Letteratura scientifica selezionata sul tema "Dysbiose buccale"

Des millions d’enfants naissent prématurément chaque année et les cliniciens restent démunis face à la difficulté de maîtriser la physiopathologie associée, ce qui limite les options thérapeutiques. Récemment, il a été suggéré que le microbiote maternel pouvait contribuer au bon déroulement de la grossesse et qu’une dysbiose pourrait entraîner une naissance avant terme. Certaines espèces commensales de Lactobacillus participeraient à une fonction de « filtre vaginal », empêchant une propagation ascendante de pathogènes vers la cavité utérine. Ce compartiment peut par ailleurs être colonisé par des bactéries buccales, suggérant la possibilité de leur dissémination par voie hématogène vers l’utérus.

Candida parapsilosis sensu stricto is the second to third most frequent cause of candidemia. Studies place this yeast as a frequent colonizer of niches of the oral cavity, predominantly in pathological conditions. We hypothesize that a buccal environment in dysbiosis enhances the virulence of C. parapsilosis sensu stricto. Objective: To evaluate at the phenotype and molecular level the production of biofilm in oral isolates of C. parapsilosis sensu stricto and correlate the results with the clinical origin (dysbiosis versus eubiosis). Material and methods: The biofilm-forming ability was compared in 50 oral isolates of C. parapsilosis sensu stricto obtained from patients with and without oral dysbiosis; by quantification of biofilm biomass and metabolic activity. The results were corroborated by optical and confocal fluorescence microscopy, and correlated with the transcriptional activity of CPH2, by RT-qPCR. The data were analyzed by Excel 2010, and InfoStat 2018, with a 95% confidence interval. Results: The metabolic activity in biofilm was significantly higher in oral dysbiosis relative to control (p = 0.0025). Basal expression of CPH2 increased 2.8 times more in oral dysbiosis related to the control condition and showed no significant differences with pathogenic isolates of this same yeast, derived from onychomycosis lesions. Conclusion: The oral cavity in dysbiosis increases the virulence of C. parapsilosis sensu stricto due to possible changes in epigenetic marks. This finding suggests that the oral cavity in dysbiosis may be an alternative route to the skin in the epidemiology of nosocomial candidemia.

Periodontitis is a chronic and multifactorial inflammatory disease that can lead to tooth loss. At present, the diagnosis for periodontitis is primarily based on clinical examination and radiographic parameters. Detecting the periodontal pathogens at the subgingival plaque requires skilled professionals to collect samples. Periodontal pathogens are also detected on various mucous membranes in patients with periodontitis. In this study, we characterized the oral microbiome profiles from buccal mucosa and supragingival space in a total of 272 healthy subjects as a control group, and periodontitis patients as a disease group. We identified 13 phyla, 193 genera, and 527 species and determined periodontitis-associated taxa. Porphyromonas gingivalis, Tannerella forsythia, Treponema denticolar, Filifactor alocis, Porphyromonas endodontalis, Fretibacterium fastiosum and Peptostreptococcus species were significantly increased in both the buccal mucosa and the supragingival space in periodontitis patients. The identified eight periodontitis-associated bacterial species were clinically validated in an independent cohort. We generated the prediction model based on the oral microbiome profiles using five machine learning algorithms, and validated its capability in predicting the status of patients with periodontitis. The results showed that the oral microbiome profiles from buccal mucosa and supragingival space can represent the microbial composition of subgingival plaque and further be utilized to identify potential microbial biomarkers for the diagnosis of periodontitis. Besides, bacterial community interaction network analysis found distinct patterns associated with dysbiosis in periodontitis. In summary, we have identified oral bacterial species from buccal and supragingival sites which can predict subgingival bacterial composition and can be used for early diagnosis of periodontitis. Therefore, our study provides an important basis for developing easy and noninvasive methods to diagnose and monitor periodontitis.

Oral lichen planus (OLP) is a chronic inflammatory autoimmune disease of the oral cavity with malignant potential affecting 1.01% of the worldwide population. The clinical patterns of this oral disorder, characterized by relapses and remissions of the lesions, appear on buccal, lingual, gingival, and labial mucosa causing a significant reduction in the quality of life. Currently, there are no specific treatments for this disease, and the available therapies with topical and systemic corticosteroids only reduce symptoms. Although the etiopathogenesis of this pathological condition has not been completely understood yet, several exogenous and endogenous risk factors have been proposed over the years. The present review article summarized the underlying mechanisms of action involved in the onset of OLP and the most well-known triggering factors. According to the current data, oral microbiota dysbiosis could represent a potential diagnostic biomarker for OLP. However, further studies should be undertaken to validate their use in clinical practice, as well as to provide a better understanding of mechanisms of action and develop novel effective intervention strategies against OLP.

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa with an unknown etiology. The role of oral microbes in the development of OLP has gained researchers’ interest. In this review, we summarized the findings of studies focused on the relationship between OLP and oral microbiome, which includes the composition of oral microbiota, molecules produced by oral microbiota or the host, and the oral environment of the host. According to the studies, the oral microbial community in OLP patients undergoes dysbiosis, and the microbial dysbiosis in OLP patients is more prominent in the buccal mucosa than in the saliva. However, no same microorganisms have been suggested to be associated with OLP in multiple investigations, implying that the functional aspects of the oral microbiota are more important in OLP development than the composition of the oral microbiota. According to studies on host factors that make up the oral environment, signal pathways involved in cellular processes, such as keratinization, inflammation, and T cell responses are triggered in OLP. Studies on the functional aspects of the oral microbiota, as well as interactions between the host and the oral microbiota, are still lacking, and more research is required.

Dysbiosis of the nasopharyngeal microbiome attracts dysbiosis of the intestinal microbiome and activation of the intestinal microbiome-brain axis. If the first sign of the disease is quickly intervened with the modulation of the activity of the microbiome, implicitly of the immune system (neuroimmunomodulation), the appearance of the disease is eliminated. There is the microbiome: buccal, nasal, intestinal, cardiac, cutaneous and even the microbiome in the brain with which Covid-19 interacts. When the evolution is complicated, it is necessary to intervene with drug treatment to support the affected organs. Although there is also renal impairment, no coronaviruses or traces were found in the patients' urine. Knowing that the infection also causes digestive symptoms, coronaviruses have been shown in faeces. It is said that in 1-2% of cases Covid-19 reaches the bloodstream. The microbiome is essential for promoting immune function to prevent and combat disease. Specifically, with regard to viral infections, there must be an adequate immune response to protect the body. The intestinal microbiota with low diversity will consequently lead to a deficient immune function. The microbiota, the intestine and the brain communicate through the microbiota-intestine-brain axis in a bidirectional way. We assume that the Covid-19 virus creates a dysbiosis of the intestinal microbiome. A healthy gut microbiome is crucial in creating an adequate response to coronavirus. A diverse microbiome is a healthy microbiome, which contains many different species that each play a role in immunity and health. The motivation of the project is the study of the influence of the intestinal microbiota in terms of health and the appearance of symptoms in Covid-19 infection. With the help of Deniplant brand natural remedies, the authors have developed several products for autoimmune, metabolic and neurological diseases that act as immunomodulators of the human microbiome.

Of particular interest is the study of colonization resistance of the oral cavity as a physiological phenomenon that reflects the ability of the microbiota and macroorganism in cooperation to protect the ecosystem of the oral cavity from pathogens. Purpose is to evaluate the significance of indicators of colonization resistance of buccal epithelial cells as a marker of homeostatic resources of mucosal immunity in recurrent respiratory diseases in children. Material and methods. 232 (5–16 years old) children were examined, including 56 children with acute bronchitis, 73 with recurrent bronchitis, 103 with community-acquired pneumonia. The control group included 31 apparently healthy children of the same age and sex. Used: conventional paraclinical and laboratory-instrumental methods, etiological verification of viruses and bacteria, colonization index and artificial colonization of buccal epitheliocytes, antiadhesive activity of saliva. Results. 64.38% of children with recurrent bronchitis and 72.82% of children with community-acquired pneumonia were born from an aggravated pregnancy and already at 3 months had signs of acute respiratory diseases. Viral antigens were detected in 63.36% of children. An inverse relationship was found between the indicators of artificial colonization and adhesion of Candida albicans on buccal epithelial cells — the lower the values of artificial colonization, the more often pneumonia and recurrent bronchitis were recorded. A significant decrease in saliva antiadhesion was found in recurrent bronchitis and community-acquired pneumonia, significantly different not only from the control, but also from patients with acute bronchitis. This contingent of patients finds itself in extremely unfavorable conditions due to the disruption of the adaptive reserves of the mucosal defense of the body. Conclusion. A decrease in the index of colonization, antiadhesive activity of saliva against the background of increasing parameters of artificial colonization in children with recurrent bronchitis and community-acquired pneumonia indicate deep dysbiosis. The high significance of screening approaches in assessing the homeostatic resources of mucosal protection of the oral cavity in children with bronchopulmonary pathology has been proven.

Recent research suggests that dysbiosis of the oral microbial community is associated with head and neck cancer (HNC). It remains unclear whether this dysbiosis causes chemo-radiotherapy (CRT)-related complications. However, to address this question, it is essential to determine the most representative oral site for microbiome sampling. In this study, our purpose was to determine the optimal site for oral sample collection and whether the presence of HNC is associated with altered oral microbiome from this site. In 21 newly diagnosed HNC patients and 27 healthy controls, microbiome samples were collected from saliva, swabs from buccal mucosa, tongue, hard palate, faucial pillars and all mucosal sites combined. Microbial DNA was extracted and underwent 16S rRNA amplicon gene sequencing. In healthy controls, analysis of observed taxonomic units detected differences in alpha- and beta-diversity between sampling sites. Saliva was found to have the highest intra-community microbial diversity and lowest within-subject (temporal) and between-subject variance. Feature intersection showed that most species were shared between all sites, with saliva demonstrating the most unique species as well as highest overlap with other sites. In HNC patients, saliva was found to have the highest diversity but differences between sites were not statistically significant. Across all sites, HNC patients had lower alpha diversity than healthy controls. Beta-diversity analysis showed HNC patients’ microbiome to be compositionally distinct from healthy controls. This pattern was confirmed when the salivary microbiome was considered alone. HNC patients exhibited reduced diversity of the oral microbiome. Salivary samples demonstrate temporal stability, have the richest diversity and are sufficient to detect perturbation due to presence of HNC. Hence, they can be used as representative oral samples for microbiome studies in HNC patients.

L'incidence de la maladie d'Alzheimer (MA), qui constitue la première cause de troubles neurocognitifs dans la population adulte, augmente dans le monde entier. A ce jour, et malgré les immenses progrès réalisés en 30 ans concernant la compréhension des mécanismes neuropathologiques, et notamment l'accumulation des protéinesTau et Béta-amyloïdes, la question de l'étiopathogénie et des différents facteurs de risque de la MA reste largement débattue. Parmi les facteurs de risque étudiés, l'inflammation chronique et les pathologies, notamment infectieuses, constituent des voies de recherche particulièrement intéressantes. Les données récentes de la littérature mettent en évidence un lien significatif entre les maladies parodontales et la MA. La cavité buccale héberge en effet un microbiote varié qui constitue un réservoir inflammatoire permanent favorisant la dissémination systémique d'espèces bactériennes, fongiques et virales. Plusieurs agents infectieux sont suspectés de jouer un rôle étiologique dans la genèse inflammatoire et l'aggravation des maladies neurodégénératives, dont la MA ; notamment les Herpes virus humains et de nombreuses bactéries parodontopathogènes. Des agents pathogènes parodontaux majeurs ont en effet été détectés dans les lésions cérébrales de patients décédés et atteints de MA, suggérant une connexion infectieuse et inflammatoire entre la sphère oro-pharyngée et le cerveau. Ce travail de thèse part ainsi du postulat que la cavité buccale représente un espace d'observation privilégié. L'étude ORAMICAL "Oral Microbiology in Alzheimer's patients" est une étude cas-témoins non randomisée conduite au CHU de Nice. Elle vise à étudier, au niveau parodontal, la présence d'un ensemble sélectionné d'espèces bactériennes et virales chez des personnes âgées de plus de 70 ans, diagnostiquées ou non pour la MA. L'objectif principal est d'établir une signature parodontale, associant virus et bactéries, qui serait significativement associée à la MA. Les objectifs secondaires sont de comparer l'hygiène et l'état bucco-dentaires dans chaque groupe de patients. Les cas et les témoins, ont été recrutés lors d'une consultation dentaire ou à la suite d'une consultation avec un gériatre au CHU de Nice. Les échantillons parodontaux ont été collectés par un écouvillonnage oral réalisé sur la dent présentant la poche parodontale la plus profonde. Les ADN microbiens (11 au total, 7 virus et 4 bactéries) ont été analysés par qPCR. Différentes données cliniques, telles que le coefficient masticatoire, la présence de mobilités, l'indice carieux ou la mesure du statut parodontal ont également été recueillies. Ce protocole d'étude est rapporté selon les Standard Protocol Items : Recommendations for Interventional Trials (SPIRIT). Les directives de l'étude STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) ont été suivies. Une première phase de faisabilité a porté sur une vingtaine de patients,13 cas et 11 témoins, ne présentant pas de différences significatives en âge et en sexe. L'état bucco-dentaire était significativement dégradé pour les cas. L'indice de plaque était significativement plus important chez les patients atteints de MA que chez les témoins, et leur niveau de dépendance était également significativement plus important. Cette étude met en évidence la présence marquée de certaines espèces bactériennes et virales dans les lésions parodontales des patients atteints de MA. Les différences (Fisher exact test) concernent le virus Varicelle-Zona (VZV), le virus Epstein-Barr (EBV), Porphyromonas gingivalis (Pg) et Fusobacterium nucleatum (Fn) qui sont détectés de manière très significative chez les cas. Bien que basée sur un nombre de participants encore modeste, cette étude met en évidence pour la première fois l'incidence accrue du VZV au niveau oral, associé à des marqueurs plus consensuels des dysbioses parodontales comme EBV, Pg et Fn
The incidence of Alzheimer's disease (AD), the leading cause of neurocognitive disorders in the adult population, is increasing worldwide. To date, and despite the immense progress made over the last 30 years in understanding the neuropathological mechanisms, and in particular the accumulation of Tau and Beta-amyloid proteins, the question of the etiopathogeny and the various risk factors of AD remains widely debated. Among the risk factors studied, chronic inflammation and pathologies, particularly infectious ones, constitute particularly interesting avenues of research. Recent data from the literature show a significant link between periodontal disease and AD. The oral cavity harbours a varied microbiota which constitutes a permanent inflammatory reservoir favouring the systemic dissemination of bacterial, fungal and viral species. Several infectious agents are suspected of playing an etiological role in the inflammatory genesis and aggravation of neurodegenerative diseases, including AD; in particular, human herpes viruses (HHV) and numerous periodontopathogenic bacteria. Major periodontal pathogens have been detected in the brain lesions of deceased AD patients, suggesting an infectious and inflammatory connection between the oropharyngeal sphere and the brain. This thesis work is based on the assumption that the oral cavity represents a privileged observation space. The ORAMICAL study "Oral Microbiology in Alzheimer's patients" is a non-randomised case-control study conducted at the Nice University Hospital. It aims to study, at the periodontal level, the presence of a selected set of bacterial and viral species in people aged over 70 years, diagnosed or not with AD. The primary objective is to establish a periodontal signature, combining viruses and bacteria, that would be significantly associated with AD. The secondary objectives are to compare oral hygiene and oral status in each group of patients. Cases and controls were recruited during a dental consultation or following a consultation with a geriatrician at the Nice University Hospital. Periodontal samples were collected by oral swabbing of the tooth with the deepest periodontal pocket. Microbial DNA (11 in total, 7 viruses and 4 bacteria) was analysed by qPCR. Various clinical data, such as masticatory coefficient, presence of mobility, caries index or periodontal status measurement were also collected. This study protocol is reported according to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT). The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) study guidelines were followed. A first feasibility phase was carried out on twenty patients, 13 cases and 11 controls, with no significant differences in age and sex. The oral status was significantly worse for the cases. The plaque index was significantly higher in AD patients than in controls, and their level of dependency was also significantly higher. This study highlights the marked presence of certain bacterial and viral species in the periodontal lesions of AD patients. The differences (Fisher exact test) concern Varicella-Zoster virus (VZV), Epstein-Barr virus (EBV), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn), which are detected to a high degree of significance in the cases. Although still based on a modest number of participants, this study highlights for the first time the increased incidence of VZV at the oral level, associated with more consensual markers of periodontal dysbiosis like EBV, Pg and Fn