Digestion + Immunity

My patients must think it odd that every time we have a conversation about immunity, it always comes back to the digestive tract. I can understand that, I guess. It’s just not what we grow up thinking about immunity!

What most people think about immunity involves avoiding getting sick, taking antibiotics, and applying antibiotic cream to wounds to keep them from becoming infected. Allergies are environmental things that we must avoid or take a pill to dull our senses to them. The only time medical doctors recommend taking probiotics is (perhaps) when prescribing antibiotics, as a way to head off the likely resulting yeast infection. So, I thought it might be useful to take a moment to examine how and why digestion is such an important part of immunity.

There are many reasons why, but for the purposes of this entry, I’ll focus on just three: the pH of the stomach, digestive enzymes, and probiotics.

The pH is the overall environment needed to destroy pathogens entering our bodies via food and water. This is intended to be extremely acidic, creating an environment in which the bad guys can’t survive, and also is the first step in breaking down food for digestion. Additionally, the proper pH is required to cue the release of other chemicals needed for the subsequent steps of digestion.

So why is this such a big deal? Well, if you ever watch TV, then you know that the answer to an upset stomach is to take Tums, Prilosec, or any number of other products and poof! You’ll feel better. But here’s the catch. Those magical products “work” by decreasing the acid in your stomach, whether that was your problem or not. And if you take them on any kind of regular basis, then you wind up permanently changing the pH in your stomach. This opens the door to bacterial and parasitic infection. You also interfere with the digestion of food, by not having the required acidity to open up certain foods to begin with, and then by not prompting the release of the other chemicals for digestion. All of this is sure to lead to an unpleasant cascade of health problems in the short term and the long term.

One of those outcomes may be insufficient enzyme release in the small intestine, where most of your nutrients are absorbed. If that occurs, then not only are you unable to get all your nutrients, but you also have larger molecules than you should further along in digestion. This can result in irritation of the digestive tract and possibly food sensitivities. Failure to digest your fats properly also means that you are unable to absorb fat soluble vitamins properly, such as vitamins A, D, E, and K. This failure of the proper sequence of events is disruptive to the cells of the small intestine.

Now to discuss those white knights of your digestive tract: probiotics. These are the naturally occurring yeast and bacteria in your small and large intestine that, if present in sufficient numbers, help to keep the riff-raff under control. If they are not sufficiently present, then opportunistic yeast and bacteria can grow excessively and make you sick. This is the most straightforward way to understand what these vital organisms do for you.

However, they play a much more significant and systemic role in your body than even that! They also seem to lower your risk of a number of things, from certain cancers throughout your body, to ear and respiratory infections, to atopic disease. We are learning more every day about the hundreds of strains of microbes and their purposes in health.

Unfortunately, the Standard American Diet (SAD) negatively impacts all of these important aspects of digestion. The high sugar, high fat, highly refined foods most Americans consume are predictably upsetting to digestion, leading to the dozens of commercials on the television about indigestion. But rather that advising people to alter the diet, they are instead advised to take this pill or that. And here we start down that slippery slope I mention above.

Secondly, the beneficial flora we call probiotics require a certain nutrient status to stay alive, and they are not fed sufficiently by the SAD. So, even if an individual never takes antibiotics (and who can say that?), they die off gradually anyway.

Most individuals would benefit from supplementation to restore some balance in the gut, in addition to eating a healthier diet complete with all the nutrients needed. Many people have a pH higher than they require; supplementation with Betaine-Pepsaine can help to restore the proper acidity. To ensure that the proper balance of enzymes is present, one can take a digestive enzyme before each meal. This can also help with managing food sensitivities. Reinoculation with probiotics can be helpful for a number of acute problems, such as diarrhea, yeast infection, or IBS, but it can also help in reinforcing the immune system in general, and providing all of the longer-term benefits discussed earlier.

Combine all of that with the fact that 70-80% of your lymphatic system is in your digestive tract, and you have the answer. This is why Dr. Renee keeps talking to you about your gut health.