The mosquito microbiota influences vector competence for human pathogens

• The midgut of mosquito disease vectors contains a diverse microbial flora.
• The microbiota can modulate the mosquito immune response and influence vector competence to human pathogens.
• The microbiota can alter susceptibility to infection through either immune priming or direct inhibition.
• The tripartite relationship between mosquito, its microbiota, and human pathogens is critical to disease transmission.
• Dissection of this tripartite interaction may lead to novel powerful tools that can complement current strategies for disease control.

The midgut of insect vectors of human disease contains not only pathogens harmful to human health, but also a diverse microbiota. This microbiota can influence insects’ susceptibility to human pathogens, and the capacity to transmit them, through different mechanisms. Understanding the interaction between the vector, its microbiota and transmitted pathogens will provide novel opportunities to limit disease transmission.