Gender differences are found in asthma susceptibility and severity. Accumulating evidence has linked airway microbiome dysbiosis with asthma and the airway microbial communities are found to be different by gender. However, whether gender modifies the link between airway microbiome and asthma has not been investigated.
We aim to evaluate gender effects in the association between airway microbiome and asthma.
We analyzed induced sputum samples from 47 subjects (n =23 asthmatics and n =24 normal controls) using 16S ribosomal RNA gene sequencing methods. The bacterial composition was analyzed for gender differences. Bacterial associations with asthma were assessed in each gender at the core taxa and genus level.
The microbiome in induced sputum differed in females versus males at the community level. There are five core bacterial taxa that appear in all samples. No gender-specific core taxa was detected. The most abundant core taxon, Streptococcus salivarius , was significantly enriched in females than in males (p=0.02). Within each gender, individuals with relatively lower abundance of S. salivarius were more likely to be asthmatic (p=0.006). Asthmatic patients of both genders contained increased Lactobacillus spp. in their sputum compared to normal controls (adjusted p=0.01). Haemophilus spp. were associated with asthma in males and not in females.
The airway microbiome differed by gender and gender effects exist in the association of airway microbial markers and asthma. Future airway microbiome studies may yield better resolution if the context of specific gender is considered. The airway microbiome is a potential mechanism driving gender differences in asthma.

Copyright © 2020. Published by Elsevier Inc.