your body speaks

Ep11: Digest & Defend – Fueling and Protecting Your Body

• Dr. Brook Sheehan

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In this episode of your body speaks, Dr. Brook Sheehan explores two vital functions that keep you thriving—digestion and immunity. Your gut does so much more than just break down food; it plays a central role in your immune system, brain function, and overall health. This episode uncovers the incredible ways your body processes nutrients, defends against threats, and adapts to its environment.

You’ll discover how digestion actually begins in the brain, why gut bacteria impact everything from mood to metabolism, and simple ways to support both your digestive and immune health.

Key Takeaways:

  • Digestion Starts in the Brain: How the cephalic phase of digestion triggers saliva, stomach acid, and enzymes before you even take a bite.
  • Your Gut’s Gateways: The role of key valves like the ileocecal valve in regulating food movement and preventing issues like bacterial overgrowth.
  • Why “You Are What You Absorb” Matters: The importance of gut integrity, enzyme production, and bile flow for proper nutrient absorption.
  • The Gut-Immune Connection: How 70% of your immune cells live in your gut and what that means for your ability to fight off illness.
  • Signs of Gut Imbalance: Bloating, brain fog, skin issues, and what your symptoms reveal about digestion and immune health.

Memorable Moments:

  • The Stomach Myth: Why it’s usually your intestines—not your stomach—causing digestive discomfort.
  • Fermented Foods & Gut Health: When probiotics and sauerkraut can help—and when they might make things worse.
  • Sneezing as an Immune Signal: What random sneezes can tell you about your body’s defense system.
  • Five Simple Immune-Boosting Steps: Small but powerful changes that can improve your body’s ability to fight off illness.

What to Expect in Future Episodes:

Next, we’ll explore dividing and depositing—how your body regenerates cells, strengthens bones, and maintains structural integrity for lifelong vitality.

Quote of the Episode:

"Your gut is the gateway to health—nourish it, protect it, and listen to its signals, and you’ll unlock a whole new level of well-being."

Connect with Dr. Brook:

Tune in now to learn how digestion and immunity work together to keep you strong, balanced, and thriving!

Oh, my stomach hurts. I ate, think I ate something bad. Oh, my stomach hurts. Does your stomach really hurt? Welcome to the Body Speaks podcast with me, Dr. Brooke Sheehan. Join me on a journey in discovering how to interpret the subtle signs your body uses to communicate with you. The whispers, the screams, and everything in between. Your body truly holds the answers for your health and well-being. It's time to discover them together. Let's dive in. Welcome back, my friend, to another episode of Your Body Speaks. Today, we are diving deep into digestion and immunity. But before I get into this, I want to share that this is part six of our Science of Being series. If you've been following along over the last four episodes, you know that we've been breaking down the incredible ways your body operates in perfect harmony when given the right support.

 In last episode, which was part five of this series, we talked about pumping and purging, how your organs help move fluid through the body, and the importance of elimination. If you missed it, be sure to go back and listen, because understanding how your body naturally moves things through the system is key to everything we are going to be covering today. And today's topic, what you eat fuels every single system in your body and your immune system. Well, that works tirelessly day in and day out to defend you from threats. But did you know that your gut also plays a massive role in both digestion and immunity? Yep. It’s not just about breaking down food. It’s about keeping you strong, balanced, and thriving. And in today's episode, we're diving into the gut system.

 What you eat fuels every single system in your body and your immune system. role in digestion and how to keep your immune system working the way that God designed it to. Are you ready? Let’s go. So let's start with digestion. You may think digestion begins in the stomach, but it actually starts in the brain. Crazy, right? This is called the cephalic phase of digestion. It is when your brain signals your body to get ready, triggering saliva production, stomach acid, and digestive enzymes. Just merely thinking and seeing food can kickstart the whole process. It is why food photography is such a lucrative business model. All the major food companies want your body salivating for their items. Now, here's something most people don't realize. Your digestive tract isn't just a long tube.

 It's actually made up of different sections separated by different gateways. Each of these gateways, like the lower esophageal sphincter, the pyloric valve, the ileocecal valve, and the valve of Houston, serve a crucial role in ensuring food moves properly through the whole system while keeping harmful substances out. The integrity of the gateway is key. If they aren't functioning properly, it can lead to acid reflux, bacterial overgrowth, or malabsorption. Have you ever heard that statement, 'you are what you eat'? That isn't entirely true. It's actually what you absorb that makes you, you. Everything is connected, and when one part isn't working, it does affect the entire system. So let's talk about two of these key valves, the ileocecal valve and the valve of Houston.

 Both of these sit on the lower portion of your body, and they're the ones that are most important. On either side, the ileocecal valve is on the right, the valve of Houston is on the left, and these act as mechanical doors, much like the sliding doors at the grocery store that open when you approach and close when you fully enter. When functioning properly, they regulate movement in the intestines. But if the valves get stuck open, you might experience diarrhea because waste is moving too quickly. But if they get stuck open, you might experience diarrhea; stuck closed, constipation can occur because things aren't moving at all. But the good news, you can physically stimulate these valves to encourage proper function. And this is a way to further strengthen your skills in listening and interpreting your body's signals.

 I will put a link in the show notes walking you through how to properly do this. It is important that you properly do this. But I want to take a moment here and give the stomach some justice. A lot of times when we're experiencing any sort of gastrointestinal distress, any sort of pain in our abdomen region, what is the first thing that you hear most people say if you haven't said it yourself? Oh, my stomach hurts. Oh, my stomach hurts. I think I ate something bad. Oh, my stomach hurts. Does your stomach really hurt? I really want to get the stomach off the hook, here, because the stomach sits right up here under your left rib cage. The stomach is housed underneath your left rib cage.

 And it is processing and dealing with a lot of things coming into it. It is the first place everything goes when it leaves the esophagus after going down the feeding tube of your body and it hits the stomach. After that, it goes into the small intestine, the large intestine, and ultimately excreted from your body. But is it really your stomach that's hurting? A lot of times, it's the stomach that's hurting. It's the stomach that's hurting. It's gastrointestinal pain. It's that small intestine, large intestine region of the body that is feeling the pain there. And we are giving the stomach too much or having the stomach carry too much of the weight on that. So I do want to say that it's not always your stomach that is hurting.

 It is actually more so your small intestine and your large intestine that's hurting. And when we use proper language, we can actually properly assign things to different areas. And this strengthens our ability to listen. This strengthens our ability to like dialogue with our body when we know proper anatomy. So that's another piece that we're going to be breaking down over the course of these episodes. And as we're learning, I'm going to be sharing different anatomical points for you to understand, like, whoa, yeah, you're right, Dr. Brooke, it isn't really my stomach because it's down here by my belly button. Okay, down there by your belly button. That's more your small intestine region. That's not your stomach that's hurting. And a lot of times when the stomach is actually, and this is a complete sidebar and a topic for a completely different episode.

 But a lot of times when the stomach is actually having problems in and of itself, the stomach truly having stomach problems, it starts to manifest as heart issues. People freak out. And we've been trained to believe that anything that's happening, if our heart is beating too fast, if something is going on, we start to believe we're having a heart attack as, you know, the most, as the biggest thing to fear; when in reality, there are a lot of different things that can go wrong. And so when stomach problems are truly stomach problems, because the stomach lives on that left side, it can actually manifest or, or look like a heart issue when in reality, it's not a heart issue. It's a stomach issue. And that's also a simple fix.

 Again, a topic for a whole different time, but I just wanted to get the stomach off the hook and stop taking the blunt of all the issues. So moving back into the digesting and the gastrointestinal, the tube from your mouth all the way down into your rectum. Another key player of this is your gut bacteria. Your gut is home to trillions. Yes. Trillions of bacteria. These little guys influence your mood, your metabolism, your blood sugar, your blood sugar, your blood sugar, your metabolism, and even your immune system. When your gut microbiome is balanced, everything runs smoothly; but it is when it is out of whack, you start seeing issues like bloating, brain fog, skin issues, and even a weakened immune system. Now, a lot of people think that popping a probiotic is the answer to all gut problems.

 And while probiotics can be helpful, the gastrointestinal tract also requires other pieces, such as digestive enzymes, stomach acid, bile production, proper valve function, gut lining integrity, and so on cannot be forgotten. Simply adding probiotics without addressing the whole system is like patching a leak without fixing the pipe because of the sheer size of the complexity of the gastrointestinal track alone. Probiotics may not be enough, friend. This is why I stress. So much the importance of listening to your body and developing the skillset to know what it is trying to say to you. If underlying issues like poor enzyme function, sluggish motility, that movement of your gut, and a valve problem, AKA gateway dysfunction, or an inflamed gut lining aren't addressed, those symptoms may persist despite taking the right supplements.

 It's important to take a full-body approach to gut. So what can you do to support your gut while you're developing the listening skills? Simple: cut back on processed foods. Your gut bacteria don't love them as much as you do; eat foods that fuel bacteria, think fiber, rich veggies and quality proteins, and not the same ones over and over have some variety. Your body does love diversity. One thing to know is that your gut bacteria don't love them as much as you do. And you've probably heard that eating probiotic-rich foods like fermented sauerkraut and kimchi are good for you, but I'd like to share a quick word of caution. As you are working on developing your intuitive skills and interpreting what is going on in your gut, experiment to see if you can handle fermented foods.

 If your symptoms of brain fog get worse or the bloating stays, likely you have something called small, intestinal bacteria overgrowth, and/ or a histamine intolerance. And if this is the case, fermented foods and probiotics actually are not for you. Stick with the fiber-rich veggies and quality protein as well as quality fats and see what happens then. Okay, off my sidebar. Let's talk about digestion support, chewing food thoroughly, eating in a relaxed state, and even drinking warm lemon water. Before meals can give your gut a much needed boost. Your body isn't designed to digest food when it's stressed. So slowing down, being mindful at mealtime makes all the difference. So here is some homework to do before the next episode.

 I'd like you to try a digestive reset this week, eliminate processed foods, dairy, and gluten, or at least pick one of these for just a few days. And if you don't like it, you can try a digestive reset. If you don't like it, you can see how your gut responds. Sometimes simple shifts make a big impact. Now let's talk immunity. Your immune system has two parts, your innate immunity and your adaptive immunity. Your innate immunity is like your body's first line of defense. It's always on guard, ready to attack anything unfamiliar. This is the immune system you were born with. Then there's the adaptive immunity. This is the immune system you were born with. Then there's the adaptive immunity. Which is more like a memory bank.

 It learns from past infections so it can fight them off better next time. Pretty cool, right? Isn't the human body freaking magnificent? It was created to adapt and protect us through all different seasons of life. And here's something else incredible about God's design. Your thymus gland, which sits right here above the breastbone, is a key player in immune development. It's a key player in your immune system. It's a key player in your immune environment. And it's larger in babies and children and shrinks as you age. Why? Because when you're young, we rely heavily on our innate immune system to protect us. But as we grow and encounter new pathogens, our adaptive immunity takes over, learning and remembering how to fight off invaders. This beautiful transition shows just how intelligently the body was designed to evolve with our environment.

 And it's a key player in your immune system. It's a key player in your environment. But here's the thing. When your immune system is overactive, it can actually cause problems. Think allergies, chronic inflammation, autoimmune issues. If you're constantly dealing with things like skin rashes, joint pain, frequent cold, your immune system might be working overtime. Processed foods, stress, poor sleep, all of these can impact your immune system and place it in a constant state of overdrive. And when that happens, it is not working efficiently or effectively. And guess what? Your gut plays a massive role in regulating your immune system. In fact, about 70% of your immune cells live in your gut. That means the state of your digestive health directly impacts your ability to fight off sickness. Here's something most people overlook: Sneezing.

 If you suddenly sneeze out of nowhere and it's not allergy related, that's actually your immune system gearing up, giving you a little nudge to pay attention. Maybe you're fighting something off before symptoms fully develop. So how do you keep your immune system strong and balanced? Here are a few simple steps. First thing, reduce sugar intake. Sugar weakens your immune system for hours. After you eat it, this is a big one. Any symptoms of achy body or congestion, stay away from sugar. Second one, manage your stress. Chronic stress depletes immune system function. Deep breathing, prayer, meditation, rest, all of these can help. Number three, support your gut. Yep, we're circling back to the beginning. A healthy gut means a stronger immune response. Number four, prioritize your sleep.

 Your immune system does its best work while you are at rest. Get your sleep when you're not feeling great. Number five, get outside. Fresh air, sunshine, and movement help regulate immune function. So here's the second part of your homework. I want you to choose one immune-boosting habit that I just mentioned and work through it this week. Maybe it's drinking more water, getting an extra hour of sleep, or maybe it's eating a lot of sugar out of your diet. These small changes do add up. All right, my friends, that's a wrap on today's episode. Your gut and immune system are so deeply connected. So the more you support one, the more you support the other. So let's recap the homework. From the digestion section, try a digestive reset by eliminating processed foods, dairy, or gluten for a few days.

 From the immune section, pick one of those immune-boosting habits and commit to it this week. And next time, we're going to be diving into how your body recreates itself through cell division and strengthens bones through depositing. You won't want to miss it. Please share this with a friend who can use a little gastrointestinal and immune-boosting support. And don't forget to like, subscribe, and comment. Thank you so much for watching. I'll see you next time. Subscribe to stay in the loop on all things [you]. Until next time, take care and be well.