Nasal microbiota and symptom persistence in acute respiratory tract infections in infants

Area of Science:

• Microbiology
• Pediatrics
• Immunology

Background:

• Infant acute respiratory infections (ARIs) may contribute to chronic respiratory conditions.
• The interaction between viruses, bacteria, and the host in infant ARIs is not fully understood.
• Nasal microbiota plays a crucial role in respiratory health and disease susceptibility.

Purpose of the Study:

• To investigate changes in nasal microbiota composition from the onset of the first symptomatic ARI in infancy to 3 weeks later.
• To explore associations between nasal microbiota dynamics and the duration of respiratory symptoms.
• To examine potential links with host, environmental, and viral factors influencing ARI outcomes.

Main Methods:

• Prospective study involving 167 infants.
• Nasal microbiota analysis using 16S ribosomal RNA-encoding gene sequencing at two time-points.
• Hierarchical clustering to identify infant microbiota clusters at ARI onset and 3 weeks post-onset.

Main Results:

• Five distinct nasal microbiota clusters were identified at ARI onset, reducing to three clusters after 3 weeks.
• Symptom persistence was significantly overrepresented in the Streptococcaceae-dominated cluster and underrepresented in the 'Others' cluster (p<0.001).
• No association was found between symptom duration and the type of respiratory virus identified.

Conclusions:

• Infant nasal microbiota composition changes significantly following the first symptomatic ARI.
• Distinct microbial profiles are associated with prolonged respiratory symptoms, suggesting a role in symptom persistence.
• These findings underscore the importance of microbiota-host interactions in infant respiratory recovery.