Glucose-mediated expansion of a gut commensal bacterium promotesPlasmodiuminfection through alkalizing mosquito midgut

Abstract

SUMMARYDietary sugar is the major energy source for mosquitoes, but its influence on mosquitoes’ capability to transmit malaria parasite remains unclear. Here we show thatPlasmodium bergheiinfection changes global metabolism ofAnopheles stephensiwith the most significant impact on glucose metabolism. Supplementation of glucose or trehalose (the main hemolymph sugar) to mosquito increasesPlasmodiuminfection by alkalizing the mosquito midgut. The glucose/trehalose diets promote rapid growth of a commensal bacterium,Asaia bogorensis, which remodels glucose metabolism and consequently increases midgut pH. The pH increase in turn promotesPlasmodiumgametogenesis. We also demonstrate the sugar composition from different natural plants influencesA. bogorensisgrowth andPlasmodiuminfection is associated with their capability to expandA. bogorensis. Altogether, our results demonstrate that dietary glucose is an important factor that determines mosquito’s competency to transmitPlasmodiumand further highlight a key role for mosquito-microbiota metabolic interactions in regulating development of malaria parasite.