Impacts of inhaled exposures on the upper respiratory tract microbiome: a systematic review

Overall, the URT microbiome remains understudied as a mediator of respiratory health effects related to inhaled exposures, while methodological heterogeneity complicates comparability across studies. Future research should prioritise benchmarked protocols, longitudinal designs, and functional analyses (e.g. metagenomics) to clarify how inhaled exposures alter microbial activity, resilience, ecological interactions, and host outcomes. This synthesis highlights the need for integrated environmental health approaches and for assessing the long-term consequences of inhaled exposures.