The traditional idea of symbiosis—long-term interactions between two organisms—is that the participants mutually benefit each other. However, researchers have debated whether the interests of the symbionts always line up with the hosts they inhabit, or whether genes that benefit symbionts might come at the expense of their hosts. A new study investigates this question through genomic sequencing and infecting plant hosts with their microbial symbionts.

The era of COVID-19 and the need to constantly wash one's hands and sanitize things have brought microbes to new levels of scrutiny, particularly for their impact on an individual's health.

While associations between microbes and their hosts, from the beneficial - think probiotics in yogurt - to the harmful - such as with viruses spread by touch - have long been known, little is known about how microbes evolve and how their evolution affects the health of their hosts.