Helminths: More on Our Missing Old Friends

I just finished reading an interesting new article from the journal, Trends in Parasitology, “Can Parasitic Worms Cure the Modern World’s Ills?”[i]  A few highlights:

1. The first subsection is entitled, “Worms Really May be Good for You, After All.”  (Um…yup.)   “…exposure to such persistent, tolerated infections…appears to be required early in life for induction of the regulatory networks that prevent autoimmunity and allergic inflammatory responses to harmless agents, and also for the homeostatic resolution of infection-fighting inflammation, once the pathogen is cleared.”  That is, helminth infection early in life means a normally modulated immune response (protection from allergies and autoimmunity) for life.
2. Definitely! “The alarming rise in each of these [allergic and autoimmune inflammatory disorders, metabolic syndrome, and the chronic low-grade inflammation that characterizes aging] appears to shadow the dysbiosis of the macrobiota resulting from the sudden and swift eradication of organisms like helminths in rapidly developing societies.”
3. Helminths modulate the “epigenetic landscape of inflammatory cells.” That is, they can shape, via blood stem cells, immune responses that have become dysfunctional in inflammatory diseases, cancer and ageing.  That’s a new one for me!  The article goes on to point out that these reversible epigenetic changes in immunity can be transgenerational, and thus, the effects of helminth infection during pregnancy are particularly of interest.  The authors refer to, for example, a fairly recent study that showed that helminth infection during pregnancy reduced “airway hyper-responsiveness” (i.e. allergic asthma) in their children.
4. “…interest is beginning to focus on whether exploiting the ant-inflammatory and tissue-repair properties of helminths can improve life span or at least improve the wellbeing and health of our ageing populations…”
5. How about this one? Helminth “…infection can lower blood cholesterol and increase insulin sensitivity to protect against obesity and associated cardiovascular disease.”
6. This one too was entirely new to me: “…a recent report showed that helminth infection and commensal bacteria interact to…maintain skin barrier function in the context of repeated challenge by pathogens, findings with potentially important implications for skin pathologies.”
7. And finally one last super cool tidbit, especially for those interested in fecal transplant. You really might want to get your poop from someone who has helminths on board!  In a study on mice, allergic asthma was ameliorated in those inoculated with a particular kind of rodent roundworm.  Interestingly though, when the mice were given antibiotics, that protection vanished.  The researchers concluded that the macro and microbiomes work together to afford the protection.  How about this though?  Transferring the “worm-modified microbiota” was sufficient to transfer the protection against allergic asthma.  Way cool.

Amazing stuff!

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[i] Harnett, MM, Harnett, W. Can parasitic Worms Cure the Modern World’s Ills?  Trends in Parasitology: 2017 Sep;33(9):694-705. doi: 10.1016/j.pt.2017.05.007.