Influenza A Infection Causes Changes in Microbiome and Brain Gene Expression

Recent research has revealed that influenza A virus infection can significantly disrupt the microbiome in both the nasal passages and gut, and may also lead to detrimental alterations in brain gene activity, specifically within the hippocampus, a key area involved in learning and memory. The study, conducted using a neonatal piglet model—which closely mimics human physiology—found that piglets infected with influenza A exhibited notable shifts in microbial communities and gene expression patterns.

Importantly, maternal vaccination against influenza during pregnancy appeared to offer protective effects. Piglets born to vaccinated sows showed fewer harmful microbiome changes and less disruption in hippocampal gene function compared to piglets of unvaccinated mothers. These findings underscore the potential of maternal immunization to safeguard offspring against neurodevelopmental risks associated with influenza infection.

The study also highlights the role of the microbiome in normal brain development. Alterations in microbial populations, especially the increase in potentially pathogenic microbes in the nasal cavity, correlated strongly with changes observed in hippocampal gene expression. This research suggests that the microbiome could be a critical factor mediating the impact of influenza A on brain health.

Led by Professor Ying Fang and Professor Christopher Gaulke at the University of Illinois Urbana-Champaign, the scientists emphasized that this investigation is among the first to connect maternal vaccination, microbiome stability, and hippocampal gene activity in a neonatal model. Future studies aim to elucidate the precise mechanisms by which influenza virus influences these biological pathways.

Overall, these findings support the importance of influenza vaccination during pregnancy as a strategy to protect infant brain development and reduce long-term health complications, including cognitive deficits, diabetes, asthma, and allergies. Continued research in this field could pave the way for novel interventions that enhance neurodevelopmental health in children exposed to viral infections.