Sex effects in the association between airway microbiome and asthma

Abstract

Background: Sex differences exist in asthma susceptibility and severity. Accumulating evidence has linked airway microbiome dysbiosis to asthma, and airway microbial communities have been found to differ by sex. However, whether sex modifies the link between airway microbiome and asthma has not been investigated. Objective: To evaluate sex effects in the association between airway microbiome and asthma. Methods: We analyzed induced sputum samples from 47 subjects (n ¼ 23 patients with asthma and n ¼ 24 normal controls) using 16S ribosomal RNA gene sequencing methods. The bacterial composition was analyzed for sex differences. Bacterial associations with asthma were assessed for each sex at the core taxa and genus levels. Results: The microbiome in induced sputum differed in women vs men at the community level. A total of 5 core bacterial taxa were found in all samples. No sex-specific core taxa were detected. The most abundant core taxon, Streptococcus salivarius, was significantly enriched in women than in men (P ¼ .02). Within each sex, individuals with relatively lower abundance of S salivarius were more likely to have asthma (P ¼ .006). For both sexes, increased Lactobacillus species were found in sputum samples of patients with patients compared with normal controls (adjusted P ¼ .01). Haemophilus species were associated with asthma in men and not in women. Conclusion:The airway microbiome differed by sex, and sex effects exist in the association of airway microbial markers and asthma. Future airway microbiome studies may yield better resolution if the context of specific sex is considered. The airway microbiome is a potential mechanism driving sex differences in asthma.

Sex Variations in the Oral Microbiomes of Youths with Severe Periodontitis

“…Leptotrichia, Prevotella_7, and Prevotella_2 showed no significant difference between males and females. Furthermore, no difference was found between males and females regarding the Simpson and Shannon indices, indicating a large number of similar strains in males and females, which is consistent with the results reported by Chen et al [ 41 ]. In contrast to our results, when Belstrøm et al used microarrays to examine the oral microbiomes of 292 Danish individuals with low levels of dental caries and periodontitis, they found that diet, BMI, age, and sex did not significantly affect microbial abundance, though socioeconomic status affected the oral microbiome profiles [ 42 ].…”

The salivary and nasopharyngeal microbiomes are associated with SARS‐CoV‐2 infection and disease severity

“…On the other hand, Lactobacillus in the upper respiratory tract microbiome was significantly associated with mortality in SARS‐CoV‐2‐positive patients 53 . It is worth noting that several studies, including a previous study from our group, have shown associations between increased Lactobacillus in the airway microbiome and respiratory diseases such as asthma and chronic obstructive pulmonary disease, indicating Lactobacillus may not be beneficial when present in the airways 22,54–56 …”

“…Before microbial DNA extraction, samples were heated at 56°C for 30 min to inactivate SARS‐CoV‐2 virus. Microbial DNA extraction of saliva and nasopharyngeal swab samples, sequencing library preparation, and 16S rRNA gene sequencing were performed as described previously 22 . Briefly, genomic DNA was extracted from nasopharyngeal swab and saliva samples using the zymoBIOMICS DNA Miniprep Kit (Zymo Research) according to the manufacturer's instructions.…”

Gender Variations in the Oral Microbiomes of Elderly Patients with Initial Periodontitis

“…A 16S rRNA gene sequencing analysis of sputum samples from patients with asthma and normal controls found that Haemophilus spp. are associated with asthma in men but not in women [ 40 ]. On the other hand, in contrast to the present study, Raju et al found a high relative abundance of Haemophilus in the saliva microbiota of females [ 41 ].…”