The influence of pre- and postnatal exposure to air pollution and green spaces on infant's gut microbiota: Results from the MAMI birth cohort study.

Background: Animal and human studies indicate that exposure to air pollution and natural environments might modulate the gut microbiota, but epidemiological evidence is very scarce.
Objectives: To assess the potential impact of pre- and postnatal exposure to air pollution and green spaces on infant gut microbiota assembly and trajectories during the first year of life.
Methods: MAMI ("MAternal MIcrobes") birth cohort (Valencia, Spain, N = 162) was used to study the impact of environmental exposure (acute and chronic) on infant gut microbiota during the first year of life (amplicon-based 16S rRNA sequencing). At 7 days and at 1, 6 and 12 months, residential pre- and postnatal exposure to air pollutants (NO ₂ , black carbon -BC-, PM _2.5 and O ₃ ) and green spaces indicators (NDVI and area of green spaces at 300, 500 and 1000 m buffers) were obtained. For the association between exposures and alpha diversity indicators linear regression models (cross-sectional analyses) and mixed models, including individual as a random effect (longitudinal analyses), were applied. For the differential taxon analysis, the ANCOM-BC package with a log count transformation and multiple-testing corrections were used.
Results: Acute exposure in the first week of life and chronic postnatal exposure to NO ₂ were associated with a reduction in microbial alpha diversity, while the effects of green space exposure were not evident. Acute and chronic (prenatal or postnatal) exposure to NO ₂ resulted in increased abundance of Haemophilus, Akkermansia, Alistipes, Eggerthella, and Tyzerella populations, while increasing green space exposure associated with increased Negativicoccus, Senegalimassilia and Anaerococcus and decreased Tyzzerella and Lachnoclostridium populations.
Discussion: We observed a decrease in the diversity of the gut microbiota and signs of alteration in its composition among infants exposed to higher levels of NO ₂ . Increasing green space exposure was also associated with changes in gut microbial composition. Further research is needed to confirm these findings.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mireia Gascon reports financial support was provided by Carlos III Health Institute Health Sciences National Library. Maria Carmen Collado reports financial support was provided by European Research Council. Maria Carmen Collado reports financial support was provided by Government of Valencia. Maria Carmen Collado reports financial support was provided by Horizon Europe. Maria Carmen Collado reports financial support was provided by Spanish Ministry of Science and Innovation. Anna Samarra reports financial support was provided by Government of Valencia. Anna Samarra reports financial support was provided by European Social Fund. Raul Cabrera Rubio reports financial support was provided by Government of Valencia. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)