The Role of Oral Pathobionts in Dysbiosis during Periodontitis Development

Abstract

An emerging concept is the tight relationship between dysbiosis (microbiota imbalance) and disease. The increase in knowledge about alterations in microbial communities that reside within the host has made a strong impact not only on dental science, but also on immunology and microbiology as well as on our understanding of several diseases. Periodontitis is a well-characterized human disease associated with dysbiosis, characterized by the accumulation of multiple bacteria that play individual and critical roles in bone loss around the teeth. Dysbiosis is largely dependent on cooperative and competitive interactions among oral microbes during the formation of the pathogenic biofilm community at gingival sites. Oral pathobionts play different and synergistic roles in periodontitis development, depending on their host-damaging and immunostimulatory activities. Host immune responses to oral pathobionts act as a double-edged sword not only by protecting the host against pathobionts, but also by promoting alveolar bone loss. Recent studies have begun to elucidate the roles of individual oral bacteria, including a new type of pathobionts that possess strong immunostimulatory activity, which is critical for alveolar bone loss. Better understanding of the roles of oral pathobionts is expected to lead to a better understanding of periodontitis disease and to the development of novel preventive and therapeutic approaches for the disease.

Osteopontin adsorption to Gram-positive cells reduces adhesion forces and attachment to surfaces under flow

“…This particularly holds true for the oral cavity where the long-standing presence of biofilms on teeth is the main cause of dental caries and periodontitis [4,5]. At the same time, the commensal oral microbiota, residing on mucosal surfaces, protects the host against opportunistic pathogens and makes a relevant contribution to human physiology.…”

Microbiology of Oral Biofilm-Dependent Diseases: Have We Made Significant Progress to Understand and Treat These Diseases?

“…Thus, the persistence of a pathogenic periodontal microbiota is necessary but not sufficient for the establishment of periodontal diseases [78,79]. Different from the cariogenic biofilm, the pathogenicity of periodontopathogenic biofilm is related to the predominance of bacterial products and components that will cause direct and indirect periodontal tissue destruction.…”

“…Bacterial virulence factors induce host immune cells to produce inflammatory mediators that interfere with the connective and bone tissues, leading to periodontal breakdown. Therefore, periodontal breakdown is mainly caused by the host immunological response induced by specific pathogenic microbial communities [77][78][79].…”

“…Shifts in the ecology of this biofilm may result in microbial dysbiosis, with a decrease in hostcompatible species and an increase in more pathogenic microorganisms [79,96,97]. Dysbiosis can be induced by various factors and conditions, which may trigger the host response and alter the periodontal microenvironment, favoring the overgrowth of periodontopathogenic species [96].…”

Modulação do biofilme de Porphyromonas gingivalis pela associação com Streptococcus gordonii e com Prevotella intermedia.

“…Muitas dessas espécies também estão presentes em indivíduos com periodonto saudável, mantendo uma relação harmoniosa com o hospedeiro (Lamont, Jenkinson, 1998). Recentes avanços no campo de pesquisa das doenças periodontais propõem um novo modelo de patogênese que postula que a periodontite é iniciada por uma comunidade microbiana desbiótica e com atividade sinergística (Hajishengallis, Lamont 2012;Jiao et al, 2014). Nesse modelo, os autores propõem que, microrganismos isoladamente promoveriam poucas alterações no sistema imune e tecidos hospedeiros, estes microrganismos podem, então, se associar e ainda assim conviver em harmonia com o hospedeiro, no entanto, a colonização de um patógeno chave, como por exemplo P.…”