Immune System Not in Your Gut

"Probably 50% of our direct immune system resides in or around the gut."

"Fully 60 percent of your adaptive immune system resides in your small intestine."

"70% of our immune system is located around the digestive system."

"About eighty percent of the full force of your defensive immune system resides in your intestines or gut."

With these "facts" floating around the internet, it was inevitable that someone concerned about milk allergy would get the idea that "the immune system resides in the gut." Sure enough, I saw this statement earlier today.

It's not true. At best, it's a misunderstanding of the role that the digestive system plays, but even that overstates the truth. In reality, it's sheer pseudoscience perpetrated by new age quacks who want to sell you their digestive enzymes or supplements or herbs or even weirder stuff. (Yes, of course our old friend NAET peddles this nonsense. Just one of many.)

The excuse that is given on these sites is often something they call "leaky gut syndrome." The mainstream medical community doesn't recognize this syndrome, and it's tough to find any medical journal articles that even address it. That doesn't matter to the alternative medicine gurus. Leaky gut appears to be yet another of the quackeries that started in the UK, that haven of ignorance about food, nutrition, and digestion, and was snapped up here in America by those looking to make a quick buck out of other peoples' ills.

It's as perfect a scam as can be imagined. Because it has no recognized existence alternative practitioners are free to invent any set of symptoms and cures they want to sell. Since all cures will be anecdotal, and many will simply involve taking an offending food out of the diet anyway, the cures might lead to an alleviation of symptoms for some. If they do, fine, that's a testimonial. If not, the sufferer will go on to another "cure." Heads they win, tails you lose.

For information that sticks to the real world of medicine, How Stuff Works has a good, plain-language explanation of the immune system. (Seventeen pages and no mention of leaky gut!)

Another straightforward set of pages are those on Allergic Reaction at eMedicinehealth.com.