Akkermansia muciniphila inhibited the periodontitis caused by Fusobacterium nucleatum

Bacillus coagulans alleviates intestinal barrier injury induced by Klebsiella pneumoniae in rabbits by regulating the TLR4/MyD88/NF-κB signalling pathway

Probiotics effectively alleviate host diarrhoea, but the specific mechanism is not clear. Therefore, we explored the protective mechanism of Bacillus coagulans (BC) on intestinal barrier injury induced by Klebsiella pneumoniae (K. pneumoniae) in rabbits by HE, immunofluorescence and 16S rRNA. The results showed that BC pretreatment alleviated the changes in average daily gain, average daily feed intake and FCR caused by K. pneumoniae in rabbits. Moreover, BC alleviated the inflammatory cell infiltration, intestinal villus reduction, crypt deepening and goblet cell reduction caused by K. pneumoniae in rabbits. Further research revealed that BC improved the intestinal barrier by improving the mechanical barrier, chemical barrier, immune barrier and microbial barrier. Specifically, BC improved the intestinal mechanical barrier by improving the intestinal structure, increasing the protein expression of PCNA, increasing the number of goblet cells, and altering the expression of occludin, claudin-1 and ZO-1. BC improved the intestinal chemical barrier by regulating the expression of MUC1 and MUC2 and inhibited the TLR4/MyD88/NF-κB signalling pathway by altering the expression levels of the inflammatory factors IL-1β, IL-6 and TNF-α, thus optimizing the intestinal immune barrier. In addition, adding BC to the diet improved the intestinal microbial barrier of rabbits by reducing the abundance of harmful bacteria and increasing the abundance of beneficial bacteria. In summary, BC protects against K. pneumoniae-induced intestinal barrier damage by improving intestinal morphology, mitigating the inflammatory response and regulating the microbial composition. Among the pretreatments, the pretreatment effect of 1 × 106 CFU/g was the best. This study provides a theoretical basis for the use of BC to prevent and treat diarrhoea caused by K. pneumoniae in rabbits.

Interspecies interactions mediated by arginine metabolism enhance the stress tolerance of Fusobacterium nucleatum against Bifidobacterium animalis

Colorectal cancer (CRC) is a common cancer accompanied by microbiome dysbiosis. Exploration of probiotics against oncogenic microorganisms is promising for CRC treatment. Here, differential microorganisms between CRC and healthy control were analyzed. Antibacterial experiments, whole-genome sequencing, and metabolic network reconstruction were combined to reveal the anti-Fusobacterium nucleatum mechanism, which was verified by co-culture assay and mendelian randomization analysis. Sequencing results showed that F. nucleatum was enriched in CRC, yet Bifidobacterium animalis decreased gradually from healthy to CRC. Additionally, F. nucleatum could be inhibited by B. animalis. Whole-genome sequencing of B. animalis showed high phylogenetic similarity with known probiotic strains and highlighted its functions for amino acid and carbohydrate metabolism. Metabolic network reconstruction demonstrated that cross-feeding and specific metabolites (acidic molecules, arginine) had a great influence on the coexistence relationship. Finally, the arginine supplement enhanced the competitive ability of F. nucleatum against B. animalis, and the mendelian randomization and metagenomic sequencing analysis confirmed the positive relationship among F. nucleatum, arginine metabolism, and CRC. Thus, whole-genome sequencing and metabolic network reconstruction are valuable for probiotic mining and patient dietary guidance.IMPORTANCEUsing probiotics to inhibit oncogenic microorganisms (Fusobacterium nucleatum) is promising for colorectal cancer (CRC) treatment. In this study, whole-genome sequencing and metabolic network reconstruction were combined to reveal the anti-F. nucleatum mechanism of Bifidobacterium animalis, which was verified by co-culture assay and mendelian randomization analysis. The result indicated that the arginine supplement enhanced the competitive ability of F. nucleatum, which may be harmful to F. nucleatum-infected CRC patients. B. animalis is a potential probiotic to relieve this dilemma. Thus, using in silico simulation methods based on flux balance analysis, such as genome-scale metabolic reconstruction, provides valuable insights for probiotic mining and dietary guidance for cancer patients.

The oral-gut microbiota axis: a link in cardiometabolic diseases

The oral-gut microbiota axis plays a crucial role in cardiometabolic health. This review explores the interactions between these microbiomes through enteric, hematogenous, and immune pathways, resulting in disruptions in microbial balance and metabolic processes. These disruptions contribute to systemic inflammation, metabolic disorders, and endothelial dysfunction, which are closely associated with cardiometabolic diseases. Understanding these interactions provides insights for innovative therapeutic strategies to prevent and manage cardiometabolic diseases.

Metagenomic characterization of oral microbiome signatures to predict upper gastrointestinal and pancreaticobiliary cancers: a case-control study

BACKGROUND

This study investigated the oral microbiome signatures associated with upper gastrointestinal (GI) and pancreaticobiliary cancers.

METHODS

Saliva samples from cancer patients and age- and sex-matched healthy controls were analyzed using 16S rRNA-targeted sequencing, followed by comprehensive bioinformatics analysis.

RESULTS

Significant dissimilarities in microbial composition were observed between cancer patients and controls across esophageal cancer (EC), gastric cancer (GC), biliary tract cancer (BC), and pancreatic cancer (PC) groups (R2 = 0.067, = 0.075, = 0.068, and = 0.044; p = 0.001, = 0.001, = 0.002, and = 0.004, respectively). Additionally, the oral microbiome composition significantly differed by the four cancer sites (p = 0.001 for EC vs. GC, EC vs. BC, EC vs. PC, GC vs. BC, and GC vs. PC; p = 0.013 for BC vs. PC). We built oral metagenomic classifiers to predict cancer and selected specific microbial taxa with diagnostic properties. For EC, the classifier differentiated cancer patients and controls with good accuracy (area under the curve [AUC] = 0.791) and included three genera: Akkermansia, Escherichia-Shigella, and Subdoligranulum. For GC, the classifier exhibited high discriminative power (AUC = 0.961); it included five genera (Escherichia-Shigella, Gemella, Holdemanella, Actinomyces, and Stomatobaculum) and three species (Eubacterium sp. oral clone EI074, Ruminococcus sp. Marseille-P328, and Leptotrichia wadei F0279). However, microbial taxa with diagnostic features for BC and PC were not identified.

CONCLUSIONS

These findings suggested that the oral microbiome composition may serve as an indicator of tumorigenesis in upper GI and pancreaticobiliary cancers. The development of oral metagenomic classifiers for EC and GC demonstrates the potential value of microbial biomarkers in cancer screening.

Polymerization of dietary fructans differentially affects interactions among intestinal microbiota of colitis mice

The intestinal microbiota plays a critical role in maintaining human health and can be modulated by dietary interventions and lifestyle choices. Fructans, a dietary carbohydrate, are selectively utilized by the intestinal microbiota to confer health benefits. However, the specific effects of different fructan types on microbial changes and functions remain incompletely understood. Here, we investigated how the intestinal microbiota responds to fructans with varying degrees of polymerization in the context of gut dysbiosis. Both low molecular weight fructo-oligosaccharides and high molecular weight levan suppressed intestinal inflammation in a colitis mouse model, mitigating intestinal fibrosis and dysbiosis. Although both the effects of fructo-oligosaccharides and levan are microbiota-dependent, distinct modulation patterns of the intestinal microbiota were observed based on the molecular weight of the fructans. Levan had a more pronounced and persistent impact on gut microbiota compared to fructo-oligosaccharides. Levan particularly promoted the abundance of Dubosiella newyorkensis, which exhibited preventive effects against colitis. Our findings highlight the importance of polymerization levels of dietary fructans in microbiota alterations and identify Dubosiella newyorkensis as a potential probiotic for treating inflammatory diseases.

Engineering Mild-Photothermal Responsive and NO Donor Prussian Blue Nanozymes Using Mild Synthesis for Inflammation Regulation and Bacterial Eradication in Periodontal Disease

Periodontitis, an infectious disease of periodontal tissues caused by oral bacterial biofilms, is characterized by reactive oxygen species (ROS) accumulation and immune microenvironment imbalance. Multifunctional nanozymes, leveraging their physiochemical properties and enzymatic activities, offer promising antibacterial and anti-inflammatory strategies for managing periodontitis. In particular, Prussian blue nanozymes (PBzymes) exhibit exceptional ROS control due to their robust catalytic activity, diverse antioxidant functions, and high biocompatibility. However, the practical application of traditional high-temperature synthesis methods is limited. This study introduces a class of metal-engineered PBzymes synthesized at room temperature, identified for their potent antioxidative activity and excellent photothermal performance at mild temperatures. Nitric oxide (NO) gas therapy offers promising strategies for targeting deep infections in periodontal tissues. Thus, sodium nitroprusside is introduced into PBzyme to create SPBzyme via an in situ loading method. NO release by SPBzyme enhances antibacterial effects and overcomes resistance linked to bacterial biofilms, resulting in mild-photothermal antibacterial properties and synergistic antioxidant effects. In vitro antibacterial assays demonstrate the superior efficacy of SPBzyme under mild temperature conditions and near-infrared light exposure. Furthermore, SPBzyme effectively reduces inflammation and has positive therapeutic effects in periodontal animal models. Overall, mild-temperature photothermal NO release nanozyme therapy represents a novel approach for treating periodontitis.

From Biofilm to Breath: The Role of Lacticaseibacillus paracasei ET-22 Postbiotics in Combating Oral Malodor

Previous studies demonstrated that sufferers with halitosis can be significantly improved with Lacticaseibacillus paracasei ET-22 (ET-22) postbiotics intervention. The objectives of this investigation were to identify the primary components responsible for inhibiting oral malodor. This study demonstrated that cell-free supernatants (CFSs) were more effective in inhibiting production of volatile sulfur compounds (VSCs). Untargeted metabolomics identified CFSs as primarily consisting of organic acids, lipids, peptides, and nucleotides. Among the potential active components, phenyllactic acid (PLA) and peptide GP(Hyp)GAG significantly inhibited microbial-induced VSCs production, with VSC concentrations reduced by 42.7% and 44.6%, respectively. Given the correlation between biofilms and halitosis, microstructural changes in biofilms were examined. PLA suppressed the biomass of the biofilm by 41.7%, while the biofilm thickness was reduced from 202.3 to 70.0 μm. GP(Hyp)GAG intervention reduced the abundance of Fusobacterium nucleatum and Streptococcus mutans within the biofilm, and the expression of biofilm-forming genes FadA and Gtfb were also suppressed by 41.8% and 59.4%. Additionally, the VSC production capacities were reduced due to the decrease in VSC producing bacteria (F. nucleatum, Prevotella intermedia, and Solobacterium moorei) and down-regulation of Cdl and Mgl genes. Collectively, the current study proved that PLA and GP(Hyp)GAG may be the main contributors to halitosis inhibition by ET-22 postbiotics.

Oral Pathogens' Substantial Burden on Cancer, Cardiovascular Diseases, Alzheimer's, Diabetes, and Other Systemic Diseases: A Public Health Crisis-A Comprehensive Review

This review synthesizes the findings from 252 studies to explore the relationship between the oral pathogens associated with periodontitis, dental caries, and systemic diseases. Individuals with oral diseases, such as periodontitis, are between 1.7 and 7.5 times (average 3.3 times) more likely to develop systemic diseases or suffer adverse pregnancy outcomes, underscoring the critical connection between dental and overall health. Oral conditions such as periodontitis and dental caries represent a significant health burden, affecting 26-47% of Americans. The most important oral pathogens, ranked by publication frequency, include the herpes virus, C. albicans, S. mutans, P. gingivalis, F. nucleatum, A. actinomycetemcomitans, P. intermedia, T. denticola, and T. forsythia. The systemic diseases and disorders linked to oral infections, ranked similarly, include cancer, respiratory, liver, bowel, fever, kidney, complications in pregnancy, cardiovascular bacteremia, diabetes, arthritis, autoimmune, bladder, dementia, lupus, and Alzheimer's diseases. Evidence supports the efficacy of dental and periodontal treatments in eliminating oral infections and reducing the severity of systemic diseases. The substantial burden that oral pathogens have on cancer, cardiovascular diseases, Alzheimer's, diabetes, and other systemic diseases poses a significant public health crisis.

Outer Membrane Vesicles Derived From Fusobacterium nucleatum Trigger Periodontitis Through Host Overimmunity

The virulent bacteria-induced host immune response dominates the occurrence and progression of periodontal diseases because of the roles of individual virulence factors from these pathogens in the initiation and spread of inflammation. Outer membrane vesicles (OMVs) as a pathogenic entity have recently attracted great attention as messenger bridges between bacteria and host tissues. Herein, the novel role of OMVs derived from Fusobacterium nucleatum in the occurrence of periodontitis is dissected. In a rat periodontitis model, it is found that OMVs derived from F. nucleatum caused deterioration of periodontitis by enhancing inflammation of the periodontium and absorption of alveolar bone, which is almost equivalent to the effect of F. nucleatum itself. Furthermore, that OMVs can independently induce periodontitis is shown. The pathogenicity of OMVs is attributed to multiple pathogenic components identified by omics. After entering human periodontal ligament stem cells (hPDLSCs) by endocytosis, OMVs activated NLRP3 inflammasomes and impaired the mineralization of hPDLSCs through NF-κB (p65) signaling, leading to the final injury of the periodontium and damage of alveolar bone in periodontitis. These results provide a new understanding of OMVs derived from pathogens and cues for the prevention of periodontitis.

Oral inoculation of Fusobacterium nucleatum exacerbates ulcerative colitis via the secretion of virulence adhesin FadA

Fusobacterium nucleatum (F. nucleatum), an anaerobic resident of the oral cavity, is increasingly recognized as a contributing factor to ulcerative colitis (UC). The adhesive properties of F. nucleatum are mediated by its key virulence protein, FadA adhesin. However, further investigations are needed to understand the pathogenic mechanisms of this oral pathogen in UC. The present study aimed to explore the role of the FadA adhesin in the colonization and invasion of oral F. nucleatum in dextran sulphate sodium (DSS)-induced colitis mice via molecular techniques. In this study, we found that oral inoculation of F. nucleatum strain carrying the FadA adhesin further exacerbated DSS-induced colitis, leading to elevated alveolar bone loss, disease severity, and mortality. Additionally, CDH1 gene knockout mice treated with DSS presented increases in body weight and alveolar bone density, as well as a reduction in disease severity. Furthermore, FadA adhesin adhered to its mucosal receptor E-cadherin, leading to the phosphorylation of β-catenin and the degradation of IκBα, the activation of the NF-κB signalling pathway and the upregulation of downstream cytokines. In conclusion, this research revealed that oral inoculation with F. nucleatum facilitates experimental colitis via the secretion of the virulence adhesin FadA. Targeting the oral pathogen F. nucleatum and its virulence factor FadA may represent a promising therapeutic approach for a portion of UC patients.

Mesaconate from Bacillus subtilis R0179 Supernatant Attenuates Periodontitis by Inhibiting Porphyromonas gingivalis in Mice

AIMS

This research sought to assess the efficacy of Bacillus subtilis (B. subtilis) R0179 and explore potential metabolites in mitigating experimental periodontitis in mice induced by Porphyromonas gingivalis (P. gingivalis) ATCC 33277.

METHODS

B. subtilis R0179 was administered to 8-week-old male C57BL/6J mice with periodontitis. Oral load of P. gingivalis ATCC 33277 and periodontal tissue loss were quantified. The cell-free supernatant (CFS) was separated to assess its anti-P. gingivalis effect. Proteomic and metabolomic analyses identified potential antibacterial components in the CFS, further evaluated for anti-P. gingivalis effects.

RESULTS

B. subtilis R0179 significantly reduced P. gingivalis ATCC 33277 levels and mitigated periodontal tissue loss in mice. The CFS, rather than inactivated B. subtilis R0179 cells, exhibited antibacterial activity. Proteomic and metabolomic analyses identified mesaconate and citraconate as key antibacterial agents. Disk diffusion assays confirmed the efficacy of mesaconate against P. gingivalis, while citraconate had no effect. Mesaconate showed a dose-dependent reduction in P. gingivalis ATCC 33277 population and periodontal tissue loss in mice.

CONCLUSION

These findings highlight B. subtilis R0179 and its metabolite mesaconate as promising candidates for therapeutic development against periodontitis by inhibiting P. gingivalis ATCC 33277 effectively.

Fusobacterium Nucleatum Aggravates Intestinal Barrier Impairment and Colitis Through IL-8 Induced Neutrophil Chemotaxis by Activating Epithelial Cells

Background

Inflammatory bowel disease (IBD) is affected by interactions between intestinal microbial factors, abnormal inflammation, and an impaired intestinal mucosal barrier. Neutrophils (NE) are key players in IBD. Fusobacterium nucleatum (F. nucleatum) is reported to contribute to IBD progression. However, the relationship between F. nucleatum, abnormal inflammation, and intestinal barrier impairment should be interpreted to understand the role of F. nucleatum in IBD.

Methods

Dextran sulfate sodium (DSS)-induced colitis model was established and mice were orally administered with F. nucleatum. F. nucleatum colonization was confirmed by fluorescence in situ hybridization (FISH) and PCR. Intestinal barrier impairment was investigated by tight junction protein expression. Immuno-histochemistry (IHC) for Ly6G and flow cytometry detection to measure NE chemotaxis in mouse colon tissues. Caco-2 monolayers were used to evaluate epithelial integrity and permeability in vitro. A transwell model involving caco-2 cells and NE co-culture was used to assess NE chemotaxis. NE chemokines were measured by ELISA. A mouse model of NE exhaustion using an anti-Ly6G antibody was used to identify the role of NEs in F. nucleatum-induced colitis. Transcriptome sequencing and bioinformatics analysis were applied to screen cytokines and signaling pathways.

Results

Administration of F. nucleatum aggravated colitis in the DSS model. F. nucleatum infection downregulates ZO-1 and Occludin expression and increases intestinal permeability. Additionally, F. nucleatum-induced NE chemotaxis decreases the integrity and permeability of the caco-2 monolayer. F. nucleatum-induced NE chemotaxis is dependent on IEC-derived interleukin 8 (IL-8) secretion, mediated by the TLR2/ERK signaling pathway. In addition, NE exhaustion in mice inhibited F. nucleatum-induced intestinal barrier impairment and colitis.

Conclusion

F. nucleatum improves NE chemotaxis by infecting intestinal epithelial cells (IECs) to secrete IL-8 and aggravate intestinal barrier impairment, contributing to the progression of intestinal inflammation. Examining and eliminating F. nucleatum could be a valuable microbiome-based method for IBD surveillance and prevention.

The interplay between microbiome and host factors in pathogenesis and therapy of head and neck cancer

Heterogeneous cancers that lack strong driver mutations with high penetrance, such as head and neck squamous cell carcinoma (HNSCC), present unique challenges to understanding their aetiology due to the complex interactions between genetics and environmental factors. The interplay between lifestyle factors (such as poor oral hygiene, smoking, or alcohol consumption), the oral and gut microbiome, and host genetics appears particularly important in the context of HNSCC. The complex interplay between the gut microbiota and cancer treatment outcomes has also received increasing attention in recent years. This review article describes the bidirectional communication between the host and the oral/gut microbiome, focusing on microbiome-derived metabolites and their impact on systemic immune responses and the modulation of the tumour microenvironment. In addition, we review the role of host lifestyle factors in shaping the composition of the oral/gut microbiota and its impact on cancer progression and therapy. Overall, this review highlights the rationality of considering the oral/gut microbiota as a critical determinant of cancer therapy outcomes and points to therapeutic opportunities offered by targeting the oral/gut microbiota in the management of HNSCC.

Oral Pathobiont-Derived Outer Membrane Vesicles in the Oral-Gut Axis

Oral pathobionts are essential in instigating local inflammation within the oral cavity and contribute to the pathogenesis of diseases in the gastrointestinal tract and other distant organs. Among the Gram-negative pathobionts, Porphyromonas gingivalis and Fusobacterium nucleatum emerge as critical drivers of periodontitis, exerting their influence not only locally but also as inducers of gut dysbiosis, intestinal disturbances, and systemic ailments. This dual impact is facilitated by their ectopic colonization of the intestinal mucosa and the subsequent mediation of distal systemic effects by releasing outer membrane vesicles (OMVs) into circulation. This review elucidates the principal components of oral pathobiont-derived OMVs implicated in disease pathogenesis within the oral-gut axis, detailing virulence factors that OMVs carry and their interactions with host epithelial and immune cells, both in vitro and in vivo. Additionally, we shed light on the less acknowledged interplay between oral pathobionts and the gut commensal Akkermansia muciniphila, which can directly impede oral pathobionts' growth and modulate bacterial gene expression. Notably, OMVs derived from A. muciniphila emerge as promoters of anti-inflammatory effects within the gastrointestinal and distant tissues. Consequently, we explore the potential of A. muciniphila-derived OMVs to interact with oral pathobionts and prevent disease in the oral-gut axis.

ALDH2 alleviates inflammation and facilitates osteogenic differentiation of periodontal ligament stem cells in periodontitis by blocking ferroptosis via activating Nrf2

This paper elucidated the effects and mechanisms of aldehyde dehydrogenase 2 (ALDH2) on periodontitis. Rat model of periodontitis and periodontal ligament stem cell (PDLSC) model of periodontitis were constructed. PDLSC were transfected by ALDH2 overexpression vectors, and then treated by ML385 (Nrf2 inhibitor), ferrostatin-1 (ferroptosis inhibitor) and FIN56 (ferroptosis inducer), respectively. ALDH2, nuclear factor erythroid 2-related factor 2 (Nrf2) and glutathione peroxidase 4 (GPX4) proteins was evaluated by immunohistochemistry and Western blot. Ferroptosis-related factors, including Fe2+ and glutathione (GSH), were assessed by commercial kits. Pro-inflammatory factors (interleukin-6 [IL-6] and tumor necrosis factor-α [TNF-α]) and osteogenic differentiation-related proteins (osteocalcin [OCN] and runt-related transcription factor 2 [RUNX2]) were scrutinized by commercial kits and Western blot. In both periodontal tissues of periodontitis rats and PDLSC model of periodontitis, down-regulated ALDH2, Nrf2, GPX4 and GSH, but elevated Fe2+ level was discovered. ALDH2 overexpression in PDLSC resulted in an increase in Nrf2 expression. In PDLSC model of periodontitis, ALDH2 increased GPX4 and GSH levels, decreased Fe2+, IL-6 and TNF-α levels, and elevated OCN and RUNX2 expression. However, these effects of ALDH2 were counteracted by ML385. Additionally, the suppression of ALDH2 on IL-6 and TNF-α levels and promotion of it on OCN and RUNX2 expression in PDLSC model of periodontitis was further intensified by ferrostatin-1, but reversed by FIN56. ALDH2 may alleviate inflammation and facilitate osteogenic differentiation of PDLSC in periodontitis by hindering ferroptosis via activating Nrf2, suggesting it to be a promising candidate for treating periodontitis.

Lacticaseibacillus rhamnosus inhibits the development of dental caries in rat caries model and in vitro

OBJECTIVES

Dental caries result from a microbial imbalance in the oral cavity. Probiotics ecologically modulate the oral microflora to prevent caries. This study evaluated the anti-cariogenic effects of two Lacticaseibacillus rhamnosus strains in vitro and in vivo to provide a more theoretical basis for its clinical applications in caries prevention.

METHODS

In the study, cariogenic biofilms were grown with L. rhamnosus (LGG) or L. rhamnosus ATCC 7469 and analyzed. Quantitative real-time PCR (qPCR), Scanning Electron Microscope (SEM), and Confocal laser scanning microscope (CLSM) were used to detect the changes in the composition and architectures; cariogenic activity was measured by the lactic acid production and Transverse Microradiography (TMR). The effects of LGG on the 12 Sprague-Dawley rat caries model were assessed using Keyes scores and micro-CT analysis. Oral microbiome changes were evaluated through 16S rRNA gene high-throughput sequencing.

RESULTS

L. rhamnosus can reduce cariogenic bacteria in biofilm by 14.7 % to 48.9 %, with LGG exhibiting more potent inhibitory effects. Both strains of L. rhamnosus can adhere to the surface of biofilms, reduce the extracellular polysaccharides (EPS) matrix, and loosen the biofilm structure. L. rhamnosus inhibited cariogenic activity by reducing the lactic acid production in biofilms. The bovine enamel blocks presented lower mineral loss values and lesion depth values in the group Core+L.rh and Core+LGG. LGG-ingested rats had significantly lower levels of moderate dentin lesions and higher mineral density than the control group. The 16 s rRNA gene sequencing revealed that LGG regulated the beta diversity of the oral microbial community in the rat dental caries model.

CONCLUSIONS

This study revealed the promising potential of L. rhamnosus, especially the LGG strain, in the ecological prevention of dental caries.

CLINICAL SIGNIFICANCE

Probiotics may provide a strategy for preventing caries by regulating the oral microecological balance. The study revealed the promising anti-caries potential of the LGG probiotic strain in vivo and in vitro. It is expected that LGG could be used as an oral probiotic for the clinical prevention and treatment of caries.

The comprehensive evaluation of oral and fecal microbiota in patients with acromegaly

PURPOSE

The alteration of the microbiota in the mouth and gut could potentially play a role in the pathogenesis of various diseases, and conversely, these diseases may have an influence on the composition of the gut microbiota. Acromegaly disease can potentially affect physiological processes in the mouth and gut. The present study was designed to investigate the relationship between acromegaly and the oral and gut microbiota, as data on this topic are scarce.

METHODS

This was a multicenter, cross-sectional study. Our study included individuals diagnosed with acromegaly (who were treated and followed up, and also as an another group of patients with newly diagnosed acromegaly) and healthy participants. All three groups were assessed and compared based on age, sex, serum IGF-1, body mass index BMI as well as their stool and oral microbiota We collected demographic information from the patients, collected fecal and oral samples, performed DNA isolation followed by 16 S rRNA sequencing, and then performed bioinformatic analysis. We also analyzed the oral and fecal samples with respect to medical and surgical treatment and disease control status, specific treatments received for acromegaly, presence of comorbidities, hypopituitarism status, presence of intestinal polyps.

RESULTS

One hundred and three patients with acromegaly, 15 newly diagnosed patients with acromegaly without comorbidities and 34 healthy controls were included in the study. The Firmicutes/Bacteroidetes ratio was significantly lower in patients with acromegaly who received treatment (medical and/or surgical) than in healthy controls. In addition, a significant difference was found in the fecal and oral microbiota of patients with acromegaly with disease control compared to healthy controls. Furthermore, a significant difference was found in the fecal and oral microbiota of patients with acromegaly without disease control. Nevertheless, it was not possible to establish a clear relationship between disease control status, the presence of intestinal polyps, the presence of type 2 diabetes and the composition of the oral and gut microbiota in acromegalic patients who had received different forms of treatment.

CONCLUSION

Patients with acromegaly show distinct gut microbiota profiles, and it is evident that factors beyond the GH/IGF-1 axis play a role in shaping the gut microbiota of individuals with acromegaly.

Akkermansia muciniphila as a Potential Guardian against Oral Health Diseases: A Narrative Review

The oral microbiome is a diverse ecosystem containing a community of symbiotic, commensal, and pathogenic microorganisms. One key microorganism linked to periodontal disease (PD) is Porphyromonas gingivalis (P. gingivalis), a Gram-negative anaerobic bacterium known to have several virulence factors that trigger inflammation and immune evasion. On the other hand, Akkermansia muciniphila (A. muciniphila), a symbiotic bacterium, has been recently shown to play an important role in mitigating inflammation and reducing periodontal damage. In vivo and in vitro studies have shown that A. muciniphila decreases inflammatory mediators and improves immune responses, suggesting its role in mitigating PD and related inflammatory systemic conditions such as diabetes, hypertension, and obesity. This review discusses the anti-inflammatory effects of A. muciniphila, its impact on periodontal health, and its potential role in managing systemic diseases. The overall aim is to elucidate how this bacterium might help reduce inflammation, improve oral health, and influence broader health outcomes.

Targeted elimination of Fusobacterium nucleatum alleviates periodontitis

Background

Fusobacterium nucleatum, a pathobiont in periodontal disease, contributes to alveolar bone destruction. We assessed the efficacy of a new targeted antimicrobial, FP-100, in eradicating F. nucleatum from the oral microbial community in vitro and in vivo and evaluated its effectiveness in reducing bone loss in a mouse periodontitis model.

Methods

A multispecies bacterial community was cultured and treated with two concentrations of FP-100 over two days. Microbial profiles were examined at 24-h intervals using 16S rRNA sequencing. A ligature-induced periodontitis mouse model was employed to test FP-100 in vivo.

Results

FP-100 significantly reduced Fusobacterium spp. within the in vitro community (p < 0.05) without altering microbial diversity at a 2 μM concentration. In mice, cultivable F. nucleatum was undetectable in FP-100-treated ligatures but persistent in controls. Beta diversity plots showed distinct microbial structures between treated and control mice. Alveolar bone loss was significantly reduced in the FP-100 group (p = 0.018), with concurrent decreases in gingival IL-1β and TNF-α expression (p = 0.052 and 0.018, respectively).

Conclusion

FP-100 effectively eliminates F. nucleatum from oral microbiota and significantly reduces bone loss in a mouse periodontitis model, demonstrating its potential as a targeted therapeutic agent for periodontal disease.

Effect of Nitrogen Doping on the Photocatalytic Properties and Antibiofilm Efficacy of Reduced TiO2 Nanoparticles

Nanomaterial-mediated antibacterial photodynamic therapy (aPDT) emerges as a promising treatment against antibiotic-resistant bacterial biofilms. Specifically, titanium dioxide nanoparticles (TiO2 NPs) are being investigated as photosensitizers in aPDT to address biofilm related diseases. To enhance their photocatalytic performance in the visible spectral range for biomedical applications, various strategies have been adopted, including reduction of TiO2 NPs. However, despite improvements in visible-light photoactivity, reduced TiO2 NPs have yet to reach their expected performance primarily due to the instability of oxygen vacancies and their tendency to reoxidize easily. To address this, we present a two-step approach to fabricate highly visible-light active and stable TiO2 NP photocatalysts, involving nitrogen doping followed by a magnesium-assisted reductive annealing process. X-ray photoelectron spectroscopy analysis of the synthesized reduced nitrogen-doped TiO2 NPs (H:Mg-N-TiO2 NPs) reveals that the presence of nitrogen stabilizes oxygen vacancies and reduced Ti species, leading to increased production of reactive oxygen species under visible-light excitation. The improved aPDT efficiency translates to a 3-fold enhancement in the antibiofilm activity of nitrogen-doped compared to undoped reduced TiO2 NPs against both Gram-positive (Streptococcus mutans) and Gram-negative (Porphyromonas gingivalis, Fusobacterium nucleatum) oral pathogens. These results underscore the potential of H:Mg-N-TiO2 NPs in aPDT for combating bacterial biofilms effectively.

Advances in biomaterials for oral-maxillofacial bone regeneration: spotlight on periodontal and alveolar bone strategies

The intricate nature of oral-maxillofacial structure and function, coupled with the dynamic oral bacterial environment, presents formidable obstacles in addressing the repair and regeneration of oral-maxillofacial bone defects. Numerous characteristics should be noticed in oral-maxillofacial bone repair, such as irregular morphology of bone defects, homeostasis between hosts and microorganisms in the oral cavity and complex periodontal structures that facilitate epithelial ingrowth. Therefore, oral-maxillofacial bone repair necessitates restoration materials that adhere to stringent and specific demands. This review starts with exploring these particular requirements by introducing the particular characteristics of oral-maxillofacial bones and then summarizes the classifications of current bone repair materials in respect of composition and structure. Additionally, we discuss the modifications in current bone repair materials including improving mechanical properties, optimizing surface topography and pore structure and adding bioactive components such as elements, compounds, cells and their derivatives. Ultimately, we organize a range of potential optimization strategies and future perspectives for enhancing oral-maxillofacial bone repair materials, including physical environment manipulation, oral microbial homeostasis modulation, osteo-immune regulation, smart stimuli-responsive strategies and multifaceted approach for poly-pathic treatment, in the hope of providing some insights for researchers in this field. In summary, this review analyzes the complex demands of oral-maxillofacial bone repair, especially for periodontal and alveolar bone, concludes multifaceted strategies for corresponding biomaterials and aims to inspire future research in the pursuit of more effective treatment outcomes.

Application of Fusobacterium nucleatum as a biomarker in gastrointestinal malignancies

The morbidity and mortality of gastrointestinal (GI) malignancies are among the highest in the world, posing a serious threat to human health. Because of the insidious onset of the cancer, it is difficult for patients to be diagnosed at an early stage, and it rapidly progresses to an advanced stage, resulting in poor treatment and prognosis. Fusobacterium nucleatum (F. nucleatum) is a gram-negative, spore-free anaerobic bacterium that primarily colonizes the oral cavity and is implicated in the development of colorectal, esophageal, gastric, and pancreatic cancers via various intricate mechanisms. Recent development in novel research suggests that F. nucleatum may function as a biomarker in GI malignancies. Detecting the abundance of F. nucleatum in stool, saliva, and serum samples of patients may aid in the diagnosis, risk assessment, and prognosis monitoring of GI malignancies. This editorial systematically describes the biological roles and mechanisms of F. nucleatum in GI malignancies focusing on the application of F. nucleatum as a biomarker in the diagnosis and prognosis of GI malignancies to promote the clinical translation of F. nucleatum and GI tumors-related research.

Preventive and Therapeutic Potential of Streptococcus cristatus CA119 in Experimental Periodontitis in Rats

Periodontitis is an inflammatory condition of the oral cavity caused by a mixed infection of various bacteria, which not only severely affects the alveolar bone and connective tissues but also displays potential correlations with distal intestinal inflammation. In this study, we aimed to elucidate the therapeutic effects of Streptococcus cristatus CA119 on experimental periodontitis in rats and its impact on intestinal morphology. The results demonstrate that CA119 is capable of colonizing the oral cavity and exerting antagonistic effects on Porphyromonas gingivalis and Fusobacterium nucleatum, thus leading to a significant reduction in the oral pathogen load. Following CA119 intervention, there was a significant alleviation of weight loss in rats induced by periodontitis (P < 0.001). CA119 also regulated the expression of IL-6 (P < 0.05), IL-1β (P < 0.001), IL-18 (P < 0.001), COX-2 (P < 0.001), iNOS (P < 0.001), and MCP-1 (P < 0.01) in the gingival tissue. Additionally, CA119 reduced oxidative stress levels in rats and enhanced their antioxidant capacity. Microcomputed tomography (micro-CT) and histological analysis revealed that CA119 significantly reduced alveolar bone loss and reversed the downregulation of OPG/RANKL (P < 0.001). Furthermore, CA119 exhibited a significant protective effect against intestinal inflammation induced by periodontal disease and improved the colonic morphology in rats. In conclusion, this study demonstrates the role of CA119 as a potential oral probiotic in the prevention and treatment of experimental periodontitis, underscoring the potential of probiotics as a complementary approach to traditional periodontal care.

Function and therapeutic prospects of next-generation probiotic Akkermansia muciniphila in infectious diseases

Akkermansia muciniphila is a gram-negative bacterium that colonizes the human gut, making up 3-5% of the human microbiome. A. muciniphila is a promising next-generation probiotic with clinical application prospects. Emerging studies have reported various beneficial effects of A. muciniphila including anti-cancer, delaying aging, reducing inflammation, improving immune function, regulating nervous system function, whereas knowledge on its roles and mechanism in infectious disease is currently unclear. In this review, we summarized the basic characteristics, genome and phenotype diversity, the influence of A. muciniphila and its derived components on infectious diseases, such as sepsis, virus infection, enteric infection, periodontitis and foodborne pathogen induced infections. We also provided updates on mechanisms how A. muciniphila protects intestinal barrier integrity and modulate host immune response. In summary, we believe that A. muciniphila is a promising therapeutic probiotic that may be applied for the treatment of a variety of infectious diseases.

Akkermansia in the gastrointestinal tract as a modifier of human health

Akkermansia sp are common members of the human gut microbiota. Multiple reports have emerged linking the abundance of A. muciniphila to health benefits and disease risk in humans and animals. This review highlights findings linking Akkermansia species in the gastrointestinal (GI) tract to health outcomes across a spectrum of disorders, encompassing those that affect the digestive, respiratory, urinary, and central nervous systems. The mechanism through which Akkermansia exerts a beneficial versus a detrimental effect on health is likely dependent on the genetic makeup of the host metabolic capacity and immunomodulatory properties of the strain, the competition or cooperation with other members of the host microbiota, as well as synergy with co-administered therapies.

Reexamining the role of Fusobacterium nucleatum subspecies in clinical and experimental studies

The Gram-negative anaerobic species Fusobacterium nucleatum was originally described as a commensal organism from the human oral microbiome. However, it is now widely recognized as a key inflammophilic pathobiont associated with a wide variety of oral and extraoral diseases. Historically, F. nucleatum has been classified into four subspecies that have been generally considered as functionally interchangeable in their pathogenic potential. Recent studies have challenged this notion, as clinical data reveal a highly biased distribution of F. nucleatum subspecies within disease sites of both inflammatory oral diseases and various malignancies. This review details the historical basis for the F. nucleatum subspecies designations and summarizes our current understanding of the similarities and distinctions between these organisms to provide important context for future clinical and laboratory studies of F. nucleatum.