Perfil da microbiota intestinal em indivíduos asmáticos e seu papel imunomodulador

Abstract

The phenomenon of dysbiosis in the intestinal microbiome can influence the host's immune development and the incidence of allergic diseases. It is believed that microbiome-host interactions, i.e., symbiosis, contribute to the proper development of the immune system, while microbial dysbiosis has been associated with a variety of inflammatory disorders, including asthma. The aim of this study is to characterize the taxonomic profile of the intestinal microbiota in asthmatic individuals participating in the World Asthma Phenotypes (WASP) and associate it with related immunomodulatory mechanisms. The assessment of the intestinal microbiota was conducted through sequencing the V4 region of the 16S rRNA gene from bacterial DNA extracted from stool samples, followed by bioinformatic analysis using the QIIME2 software. Association with the immune response was investigated using markers such as skin prick test positivity, induced sputum cellularity, and cytokine levels in nasal lavage. Although all predominant phyla, such as Tenericutes, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, were consistent between asthmatics and non-asthmatics, differences in relative abundances were observed. No significant differences in bacterial richness or diversity were identified between asthmatics and non-asthmatics based on alpha diversity. However, a statistically significant dissimilarity in beta diversity was observed. The genus Bacteroides was the most abundant, contributing to the dissimilarity within the asthmatic group, while Prevotella was more prevalent in non-asthmatics. The presence of Bacteroides in the microbiota of asthmatics correlated with IL-4 production in nasal lavage. These results reinforce the understanding of differences in the microbial community between asthmatic and non-asthmatic individuals.