Exposure to metal mixtures may decrease children’s cognitive flexibility via gut microbiota

Previous studies on metals and children’s cognition were mostly on single metal; however, real exposure environment is mixed and complex. Although recent studies on metal mixtures show the overall effect on children’s cognitive ability, the underlying mechanism is still unclear. This study aimed to explore the overall effects of multiple metals on children’s cognitive flexibility and identify key metals and their possible mechanisms. This is a case-control study in 19 children aged 10–11 years to explore the mixed effects analysis of single-metal and overall effects of 19 urinary metals mixture using the bayesian kernel machine regression (BKMR) model. We found that exposure to 19 metals mixture has an adverse effect on the cognitive flexibility of children. We were able to identify that Cu, Co, Al, and Pb are the key metals that affect children’s cognitive flexibility in metal mixtures exposure. Key metals may affect children’s cognitive flexibility by disturbing the gut microbiota. This study provided new evidence about the impact of exposure to metal mixtures on children’s cognition. More research are needed to confirm our results and further elucidate the underlying mechanisms of gut microbiota.