Leaky Gut and Hair Loss

You probably already know how frustrating and discouraging it can be to experience hair loss or thinning - especially as a woman.

Oftentimes, when you reach out to your doctor for help, they don’t have a firm diagnosis, don’t seem to care about a solution, or simply shrug and tell you “it happens.”

Well, in Functional Medicine, we want to know WHY it’s happening - and then treat it at the root cause. This is the same approach I take toward any symptom or condition - from hair loss to hot flashes to high blood pressure and beyond!

And in Functional Medicine, we first look to the gut or digestive tract whenever we’re searching for the root cause or causes of a symptom or condition.

Why? Well, because the epithelial tissue or “inside skin” of your digestive tract has the greatest surface area in the body, and therefore has the most direct interaction with the environment of any organ system.

Your gut has a big job to do, and lots of responsibilities beyond what you might consider “digestion.” Sure, one of the main roles of the gut is to break down and absorb nutrients from food.

But it also houses most of your microbiome, the trillions of bacteria, fungi, archaea, viruses, phages, and protozoa that live in and on your body, and whose balance can dramatically impact your health - more on that in a bit.

And, most importantly for maintaining healthy hair, the internal epithelial layer is responsible for keeping bad stuff out of your body.

It’s a barrier that serves to distinguish friend from foe - and when the gut wall is breached, the gut signals to the immune system to take action against any invaders.

What does all of this have to do with hair loss?

One of the top root causes of hair loss and thinning is autoimmunity. This type of hair loss is typically called alopecia areata, but some people with autoimmune-based hair loss are also diagnosed with telogen effluvium, and it can have different sub-type names, depending on the pattern of hair loss, whether it’s diffuse or patchy or on the scalp or involves other hair-covered areas of the body.

But even if you don’t have this diagnosis, your hair loss could be linked to leaky gut, otherwise known as increased intestinal permeability.

Thankfully, if you treat the source of autoimmunity itself - which almost always involves leaky gut, you can improve many types of hair loss or thinning. It’s not always easy to treat this root cause, but if you feel like you’ve tried everything and are still losing hair, it’s time to consider the gut.

The breakdown of the healthy gut barrier creates the environment that allows or triggers many autoimmune diseases to start. Research has linked leaky gut to hashimoto’s thyroiditis, multiple sclerosis, rheumatoid arthritis, lupus, type 1 diabetes, and many other autoimmune conditions - including hair loss.

But to understand this key connection, we need to understand what leaky gut is, exactly.

The cells that form the inside of your intestinal wall are all lined up, side-to-side, creating a barrier between the “outside world” of your digestive tract, and the inside of your body - which is your bloodstream, in this case.

Structures called tight junctions, which are made up of complex regulatory proteins, help maintain this barrier, and they are incredibly influenced by certain members of the microbiome. The intestinal mucous layer has recently been discovered to have an important role in maintaining a leak-free gut as well.

This barrier is super important for keeping the right things out and letting the right things in. For example, it selectively allows water and nutrients from food to pass through the barrier, while blocking potential invaders like unfriendly bacteria or viruses.

But, more often than we’d like, the connection between the cells is disrupted or broken, creating what you might think of as little leaks in that barrier, where things can get into the bloodstream that don’t belong there.

And guess what happens to stuff that doesn’t belong in our bloodstream? That’s right, the body sends the immune system over to take care of it.

And that immune response often results in the release of histamine and other immune compounds called immunoglobulins, which then enter the bloodstream and start a search and destroy mission against whatever molecule managed to sneak through that wall.

Sounds like a good thing, right? We don’t want toxins or viruses wandering free in our bloodstream.

But the problem with leaky gut is that your immune system can get confused - because there typically isn’t some big infection to fight or invader trying to harm you. Sometimes the particle that sneaks through a leaky gut is as innocuous as a bit of carrot, or a friendly bacteria that just ends up in the wrong place at the wrong time.

This often results in a generally over-active immune system - one that’s prone to allergic reactions, chronic inflammation, and eventually autoimmunity - which happens when your immune system attacks any number of organs and tissues in your body, including the hair follicle.

How do you know if you have leaky gut?

While there isn’t one standardized test to definitively diagnose leaky gut or increased intestinal permeability, there are valid labs that can give us clues to the degree of leakiness and the possible sources.

1. The first test measures zonulin, a protein that is made by the intestinal tract that increases leakiness in the gut. The presence of zonulin in the blood or in the stool is considered direct evidence of increased intestinal permeability. But zonulin can be high in the stool one day and low another, meaning that you could have leaky gut even if zonulin levels aren’t high on lab testing.
2. Another test measures the absorption of lactulose and mannitol. The person using this test drinks a solution containing both lactulose and mannitol. Then their urine is collected over several hours, and the concentrations of lactulose and mannitol in the urine are analyzed. A higher ratio of lactulose to mannitol is believed to indicate higher small intestine permeability.
3. My preferred lab testing to assess both the evidence of leaky gut and its potential triggers is a Comprehensive Stool Analysis. This incredibly detailed test provides a wealth of information about the composition of the gut microbiota, digestive function, and immunological activity that can give us clues about underlying causes for increased intestinal permeability. I recommend and interpret this test for my 1:1 consultation clients often, and it always gives us clear next steps to take. You can find more information about this kind of advanced functional testing in my Free Functional Hair Growth Checklist HERE.

Here’s an important note: you can have leaky gut even if you don’t have digestive symptoms.

While inflammatory gut diseases like stomach ulcers, Chron’s disease, IBS, and ulcerative colitis are obvious signs of leaky gut, autoimmune symptoms can also indicate increased intestinal permeability. Think of food allergies or sensitivities, psoriasis, raynaud’s syndrome, hashimotos, celiac disease, rheumatoid arthritis, and even type 1 diabetes as signs of leaky gut, too. 

If you’re experiencing persistent hair loss and thinning, and you have any of these conditions and symptoms as well, there’s a good chance that your gut needs deeper investigation.

Once we determine that leaky gut is contributing to hair loss and thinning - or any of the other symptoms I mentioned - we can begin to address it at the root.

This is where things get complicated, because leaky gut and microbiome imbalances, otherwise called dysbiosis, almost always go hand-in-hand. And rebalancing unruly gut microbes is a big task - and it’s different for each individual.  But there are a few steps that anyone can take to reduce the leakiness of their intestinal barrier.

The first involves a protein found in grains called gluten - if you’ve been hanging around in functional medicine circles for awhile, you’ve probably heard of it. Gluten is one of the top causes of leaky gut because it tends to irritate the intestinal lining, creating chronic inflammation and, secondarily, increased intestinal permeability. When it is most problematic, gluten can trigger celiac disease, an autoimmune condition that results in severe damage to the small intestine. Most people with leaky gut benefit greatly from a gluten-free diet.

But resolving increased intestinal permeability goes beyond simply avoiding inflammatory or reactive foods. Restoring the strength of your tight junctions is also important.

There are several strains of bacteria that have emerged as particularly helpful for maintaining tight junctions, including akkermansia muciniphila and Lactobacillus salivarius UCC118.  Both of these strains are available in probiotic form, and have clinical research showing their role in reversing leaky gut.

Immunoglobulin G, a molecule that signals for immune support, can also help heal and seal leaky gut. Researchers found that immunoglobulins bind microbes and toxins in the GI tract and eliminate them before they can trigger the immune system, which resets healthy immune tolerance and builds a stronger barrier.

Depletions of zinc, a crucial micronutrient for maintaining gut integrity, can also trigger increased gut permeability.  Optimal ranges for RBC Zinc and other micronutrients that are involved in hair loss and thinning can be found in my Hair Loss Deep Dive Tutorial - check it out HERE.

As I said at the beginning, restoring hair loss that is caused by leaky gut is an incredibly complicated process with many steps. It’s easy to feel overwhelmed, and it’s far from a quick fix - it can take months to years for autoimmune hair loss to regrow, even when you treat the root cause. But healing is possible, so don’t give up!

Leaky gut may be only one of several root causes for your hair loss and thinning - so be sure to download your free Functional Hair Growth Checklist HERE. If you’re looking for the next best step, that’s a great place to start.