Effects of Microplastic on Human Gut Microbiome: Detection of Plastic-Degrading Genes in Human Gut Exposed to Microplastics—Preliminary Study

Microplastics are major pollutants in the environment, and it is currently established that microplastics have already entered human food chains and been incorporated into the human body through ingestion and inhalation. Several works in animal models have already reported the adverse effect of microplastic exposure on biological systems; however, the effect of microplastic contamination on human health is still far from understood. In previous work, we reported microplastic contamination in the digestive tract of the Indonesian coastal and highland population. Using the same stool samples, we extended our previous work by investigating gut microbial composition in samples with and without microplastic contamination using next-generation sequencing. We found that microplastic contamination does not affect overall gut microbial composition and the abundance of gut-health-related genes. However, we found a negative and positive correlation between specific types of microplastics with certain bacterial taxa, especially from the genera Roseburia, Clostridium, and Prevotella. Despite the lack of a profound effect on the gut microbiome, we detected for the first time the presence of genes encoding plastic-degrading enzymes in the human gut microbiome, suggesting an adaptation of gut microbiome to microplastic contamination.