When a patient walks into my office, their skin is the first thing I see, and what I’ve found in my almost 30 years as a gastroenterologist, is that what is going on in your gut almost always shows up on your skin. In this episode, I’m going to go over the connection between what’s happening in your gut, and what’s going on in your skin.
Thank you for being a part of our community! For the latest in digestive wellness go to https://gutbliss.com/ and follow us on Instagram for more gut health info.
When it comes to your appearance, your GI tract might actually play a bigger role than your genes, because without a healthy gut, it’s really hard to have healthy skin. Your digestive tract is like the soil, and your skin is like the plant; if the soil isn’t in good shape, the plant is not going to bloom properly.
On today’s show, when a patient walks into my office, their skin is the first thing I see. Before I examine their abdomen or do a rectal exam or take a look at their colon; before I do any of that, the first thing that I notice is their skin. And what I have found in my almost 30 years as a gastroenterologist, is that what is going on in your gut almost always shows up on your skin. Just like how an ophthalmologist can diagnose high blood pressure or diabetes or even some types of cancer when they examine your eyes; I can tell a lot about your gut health by examining your skin. And sometimes when I’m all up in someone’s skin checking out their rosacea or their acne, they ask me: “Aren’t you supposed to be a butt doctor? Why are you so focused on my skin?” And yes, it’s true, I am a frustrated dermatologist, but my interest stems from this profound connection between the two organs. In this intro episode, I’m going to go over the connection between what’s happening in your gut, and what’s going on in your skin, and that’s going to provide a background for us to build on when we get into the specifics of different skin conditions in the upcoming episodes.
Like your gut, your skin is also a digestive organ. In fact, your skin is your body’s second largest digestive organ with a surface area of about 300 square feet. Your gut is a lot bigger at about 4,000 square feet. Like your gut, your skin absorbs things, it secretes substances like water, salt and oils, and it excretes waste matter like urea, ammonia, and heavy metals. Think about when you put on make-up or lotion. A few hours later, it’s nowhere to be found because it has been absorbed into your body through your skin. It has literally been eaten by your skin!
But in order for something to be absorbed by your skin, it has to pass through a physical barrier. That barrier consists of an epithelial lining made up of squamous cells, and on top of that physical barrier, your skin also has a chemical barrier of lipids – fatty molecules that help to reinforce the physical barrier. That fatty layer helps to prevent water from evaporating through your skin and keeps your skin nice and lubricated, but even more importantly, the lipid barrier helps to prevent pathogens from getting inside your body through your skin. For example, the lipids on your skin repel Staph aureus, the bacteria responsible for many skin infections. Staph aureus lives harmlessly on many people’s skin, but only causes an infection if it gets into the skin – through a cut, or some other breach in the physical and chemical barrier. So one of the most important functions of your skin is this barrier function to keeps things outside of your body.
Your gut also has a physical and chemical barrier. Your gut lining is made-up of intestinal epithelial cells and some of those cells secrete mucus, which like the lipid layer in your skin, helps to keep things in your gut moist and lubricated so that the products of digestion can move through easily. That mucus layer also traps and repels invading pathogens. In fact, the mucus layer in your gut is one of the most important defenses against viruses like SARS-CoV-2 and poliovirus. In your gut, there’s also a third layer of protection, and that’s the trillions of microbes that live in your digestive tract known as your gut microbiome.
I want to point out something that may be obvious to you, but honestly, I had been a doctor for over a decade before I really thought about this: when you eat something, it is not actually in your body. It’s in this 30 foot long hollow tunnel that runs from your mouth to your anus, known as your digestive tract. In order for nutrients and other substances to get from your gut into your body, they have to pass through your gut’s multitude of microbes, the mucus layer, and the physical barrier of your intestinal epithelial cells. And then – and only then – are they actually inside your body.
Like your skin, the lining of your gut is in constant contact with the environment because it’s exposed to everything that you ingest. And one of its main functions is to maintain a highly selective barrier for entry.
We ingest toxins and viruses all the time that our GI tract keeps outside of our body by never allowing them to penetrate the microbiome, the mucus layer and the gut lining. Think of the inside of your body as an exclusive club that people are trying to get into. There’s a bouncer at the door and they check you up and down and decide whether or not they’re going to let you in. And this is a very selective process! Poorly digested food particles – sorry, you can’t come in. Undesirable viruses – sorry, your name is not on the guest list. Toxins in food – nope, not letting you in. And who is that bouncer at the door that is keeping the vibe inside your body healthy and safe and keeping out the undesirables? It’s your microbes! Yes, those trillions of microorganisms that live in and on your body, mostly in your gut, are the ones who help to maintain the selectivity of that barrier by interacting with immune cells on the other side of the lining. So the immune cells are like the security guards inside the club and if there are some bad players who are about to bust in, or maybe who got in and now need to be evicted, the bouncer (aka your gut microbes) calls in security (aka your immune system) to handle the situation. So it’s a hand and glove relationship between your microbes on one side, and your immune cells on the other – just like the bouncers and security guards work closely together to maintain a safe environment in the club. At least I think that’s how it still works at the club; it’s been a while since I’ve been to one.
Now, here is what I want you to know about how what’s happening in your gut can create a problem for your skin: If that gut barrier is breached, then a substance that you might otherwise never react to can cause a reaction because now it’s getting inside your body and triggering an immune response.
So I want you to imagine a scenario where you’ve taken antibiotics for a respiratory tract infection. So now your gut microbiome is compromised because the antibiotics have killed off a lot of your healthy gut bacteria. And you’re also taking ibuprofen because you’re feeling kind of achy. Now your gut lining is compromised because NSAIDs like ibuprofen increase the permeability of your epithelial barrier by literally poking holes in your gut lining. The cold and flu medicine you’re taking also contains a decongestant to help dry up your mucus secretions, so now your mucus layer is also thinned out and compromised. You’re feeling kind of sorry for yourself because you have this terrible cold, and you don’t feel like cooking, so you heat up some frozen pizza, and decide to have some ice cream. Unfortunately, ultra-processed foods like frozen pizza and ice cream are full of preservatives and emulsifiers. Those chemicals now have an open door to enter your body through that compromised microbial layer, the thinned out mucus layer, and the more permeable epithelial barrier – what we commonly refer to as leaky gut.
A lot of the time people think they’re allergic to all these different things, but often it’s not the substance itself that’s causing the allergic reaction; it’s the fact that it’s getting inside your body when it should normally be on the outside of your skin. That’s the problem.
A pediatric study took children with eczema, measured their intestinal permeability, and put them on a strict elimination diet. In 2 weeks, several of the children had improvements in their intestinal permeability, and the ones that had the most gut improvement also had the most improvement in their eczema. So from a therapeutic point of view, it’s really important to consider what’s going on with your gut if you’re trying to heal something on your skin, because translocation of substances through your gut lining can allow these substances to enter your bloodstream and trigger an immune response in another organ like your skin. A lot of skin problems are systemic, meaning they’re a manifestation of something going on elsewhere in the body. And that “elsewhere” is frequently your gut. Let me give you some examples of how that works:
Rosacea is a type of auto-immune disease that has been linked to inflammation and bacterial imbalance in the gut–a condition called dysbiosis. SIBO (small intestinal bacterial overgrowth), is a form of dysbiosis, and SIBO is 10 times more common in people with rosacea! Rosacea is one of the most common symptoms I see in my bloated patients whose gut microbiome is disrupted. And again, what I notice most dramatically is that when my patients gut inflammation clears up, their rosacea does too.
About 10-20% percent of people with celiac disease have a rash called dermatitis herpetiformis (DH) that responds dramatically to a gluten-free diet. As the changes in their gut from the celiac disease normalize when they remove gluten, their dermatitis herpetiformis also clears up.
Crohn’s disease and ulcerative colitis can cause ulcers and nodules on the skin (two conditions called pyoderma gangrenosum and erythema nodosum) and treating the inflammation in the gut also clears up the skin lesions, so there is a direct relationship between the inflammation in the gut and on the skin in those patients. And what’s even more interesting is that the skin lesions tend to erupt when the gut disease is active. I’ve had patients with Crohn’s disease who develop these big red nodules on their arms and legs – erythema nodosum – that are incredibly painful. And as we get their gut symptoms into remission, their skin lesions just melt away. Literally, they disappear.
Skin problems in some of these inflammatory gut conditions can also be caused by the medications we’re using to treat the gut inflammation, especially drugs like steroids and antibiotics. Antibiotics are a common treatment for acne and rosacea, but they’re a shortsighted fix, since in the long run they can lead to overgrowth of pathogenic bacteria and decreased numbers of essential good bacteria in the gut. This imbalance also shows up on the skin and scalp, where it can profoundly affect your appearance. In the next couple of episodes as I go over each of these skin conditions, I’m also going to give you alternative treatment options to heal both your gut and your skin.
I want to leave you with 3 takeaways about the gut-skin axis:
So that’s it for this edition of the Gutbliss podcast on an introduction to the gut-skin connection.
Coming up next week: I’m going to tell you precisely what ingredients to stay away from, and which ones you should be ingesting every day to heal your skin from the inside out – and I’m referring to both personal care products that you put on your body, as well as the actual food that you put in your body.
share this PODCAST:
