PT - JOURNAL ARTICLE AU - David Fast AU - Aashna Duggal AU - Edan Foley TI - <em>Lactobacillus plantarum</em> is a pathobiont for adult Drosophila AID - 10.1101/049981 DP - 2016 Jan 01 TA - bioRxiv PG - 049981 4099 - http://biorxiv.org/content/early/2016/04/22/049981.short 4100 - http://biorxiv.org/content/early/2016/04/22/049981.full AB - Pathobionts are a unique class of symbionts that cause fulminant, and potentially life-threatening disease in animal hosts under specific circumstances. Despite the relevance of pathobiont containment for prolonged health, we know verylittle about the basis for pathobiont-dependent disease in an animal host. We found that mono-association of adult Drosophila with Lactobacillus plantarum, a widely reported fly commensal, and member of theprobiotic Lactobacillus genus, curtails adult longevity and causes extensive intestinal pathology within the host. Intestinal disease includes widespread loss of progenitor cells, disrupted epithelial organization, and impaired barrier function. We show that this phenotype is reverted in flies mutant for the immune deficiency gene, a regulatory component of fly innate defenses against gut bacteria. Our study uncovers a previously unknown pathogenic aspect of Lactobacillus plantarum association with Drosophila and establishes a simple model for the mechanistic exploration of pathobiont biology.