Research into how gut health affects all other aspects of our body’s health is one of the fastest-growing areas of medical research. The fact that bone broth can help the condition known as Leaky Gut is becoming part of medical wisdom for many forward-thinking doctors. For a long time, however, no one knew why it worked so well. Now research is confirming that collagen is the key. Collagen is an essential building block of all tissue creation – including within your digestive tract.
Why Does Collagen Work for Gut Health?
Collagen is a kind of protein, which means that it is made up of amino acids, namely glycine and proline, as well as a few others . There is also not just one kind of collagen. In fact, there are over two dozen types of collagen, although roughly 85% of the collagen in the body is made up of Type I, II, or III (or a combination of these three types).
Collagen is unique in the way that it “packs” itself into the body to create tissue. The abundant Type I Collagen is so strong in fact that some experts claim that it is “hard as steel.” Collagen forms strong yet pliable matrices within the body through something called “fibrils.” You can think of collagen as the “stuff that makes up stuff” that holds your body together. This means cartilage, muscle tissues and skin, and also bone, teeth, parts of the eyes, and organ tissue.
As stated before, Type I Collagen is the most prevalent type of collagen found in the body. It is also found in the digestive tract, along with Type III collagen. Foods and supplements that contain Type I and Type III collagen are excellent sources for improving gut health, as we shall see below.
The Evidence: How Collagen Helps Your Digestive Tract
Besides simply improving gut health in general, research has indicated that collagen may provide relief for specific gut-related problems. Here are just a few of the studies and their key findings:
#1 – Collagen Helps Balance Stomach Acid.
Did you know that we have an epidemic of low stomach acid, also called Hypochlorhydria, in the world today? This is an issue that is talked about very little but can have vast consequences for your health. Stomach acid imbalance is linked to autoimmune disorders, hypothyroidism, the use of antacids and proton pump inhibitors, bad bacterial overgrowth (like H. Pylori), traditional cancer treatments including radiation therapy, gastric bypass surgery, vitamin and mineral deficiencies, stress… and the list goes on .
The issues above are relevant to just about everyone on the planet right now! Stomach acid helps your food to break down nutrients from the food you consume to be distributed where they need to go. You do the math: since most everyone has some kind of imbalance that can lead to low stomach acid, just about everyone has nutrient absorption issues as well.
Fortunately, specific lifestyle changes, as well as targeted supplementation, has been shown to help restore just the right amount of stomach acid to your system. Collagen supplementation can play a key part in this. A study published in the American Journal of Physiology  found that the amino acid glycine found in large abundance in collagen helped to boost gastric juices. A German study conducted in 2017 generated similar findings .
#2 – Collagen Helps Hydrate the Digestive Tract.
The gut needs water to help move things along, which is one good reason why drinking water throughout the day is so important .
Healthy collagen is considered a “hydrophilic” molecule, mainly because of its unique relationship with sugar molecules in a process called collagen glycation . The collagen-sugar matrix is attracted to water as well as acidic substances.
When foods with collagen in it or collagen in supplement form are ingested, water begins to surround it, and this water (as well as stomach acid) can pass through the GI tract easier. This whole process helps with the breakdown of carbohydrates and other proteins and, thus, leads to better nutrient absorption and better health.
#3 – Collagen Helps to Repair the Stomach and Intestines.
Type I and III collagen are raw materials for almost all the connective tissue in the digestive system. Thus, the theory goes, by adding more collagen to the mix, you can repair the stomach and intestines and avoid complications like Leaky Gut (see below).
A 2004 study  conducted by the Medical Academy of Białystok in Poland found that one of the major characteristics in people with stomach cancer is defects in collagen metabolism. This makes sense since collagen also plays a vital part in gene expression, enzyme activity, and regulation of cellular growth.
#4 – Collagen Helps with Irritable Bowel Syndrome (IBS) and Stomach Ulcers.
With all the functions collagen helps within the digestive system and the body as a whole, it is no wonder that studies have indicated collagen supplementation can help with both Irritable Bowel Syndrome and stomach ulcers.
A 2003 study published in the Journal of Clinical Pathology found that individuals with IBS were more likely to have lower serum collagen levels than those who did not have IBS, especially collagen type IV . In addition, a 2000 Nebraska Medical Center study found that the collagen in plain old chicken soup helped to reduce inflammation in the body as a whole, including in the gut. They traced this effect to its ability to turn off pro-inflammatory mechanisms within immune system cells .
Finally, a more recent Brazilian study published in the Journal of Medicinal Food found that a combination of whey protein and collagen supplementation helped to protect against ethanol-induced ulcerative lesions in the gut . Ethanol  is produced as part of a fermentation process that may occur when food particles, especially sugars, stagnate in the gut and begin to “outgas.” These gases can be dangerous for brain health as well since they can pass through the blood-brain barrier and have a neurotoxic effect.
#5 – Collagen Helps with Leaky Gut.
Finally, there is the help that collagen may be able to provide for the millions of individuals who suffer from Leaky Gut.
Leaky Gut is also called intestinal permeability and occurs when tiny holes form in the digestive tract. This allows foreign matter to enter into the bloodstream where the immune system sees them as “invaders” and launches attacks, or autoimmune reactions, to them. The vicious cycle leads to chronic confusion for the immune system, and in many cases, to autoimmune diseases.
It is now known that roughly 80% of our immune system cells reside in the gut. The millions of tiny microscopic folds in the intestinal walls called “villi” are actually made of collagen. For this reason, collagen is thought to help “seal” the gut, allowing food particles to stay inside the intestines where they belong.
Much more research is definitely needed to find out how collagen can help with conditions like Leaky Gut and IBS as well as help digestive health as a whole. In the meantime, the growing body of research that is out there now paints a promising picture for the power of quality collagen supplements to provide relief to the millions of Americans who suffer from GI distress.