PLoS Pathogens: Influence of Microbiota on Viral Infections

With the advent of the Human Microbiome Project, we are now aware of the number and diversity of microbes that make the human body their primary place of residence. Consequently, the microbiota can no longer be ignored when studying host–pathogen interactions. The influences of microbiota on virus infections could be either protective or detrimental for the host. Whereas the microbiota positively regulate adaptive immune responses against influenza, they suppress antivirus adaptive responses against MMTV and facilitate replication of poliovirus and reovirus by enhancing virus attachment to target cells. Thus, microbiota play a dual role in virus–host interactions. An open question that currently drives research related to microbiota is how the microbiota can be manipulated so that the host is protected from deleterious infections. In the case of pathogens that take advantage of the microbiota, one can hope to find a way to ablate these interactions, thus preventing pathogen spread/propagation. This could be done either by manipulating the composition of the microbiota (ablation of a specific microbe exploited by a virus) or by blocking interactions between the viral pathogen and specific bacterial compounds that benefit the pathogen. Future discoveries in the area of microbiota–pathogen interactions will undoubtedly unveil new opportunities for therapeutic interventions in infectious disease.