This interdisciplinary project attempts to capture the first evidence of communication between the gut microbiome and the germline in humans. Work by the Hackett group and others has shed light on this “gut-germline axis” across phyla, with recent work in mice showing that the paternal gut microbiome can affect offspring fitness. By combining machine learning approaches on cohort study data with in vivo (mouse) and in vitro (cell culture) experiments, we hope to bring novel insights into the role of the microbiome on human reproduction and its impact on the next generation.