Resumo:
Oral dysbiosis, especially in periodontitis, has been linked to the pathophysiology of systemic
diseases, including asthma. The anatomical connection between the oral cavity and the lungs
provides many opportunities for the oral microbiota to impact the lung microbiota in health and
disease. In addition to the possibility of passive transfer of bacteria, changes in the composition
of the oral microbiota can lead to a deficient immune response and reduced tolerance to
commensal microorganisms. The present observational study aimed to carry out a metagenomic
investigation of the subgingival biofilm of individuals with severe asthma, mild asthma and
without asthma, to evaluate the relationship between the subgingival microbiome and asthma.
Subgingival biofilm samples were collected from thirty individuals at the Asthma Control
Program Outpatient Clinic in Bahia (ProAR). They were distributed into six groups, according
to diagnosis for asthma and periodontitis. Total DNA extraction and metagenomic analysis
were performed using next-generation sequencing based on the 16s-rRNA gene (Illumina
MiSeq). Data were analyzed descriptively, using the average of the samples of each group. For
ecological analysis, alpha diversity was estimated using the Shannon index, and beta diversity
using principal coordinate analysis (PCoA) and the Bray-Curtis distance method. This study
provides the first insights into the composition of the subgingival microbiome in individuals
diagnosed with periodontitis and different diagnoses of asthma. The presence/greater
abundance of genera considered more pathogenic from the periodontal point of view, like
Aggregatibacter, Treponema, Selenomonas e Campylobacter, can be seen in individuals with
severe asthma and periodontitis. At the same time, there is a greater risk towards dysbiosis for
individuals with asthma and without periodontitis, especially with severe asthma, who have
higher levels of Porphyromonas. New studies are suggested based on the genera highlighted in
this research.
