Exposure to pesticide residues impacts human gut microbiome – a biomonitoring study across Europe and Argentina

The SPRINT consortium assessed exposure to more than 200 pesticides and metabolites through a biomonitoring campaign collecting biospecimens from ~700 participants across 10 European countries and Argentina. Participants also wore silicone wristbands to capture environmental exposure. Here, we evaluated how measured pesticide residues are associated with gut microbiome composition, diversity, and functionality. Total pesticide burden in blood, urine, faeces and wristbands was significantly associated with microbiome composition, highlighting the importance of studying combined exposures rather than individual compounds. Higher pesticide concentrations were linked to a reduced abundance of several beneficial bacterial genera. Eight individual pesticides were associated with microbiome composition, with effect sizes comparable to established determinants such as alcohol consumption or age. To explore functional implications, bacterial gene families were mapped to Gene Ontology (GO) terms . Most tested compounds were associated with one or more GO terms., including pathways related to vitamin production and SCFA production. Overall, our findings indicate that a broader range of pesticides than previously recognized can impact the gut microbiome. Given the widespread and repeated exposure to pesticide mixtures, these findings raise concerns regarding potential unintended health impacts and underscore the need to integrate microbiome endpoints into future pesticide risk assessments.