Autoimmunity and Exposure to Animals and Dirt

Autoimmune conditions are more common in westernized societies. This is in part because we lack exposure to dirt and animals, which help to tone our immune systems. This would suggest that increasing your exposure to dirt and animals could help balance your immune system. This can be true, but it is not an absolute rule. In fact, one study has shown that visiting a farm can actually increase asthma. Let’s discuss.

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Autoimmunity and Exposure to Animals and Dirt

Dr. Michael Ruscio: Hi, this is Dr. Ruscio. Let’s discuss exposure to dirt and animals and how that impacts autoimmunity. You’ve likely heard that westernized societies, because of lack of exposure to dirt and animals and because of their high levels of hygiene, have higher levels of autoimmune conditions, like Hashimoto’s thyroiditis, multiple sclerosis, rheumatoid arthritis, celiac disease, inflammatory bowel disease, what have you. Yes, this is true.

And a definite factor in this is the fact that we need exposure to dirt, animals, bacteria, what have you, to train our immune systems as they’re developing so as to prevent our immune systems from attacking ‘self.’

And that’s essentially what an autoimmune condition is. It’s when you have an immune cell that attacks a healthy cell of your body that it shouldn’t.

So one of the ways that we can make sure the immune system develops is by having this early life exposure to dirt, animals, bacteria. And that exposure helps train the immune system so it has a good aim, and the immune cells will only kill bad stuff and not attack healthy tissue of your body as it does in autoimmune conditions.

So this has led to the thinking that, “Well, if I am a young adult or an adolescent or a full-grown adult and I have an autoimmune condition or an immune-mediated condition, like allergy or eczema or what have you, perhaps exposure right now to more dirt and bacteria and animals can help with that condition.”

And this is certainly an understandable hypothesis. And there’s certainly some evidence showing that by gaining exposure to animals, to dirt, visiting the forest, visiting the farm, what have you, can help with autoimmune conditions and immune-mediated conditions.

But it’s not an absolute rule. And this is very important. And this is what brings me to a study Trusted SourcePubMedGo to source I wanted to discuss, which essentially showed that for those that already had certain forms of immune-mediated conditions—in this case, specifically asthma—visiting a farm actually made the asthma worse. And I’ll put the study abstract up here on the screen.

And I’ll quote for you, and I’m actually paraphrasing: our findings suggest that intermittent exposure to farm animals increased the risk of allergic asthma in urban children visiting farms.

So some key points there. Urban children, meaning they did not grow up on a farm, but they’re visiting a farm, actually increased asthma.

Now, why is this? It’s probably because you need to be growing up in an environment for that environment to be healthy for you. So if you grow up on a farm, you have a very well-tuned or toned immune system that can deal with lots of exposure to dirt and animals and what have you.

But if you did not grow up on the farm, you don’t have that level of training for an immune system. So when you just visit the farm periodically, your immune system may not know what’s going on. And it may react negatively, as we saw in this study where they actually showed that, ironically, visiting a farm actually made asthma worse.

Now, I’ll give you another example. We see many people in hunter-gatherer bands have a high level of bacteria in their intestines. And they also eat a high carbohydrate, high fiber diet.

And what happens sometimes is we think that that will be healthy for westerners with gut conditions like IBS and IBD. And while in some ways and cases it can be, there’s also certainly a subset of people where eating a higher carb, higher fiber diet actually makes them much worse.

And they need the opposite, which is actually eating a lower carb and a lower fermentability-type diet, as seen in diets like the low FODMAP diet.

So what this all means is that the immune system is complex. And what works for one group will not necessarily work for another group. Meaning, if you grew up on a farm, being on a farm is healthy for you. But if you did not grow up on a farm, visiting the farm may not be healthy for you.

And to outline that a little more, if you grew up on a farm, you’re likely going to have less asthma and other immune-mediated and autoimmune conditions. But it doesn’t mean that if you did not grow up on the farm and then you visit the farm you’ll help things like asthma and immune-mediated and autoimmune conditions.

So coming back to the other example of the gut, if you grew up in a hunter/gatherer band with lots of bacterial exposure, eating high carb/high fiber diets, and you have great digestion, it doesn’t mean that if you grew up in the United States and you, at age 28, tried to go on that higher carb/higher fiber diet it would work well for you. It may, but we want to make sure not to miscontextualize some of these things.

So the immune system is complex. Not every finding in one group of people is going to be helpful for another group of people. What I really think this all comes down to is learn to listen to your body.

If you read a bunch of information that says that people that grow up on farms have less inflammation, less asthma, less allergy, it doesn’t mean that if you did not grow up on a farm you can visit a farm and expect to garner those same benefits.

And also, if you did not grow up in a non-westernized, hunter/gatherer-type society, it doesn’t mean that you may benefit from that type of diet.

But if you learn to listen to your own body, you’ll eventually find your own truth instead of getting misled by different information that you read.

And of course, sometimes that information can be helpful and can lead you to what will ultimately be helpful for you. But it’s always important to make sure you listen to your own body and trust in the experience that you’re having.

So in this case, a very interesting study that shows that even though farm life has been shown to be protective for the immune system, it seems that you need to have exposure to that farm life from early in life—infancy, maybe even in utero onward—to garner the full benefit.

And if you don’t grow up in that atmosphere but you just visit the farm, it may actually be slightly deleterious for your health for some people. So always remember to listen to your body and take your own experience into account.

So this is Dr. Ruscio. I hope this information helps you get healthy and get back to your life. Thanks!

If you need help with autoimmunity,
click here.
To be notified when my print book becomes available & get a free gut health eBook, click here
If you are a healthcare provider looking to sharpen your clinical skills, click here.

What do you think? I would like to hear your thoughts or experience with this.

Dr. Ruscio is your leading functional and integrative doctor specializing in gut related disorders such as SIBO, leaky gut, Celiac, IBS and in thyroid disorders such as hypothyroid and hyperthyroid. For more information on how to become a patient, please contact our office. Serving the San Francisco bay area and distance patients via phone and Skype.


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