The Effects of Corticosteroids on the Respiratory Microbiome: A Systematic Review

Abstract

Background: Since its discovery, the respiratory microbiome has been implicated in the pathogenesis of multiple pulmonary diseases. Even though corticosteroid treatments are widely prescribed for pulmonary diseases, their effects on the respiratory microbiome are still poorly understood. This systematic review summarizes the current understanding of the effects of corticosteroids on the microbiome of the airways.Research Question: How does treatment with corticosteroids impact the respiratory microbiome?Study Design and Methods: According to the PRISMA guidelines, Embase, Medline, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were systematically searched for all observational or randomized-controlled studies comparing the microbiome parameters of patients receiving corticosteroids to those of controls. The primary outcomes of interest were changes in the diversity, composition and total burden of the respiratory microbiome as assessed by culture-independent molecular methods.Results: Out of 1,943 identified reports, five studies could be included: two on patients with asthma, two on patients with chronic obstructive pulmonary disease and one on patients with chronic rhinosinusitis. The studies were highly heterogeneous with regards to the methods used and the populations investigated. Microbiome diversity increased with corticosteroids at least transiently in three studies and decreased in one study. The effects of corticosteroids on the composition of the respiratory microbiome were significant but without a clear shared direction. A significant increase in microbial burden after corticosteroids was seen in one study.Interpretation: Data on the effect of corticosteroids on the respiratory microbiome are still limited, with considerable heterogeneity between studies. However, available data suggest that corticosteroid treatment may have significant effects on the composition and possibly the diversity of the respiratory microbiome. Further research is needed to better understand the influence of corticosteroids on the respiratory microbiome and thus better target its widespread therapeutic use.

Impact of COVID-19 and Antibiotic Treatments on Gut Microbiome: A Role for Enterococcus spp.

“…In this study, the potential improvement of inflammation caused by the corticosteroids appeared mediated by a positive effect on the colonic mucin synthesis [ 41 ]. In a recent systematic review not including COVID-19, the impact of corticosteroids on the respiratory microbiome was controversial, showing both positive and negative effects and proving that more studies are needed to define their impact [ 42 ]. Akkermansia , usually found in the mucous layer of the intestine, has been associated with immunomodulatory responses of the intestinal barrier [ 43 ] and correlated with days on remdesivir and corticosteroids or heparin.…”

Impact of Therapeutics on Unified Immunity During Allergic Asthma and Respiratory Infections

“…Augmenting differences in the airway microbiome among asthmatics, CS use is associated with significant changes on the composition (and probably diversity) of the airway microbiome in patients with asthma, COPD and chronic rhinosinusitis ( 233 ). Treatment with CS is associated with decreased relative abundance of Prevotella species and increased Pseudomonas species in asthmatics ( 234 ).…”

“…These studies suggest that CS use can affect the microbiome and neutrophilic inflammation and that the airway dysbiosis and steroid resistance are interrelated. However, as there is considerable heterogeneity between studies with respect to study cohorts, treatment duration, doses and type of evaluated CS ( 233 ), further studies are needed to clarify the impact CS have in airway dysbiosis during asthma and other respiratory diseases.…”

16S rRNA sequencing for profiling microbial communities in idiopathic granulomatous mastitis

“…An important factor patient variable that interpatient metagenomic variability could be attributed to would be treatment exposure. Previous studies have described steroid treatment affecting microbiomes in different sites, including the lungs, gut and vagina [43][44][45][46] . As a lipid soluble drug, corticosteroids would penetrate fatty breast tissue and could modify pus microbiome in IGM 47 .…”