma. Early diagnosis has improved with the development of sensitive serologic assays (e.g., antimitochondrial antibodies, antinuclear antibodies) and the introduction of newer biomarkers. Risk stratification has become standardized with the help of GLOBE and UK-PBC scores, alongside non-invasive tools such as vibration-controlled transient elastography, enabling earlier intervention. Ursodeoxycholic acid (UDCA) is the first-line therapy; however, 30–40% of patients show an incomplete response, increasing their risk of liver failure and mortality. Second-line therapies have emerged which provide viable treatment avenues for those who do not respond to UDCA or are unable to tolerate it. However, in certain situations, such as decompensated cirrhosis, carcinoma, or refractory pruritus, liver transplantation constitutes the only curative therapy. While PBC has excellent post-liver transplant (post-LT) outcomes, patients with PBC face higher waitlist mortality as they tend to have lower MELD scores. Management post-LT includes the use of UDCA, immunosuppressants, and surveillance for recurrent PBC. Our review highlights the recent advances in medical management and transplant risk stratification of patients at risk of decompensation, as well as the perioperative transplant period outcomes and long-term post-transplant management strategies in patients with PBC. Full article

Background/Objectives: Cholesterol is an essential lipid required for membrane structure and normal physiological functions. However, dysregulation of cholesterol homeostasis, manifesting as hypercholesterolemia, can precipitate a range of metabolic and cardiovascular diseases. Blautia species are important gut commensals, but their role in cholesterol metabolism remains poorly defined. Methods: A total of 63 Blautia strains isolated from human fecal samples were screened for cholesterol conversion using the o-phthalaldehyde colorimetric assay in cholesterol-containing media with or without oxgall. Cholesterol removal by live and heat-inactivated cells was compared. Metabolomic, transcriptomic, and proteomic analyses were employed to investigate molecular mechanisms and involved genes. Results: Nine strains significantly lowered cholesterol levels (live cells: 31–78%; heat-inactivated cells: 8–64%), with the B. hominis strain HA2291, the Blautia sp. strain HA3515, and the B. coccoides strain HA4419 showing the strongest activity. Oxgall increased cholesterol removal by live cells to 74–83%, indicating bile-tolerant metabolism activity. Metabolomic profiling revealed that B. hominis HA2291 transformed cholesterol into cholest-4-en-3-one and epicholestanol. An SCP2-like protein, RS03310, was identified as a candidate cholesterol-interacting factor; its recombinant form catalyzed measurable NAD⁺-dependent cholesterol oxidation in vitro. Conclusions: Blautia hominis HA2291 may employ multiple in vitro strategies for cholesterol-lowering, including cell-surface adsorption (heat-inactivated cells), bile-enhanced removal (oxgall effect), and enzymatic transformation, with the gene RS03310 implicated as the main contributor. These findings provide in vitro mechanistic insights into Blautia-mediated cholesterol metabolism, highlight RS03310 as a candidate gene associated with cholesterol biotransformation, and advance our understanding of the potential role of Blautia in host cholesterol homeostasis. Full article

Zoonotic pathogens could persist in their environment and be introduced into the food-chain. With careful screening and selection, lactic acid bacteria (LAB) could be used as direct-fed microbials (DFMs) to control these pathogens in food animals. Previously isolated LAB (n = 250) were evaluated for inhibition against Shiga-toxigenic Escherichia coli (STEC) and Salmonella enterica, using agar spot test. Tests revealed that LAB were more effective against Salmonella than STEC, with 67% showing excellent (>15 mm) inhibition. LAB (n = 65) exhibiting significant pathogen inhibition (zones > 10 mm) were tested for acid (pH: 2, 4, 5, 7) and bile (0, 0.1, 0.3, 0.5%) tolerance, and biofilm-forming capabilities. About half of the tested LAB exhibited excellent to very good tolerance. All LAB formed biofilms, with 33% forming strong biofilms. LAB (n = 59) were also examined for susceptibility to commonly used antibiotics due to their intrinsic or acquired antibiotic resistance (AR), transferrable to pathogens. Only S. thermophilus S-2 showed susceptibility to all the antibiotics. The majority were susceptible to erythromycin (88%), followed by ampicillin (85%), clindamycin (64%), tetracycline (58%), vancomycin (44%), streptomycin (15%), and gentamicin (9%). Overall, LAB showed strong inhibition against pathogens, along with survival capabilities for environmental stress conditions, and could be considered for potential DFM applications. Full article

While our group previously demonstrated the calming effects of Melissa officinalis extract (MOE) in dogs, the underlying brain-level mechanisms remain unclear. To address this, we investigated these mechanisms in rats using an untargeted metabolomics approach. Twenty-four male Wistar rats were divided into three groups (eight rats per group): control (standard diet, SD), a group fed a high-fat high-sucrose diet (HFHSD), and HFHSD administrated with a hydro-alcoholic standardized MOE (HFHSD MOE) at a dose of 200 mg/kg. Body weight, behavior through elevated plus maze (EPM), and glucose tolerance using the oral glucose tolerance test (OGTT) were monitored. After 12 weeks of supplementation, plasma and brain metabolomes were explored using non-targeted metabolomics. Although the EPM revealed no significant behavioral improvement, the OGTT showed a significant reduction in blood glucose area under the curve (AUC, p < 0.05), suggesting a metabolic effect of MOE. Metabolomic analysis highlighted two key pathways: (1) bile acid biosynthesis in plasma, as previously observed in our dog study, and (2) pentose phosphate metabolism in the brain. These results provide insight into central and peripheral mechanisms influenced by MOE and generate hypotheses on pathways potentially linked to previously reported behavioral effects in dogs, offering targets for nutritional interventions. Full article

This study evaluated the probiotic, technological, and safety properties of 124 lactic acid bacteria isolated from traditional Beyaz cheese, and the in situ survival of selected strains in fermented milk. Eighteen isolates showing over 80% tolerance in simulated gastric juice (pH 3.0) were subjected to further characterization. On the basis of 16S rRNA gene sequencing, most isolates belong to Lacticaseibacillus paracasei and Lactiplantibacillus plantarum, while Lactobacillus helveticus, Lentilactobacillus kefiri, and Limosilactobacillus fermentum were also identified. L. plantarum EH140 showed the greatest resistance to the simulated gastric environment (pH 2.0), whereas L. paracasei EH131 exhibited the highest bile salt tolerance. L. plantarum EH106 demonstrated strong auto-aggregation, and L. fermentum EH132 displayed notable hydrophobicity. Nine isolates exhibited bile salt hydrolase activity, but none showed γ-hemolysis, gelatinase, or DNase activity. All the isolates were susceptible to ampicillin, erythromycin, clindamycin, and chloramphenicol. Organic acid analysis revealed lactic acid as the major metabolite, followed by acetic acid. Virulence gene screening identified the efaAfs gene only in L. paracasei strains, and no biogenic amine genes were detected. The selected isolates maintained viability above 6 log CFU/mL in milk during storage. Overall, L. plantarum EH106, EH109, EH140, and EH141 were identified as the most promising candidates because of their safety and superior probiotic potential. Full article

Fipronil (FPN), a widely used insecticide, poses health risks through environmental contamination. Although its toxicity is increasingly recognized, the impact of fipronil on glucose metabolism remains poorly understood. In this study, mice on a normal diet (ND) or high-fat diet (HFD) received a daily oral administration of fipronil (0, 0.25, 1, or 4 mg/kg) for 35 days. Blood glucose and insulin were measured, and glucose/insulin/pyruvate tolerance tests were performed. We found that fipronil compromised glucose tolerance in mice fed an ND. Gut microbiota composition was assessed by 16S rRNA sequencing and the expression of inflammatory factors was detected in the tissues. Serum fibroblast growth factor 15 (FGF15) and bile acid were determined. In HFD-fed mice, fipronil exacerbated glucose metabolic disorders and enhanced insulin resistance. These metabolic disturbances were associated with gut microbiota dysbiosis, particularly a marked reduction in Akkermansia muciniphila (A. muciniphila) abundance, and increased systemic inflammation. Fipronil exposure also decreased serum FGF15 and elevated serum bile acids. Our results suggest that fipronil disrupts glucose metabolism in association with gut microbiota alterations, impairment of the FGF15-bile acid axis, and induction of inflammation, highlighting its potential relevance to diabetes risk. Further studies are warranted to validate our findings. Full article

The probiotic efficacy of H. coagulans relies on the bile salt tolerance of its vegetative cells, yet direct evidence linking this trait to intestinal colonization remains limited. This study integrated phenotypic screening, in vitro gastrointestinal simulation, in vivo colonization assays, and comparative genomics to address this gap. Among 50 strains, two highly bile salt-tolerant isolates (ATCC 7050 and Idrc019) were identified. In vitro assays using a simulated gastrointestinal model demonstrated that the spores of tolerant strains exhibited a significantly higher germination rate in the intestinal phase. Subsequently, in vivo time-course experiments demonstrated that tolerant strains exhibited superior intestinal proliferation and modulated the gut microbiota by enriching beneficial genera such as Blautia. Comparative genomic analysis revealed five variable genes associated with bile salt tolerance. Notably, BF29_941 (encoding a pilus assembly protein) was significantly upregulated under bile salt stress, suggesting a potential role in cell aggregation as a tolerance mechanism. These findings establish bile salt tolerance as a critical determinant of intestinal colonization in H. coagulans. Full article

Faecalibacterium prausnitzii, a major butyrate-producing gut commensal with anti-inflammatory activity, is extremely oxygen-sensitive, limiting its use as a probiotic. Dietary prebiotics may enhance its growth and resilience, thereby influencing host immune responses. This study examined how distinct classes of prebiotics including oligosaccharides (fructooligosaccharides, arabinoxylan), nondigestible polysaccharides (inulin, pectin, resistant starch, golden kiwi fiber), and the vitamin riboflavin affect the growth kinetics, bile tolerance, and immunomodulatory properties of F. prausnitzii. Doubling times were quantified in MRS medium supplemented with 0–2% prebiotics, bile tolerance was assessed under 0–0.5% bile salts, and immunomodulatory response was evaluated by measuring TNF-α expression in monocytic THP-1 cells exposed to bacterial supernatants. All prebiotics significantly reduced doubling times compared with controls, with FOSs, inulin, pectin, resistant starch, and riboflavin showing clear dose-dependent stimulation. Prebiotics also mitigated bile-induced growth delays, though with substrate-specific patterns; pectin and FOSs conferred the strongest protection. Culture supernatants significantly altered TNF-α expression, with pectin inducing the greatest response, followed by arabinoxylan, FOSs, and golden kiwi fiber. Overall, prebiotics enhanced F. prausnitzii growth, increased stress resilience, and differentially modulated immune-related metabolites. Pectin emerged as a particularly effective substrate for promoting microbial function and host-relevant immunomodulation. Full article