Overview

• Parallel studies published in Nature Communications and The Lancet Microbe found that distinct microbial communities in the upper airway and gut correlate with lower incidence of severe viral respiratory infections in infancy.
• High levels of Bifidobacterium longum detected in gut samples from the first week of life were linked to a significantly reduced risk of hospital admission for viral lower respiratory tract infections within two years.
• Data revealed that viral episodes in infants often precede shifts in upper airway bacteria, including increases in Streptococcus and Moraxella that can drive secondary infections.
• Mode of delivery emerged as a determinant of initial microbiota composition, with vaginal birth favoring microbial signatures associated with respiratory resilience.
• Investigators are now examining causal pathways and designing precision probiotics to bolster beneficial microbes and prevent infant respiratory illnesses.