Search Results (1,708)

Background/Objectives: Implant-associated infections are challenging conditions in orthopedic surgery. This experimental study aimed to evaluate phage localization within infected tissues following different routes of administration. Methods: An implant-related infection model was created using methicillin-resistant Staphylococcus aureus (MRSA) in twenty-four rats. Subjects were randomly divided into four groups depending on the bacteriophage administration route. Three rats were designated as the control group. Phage suspension was applied intraperitoneally, intravenously, orally and locally at 0.1 mL/day of 1 × 10⁸ PFU/mL suspension for three consecutive days. In the control group, intravenous, intraperitoneal and oral phage suspensions were administered separately at the same dose for 3 days. After completion of the experiment, tibia samples were taken in the experimental group. Additionally, liver, kidney, stomach, brain, heart muscle and striated muscle tissue samples were taken from the three subjects in the control group. Results: In the control group, unconfirmed phage-like structures were incidentally observed in some mitochondria of renal proximal tubular epithelial cells on transmission electron microscopy. In the experimental group, there was a strong positive linear relationship between the total number of bacteria and the number of bacteriophage clusters, independent of the groups. Conclusions: Bacteriophage clusters were detected in infected tibial tissues after all administration routes, suggesting phage localization at the infection site. Unexpected phage-like clusters were observed within mitochondria of proximal tubular epithelial cells in the control animals. This finding should be regarded as an unconfirmed incidental finding requiring further validation. Full article

Background: The oral microbiome has emerged as a potential contributor to cardiovascular physiology through its role in the enterosalivary nitrate–nitrite–nitric oxide pathway. Oral nitrate-reducing bacteria convert dietary nitrate into nitrite, which can subsequently be reduced to nitric oxide, a signaling molecule associated with vascular tone, endothelial function, platelet activity, and blood pressure regulation. Disruption of this pathway has been associated with reduced nitric oxide bioavailability and impaired vascular responses. Methods: This narrative review summarizes current evidence regarding the relationship between the oral microbiome, nitrate metabolism, and cardiovascular function. Relevant literature was identified through searches of PubMed/MEDLINE and Google Scholar up to May 2026. Evidence from mechanistic, observational, and interventional human studies was reviewed and synthesized thematically. Results: Available evidence suggests that oral nitrate-reducing bacteria may influence nitric oxide bioavailability and vascular function. Studies have reported associations between oral microbiome disruption and changes in blood pressure, endothelial responsiveness, plasma nitrite concentrations, and other surrogate cardiovascular markers. However, findings remain heterogeneous and are influenced by factors such as diet, oral hygiene practices, smoking status, medication use, oral health, and underlying cardiometabolic conditions. Most studies are limited by small sample sizes, short intervention durations, and reliance on surrogate outcomes rather than major cardiovascular events. Conclusions: The oral microbiome may influence cardiovascular health through its role in nitrate metabolism and nitric oxide bioavailability. However, current evidence is largely limited to surrogate vascular outcomes, while data on major cardiovascular events remain scarce. Further longitudinal and interventional studies are needed to clarify causality and evaluate microbiome-targeted interventions. Full article

Background/Objectives: The aim of this study was to investigate primary colonizers adhering to the oral biofilm on five adhesive restorative materials. Methods: For each material (Admira Fusion, Clearfil AP-X, Durafill VS, Filtek Supreme XTE, and Venus Diamond), sixteen test specimens were prepared according to a standardized protocol. For pellicle formation, the specimens were incubated for two hours at 37 °C with sterile-filtered inactivated human saliva. The bacteria (Streptococcus oralis (S. oralis), Streptococcus gordonii (S. gordonii), Streptococcus sanguinis (S. sanguinis), Streptococcus mitis (S. mitis), and Actinomyces naeslundii (A. naeslundii)) were cultivated and suspended. A bacteria mix was prepared from the suspensions. The specimens with pellicles were wetted with the bacterial mix and incubated at 37 °C for 8 h. The total genomic DNA of the adhered bacteria was isolated and subsequently quantified using SYBR Green qPCR. Results: For S. gordonii, S. oralis, and A. spp., no significant differences in the amount of adhered bacterial DNA were found between the different materials. S. mitis DNA concentration was significantly higher on Filtek Supreme XTE compared to the other materials. Significantly higher DNA concentrations of S. sanguinis could also be detected on Filtek Supreme XTE compared to Clearfil AP-AX and Durafill VS. Conclusions: The investigated restorative materials showed species-specific differences in bacterial adhesion, with Filtek Supreme XTE exhibiting higher adhesion of S. mitis and S. sanguinis, whereas no differences were observed for the other tested species. Full article

Pancreatic cancer (PC) remains one of the malignancies with the most unfavorable prognosis and limited treatment options. The lack of biomarkers for early diagnosis and the asymptomatic nature of the disease contribute to delays in diagnosis and high mortality rates. In recent years, the role of the human microbiota in cancer biology has become increasingly significant, and the oral microbiota in particular has been found to be involved in the pathogenesis and prognosis of several neoplasms. This review summarizes the current evidence relating the salivary microbiota to PC in three key areas: screening and diagnostic potential, pathophysiology and tumor progression, as well as presenting prognostic implications and potential influence on therapy. With regard to early diagnosis, it has been reported that patients with PC have reduced levels of Neisseria elongata (N. elongata) and Streptococcus mitis (S. mitis) and elevated levels of Granulicatella adiacens. Several studies have shown that bacteria present in the saliva can migrate from the oral cavity to pancreatic tissue via hematogenous or enteric routes, where they may actively contribute to tumor development and progression. In particular, it has been shown that Porphyromonas gingivalis (P. gingivalis) and Veillonella atypica (V. atypica) translocate from the mouth to pancreatic tumors, promoting carcinogenesis by inducing a pro-inflammatory tumor microenvironment. Furthermore, some studies have identified certain species associated with prognosis and response to PC treatment. Despite the encouraging results, differences in study methodology, the lack of standardized methods and the scarcity of longitudinal data currently hinder clinical application. Large-scale, multi-omics prospective studies are needed to clarify causality and validate their clinical utility. Overall, the salivary microbiota represents a promising and non-invasive tool for improving early diagnosis, understanding prognosis and enhancing the management of PC. Full article

Background/Objectives: Oral and maxillofacial infections present polybacterial profiles, including both aerobic and anaerobic bacteria. Increasing antibiotic resistance poses a significant challenge to pharmacological treatment of these infections. The aim of this study was to present a bacterial profile and assess antibiotic resistance found in these infections. Methods: This retrospective analysis is based on medical records of 224 patients affected with maxillofacial infections. Microbiological cultures and antibiotic susceptibility testing were performed for all patients. Results: In 78.57% of the patients, a positive microbiological culture was obtained. A total of 72.72% of culture-positive patients showed multi-bacterial cultures (128/176). Predominant bacteria included Streptococcus, detected in 156 cases (39%), followed by Staphylococcus, found in 64 cases (16%), and Prevotella, detected in 56 of 400 total bacterial isolates (14%). The most often isolated aerobic strains were Streptococcus mitis/oralis detected in 64 (16%) cases and Staphylococcus epidermidis detected in 48 cases (12%), while the most common anaerobic strains were Prevotella buccae detected in 14 cases (3.5%). Streptococcus and Staphylococcus exhibited the greatest resistance to clindamycin, accounting for 51.74% and 47.63%, respectively. Aerobic Gram-positive cocci were more resistant to penicillin and amoxicillin than to cephalosporins. Among obligate anaerobes, the lowest antibiotic resistance seen was to metronidazole. The obligate anaerobes except Prevotella were sensitive to clindamycin. Conclusions: A high rate of clindamycin resistance among aerobic and facultatively anaerobic Gram-positive cocci indicates the need to reassess the use of clindamycin in empirical therapy. The bacterial composition of infections suggests the need to use combined antibiotic therapy. First- and second-generation cephalosporins may be an effective alternative to penicillin and its derivatives. Full article

Salivary microbiota constitutes complex microbial assemblages and acts as a source of reliable non-invasive biomarkers for evaluating growth, metabolism, and health status of farm animals. This review explores the research value of saliva and its resident microbes in livestock health monitoring. We summarize saliva composition, physiological functions, and sampling protocols for pigs, cattle, sheep, and goats. Core microbial taxa of monogastric and ruminant species are outlined, together with their roles in digestion, rumen fermentation, growth, and stress responses. We also present classic salivary diagnostic indicators and the impacts of oral bacteria on common livestock diseases. Current research is limited by undefined causal relationships, low diagnostic specificity, and heterogeneous technical standards, and thus fails to support accurate diagnosis at the individual animal level. Future studies should elucidate microbial interaction mechanisms, standardize experimental protocols, and establish multi-index evaluation models. This review advances theoretical research and promotes the practical application of salivary microbiota in precision livestock farming. Full article

Background: Cervical cancer is primarily caused by the human papillomavirus (HPV), with persistent infections progressing to low- (LGSIL) and high-grade (HGSIL) lesions. Emerging evidence indicates that the cervicovaginal microbiota influences HPV persistence and disease progression, although the underlying metabolic mechanisms remain unclear. Therefore, we assessed the relationship between the cervicovaginal microbiota and the metabolic milieu in women with cervical dysplasia and HPV infections. Methods: We recruited 36 non-menopausal, non-pregnant women who were classified as negative, LGSIL, or HGSIL based on pathology and HPV results. Cervical swabs were collected for genomic DNA extraction to characterize bacterial communities using 16S rRNA sequencing and to perform HPV genotyping. Cervical lavages were collected for untargeted metabolomic profiling using Gas Chromatography-Mass Spectrometry. Integrative multiomic analysis was performed using the MIMOSA2 pipeline. Results: Although bacterial community structure was not different between groups, women with HGSIL had higher richness and exhibited a higher abundance of Prevotella bivia, Prevotella buccalis, and Lachnospiraceae G-9 oral taxon 924. Lesion-positive samples had shifts in tyramine and putrescine, biogenic amines linked to cancer development. Specifically, Pseudomonas was identified as a potential contributor to tyramine oxidation. Conclusions: Cervical lesions and HPV risk are associated with shifts in the cervicovaginal microbial metabolic milieu, highlighting the role of low-abundant anaerobic bacteria. Despite the small sample size, biogenic amines were associated with anaerobic taxa and microbial dysbiosis. These findings warrant further assessment of microbial-derived metabolites and their potential to promote tumor progression by driving a pro-inflammatory, metabolically altered microenvironment. Full article

Background/Objectives: Metabolic syndrome (MetS) is a pressing global health challenge comprising obesity, hyperglycemia, hypertension, and hyperlipidemia. Conventional polypharmacy often presents long-term compliance issues and side effects. Eucommia ulmoides Oliv., a traditional medicinal and edible plant rich in iridoids, lignans, flavonoids, and polysaccharides, has emerged as a promising natural intervention. This review aims to systematically summarize the bioavailability and multifaceted pharmacological mechanisms of E. ulmoides and its bioactive components in alleviating MetS. Methods: We comprehensively reviewed the recent in vitro and in vivo literature to map the functional evidence, specific signaling pathways, and gut microbiota–host interactions associated with E. ulmoides extracts and its key phytochemicals (e.g., asperuloside) against various metabolic dysfunctions. Results: Current evidence indicates that E. ulmoides operates through a “multi-component, multi-target, and multi-pathway” paradigm. For hyperlipidemia and obesity, it activates hepatic lipid metabolism (PPARα/CPT1A, FXR/CYP7A1) and mitigates oxidative stress (Nrf2/ARE). Furthermore, it dose-dependently reshapes the gut microbiota by enriching beneficial bacteria like Akkermansia and increasing butyrate production, exerting profound gut–liver axis regulation. It also ameliorates hypertension by activating the ACE2-Ang-(1–7)-Mas axis, improves insulin resistance via the AMPK/PI3K/Akt cascade, and manages hyperuricemia by modulating XOD and renal transporters. Notably, the low oral bioavailability of its glycosides highlights the crucial role of gut microbial hydrolysis in its efficacy. Conclusions: E. ulmoides holds substantial therapeutic potential as a multi-target natural supplement for MetS. However, future translational applications necessitate large-scale randomized clinical trials, multi-omics studies to further clarify host–microbiome interactions, and the development of standardized formulations to ensure clinical efficacy. Full article

The oral cavity harbors a complex microbial community where pathogens implicated in dental caries and periodontitis can heavily colonize toothbrushes, transforming them into persistent sources of contamination that threaten both oral and systemic health. Consequently, this study evaluated the bactericidal efficacy of 275 nm ultraviolet light-emitting diode (UV-LED) irradiation against common oral bacteria in vitro and its practical utility for extraoral toothbrush sanitization. Suspensions of Streptococcus mutans, Streptococcus sanguinis, Porphyromonas gingivalis, and Fusobacterium nucleatum were irradiated for 3 min, 6 min, and 9 min. Bacterial growth and bactericidal effects were measured using growth curve and colony-forming unit assays, respectively. LIVE/DEAD staining and crystal violet staining were used to evaluate the bacterial viability and multispecies biofilm formation after irradiation. Additionally, the sanitization effects of a 275 nm UVC-based portable device on used toothbrushes were investigated. Direct UVC irradiation at 275 nm exhibited strong bactericidal effects against common oral bacteria in vitro. UVC irradiation also showed great sanitization effects on used toothbrushes. In summary, the vulnerability of common oral bacteria to 275 nm UVC, combined with its sanitizing efficacy on used toothbrushes, establishes a solid basis for extraoral sanitization, offering a reliable strategy to mitigate the risk of oral pathogen transmission from contaminated toothbrushes. Full article

Background and Objectives: This study aims to evaluate the recent literature on the oral–gut connection in the context of periodontal disease, emphasizing the significance of systemic risk associated with chronic inflammation. This review explores whether chronic inflammation resulting from periodontal disease can induce systemic conditions through alterations in the gut microbiome and whether periodontal treatment may contribute to overall health improvement. Materials and Methods: A systematic database search was performed using pre-established search strategies. Searches were conducted in three databases between 1 and 20 October 2025. A total of 578 articles were screened for eligibility based on inclusion and exclusion criteria. Two authors agreed on the selection process used. The methodological quality of the included studies was assessed using the Newcastle–Ottawa scale and the Risk of Bias 2 Tool. Results: Eleven studies were considered eligible for inclusion in the review. The gut microbiome is similar to the oral microbiome in patients with periodontitis. Gut microbial shifts may drive systemic inflammation and metabolic dysfunction. Tooth loss and gum disease are linked to alterations in the gut bacteria, potentially compromising the intestinal barrier permeability. In contrast, the presence of natural teeth may prevent oral–gut bacterial transmission. Changes in the gut microbiota are correlated with improvements in periodontal status after non-surgical periodontal therapy. Conclusions: The evidence presented in this review supports an association between periodontitis, oral–gut microbial alterations, and systemic inflammatory conditions. However, most available studies are observational, limiting causal inference. Targeted modulation of the gut microbiome may represent a promising area for future research, but its clinical applicability remains inconclusive. Full article

Several studies on diet and microbiome have predominantly focused on the gut microbiome. However, much of the salivary microbiome remains unexplored. This study examined the influence of Thai desserts with varying glycemic indices on the salivary microbiome. A total of 30 healthy adults aged 18–45 years were enrolled in a randomized trial and allocated to one of three intervention groups, with each receiving a culturally specific Thai dessert standardardized to provide 50 g of available carbohydrates: Phetchaburi’s Custard Cake (PCC; low-GI, 192 g), Saraburi’s Curry Puff (SCP; medium-GI, 98 g), or Lampang’s Crispy Rice Cracker (LCRC; high-GI, 68 g). Salivary and dessert microbiome compositions were characterized at baseline and 24 h post-intervention using 16S rRNA sequencing to evaluate bacterial diversity and relative abundance across multiple taxonomic levels. Firmicutes were highly abundant (over 76%) in all Thai desserts tested. Proteobacteria were found in both SCP (15.1 ± 6.6%) and LCRC (6.5 ± 3.4%). Actinobacteriota was slightly higher in the high-GI group (6.3 ± 3.1%) compared to the medium-GI group (3.0 ± 2.2%). Bacillus was dominant in PCC, while Streptococcus, Carnobacterium, and Clostridium sensu stricto 1 were prevalent in SCP. Anoxybacillus, Clostridium sensu stricto 12, Terrilactibacillus, Geobacillus, and Weissella were found in LCRC. Desserts with different types of glycemic index showed modest short-term changes in the relative abundance of some salivary bacteria. Notably, Porphyromonas showed a relative increase in the high-GI group compared to the low-GI group (1.8 [0.3, 4.0] vs. −1.9 [−3.2, 0.8], p < 0.05), while Streptococcus, saccharolytic bacteria, slightly increased in both the high-GI and medium-GI groups. Prevotella showed a slight relative decrease in the low-GI group. Although these microorganisms have been previously associated with dysbiosis and periodontitis in longer-term studies, the clinical relevance of these short-term compositional changes remains unclear and should be interpreted with caution. These preliminary findings suggest that local Thai desserts with varying GIs may be associated with transient shifts in salivary microbiota composition; however, whether such changes contribute to dysbiosis or adverse oral health outcomes requires further investigation through longitudinal studies with larger sample sizes. Full article

Background: Streptococcus mutans is a key etiological agent of dental caries, and its ability to form biofilms significantly increases resistance to antimicrobial agents. This study evaluated the activity of selected oral antiseptics against both planktonic and biofilm forms of S. mutans. Methods: Seven pure antiseptic compounds and nine commercially available mouthwashes were tested. Minimal inhibitory concentrations (MICs) were determined using a microdilution method, and their clinical relevance was assessed using the Clinical Efficiency of MIC (CEMIC) index. Antibiofilm activity was evaluated using a crystal violet assay and by measuring biofilm thickness using 3D microscopy and the Biofilm Thickness Analyzer application. Results: The highest antibacterial and antibiofilm activity was observed for octenidine (OCT), chlorhexidine (CHX), and polyhexanide (PHMB), as well as for mouthwashes containing these agents, all showing high CEMIC values. Hydrogen peroxide (H₂O₂) and fluoride-containing formulations also demonstrated notable activity. In contrast, ethacridine lactate and boric acid showed variable effects, while sodium hypochlorite and potassium permanganate exhibited weak antibacterial activity and no antibiofilm effect. Conclusions: OCT, CHX, and PHMB were the most effective against both planktonic and biofilm forms of S. mutans. H₂O₂ and fluoride-containing formulations also showed promising activity. These findings support the role of selected antiseptics in reducing dental plaque formation, a key factor in the development of oral diseases. Full article

Probiotics are known to benefit human health through improving the gut environment. This study aimed to investigate whether Streptococcus salivarius (S. salivarius) G7 exhibits probiotic properties and evaluated its effectiveness and suitability for oral health applications. Whole-genome sequencing of S. salivarius was performed using Novo assembly and bioinformatics analysis. To determine probiotic suitability, the required metabolic profiles were obtained through performing a hemolysis test, antibiotic susceptibility test, D-lactate production assay, and cytotoxicity assay according to the methods recommended in World Health Organization guidelines. To investigate the oral health impacts of S. salivarius, the acidogenicity and antimicrobial activity of S. salivarius were investigated. Finally, oral biofilms treated and untreated with S. salivarius were investigated. The phylogenetic and bioinformatic analyses confirmed the taxonomic identity of S. salivarius. Also, it has been proven that this bacterium carries no virulence factors or transmissible antibiotic resistance genes. S. salivarius G7 exhibited low antibiotic resistance, cytotoxicity, and acidogenicity, while also displaying antimicrobial activity against oral disease-related bacteria, and was able to maintain eubiosis in oral biofilms. S. salivarius G7 met all the safety assessment criteria required by current probiotic guidelines and exhibited beneficial properties for oral health. Therefore, this strain may represent a safe and promising probiotic candidate for oral health applications. Full article

Periodontal disease is a chronic inflammatory condition driven by polymicrobial biofilms whose interaction with the host immune response drives the destruction of tooth-supporting tissues. Within these communities, bacterial cell–cell communication—particularly quorum sensing (QS)—coordinates virulence factor expression, biofilm maturation, and interspecies behaviour, allowing pathogens to mount population-dependent attacks on the host. Disrupting these signals has therefore drawn growing attention as an anti-virulence strategy for biofilm-associated oral infection. Quorum quenching (QQ)—the inhibition or disruption of QS pathways—prevents bacteria from coordinating these virulence-related activities. The candidate inhibitors investigated to date fall into three broad classes: conventional antibiotics used at sub-inhibitory concentrations, plant-derived natural compounds, and synthetic molecules designed to interfere with signal synthesis, signal reception, or signal transduction. In experimental work on periodontal pathogens, agents from each class reduce biofilm formation, suppress virulence factor production, and disrupt microbial communication within polymicrobial biofilms. Clinical translation, however, lags behind the laboratory evidence. Most data still come from in vitro systems and animal models, and the ecological complexity of the oral biofilm makes therapeutic targeting difficult: signals that drive virulence in pathogens also support cooperation among commensals. Toxicity profiles, pharmacokinetics, and well-powered clinical trials are needed before quorum-quenching agents can be considered for routine periodontal care. Even with these caveats, targeting bacterial communication offers a different therapeutic logic from conventional antimicrobials: attenuating virulence rather than killing cells, and so exerting weaker selective pressure for resistance. Further dissection of QS networks in oral biofilms—and the rational design of quenching agents that act on pathogenic rather than commensal signalling—may yield useful adjuncts to current periodontal therapy. Full article

Background/Objectives: Eubacterium limosum El1405 is a novel probiotic candidate strain that has been shown to exert prominent anti-inflammatory and anti-tumor bioactivities, with potential antibacterial activity against pathogenic bacteria. This study aimed to systematically evaluate the safety of E. limosum El1405 and its probiotic functions and protective effects against pathogenic bacterial infection. Methods: The safety of E. limosum El1405 was assessed through in vitro assays of hemolytic and gelatinase activities and a 28-day subchronic oral toxicity mouse model. In the mouse model, three different doses (low, medium, and high) of E. limosum El1405 were tested, and physiological status, visceral histopathology, hematological profiles, serum biochemistry, and cytokines were measured. The antibacterial activity of the strain against pathogenic bacteria was determined in vitro. A Salmonella Typhimurium -infected mouse model was used to assess its potential to protect against infection. Results: In vitro safety assays confirmed that E. limosum El1405 possessed no hemolytic or gelatinase activity. In the 28-day subchronic oral toxicity test, low, medium, and high doses of El1405 caused no significant alterations in mouse body weight, visceral index, organ histopathology, hematological parameters, serum biochemistry, or cytokine levels. The strain exhibited antibacterial activity against S. Typhimurium in vitro. In S. Typhimurium-infected mice, El1405 intervention effectively mitigated S. Typhimurium-induced damage, reduced visceral bacterial loads, decreased pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) in the ileum and serum, and elevated the anti-inflammatory cytokine IL-10. Conclusions:E. limosum El1405 displays a favorable safety profile and promising probiotic effects, including antibacterial capacity and anti-inflammatory protective effects against S. Typhimurium infection, supporting further exploration and development of E. limosum El1405 as a novel functional probiotic strain for clinical and health applications. Full article