In the microscopic life that thrives around coral reefs, researchers have discovered an interplay between viruses and microbes that defies conventional wisdom. As the density of microbes rises in an ecosystem, the number of viruses infecting those microbes rises with it. It has generally been assumed that this growing population of viruses, in turn, kills more and more microbes, keeping the microbial population in check. It’s a model known as “kill-the-winner” — the winners being the blooming microbial cells and the killers being the viruses (mostly bacteria-killing viruses known as bacteriophages) that infect them.
When you think parasites you probably don’t think of anything helpful. However, this isn’t the case and certain parasites inadvertently help the host by helping themselves. In fact, researchers have discovered how intestinal worm infections cross-talk with gut bacteria to help the immune system.