[ttraub]

There are numerous accounts on the internet of medical tourists trekking to Southeast Asia or Mexico to acquire helminths or similar parasitical organisms reputed to calm down the body's immune response. Specifically, sufferers of Crohn's Disease have reported relief from symptoms after taking in (via a cut in the skin, or walking barefoot in feces, or drinking contaminated water) a few helminths.[1]

Too many helminths seems to have deleterious effects, however, so there seems to be a balance that must be struck.

There is evidence that these worms affect the microbial mixture in the gut.[2]

Generally speaking, modern humans live in sterile conditions whereas we have ferocious immune systems which evolved to handle filthy conditions. The theory is, given too little work to do, some people's immune systems start to attack the self.

Anecdotally, I have an incredibly healthy daughter; we never hesitated to expose her to as many strangers as possible. "Would you like to hold our baby?" She also got mother's milk for several years (advantage of being an only child). Almost never gets sick and when she does, it's for less than 24 hours. Hopefully it stays that way :)

1. https://www.healthline.com/health/crohns-disease/hook-worms#...

2. https://www.sciencemag.org/news/2016/04/parasitic-worms-may-...

[lostlogin]

> modern humans live in sterile conditions whereas we have ferocious immune systems which evolved to handle filthy conditions.

Day care centres are what their immune system is designed to fight. I’m not sure how old your daughter is, but I have never been sicker than the few years my child attended one. I work in a hospital and my wife is a teacher, so it’s not like we weren’t exposed to bugs.

No matter how clean the child care centre, kids are a Petrie dish of horrible diseases.

[jxramos]

The thing I don't get is how does the immune system simply not "atrophy" like any other system in the body that doesn't get used?

[ttraub]

As I understand it, our immune systems are pretty busy even under today's sanitary conditions. We're constantly fighting off bacterial and viral invaders, 24x7. But, I guess we're just not as busy as we could be.

[eurasiantiger]

The modern western inland diet contains a lot of wheat and other grains which have more omega-6 than omega-3 polyunsaturated fatty acids. PUFAs are used in the synthesis of immune factors (interleukins, cytokines, ...) and this imbalance in the omega-3:omega-6 ratio causes more aggressive versions of those immune factors to be produced.

Then there’s sugar, processed food, work stress, particle emissions, microbes in indoor air... there are plenty of reasons for our immune system to attack itself.