[Oral microbiota and liver]. / Microbiote buccal et foie.

The liver has many important biological functions for the body, as it is involved in the storage and distribution of nutrients (carbohydrates to glycogen, lipids to triglycerides), the digestion of fats, the synthesis of blood proteins, and the detoxification of alcohol and drugs. The liver can be affected by various diseases such as viral or drug-induced hepatitis, fibrosis and cirrhosis, in which damaged hepatocytes are progressively replaced by scar tissue.

Title: Microbiote buccal et foie. Abstract: Le foie possède de nombreuses fonctions biologiques importantes pour l'organisme. Il peut être atteint par diverses maladies, telles que les hépatites virales ou médicamenteuses, la fibrose et la cirrhose. Lors de ces affections, les hépatocytes endommagés sont progressivement remplacés par du tissu cicatriciel. Par ailleurs, une altération du microbiote oral peut être à l'origine d'une altération des réponses immunitaires et ainsi contribuer au développement d'une inflammation qui touchera également le foie. En effet, les personnes souffrant d'hémochromatose ou de stéatose hépatique non alcoolique présentent des anomalies importantes du microbiote oral. De même, des concentrations élevées de certaines bactéries colonisant la cavité buccale, telles que Porphyromonas gingivalis, sont associées à des facteurs de risque accrus de stéatose hépatique non alcoolique.

Tolerance to intraoral biofilms and their effectiveness in improving mouth dryness and modifying oral microbiota in patients with primary Sjögren's syndrome: "Predelfi study".

Introduction: Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by exocrine gland dysfunction. No therapeutic strategy is sufficient on its own for the management of dry mouth and therapeutic innovations are required. Methods: This Predelfi study was a single-center, prospective, comparative, randomized, double-blind, cross-over controlled study with the primary objective of assessing the tolerance to and effectiveness of two adhesive biofilms (containing prebiotics and, sodium alginate, respectively) in patients with pSS and hyposialia (#NCT04206826 in ClinicalTrials.gov). Secondary objectives were to obtain initial data regarding the clinical effectiveness of such biofilms in the improvement of signs and symptoms related to dry mouth and potential changes in the oral microbiota. Ten pSS patients with pSS were included (9 females and 1 male) with a mean age of 58.1 ± 14.0 years. Results and discussion: Tolerance to the prebiotic and sodium alginate biofilms was assessed by the patients (visual analog scale [VAS] score 66.7 and 87.6, respectively) and the practitioner (90 and 100, respectively). The absolute changes in the VAS scores at the start and end of each treatment period highlighted an improvement in mouth dryness for the sodium alginate versus the prebiotic biofilm. The VAS scores for other parameters (mouth burning sensation; taste alteration; chewing; swallowing and speech difficulties) remained globally comparable between the two groups. Unstimulated salivary flow showed no changes regardless of the biofilm used. Regarding the oral microbiota, the sodium alginate biofilm increased the abundance of the Treponema genus, whereas the use of the prebiotic biofilm as the first treatment increased the abundance of the genera Veillonella and Prevotella. Nevertheless, the prebiotic biofilm appeared to stimulate "milder" genera with regard to periodontal infections. Furthermore, pre-treatment with the prebiotic biofilm prevented the emergence of the Treponema genus induced by subsequent treatment with the sodium alginate biofilm, suggesting a potential protective effect.

Prenatal exposure to persistent organic pollutants and molar-incisor hypomineralization among 12-year-old children in the French mother-child cohort PELAGIE.

BACKGROUND: Exceptional episodes of exposure to high levels of persistent organic pollutants have already been associated with developmental defects of enamel among children, but knowledge is still scarce concerning the contribution of background levels of environmental contamination. METHODS: Children of the French PELAGIE mother-child cohort were followed from birth, with collection of medical data and cord blood samples that were used to measure polychlorinated biphenyls (PCBs), organochlorine pesticides (OCs), and perfluorinated alkyl substances (PFASs). At 12 years of age, molar-incisor hypomineralization (MIH) and other enamel defects (EDs) were recorded for 498 children. Associations were studied using logistic regression models adjusted for potential prenatal confounders. RESULTS: An increasing log-concentration of ß-HCH was associated with a reduced risk of MIH and EDs (OR = 0.55; 95% CI, 0.32-0.95, and OR = 0.65; 95% CI, 0.43-0.98, respectively). Among girls, intermediate levels of p,p'-DDE were associated with a reduced risk of MIH. Among boys, we observed an increased risk of EDs in association with intermediate levels of PCB 138, PCB 153, PCB 187, and an increased risk of MIH with intermediate levels of PFOA and PFOS. CONCLUSIONS: Two OCs were associated with a reduced risk of dental defects, whereas the associations between PCBs and PFASs and EDs or MIH were generally close to null or sex-specific, with an increased risk of dental defects in boys. These results suggest that POPs could impact amelogenesis. Replication of this study is required and the possible underlying mechanisms need to be explored.

Microbiota in Periodontitis: Advances in the Omic Era.

The complexity of the oral microbiome continues to astound researchers even with the advancement of multi-disciplinary strategies being used to study these microorganisms in relation to the human body. There is extensive literature available that explains how oral bacterial communities exist within the biofilm and maintains a balance with the host immune system, but when this balance is tipped disease can occur. The purpose of this review is to highlight the subgingival microbial compositions during health and periodontal disease using next generation sequencing techniques, as well as determining the types of functional activities that partake during these states. The subgingival microbiota is a fluid structure that can adapt accordingly to the environment and the identification of signature biomarkers may aid in the assessment of risk and disease severity in an individual to complement clinical diagnosis in the future.

Porphyromonas gingivalis outside the oral cavity.

Porphyromonas gingivalis, a Gram-negative anaerobic bacillus present in periodontal disease, is considered one of the major pathogens in periodontitis. A literature search for English original studies, case series and review articles published up to December 2019 was performed using the MEDLINE, PubMed and GoogleScholar databases, with the search terms "Porphyromonas gingivalis" AND the potentially associated condition or systemic disease Abstracts and full text articles were used to make a review of published research literature on P. gingivalis outside the oral cavity. The main points of interest of this narrative review were: (i) a potential direct action of the bacterium and not the systemic effects of the inflammatory acute-phase response induced by the periodontitis, (ii) the presence of the bacterium (viable or not) in the organ, or (iii) the presence of its virulence factors. Virulence factors (gingipains, capsule, fimbriae, hemagglutinins, lipopolysaccharide, hemolysin, iron uptake transporters, toxic outer membrane blebs/vesicles, and DNA) associated with P. gingivalis can deregulate certain functions in humans, particularly host immune systems, and cause various local and systemic pathologies. The most recent studies linking P. gingivalis to systemic diseases were discussed, remembering particularly the molecular mechanisms involved in different infections, including cerebral, cardiovascular, pulmonary, bone, digestive and peri-natal infections. Recent involvement of P. gingivalis in neurological diseases has been demonstrated. P. gingivalis modulates cellular homeostasis and increases markers of inflammation. It is also a factor in the oxidative stress involved in beta-amyloid production.

Gender inequality among medical, pharmaceutical and dental practitioners in French hospitals: Where have we been and where are we now?

INTRODUCTION: Women are under-represented in senior academic and hospital positions in many countries. The authors aim to assess the place and the evolution of all appointed female and male health practitioners' working in French public Hospitals. MATERIALS AND METHODS: Data of this observational study were collected from the National Management Centre (Centre National de Gestion) from 2015 up to January 1, 2020. First, the authors described demographic characteristics and specialties of all appointed medicine, pharmacy, and dentistry doctors' working as Hospital Practitioners, Associate Professors, and Full Professors in French General and University-affiliated Hospitals in 2020. Then, they retrospectively reported the annual incidence of new entrance according to gender and professional status from 1999 to 2019 thanks to the appointment date of all practitioners in activity between 2015 and 2020. RESULTS: In 2020, 51 401 appointed practitioners (49.7% of female) were in activity in French public hospitals with a large majority being medical doctors (92.4%) compared to pharmacists (6%) and dentists (1.6%). Women represented 52.5% of the Hospital Practitioners, 48.6% of the Associate Professors, and 22.0% of the Full Professors (p < 0.001). There were disparities between the rates of female Full Professors in medicine (20.6%), pharmacy (36.1%), and dentistry (44.3%, p < 0.001). Women were appointed Hospital Practitioners and Associate Professors earlier than men (respectively 37.1 versus 38.8 years, p < 0.001 and 36.1 versus 36.5 years, p = 0.04), and at a later age among Full Professors (43.7 versus 41.9 years, p < 0.001). Compared to men, the annual proportion of appointed women varied significantly between 1999 and 2019 from 47.6% to 60.4% for Hospital Practitioners, from 50.0% to 44.6% for Associate Professors, and from 11.2% to 33.3% for Full Professors (p < 0.001 for trend). CONCLUSIONS: Although more and more women occupy positions in French hospitals, there is still a gender gap regarding access to Full Professor status in medicine and pharmacy, but not in dentistry. The disparity in numbers makes comparison difficult. Despite a trend towards gender equality during the last twenty years, it has not yet been achieved regarding access to the highest positions.

Oral Health Disorders in Parkinson's Disease: More than Meets the Eye.

Despite clinical evidence of poor oral health and hygiene in Parkinson's disease (PD) patients, the mouth is often overlooked by both patients and the medical community, who generally focus on motor or psychiatric disorders considered more burdensome. Yet, oral health is in a two-way relationship with overall health-a weakened status triggering a decline in the quality of life. Here, we aim at giving a comprehensive overview of oral health disorders in PD, while identifying their etiologies and consequences. The physical (abnormal posture, muscle tone, tremor, and dyskinesia), behavioral (cognitive and neuropsychiatric disorders), and iatrogenic patterns associated with PD have an overall detrimental effect on patients' oral health, putting them at risk for other disorders (infections, aspiration, pain, malnutrition), reducing their quality of life and increasing their isolation (anxiety, depression, communication issues). Interdisciplinary cooperation for prevention, management and follow-up strategies need to be implemented at an early stage to maintain and improve patients' overall comfort and condition. Recommendations for practice, including (non-)pharmacological management strategies are discussed, with an emphasis on the neurologists' role. Of interest, the oral cavity may become a valuable tool for diagnosis and prognosis in the near future (biomarkers). This overlooked but critical issue requires further attention and interdisciplinary research.

Method for screening antimicrobial gels against multi-species oral biofilms.

We described a microtiter plate-based method that was effectively tailored for testing gel formulations against oral multispecies biofilms established on peg-lids. This method lifts the limitations imposed mainly by the anaerobic nature of the targeted bacterial species and the viscous properties of the targeted treatments.

Screening for prevalence and abundance of Capnocytophaga spp by analyzing NGS data: A scoping review.

BACKGROUND: Capnocytophaga spp. are commensal bacteria of the oral cavity and constitute a genus of the core microbiome. OBJECTIVE: This genus is responsible for many local and systemic conditions in both the immunocompetent and immunocompromised patients, but its beneficial or deleterious role in the microbiota has been little explored. DESIGN: Online databases were used to identify papers published from 1999 to 2019 based on next-generation sequencing (NGS) data to study comparative trials. Work using other identification methods, case reports, reviews, and non-comparative clinical trials was excluded. RESULTS AND CONCLUSION: We selected 42 papers from among 668 publications. They showed a link between the abundance of Capnocytophaga spp. in the oral microbiota and various local pathologies (higher for gingivitis and halitosis; lower in active smokers, etc.) or systemic diseases (higher for cancer and carcinomas, IgA nephropathy, etc.). After discussing the limits inherent to the NGS techniques, we present several technical and biological hypotheses to explain the diversity of results observed between studies, as well as the links between the higher or lower abundance of Capnocytophaga spp and the appearance of local or systemic conditions and diseases.

Oral dysbiosis induced by Porphyromonas gingivalis is strain-dependent in mice.

Background: Porphyromonas gingivalis strain W83, one of the most widely investigated, is considered virulent in the context of periodontitis. The recently isolated P. gingivalis TDC60 has been reported to be highly pathogenic, although it has not yet been investigated in a mouse periodontitis model by oral gavage. Aim: Our aim was to compare the virulence of both strains by evaluating their impact on alveolar bone loss and the composition of oral microbiota. Methods: We inoculated by oral gavage C57BL/6 mice with either one of the two P. gingivalis strains and compared to a sham-treated group, without antibiotics pre-treatment. The mandibular alveolar bone of treated mice and controls were assessed, one month after the final inoculation, by microCT measurements. Moreover, at this time, we characterized their oral microbiota by 16S rRNA gene sequencing. Results: While P. gingivalis W83 successfully initiated periodontitis, TDC60-treated mice only experienced moderate lesions. Furthermore, only W83-treated mice exhibited a specific distinct microbiota, with significantly lower richness and evenness than other samples, and decreased proportions of taxa usually found in healthy individuals. Conclusion: This association between alveolar bone loss and a major persistent shift of the oral microbiota gives insights into virulence discrepancies among these bacterial strains.

Adhesion of Staphylococcus aureus to epithelial cells: an in vitro approach to study interactions within the nasal microbiota.

Introduction. Staphylococcus aureus is a skin and mucous commensal bacterium of warm-blooded animals. In humans, the nose is the main ecological niche of S. aureus, and nasal carriage is a risk factor for developing an endogenous infection. S. aureus nasal colonization is a multifactorial process, involving inter-species interactions among the nasal microbiota.Aims. The objectives of this study were to characterize the microbiota of carriers and non-carriers of S. aureus and to demonstrate the importance of inter-species relationships in the adhesion of S. aureus, a key step in nasal colonization.Methodology. First, we characterized the nasal microbiota from 30 S. aureus carriers and non-carriers by a culturomic approach. We then evaluated the adhesion of S. aureus, first alone and then along with other bacteria of the nasal microbiota. To do that, we used an in vitro model to measure the interactions among bacteria in the presence of epithelial cells.Results. Analysis of the nasal microbiota of the carriers and non-carriers of S. aureus made it possible to observe that each microbiota has specific features in terms of composition. However, this composition differs significantly between carriers and non-carriers mainly through two bacterial groups: coagulase-negative staphylococci and corynebacteria. In a second part, adhesion of S. aureus to epithelial cells showed competition between S. aureus and these bacteria, suggesting a limitation of nasal colonization by S. aureus.Conclusion. These findings demonstrate the existence of a negative correlation between S. aureus and other species which inhibits adhesion and could limit nasal colonization.

The events that may contribute to subgingival dysbiosis: a focus on the interplay between iron, sulfide and oxygen.

This minireview considers the disruption of the host-microbiota harmless symbiosis in the subgingival niche. The establishment of a chronic infection by subversion of a commensal microbiota results from a complex and multiparametric sequence of events. This review narrows down to the interplay between oxygen, iron and sulfide that can result in a vicious cycle that would favor peroxygenic and glutathione producing streptococci as well as sulfidogenic anaerobic pathogens in the subgingival niche. We propose hypothesis and discuss strategies for the therapeutic modulation of the microbiota to prevent periodontitis and promote oral health.

[Protein arginine deiminase of oral microbiome plays a causal role in the polyarthritis rheumatoid initiating]. / Peptidylarginine désiminases du microbiote buccal et polyarthrite rhumatoïde.

In the last decade, the association between the periodontitis and rheumatoid arthritis (RA) has been established, suggesting that oral microbiome plays a causal role by initiating this chronic autoimmune inflammatory disease of articulation. Both pathogenesis are similar in term of chronic inflammation, tissue breakdown and bone resorption. Molecular aspects have also revealed that citrullination, a post-translational modification catalyzed by peptidyl-arginine deiminases (PADs), is involved in both diseases. For RA, citrullinated proteins production leads to the synthesis the of anti-citrullinated protein antibodies triggering the loss of immune tolerance. In humans, five PADs have been identified. Recently, studies have found that only Porphyromonas species possess PAD. Thus, a major periodontal pathogen, Porphyromonas gingivalis, is able to generate citrullinated epitopes, and could consequently induce anti-citrullinated protein antibodies. In this review, citrullination process, periodontitis and RA are described to put them in relation with molecular, clinical and epidemiological studies establishing the association between periodontitis and RA.

TITLE: Peptidylarginine désiminases du microbiote buccal et polyarthrite rhumatoïde. ABSTRACT: Ces dernières années, des études se sont focalisées sur l'existence d'une association entre la parodontite et la polyarthrite rhumatoïde (PR), suggérant l'implication du microbiote buccal dans le déclenchement de cette maladie auto-immune des articulations. D'un point de vue clinique, les deux pathologies reposent sur un processus inflammatoire qui conduit à une érosion osseuse. Elles font également intervenir une modification post-traductionnelle appelée citrullination. Dans le cas de la PR, la citrullination de certains sites protéiques par les peptidylarginine désiminases (PAD) aboutit à la production d'auto-anticorps. C'est la découverte d'une PAD exprimée par la bactérie Porphyromonas gingivalis qui a orienté de nombreuses études vers l'analyse d'une association entre ces deux pathologies.

Periodontal pathogens and clinical parameters in chronic periodontitis.

The use of next generation sequencing and bioinformatics has revealed the complexity and richness of the human oral microbiota. While some species are well known for their periodontal pathogenicity, the molecular-based approaches for bacterial identification have raised awareness about new putative periodontal pathogens. Although they are found increased in case of periodontitis, there is currently a lack of data on their interrelationship with the periodontal measures. We processed the sequencing data of the subgingival microbiota of 75 patients with hemochromatosis and chronic periodontitis in order to characterize the well-described and newly identified subgingival periodontal pathogens. We used correlation tests and statistical models to assess the association between the periodontal pathogens and mean pocket depth, and to determine the most relevant bacterial biomarkers of periodontitis severity. Based on correlation test results, nine taxa were selected and included in the statistical models. The multiple linear regression models adjusted for systemic and periodontal clinical variables showed that mean pocket depth was negatively associated with Aggregatibacter and Rothia, and positively associated with Porphyromonas. Furthermore, a bacterial ratio that was previously described as a signature of dysbiosis in periodontitis (%Porphyromonas+%Treponema+%Tannerella)/(%Rothia+%Corynebacterium) was the most significant predictor. In this specific population, we found that the best model in predicting the mean pocket depth was microbial dysbiosis using the dysbiosis ratio taxa formula. While further studies are needed to assess the validity of these results on the general population, such a dysbiosis ratio could be used in the future to monitor the subgingival microbiota.

Increased transferrin saturation is associated with subgingival microbiota dysbiosis and severe periodontitis in genetic haemochromatosis.

Genetic haemochromatosis (GH) is responsible for iron overload. Increased transferrin saturation (TSAT) has been associated with severe periodontitis, which is a chronic inflammatory disease affecting tissues surrounding the teeth and is related to dysbiosis of the subgingival microbiota. Because iron is essential for bacterial pathogens, alterations in iron homeostasis can drive dysbiosis. To unravel the relationships between serum iron biomarkers and the subgingival microbiota, we analysed samples from 66 GH patients. The co-occurrence analysis of the microbiota showed very different patterns according to TSAT. Healthy and periopathogenic bacterial clusters were found to compete in patients with normal TSAT (≤45%). However, significant correlations were found between TSAT and the proportions of Porphyromonas and Treponema, which are two genera that contain well-known periopathogenic species. In patients with high TSAT, the bacterial clusters exhibited no mutual exclusion. Increased iron bioavailability worsened periodontitis and promoted periopathogenic bacteria, such as Treponema. The radical changes in host-bacteria relationships and bacterial co-occurrence patterns according to the TSAT level also suggested a shift in the bacterial iron supply from transferrin to NTBI when TSAT exceeded 45%. Taken together, these results indicate that iron bioavailability in biological fluids is part of the equilibrium between the host and its microbiota.

New growth media for oral bacteria.

New growth media have been designed for the iron-controlled co-cultures of three oral bacteria. These media share a common core composition enabling the switch from mono- to co-cultures, and efficiently promote both planktonic and biofilm cultures of Porphyromonas gingivalis, Treponema denticola and Streptococcus gordonii.

Periodontal reconstruction by heparan sulfate mimetic-based matrix therapy in Porphyromonas gingivalis-infected mice.

BACKGROUND: Periodontitis is a set of chronic inflammatory diseases affecting the supporting structures of the teeth, during which a persistent release of lytic enzymes and inflammatory mediators causes a self-perpetuating vicious cycle of tissue destruction and repair. A matrix-based therapy using a heparan sulfate (HS) analogue called ReGeneraTing Agent (RGTA) replaces destroyed HS by binding to available heparin-binding sites of structural molecules, leading to restoration of tissue homeostasis in several inflammatory tissue injuries, including a hamster periodontitis model. METHODS: The ability of RGTA to restore the periodontium was tested in a model of Porphyromonas gingivalis-infected Balb/cByJ mice. After 12 weeks of disease induction, mice were treated weekly with saline or RGTA (1.5 mg/kg) for 8 weeks. Data were analyzed by histomorphometry. RESULTS: RGTA treatment restored macroscopic bone loss. This was related to (1) a significant reduction in gingival inflammation assessed by a decrease in infiltrated connective tissue, particularly in cells expressing interleukin 1ß, an inflammatory mediator selected as a marker of inflammation; (2) a normalization of bone resorption parameters, i.e. number, activation and activity of osteoclasts, and number of preosteoclasts; (3) a powerful bone formation reaction. The Sharpey's fibers of the periodontal ligament recovered their alkaline phosphatase coating. This was obtained while P. gingivalis infection was maintained throughout the treatment period. CONCLUSIONS: RGTA treatment was able to control the chronic inflammation characteristic of periodontitis and blocked destruction of periodontal structures. It ensured tissue regeneration with recovery of the periodontium's anatomy.

Antibacterial activities of natural lichen compounds against Streptococcus gordonii and Porphyromonas gingivalis.

The oral bacteria not only infect the mouth and reside there, but also travel through the blood and reach distant body organs. If left untreated, the dental biofilm that can cause destructive inflammation in the oral cavity may result in serious medical complications. In dental biofilm, Streptococcus gordonii, a primary oral colonizer, constitutes the platform on which late pathogenic colonizers like Porphyromonas gingivalis, the causative agent of periodontal diseases, will bind. The aim of this study was to determine the antibacterial activity of eleven natural lichen compounds belonging to different chemical families and spanning from linear into cyclic and aromatic structures to uncover new antibiotics which can fight against the oral bacteria. The compounds were screened by broth microdilution assay. Three compounds were shown to have promising antibacterial activities where the depsidone core with certain functional groups constituted the best compound, psoromic acid, with the lowest MICs=11.72 and 5.86µg/mL against S. gordonii and P. gingivalis, respectively. The compounds screened had promising antibacterial activity which might be attributed to some important functional groups as discussed in our study. The best compounds did not induce the death of gingival epithelial carcinoma cells (Ca9-22). These results introduce new compounds having potent antibacterial activities against oral pathogens causing serious medical complications.

Evaluation of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of human oral Capnocytophaga species.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was evaluated for rapid identification of cfxA PCR positive and negative Capnocytophaga strains. Colonies were grown on blood agar, incubated anaerobically at 37 °C for 48 h, and were then evaluated by MALDI-TOF MS and 16S rRNA gene sequencing. Both methods identified all colonies to the genus level. The MALDI-TOF MS method gave the same result, at the species level, as 16S rRNA gene sequencing for 41/53 Capnocytophaga sp. strains (77.4%), but the limit of this technique was the absence of some species (C. leadbetteri, C. AHN) in the Biotyper-Bruker® database used in this study. Distinction between the cefotaxime resistant and susceptible strains was unsuccessful using the MALDI-TOF MS method. This technique had low discriminatory power to rapidly detect beta-lactamase-producing Capnocytophaga strains in clinical samples. However, the results from a score-oriented dendrogram confirmed MALDI-TOF MS is a rapid, inexpensive, and reliable method for Capnocytophaga species identification. Enrichment of the reference database used (Biotyper®) will improve future results.

Periodontal status and serum biomarker levels in HFE haemochromatosis patients. A case-series study.

AIM: To investigate the association between periodontal status and serum biomarkers in patients with HFE haemochromatosis. MATERIAL AND METHODS: This clinical case series included 84 HFE-C282Y homozygous patients. Periodontal evaluation was performed using clinical attachment level, probing depth, gingival bleeding index, visible plaque index and gingival index. Serum markers of iron metabolism were collected from medical records. The relationship between serum biomarkers of iron burden and the severity of periodontitis was investigated. RESULTS: The study population consisted of 47 men and 37 women, routinely treated in the Unit of Hepatology, University Hospital, Rennes. All patients presented with periodontitis (mild: n = 1, moderate: n = 37 and severe: n = 46). There was a positive association between transferrin saturation >45% and the severity of periodontitis (adjusted odds ratio = 5.49, p = .002). CONCLUSION: Severe periodontitis is associated with the severity of iron burden in patients with HFE-related hereditary haemochromatosis. Dental examination should be included in the initial assessment of all these patients.