I had an allergist tell me about a study that supported this idea recently : Introduction of pig whipworm eggs into the digestive tract of IBS patients reduced symptoms for a some patients. Pretty fascinating actually.

I was seeing the allergist for my eczema and he asked me if I experienced symptom relief when traveling abroad, which I did in Honduras. He thought I may have been exposed to a parasite there that diverted my overactive immune response. go figure.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3149054/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1856386/

As I understood it the reason why some parasites can have beneficial impact on some autoimmune disorders is because they have evolved the ability to suppress the immune system, not because they overwork the immune system. But I've really only heard of this being a thing with IBS.

Less of an old myth and more like well accepted scientific fact: https://www.nature.com/articles/s41591-019-0675-0

Excess calorie intake causes chronic inflammation, which gradually causes a plethora of other problems. There's also autoimmune conditions as a consequence of viral infections, so many of that from covid in recent years.

I had terrible grass and pollen allergies until I started mowing my own lawn and gardening without gloves. Exposure therapy is a thing. It works at least for some people.

What you're referring to is inflammation and is real but kind of misunderstood.

If you want to reduce inflammation you should exercise regularly. This seems obvious but, to me, people will come up with conspiracy after conspiracy to explain this. But the basics - moving a bunch - work really well. The American Lifestyle is progressively more and more sedentary, and we're blaming our woes on sunscreen or something.