Oral spirochetes: Pathogenic mechanisms in periodontal disease

Effect of Dietary Composite Probiotic Supplementation on the Microbiota of Different Oral Sites in Cats

Probiotics demonstrated effectiveness in modulating oral microbiota and improving oral health in humans and rodents. However, its effects and applications on the oral microbiota of cats remain underexplored. Twelve healthy cats were randomly assigned to a control group (CON) and a composite probiotic group (CPG) for a 42-day trial. The CPG diet included additional supplementation of Bifidobacterium animalis subsp. lactis HN019, Lactobacillus acidophilus NCFM, and Lactobacillus casei LC-11, each at approximately 1 × 1010 CFU/kg. On days 0 and 42, microbial samples were collected from the gingiva, tooth surfaces, and tongue of all cats for 16S rRNA gene sequencing. Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla across all oral sites. The CPG treatment enriched seven genera, such as Moraxella, Actinomyces, and Frederiksenia in the gingiva. Meanwhile, Bergeyella and Streptococcus were enriched on the tooth surfaces, while Bergeyella, Flavobacterium, and Luteimonas were enriched on the tongue. Furthermore, the composite probiotic effectively suppressed eight genera, such as Bacteroides, Desulfovibrio, and Filifactor in the gingiva of CPG cats, as well as Helcococcus, Lentimicrobium, and Campylobacter on tooth surfaces, and Porphyromonas, Treponema, and Fusibacter on the tongue. These findings suggest that the composite probiotic used in this study modulates the feline oral microbiota by supporting beneficial or commensal bacteria and inhibiting oral pathogens, demonstrating potential to improve oral health in cats.

First Exploration of the Altered Microbial Gut-Lung Axis in the Pathogenesis of Human Refractory Chronic Cough

PURPOSE

Cough represents a natural mechanism that plays an important defensive role in the respiratory tract, but in some conditions, it may become persistent, nonproductive, and harmful. In general, refractory chronic cough (RCC) occurs in about 20% of individuals; hence, we aimed to assess the presence of altered gut-lung communication in RCC patients through a compositional and functional characterization of both gut (GM) and oral microbiota (OM).

METHODS

16S rRNA sequencing was used to characterize both GM and OM composition of RCC patients and healthy controls (HC). PICRUST2 assessed functional changes in microbial communities while gas chromatography was used to evaluate fecal short-chain fatty acid levels and serum-free fatty acid (FFA) abundances.

RESULTS

In comparison with HC, RCC patients reported increased saliva alpha-diversity and statistically significant beta-diversity in both GM and OM. Also, a, respectively, significant increased or reduced Firmicutes/Bacteroidota ratio in stool and saliva samples of RCC patients has been shown, in addition to a modification of the abundances of several taxa in both GM and OM. Moreover, a potential fecal over-expression of lipopolysaccharide biosynthesis and lipoic acid metabolism pathways and several differences in serum FFA levels have been reported in RCC patients than in HC.

CONCLUSION

Since differences in both GM and OM of RCC patients have been documented, these findings could provide new information about RCC pathogenesis and also pave the way for the development of novel nutritional or pharmacological interventions for the management of RCC through the restoration of eubiotic gut-lung communication.

Shotgun metagenomic analysis of the oral microbiome in gingivitis: a nested case-control study

Background

Gingivitis, i.e. inflammation of the gums, is often induced by dentalplaque. However, its exact link to the oral microbiota remains unclear.

Methods

In a case-control study involving 120 participants, comprising 60 cases and 60 controls (mean age (SD) 36.6 (7.6) years; 50% males), nested within a prospective multicentre cohort study, we examined theoral microbiome composition of gingivitis patients and their controlsusing shotgun metagenomic sequencing of saliva samples. Participants underwent clinical and radiographic oral health examinations, including bleeding on probing (BOP), at six tooth sites. BOP ≥33%was considered 'generalized gingivitis/initial periodontitis'(GG/IP), and BOP <33% as 'healthy and localized gingivitis'(H/LG). Functional potential was inferred using HUMANn3.

Results

GG/IP exhibited an increase in the abundance of Actinomyces, Porphyromonas, Aggregatibacter, Corynebacterium, Olsenella, and Treponema, whereas H/LG exhibited an increased abundance of Candidatus Nanosynbacter. Nineteen bacterial species and fourmicrobial functional profiles, including L-methionine, glycogen, andinosine-5'-phosphate biosynthesis, were associated with GG/IP. Constructing models with multiple markers resulted in a strong predictive value for GG/IP, with an area under the curve (ROC) of 0.907 (95% CI: 0.848-0.966).

Conclusion

We observed distinct differences in the oral microbiome between the GG/IP and H/LG groups, indicating similar yet unique microbial profiles and emphasizing their potential role in progression of periodontal diseases.

Triptolide mitigates the inhibition of osteogenesis induced by TNF-α in human periodontal ligament stem cells via the p-IκBα/NF-κB signaling pathway: an in-vitro study

BACKGROUND

Triptolide is a widely utilized natural anti-inflammatory drug in clinical practice. Aim of this study was to evaluate effects of triptolide on hPDLSCs osteogenesis in an inflammatory setting and to investigate underlying mechanisms.

METHODS

Using the tissue block method to obtain hPDLSCs from extracted premolar or third molar. Flow cytometry, osteogenic and adipogenic induction were carried out in order to characterise the features of the cells acquired. hPDLSC proliferative activity was assessed by CCK-8 assay to determine the effect of TNF-α and/or triptolide. The impact of triptolide on the osteogenic differentiation of hPDLSCs was investigated by ALP staining and quantification. Osteogenesis-associated genes and proteins expression level were assessed through PCR and Western blotting assay. Finally, BAY-117,082 was used to study the NF-κB pathway.

RESULTS

In the group treated with TNF-α, there was an elevation in inflammation levels while osteogenic ability and the expression of both osteogenesis-associated genes and proteins decreased. In the group co-treated with TNF-α and triptolide, inflammation levels were reduced and osteogenic ability as well as the expression of both osteogenesis-associated genes and proteins were enhanced. At the end of the experiment, both triptolide and BAY-117,082 exerted similar inhibitory effects on the NF-κB pathway.

CONCLUSION

The osteogenic inhibition of hPDLSCs by TNF-α can be alleviated through triptolide, with the involvement of the p-IκBα/NF-κB pathway in this mechanism.

Lysinoalanine cross-linking is a conserved post-translational modification in the spirochete flagellar hook

Spirochetes cause Lyme disease, leptospirosis, syphilis, and several other human illnesses. Unlike other bacteria, spirochete flagella are enclosed within the periplasmic space where the filaments distort and push the cell body by the action of the flagellar motors. We previously demonstrated that the oral pathogen Treponema denticola (Td) and Lyme disease pathogen Borreliella burgdorferi (Bb) form covalent lysinoalanine (Lal) cross-links between conserved cysteine and lysine residues of the FlgE protein that composes the flagellar hook. In Td, Lal is unnecessary for hook assembly but is required for motility, presumably due to the stabilizing effect of the cross-link. Herein, we extend these findings to other, representative spirochete species across the phylum. We confirm the presence of Lal cross-linked peptides in recombinant and in vivo-derived samples from Treponema spp., Borreliella spp., Brachyspira spp., and Leptospira spp. As was observed with Td, a mutant strain of Bb unable to form the cross-link has greatly impaired motility. FlgE from Leptospira spp. does not conserve the Lal-forming cysteine residue which is instead substituted by serine. Nevertheless, Leptospira interrogans FlgE also forms Lal, with several different Lal isoforms being detected between Ser-179 and Lys-145, Lys-148, and Lys-166, thereby highlighting species or order-specific differences within the phylum. Our data reveal that the Lal cross-link is a conserved and necessary posttranslational modification across the spirochete phylum and may thus represent an effective target for the development of spirochete-specific antimicrobials.

DAMPs and alarmin gene expression patterns in aging healthy and diseased mucosal tissues

Introduction

Periodontitis is delineated by a dysbiotic microbiome at sites of lesions accompanied by a dysregulated persistent inflammatory response that undermines the integrity of the periodontium. The interplay of the altered microbial ecology and warning signals from host cells would be a critical feature for maintaining or re-establishing homeostasis in these tissues.

Methods

This study used a nonhuman primate model (Macaca mulatta) with naturally-occurring periodontitis (n = 34) and experimental ligature-induced periodontitis (n = 36) to describe the features of gene expression for an array of damage-associate molecular patterns (DAMPs) or alarmins within the gingival tissues. The animals were age stratified into: ≤3 years (Young), 7-12 years (Adolescent), 12-15 years (Adult) and 17-23 years (Aged). Gingival tissue biopsies were examined via microarray. The analysis focused on 51 genes representative of the DAMPs/alarmins family of host cell warning factors and 18 genes associated with tissue destructive processed in the gingival tissues. Bacterial plaque samples were collected by curette sampling and 16S rRNA gene sequences used to describe the oral microbiome.

Results

A subset of DAMPs/alarmins were expressed in healthy and naturally-occurring periodontitis tissues in the animals and suggested local effects on gingival tissues leading to altered levels of DAMPs/alarmins related to age and disease. Significant differences from adult healthy levels were most frequently observed in the young and adolescent animals with few representatives in this gene array altered in the healthy aged gingival tissues. Of the 51 target genes, only approximately ⅓ were altered by ≥1.5-fold in any of the age groups of animals during disease, with those increases observed during disease initiation. Distinctive positive and negative correlations were noted with the DAMP/alarmin gene levels and comparative expression changes of tissue destructive molecules during disease across the age groups. Finally, specific correlations of DAMP/alarmin genes and relative abundance of particular microbes were observed in health and resolution samples in younger animals, while increased correlations during disease in the older groups were noted.

Conclusions

Thus, using this human-like preclinical model of induced periodontitis, we demonstrated the dynamics of the activation of the DAMP/alarmin warning system in the gingival tissues that showed some specific differences based on age.

Influence of Gallic Acid-Containing Mouth Spray on Dental Health and Oral Microbiota of Healthy Dogs: A Pilot Study

The pilot study aimed to investigate the effects of GAMS on oral microbiota in healthy dog subjects. Thirty-eight dogs were recruited and randomly allocated to the placebo (n = 19) and treatment groups (n = 19). The dogs were treated with mouth spray once daily for 42 days. The changes in the gingival index (GI), plaque index (PI), and calculus index (CI) were measured at baseline (day 0) and end of the study (42nd day). The changes in the oral microbial composition of representative dogs (placebo, n = 7; and treatment, n = 7) were also evaluated at baseline and end of the study. Oral microbial composition was assessed by sequencing. The sequences were annotated using the QIIME 2.0^TM. The GI, PI, and CI indexes were reduced after the GAMS usage. The abundance of the commensal bacterial phylum Actinobacteria and Chloroflexi, genera Frederiksenia, and Bergeyella was improved after six weeks of GAMS usage. GAMS reduced the pathogenic bacterial species, including Neisseria sp., Desulfobulbus sp., Capnocytophaga canis, and Corynebacterium mustelae. Moreover, some pathogenic bacterial abundances were increased at the end of the study. All the microbial variations were observed within the group. The inter-group analysis revealed that the changes were unrelated to GAMS usage. Further studies need to be carried out using more experimental subjects to confirm the effectiveness of GAMS. More metagenomic data are required to evidence the GMAS impact on the oral microbiome of healthy dogs.

Lysinoalanine crosslinking is a conserved post-translational modification in the spirochete flagellar hook

Spirochete bacteria cause Lyme disease, leptospirosis, syphilis and several other human illnesses. Unlike other bacteria, spirochete flagella are enclosed within the periplasmic space where the filaments distort and push the cell body by action of the flagellar motors. We previously demonstrated that the oral pathogen Treponema denticola (Td) catalyzes the formation of covalent lysinoalanine (Lal) crosslinks between conserved cysteine and lysine residues of the FlgE protein that composes the flagellar hook. Although not necessary for hook assembly, Lal is required for motility of Td, presumably due to the stabilizing effect of the crosslink. Herein, we extend these findings to other, representative spirochete species across the phylum. We confirm the presence of Lal crosslinked peptides in recombinant and in vivo -derived samples from Treponema spp., Borreliella spp., Brachyspira spp., and Leptospira spp.. Like with Td, a mutant strain of the Lyme disease pathogen Borreliella burgdorferi unable to form the crosslink has impaired motility. FlgE from Leptospira spp. does not conserve the Lal-forming cysteine residue which is instead substituted by serine. Nevertheless, Leptospira interrogans also forms Lal, with several different Lal isoforms being detected between Ser-179 and Lys-145, Lys-148, and Lys-166, thereby highlighting species or order-specific differences within the phylum. Our data reveals that the Lal crosslink is a conserved and necessary post-translational modification across the spirochete phylum and may thus represent an effective target for spirochete-specific antimicrobials.

Significance Statement

The phylum Spirochaetota contains bacterial pathogens responsible for a variety of diseases, including Lyme disease, syphilis, periodontal disease, and leptospirosis. Motility of these pathogens is a major virulence factor that contributes to infectivity and host colonization. The oral pathogen Treponema denticola produces a post-translational modification (PTM) in the form of a lysinoalanine (Lal) crosslink between neighboring subunits of the flagellar hook protein FlgE. Herein, we demonstrate that representative spirochetes species across the phylum all form Lal in their flagellar hooks. T. denticola and B. burgdorferi cells incapable of forming the crosslink are non-motile, thereby establishing the general role of the Lal PTM in the unusual type of flagellar motility evolved by spirochetes.

Case report: Sarcocystis speeri, Aspergillus fumigatus, and novel Treponema sp. infections in an adult Atlantic spotted dolphin (Stenella frontalis)

A complete postmortem examination, including a computed tomography scan “virtopsy” (virtual necropsy), gross necropsy, cytology, histology, and molecular diagnostics were performed to investigate the cause of death of a deceased adult male Atlantic spotted dolphin (Stenella frontalis) that stranded on Pensacola Beach, Florida, USA in February 2020. Significant findings included chronic inflammation of the meninges, brain, and spinal cord with intralesional protozoa (identified as Sarcocystis speeri via 18S rRNA and ITS-1 sequences), suppurative fungal tracheitis and bronchopneumonia (identified as Aspergillus fumigatus via ITS-2 gene sequence) and ulcerative bacterial glossitis (associated with a novel Treponema species, Candidatus Treponema stenella, identified via 23S rRNA gene sequence). This is the first reported case of S. speeri in a marine mammal. Little is understood about the epidemiology of S. speeri, including the identity of its intermediate hosts. The findings of this case suggest that S. frontalis may be a capable aberrant host and experience morbidity and mortality from this parasite. It is suspected that the novel Treponema and Aspergillus fumigatus infections were opportunistic or secondary to immunosuppression, either due to S. speeri infection or other co-morbidities.

Association between salivary microbiota and renal function in renal transplant patients during the perioperative period

Introduction

Renal transplantation is an effective treatment for the end stage renal disease (ESRD). However, how salivary microbiota changes during perioperative period of renal transplant recipients (RTRs) has not been elucidated.

Methods

Five healthy controls and 11 RTRs who had good recovery were enrolled. Saliva samples were collected before surgery and at 1, 3, 7, and 14 days after surgery. 16S rRNA gene sequencing was performed.

Results

There was no significant difference in the composition of salivary microbiota between ESRD patients and healthy controls. The salivary microbiota of RTRs showed higher operational taxonomic units (OTUs) amount and greater alpha and beta diversity than those of ESRD patients and healthy controls, but gradually stabilized over time. At the phylum level, the relative abundance of Actinobacteria, Tenericutes and Spirochaetes was about ten times different from ESRD patients or healthy controls for RTRs overall in time. The relative abundance of Bacteroidetes, Fusobacteria, Patescibacteria, Leptotrichiaceae and Streptococcaceae was correlated with serum creatinine (Scr) after renal transplantation.

Discussion

In short, salivary microbiota community altered in the perioperative period of renal transplantation and certain species of salivary microbiota had the potential to be a biomarker of postoperative recovery.

Distribution characteristics of oral microbiota and its relationship with intestinal microbiota in patients with type 2 diabetes mellitus

Introduction

Type 2 diabetes mellitus (T2DM) has a high incidence rate globally, increasing the burden of death, disability, and the economy worldwide. Previous studies have found that the compositions of oral and intestinal microbiota changed respectively in T2DM; whether the changes were associated or interacted between the two sites and whether there were some associations between T2DM and the ectopic colonization of oral microbiota in the gut still need to be identified.

Research design and methods

We performed a cross-sectional observational study; 183 diabetes and 74 controls were enrolled. We used high-throughput sequencing technology to detect the V3-V4 region of 16S rRNA in oral and stool samples. The Source Tracker method was used to identify the proportion of the intestinal microbiota that ectopic colonized from the oral cavity.

Results

The oral marker bacteria of T2DM were found, such as Actinobacteria, Streptococcus, Rothia, and the intestinal marker bacteria were Bifidobacterium, Streptococcus, and Blautia at the genus level. Among them, Actinobacteria and Blautia played a vital role in different symbiotic relationships of oral and intestinal microbiota. The commonly distributed bacteria, such as Firmicutes, Bacteroidetes, and Actinobacteria, were found in both oral and intestine. Moreover, the relative abundance and composition of bacteria were different between the two sites. The glycine betaine degradation I pathway was the significantly up-regulated pathway in the oral and intestinal flora of T2DM. The main serum indexes related to oral and intestinal flora were inflammatory. The relative abundance of Proteobacteria in the intestine and the Spirochete in oral was positively correlated, and the correlation coefficient was the highest, was 0.240 (P<0.01). The proportion of ectopic colonization of oral flora in the gut of T2DM was 2.36%.

Conclusion

The dysbacteriosis exited in the oral and intestine simultaneously, and there were differences and connections in the flora composition at the two sites in T2DM. Ectopic colonization of oral flora in the intestine might relate to T2DM. Further, clarifying the oral-gut-transmitting bacteria can provide an essential reference for diagnosing and treating T2DM in the future.

Gastroesophageal reflux disease and oral symptoms: A two-sample Mendelian randomization study

Background: The association between Gastroesophageal reflux disease (GERD) and oral symptoms has been reported in observational studies, but the causality of GERD to oral symptoms remained unknown. We aimed to assess the causal effect of GERD on five oral symptoms (mouth ulcers, toothache, loose teeth, bleeding gums, and periodontitis) using the two-sample Mendelian randomization (MR) method. Methods: Summary-level statistics for GERD and five oral symptoms were obtained from large-scale genome-wide association studies. Rigorous quality control of genetic instruments was conducted before MR analysis. Several analytical methods, including the inverse-variance weighted (IVW) method, MR-Egger regression, weighted median, maximum likelihood, and robust adjusted profile score (RAPS) were utilized, and the results of IVW were taken as the main results. The MR-Egger intercept test, Cochran's Q test, and leave-one-out test were used as sensitivity analysis for quality control. Results: After Bonferroni, IVW detected a significant effect of GERD on mouth ulcers (OR = 1.008, 95% CI = 1.003-1.013, p = 0.003), loose teeth (OR = 1.009, 95% CI = 1.005-1.012, p = 9.20 × 10^-7), and periodontitis (OR = 1.229, 95% CI = 1.081-1.398, p = 0.002). Consistent patterns of associations were observed across several MR models and sensitivity analysis found little evidence of bias. Nominal significant associations were observed in toothache and bleeding gums (p < 0.05), and heterogeneity was detected. Conclusion: Our MR analyses supported the positive causal effect of GERD on oral symptoms, especially for mouth ulcers, loose teeth, and periodontitis. Our findings might shed light on the mechanism of oral disease and might imply that oral care should be enhanced in patients with GERD.

Comparing proteome changes involved in biofilm formation by Streptococcus mutans after exposure to sucrose and starch

Streptococcus mutans is a main organism of tooth infections including tooth decay and periodontitis. The aim of this study was to assess the influence of sucrose and starch on biofilm formation and proteome profile of S. mutans ATCC 35668 strain. The biofilm formation was assessed by microtiter plating method. Changes in bacterial proteins after exposure to sucrose and starch carbohydrates were analyzed using matrix-assisted laser desorption/ionization mass spectrometry. The biofilm formation of S. mutans was increased to 391.76% in 1% sucrose concentration, 165.76% in 1% starch, and 264.27% in the 0.5% sucrose plus 0.5% starch in comparison to biofilm formation in the media without sugars. The abundance of glutamines, adenylate kinase, and 50S ribosomal protein L29 was increased under exposure to sucrose. Upregulation of lactate utilization protein C, 5-hydroxybenzimidazole synthase BzaA, and 50S ribosomal protein L16 was formed under starch exposure. Ribosome-recycling factor, peptide chain release factor 1, and peptide methionine sulfoxide reductase MsrB were upregulated under exposure to sucrose in combination with starch. The results demonstrated that the carbohydrates increase microbial pathogenicity. In addition, sucrose and starch carbohydrates can induce biofilm formation of S. mutans via various mechanisms such as changes in the expression of special proteins.

Characteristics of oral microbiome of healthcare workers in different clinical scenarios: a cross-sectional analysis

The environment of healthcare institutes (HCIs) potentially affects the internal microecology of medical workers, which is reflected not only in the well-studied gut microbiome but also in the more susceptible oral microbiome. We conducted a prospective cross-sectional cohort study in four hospital departments in Central China. Oropharyngeal swabs from 65 healthcare workers were collected and analyzed using 16S rRNA gene amplicon sequencing. The oral microbiome of healthcare workers exhibited prominent deviations in diversity, microbial structure, and predicted function. The coronary care unit (CCU) samples exhibited robust features and stability, with significantly higher abundances of genera such as Haemophilus, Fusobacterium, and Streptococcus, and a lower abundance of Prevotella. Functional prediction analysis showed that vitamin, nucleotide, and amino acid metabolisms were significantly different among the four departments. The CCU group was at a potential risk of developing periodontal disease owing to the increased abundance of F. nucleatum. Additionally, oral microbial diversification of healthcare workers was related to seniority. We described the oral microbiome profile of healthcare workers in different clinical scenarios and demonstrated that community diversity, structure, and potential functions differed markedly among departments. Intense modulation of the oral microbiome of healthcare workers occurs because of their original departments, especially in the CCU.

The interplay between oral microbes and immune responses

Oral microbes play a critical role in maintaining oral homeostasis. Microbial dysbiosis promotes disease pathogenesis through several mechanisms. Recent studies have revealed that microbial imbalance and sustained inflammation are involved in disease progression. The adverse interaction triggered by a host immune response to microorganisms can lead to oral and systemic diseases. Here, we reviewed how oral microbes communicate with hosts during the development of local and distant inflammation. Elucidation of these processes may reveal future directions in this field and the potential targets of novel biological therapies for oral and systemic diseases.

The Characteristics of Microbiome and Cytokines in Healthy Implants and Peri-Implantitis of the Same Individuals

AIM

To characterize the profile of submucosal microbiome and cytokine levels in peri-implant crevicular fluid (PICF) from clinically healthy implants and peri-implantitis in the same individuals.

MATERIAL AND METHODS

A total of 170 patients were screened and, finally, 14 patients with at least one healthy implant and one peri-implantitis implant were included. Submucosal microbiota and cytokines from 28 implants were analyzed using 16S rRNA gene sequencing and multifactor assays, respectively. Correlations of clinical indexes and microbiota or cytokines were analyzed using Spearman's correlation coefficient. A random forest classification model was constructed.

RESULTS

Peri-implantitis sites harbored higher microbial diversity, as well as more Gram-negative bacteria and anaerobic bacteria, compared with healthy implants sites. The genera of Peptostreptococcaceae XIG-1, Treponema, Porphyromonas, and Lachnospiraceae G-8, as well as the cytokines of IL-17A, IL-6, IL-15, G-CSF, RANTES, and IL-1β were significantly higher in peri-implantitis than healthy implants. Furthermore, these genera and cytokines had positive relationships with clinical parameters, including probing depth (PD), bleeding on probing (BOP), and marginal bone loss (MBL). The classification model picked out the top 15 biomarkers, such as IL-17A, IL-6, IL-15, VEGF, IL-1β, Peptostreptococcaceae XIG-1, Haemophilus, and Treponema, and obtained an area under the curve (AUC) of 0.85.

CONCLUSIONS

There are more pathogenic bacteria and inflammatory cytokines in peri-implantitis sites, and biomarkers could facilitate the diagnosis of peri-implantitis.

Immune Responses Regulated by Key Periodontal Bacteria in Germ-Free Mice

The immune dysregulation induced by periodontal bacteria has important roles in the development of periodontitis. However, the role of key periodontal bacteria in local and systemic immunity has not been comprehensively studied. Herein, to explore immunoregulation maps of key periodontal bacteria, a mono-colonized germ-free mice model with P. gingivalis, F. nucleatum, and T. denticola for two weeks was designed in this study. The alveolar bone loss was determined by micro-CT. A total of 14 types of innate and adaptive immune cells of the gingiva, spleen, and colon were detected by multi-color flow cytometry. P. gingivalis induced the strongest innate immune response in gingiva and mononuclear phagocytes (MNPs) changed most significantly, compared to F. nucleatum and T. denticola. Immune dysregulation of the colon was widely induced by F. nucleatum. T. denticola mainly induced immune disorder in spleen. ILC3s, Tregs, CD11B+ dendritic cells s, MNPs, macrophages, and plasmacytoid dendritic cells were the main types in response to key periodontal bacteria. However, the alveolar bone loss was not induced by key periodontal bacteria. In conclusion, the overall immunoregulation of monomicrobial stimuli to decipher the complexities of periodontitis was provided in this study. P. gingivalis, F. nucleatum, and T. denticola have different effects on local and systemic immunity in gingiva, colon, and spleen of germ-free mice.

Gut microbiota in nonalcoholic fatty liver diseases with and without type-2 diabetes mellitus

BACKGROUND AND AIMS

The association between nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) is not very well described but gut microbiota composition is mentioned as a risk factor. The present study aimed to characterize the differences of dominant gut microbiota phyla among people with NAFLD as compared to T2DM and control groups.

PATIENTS AND METHODS

The major bacterial phylum of gut microbiota including Bacteroidetes, Firmicutes, Actinobacteria, Proteobacteria, and total bacteria of 15 NAFLD patients with T2DM, 15 NAFLD patients without T2DM, 15 patients with T2DM, and 20 healthy control subjects were assessed by a quantitative PCR (qPCR).

RESULTS

NAFLD patients with T2DM had significantly higher BMI, triglyceride level, and total cholesterol level were compared with controls (Pv < 0.05). Bacteroidetes and Firmicutes phyla were significantly low in NAFLD patients with T2DM (Firmicutes, 2.55 ± 2.25, Pv 0/0002 and Bacteroidetes, 1.55 ± 2.29, Pv 0/0007), while the content of Proteobacteria and Actinobacteria was high in NAFLD patients with T2DM group and there were no significant differences between phyla with NAFLD patients with T2DM group (Pv > 0.05). Furthermore, Firmicutes copy number was lower in the separate groups of NAFLD and T2DM as compared to the healthy controls (Pv < 0.05).

CONCLUSIONS

This study performed gut microbiota for the first time among NAFLD and TDM patients separately and together. This investigation indicated that NAFLD patients with T2DM have a different gut composition in comparison to NAFLD, T2DM alone, which could be associated with disease development.

Origin of symbiotic gut spirochetes as key players in the nutrition of termites

Termites harbour symbiotic spirochetes in their hindguts, which have long been considered treponemes, although they represent separate lines of descent from known species of Treponema. 'Termite gut treponemes' have a mutualistic relationship with the host termites with their physiological properties including CO₂ -reductive acetogenesis, from which the resulting acetate fulfils most of the respiratory requirement of the host. Song and co-workers showed that a spirochetal isolate (strain RmG30) from a Madeira cockroach represents the earliest branching lineage of extremely diverse termite (Treponema) cluster I and was a simple homolactic fermenter, suggesting that CO₂ -reductive acetogenesis exhibited by some members of termite cluster I originated via horizontal gene transfer. Phylogenomic and 16S rRNA sequence-based phylogenetic analyses indicated a deeply-branched sister clade containing termite cluster I was distinguishable as a family-level lineage. In this context, a new family, 'Termitinemataceae' has been proposed for this clade. Strain RmG30 has been designated as the type strain of Breznakiella homolactica gen. nov. sp. nov. named after John A. Breznak, an American microbiologist distinguished in termite gut microbiology. The study has posed important questions for the future, including the actual roles of the termite spirochetes in each termite lineage and the evolutionary process of their physiological properties.

Treatment challenges and delivery systems in immunomodulation and probiotic therapies for periodontitis

Introduction: Periodontitis is a widespread illness that arises due to disrupted interplay between the oral microbiota and the host immune response. In some cases, conventional therapies can provide temporary remission, although this is often followed by disease relapse. Recent studies of periodontitis pathology have promoted the development of new therapeutics to improve treatment options, together with local application using advanced drug delivery systems.Areas covered: This paper provides a critical review of the status of current treatment approaches to periodontitis, with a focus on promising immunomodulation and probiotic therapies. These are based on delivery of small molecules, peptides, proteins, DNA or RNA, and probiotics. The key findings on novel treatment strategies and formulation of advanced delivery systems, such as nanoparticles and nanofibers, are highlighted.Expert opinion: Multitarget therapy based on antimicrobial, immunomodulatory, and probiotic active ingredients incorporated into advanced delivery systems for application to the periodontal pocket can improve periodontitis treatment outcomes. Translation of such adjuvant therapy from laboratory to patient is expected in the future.

Local drug delivery systems as therapeutic strategies against periodontitis: A systematic review

Periodontitis is a chronic inflammation of the soft tissue surrounding and supporting the teeth, which causes periodontal structural damage, alveolar bone resorption, and even tooth loss. Its prevalence is very high, with nearly 60% of the global population affected. Hence, periodontitis is an important public health concern, and the development of effective healing treatments for oral diseases is a major target of the health sciences. Currently, the application of local drug delivery systems (LDDS) as an adjunctive therapy to scaling and root planning (SRP) in periodontitis is a promising strategy, giving higher efficacy and fewer side effects by controlling drug release. The cornerstone of successful periodontitis therapy is to select an appropriate bioactive agent and route of administration. In this context, this review highlights applications of LDDS with different properties in the treatment of periodontitis with or without systemic diseases, in order to reveal existing challenges and future research directions.

Measurement of the Level of Nitric Oxide in Exhaled Air in Patients Using Acrylic Complete Dentures and with Oral Pathologies

The measurement of nitric oxide (NO) in exhaled air is used in diagnostics and monitoring of the pathologies in the respiratory system but also in the oral cavity. Researchers have shown a huge increase of its level in asthma and diseases in the oral cavity. It seems reasonable to research the impact of pathologies in the oral cavity on the level of NO in exhaled air. The purpose of this study was to determine the impact of inflammation in the oral cavity (according to the material of dentures) on the level of nitric oxide in exhaled air. Three groups of patients were examined in this study. The hygiene of acrylic dentures, hard tissues, periodontal tissues, hygiene of the oral cavity, and level of NO in exhaled air were examined. Prosthetic stomatitis, denture plaque, tooth decay, poor sanitation and periodontitis increase levels of NO.

The critical role of Faecalibacterium prausnitzii in human health: An overview

Faecalibacterium prausnitzii (F. prausnitzii) is one of the most abundant bacterial species in the colon of healthy human adults and representing more than 5% of the total bacterial population. Recently, it has been known as a major actor in human intestinal health and a biosensor. Changes in this species population richness and quantity have been observed in many illnesses and several investigations have reported that abundance of F. prausnitzii is reduced in different intestinal disorders. In the current review, we aim to consider literature from various library databases and electronic searches (Science Direct, PubMed, and Google Scholar) which were randomly collected and serve as an overview of different features of F. prausnitzii including metabolites, anti-inflammatory action, and correlation of dysbiosis of this bacterium with various complications in human.