Scientific American finds that we really do need to get some worms to stay healthy:
At one point in the not too distant past we had three lines of defense against disease: the immune system, the microbiome, and fauna, like intestinal worms. William Parker, an immunologist at Duke University Medical Center likens these lines of defense to a three-legged stool to illustrate this relationship.
The intestinal worms, known as helminths, are part of the macrobiome—a term largely unknown in the realms of the general public and science nerds alike. This is partly due to the fact that current research on the macrobiome is dwarfed by the over-abundance of research on the microbiome (ironic, isn’t it?). But more likely it’s a novel term due to the fact that since the 1960s, in developed nations, we’ve all but eradicated the macrobiome. Without that third leg, our defense system collapses.
Now there’s growing evidence that the constant pressure actually helped tone and develop our immune systems as our immunity evolved along with the worms and bugs that lived inside of us.
Without that constant pressure our immune systems have an annoying tendency to over-react, much like the Hulk, blowing out of proportion over that harmless pollen grain that could trigger allergic responses, and misinterpreting our own bodies as something that needs to be destroyed, as can be seen in autoimmune disorders.
[Parker’s team] found that by adding a single helminth they saw the microbiome shift to a much more “healthy-looking” state.
“It’s very difficult to decipher the fingerprint of a healthy microbiome,” admits Erin McKenney, a Ph.D. candidate in the biology department at Duke University, and lead author on the study. “But, what you can do is eyeball these big shifts in bacterial communities.”