STD: Edited by Joseph A. DuncanHost–vaginal microbiota interactions in the pathogenesis of bacterial vaginosisMuzny, Christina A.a; Łaniewski, Pawełb; Schwebke, Jane R.a; Herbst-Kralovetz, Melissa M.b Author Information aDivision of Infectious Diseases, University of Alabama at Birmingham, Birmingham, Alabama bUniversity of Arizona College of Medicine, Phoenix, Arizona, USA Correspondence to Christina A. Muzny, MD, MSPH, Medicine & Epidemiology, Division of Infectious Diseases, University of Alabama at Birmingham, ZRB 242, 1530 3rd Avenue South, Birmingham, AL 35294, USA. Tel: +1 205 975 3298; fax: +1 205 975 7764; e-mail: [email protected] Current Opinion in Infectious Diseases 33(1):p 59-65, February 2020. | DOI: 10.1097/QCO.0000000000000620 Buy Metrics Abstract Purpose of review The cause of bacterial vaginosis, the most common cause of vaginal discharge in women, remains controversial. We recently published an updated conceptual model on bacterial vaginosis pathogenesis, focusing on the roles of Gardnerella vaginalis and Prevotella bivia as early colonizers and Atopobium vaginae and other bacterial vaginosis-associated bacteria (BVAB) as secondary colonizers in this infection. In this article, we extend the description of our model to include a discussion on the role of host–vaginal microbiota interactions in bacterial vaginosis pathogenesis. Recent findings Although G. vaginalis and P. bivia are highly abundant in women with bacterial vaginosis, neither induce a robust inflammatory response from vaginal epithelial cells. These early colonizers may be evading the immune system while establishing the bacterial vaginosis biofilm. Secondary colonizers, including A. vaginae, Sneathia spp., and potentially other BVAB are more potent stimulators of the host–immune response to bacterial vaginosis and likely contribute to its signs and symptoms as well as its adverse outcomes. Summary Elucidating the cause of bacterial vaginosis has important implications for diagnosis and treatment. Our current bacterial vaginosis pathogenesis model provides a framework for key elements that should be considered when designing and testing novel bacterial vaginosis diagnostics and therapeutics. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.