Healthy Gut Function Can Boost Your Immune System


By Dr. Justin Marchegiani

Healthy gut function can help improve and boost your immune system.  It is your gut that helps to improve your body’s ability to fight infections. Our localized immune system is where 80% of your immune system is.

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GALT – Gut-associated lymphoid tissue

Your gut is interacting with food every day and you do not get want to get weak in regards to your body and your immune system. Don’t make your immune system go after bad foods.  Eat whole foods and following a paleo template is a good approach. You don’t want your immune system stressing out because of certain foods that are coming into play whether it is gluten, refined whole dairy, lots of refined sugar, and bad things like that. We have similar stuff happening with the small intestine where we have a lot of microvilli which are kind of like little vacuum cleaners that will like suck up a lot of the nutrients and vitamins that we take.

MALT – Mucosa-associated lymphoid tissue

These are where your immune cells live.  If we have infections, that is going to create stress on the microvilli. Celiac disease wear down microvilli and that affects your body’s ability to absorb nutrition as well as affects your immune system, too.  I find that a lot of people have a weak immune system because of their gut.  It is not so much that their gut is weak but it’s that their gut is so preoccupied fighting things it should not be having to fight.

In the small intestine we have other nutrients that are vital for our immune system. We have a couple of things that are being produced:

  • We have different kinds of B vitamins — B1 or thiamine, B2 or riboflavin, B3 or niacin, B9 or folate, and B12 or methylated B12.  These are really important. We also have butyric acid. Butyrate is the same kind of fat we see in butter but butyric acid is going to make it harder for a lot of the bad bacteria to grow.  So infections, bacteria and viruses tend to not like in acidic environments as it makes it harder for those critters to grow and our immune cells love that.  It keeps the immune system strong.  Good fatty acids are our immune system’s friend.
  • We also have things like Vitamin C which you’re not going to get as much of that but you need healthy absorption of these nutrients. If you have good vitamin C in there or if you are consuming vitamin D, you need to absorb it.  So we need to have good gut function to absorb.
  • We also have Vitamin K1 and K2 which are very important.
  • Zinc and a lot of minerals that we need good hydrochloric acid levels from.

How the localized immune system works

When you create an antibody and you tag a protein.  Let’s say you have this virus. What happens is we tag it with an antibody. So have you ever gone to like a big city like San Francisco? I used to live there.  You park your car, right? And the parking attendants would come by and they put a piece of chalk and they put a mark across the back tire and what we used to do, we used to come back and erase that mark, but that mark was there to tag, the tag use and then when they come back an hour later if you were still there they knew you were there and they wrote you a ticket.  We used to like erase that but your immune system is doing something similar. It is tagging that virus and then that allows other immune cells, other T cells or natural killer cells to kind of come in there and be able to attack it later.  So your immune system tags stuff very similarly and with a healthy gut function, because so much of your antibodies are here in the GALT and the MALT, it really, really helps your immune response.


Autoimmunity starts in the gut and it starts in the gut via leaky gut.  We have gut permeability and again, leaky gut is the same thing as gut permeability.  Those tight junctions open up and it allows undigested food particles to get into the bloodstream which stresses out the immune system.  Alessio Fasano, a gastroenterologist at Harvard, says that almost all autoimmunity starts in the gut and if you have an increased autoimmune response, you are going to have a weakened immune system.

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The entire contents of this website are based upon the opinions of Dr. Justin Marchegiani unless otherwise noted. Individual articles are based upon the opinions of the respective author, who retains copyright as marked. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from the research and experience of Dr. Justin and his community. Dr. Justin encourages you to make your own health care decisions based upon your research and in partnership with a qualified healthcare professional. These statements have not been evaluated by the Food and Drug Administration. Dr. Marchegiani’s products are not intended to diagnose, treat, cure or prevent any disease. If you are pregnant, nursing, taking medication, or have a medical condition, consult your physician before using any products.