About a year ago, Philipp Schwabl, a research scientist and physician specializing in intestinal diseases at the Medical University of Vienna, read an article about plastic pollution and started to connect the dots. About 8 million metric tons of plastic waste enters the oceans every year; eventually those bottles and bags break down into particles. Schwabl wondered whether tiny plastic particles—known as microplastics—are entering the food chain and being consumed by people and, if so, whether they could harm cells and tissue in the human gut. Schwabl could find no definitive answers, so he decided to undertake his own study. Serendipitously, he discovered that Bettina Liebmann, an analytical chemist who heads Environment Agency Austria’s effort to analyze microplastics, was based a few minutes’ bicycle ride away. The pair teamed up and in October 2018 released the outline of a small pilot study, now undergoing peer review, that they say is