Bone Broth: The Old-School Gut Remedy Modern Science Is Finally Taking Seriously
Updated: Aug 26
Your grandmother called it chicken soup. Functional medicine calls it gut support. Science is beginning to explain why both may have a point.
Created by Christopher Caffrey, ACNP, PMHNP, Functional Medicine-trained
June 29th, 2026
Key Takeaways:
Bone broth is a functional food, not a miracle cure. It provides collagen-derived amino acids such as glycine, proline, and glutamine that may support the gut lining, connective tissue, and recovery.
Gut barrier health matters. The intestinal lining is only one cell thick, and when that barrier is disrupted, digestive symptoms and inflammation can become more likely. Bone broth may offer nutritional support while that barrier heals.
The evidence is promising, but still limited. Some human research supports ingredients like glutamine and collagen-related compounds, while much of the direct bone broth research is still early and includes animal studies.
A short gut reset can help identify food triggers. Pairing bone broth with a temporary elimination approach, such as a 14-day low-lectin plan, can be used as a structured experiment rather than a permanent restrictive diet.
The bigger goal is rebuilding the gut environment. Bone broth works best as part of a broader strategy that includes nutrition, stress reduction, sleep, adequate protein, and identifying the underlying causes of digestive symptoms.
If you walked into a hospital 100 years ago feeling sick, exhausted, nauseated, or unable to eat, there was a decent chance somebody would eventually hand you broth. There was no microbiome test, nobody checked your zonulin, and nobody discussed tight-junction proteins or whether your intestinal cells were getting enough glutamine. They put bones in water, cooked them for a very long time, and gave you the liquid.
Primitive? Maybe. But sometimes traditional medicine gets something right long before science fully explains why.
Bone broth has been used across cultures as a restorative food during illness and recovery. More recently, it has found a home in functional medicine, gut-healing protocols, and ancestral nutrition. In a 2026 episode of The Dr. Josh Axe Show, Dr. Kellyann Petrucci discussed decades of clinical use of bone broth and simplified dietary approaches in people struggling with digestive dysfunction, inflammation, and chronic symptoms.[1]
Of course, the internet has done what it usually does and turned bone broth into something bordering on mythology. Depending on the headline, one cup can apparently repair your gut, erase wrinkles, reverse aging, balance hormones, fix your joints, and perhaps refinance your house.
We do not need to go that far. Bone broth is interesting enough without making it magical.
A 2025 review from Mayo Clinic researchers specifically examined bone broth and intestinal-barrier health. The authors concluded that several nutrients found in bone broth—including glycine, proline, glutamine, arginine, histidine, and certain minerals—have biological roles relevant to intestinal integrity, inflammation, and nutrient absorption.[2]
That does not prove bone broth cures “leaky gut.” It does give us a reasonable biological explanation for why a collagen-rich, amino-acid-rich food may support tissues that are under constant repair.
And few tissues work harder than your intestinal lining.
Your Gut Is Basically a One-Cell-Thick Border Crossing
Most people imagine the intestine as a pipe. Food goes in one end, digestion happens in the middle, and the rest is self-explanatory.
Biologically, it is much more interesting.
The inside of your intestinal tract is technically still part of the outside world. Food, bacteria, bacterial fragments, medications, alcohol, environmental compounds, and whatever questionable gas-station snack you ate at 11 p.m. all travel through a tube running through your body. Your intestinal barrier has the difficult job of deciding what gets absorbed and what stays out.
That barrier includes mucus, immune cells, secretory IgA, intestinal microorganisms, and a remarkably thin layer of epithelial cells separating the intestinal contents from the tissues and circulation beneath them.[2,3]
In many areas, that lining is essentially one cell thick. Those cells are connected by structures known as tight junctions, which help regulate what passes between them. Think of your intestinal barrier like airport security. Amino acids and glucose arrive with valid boarding passes and are waved through. Bacterial toxins and other unwanted substances should remain on the other side.
The goal is not to create an impermeable wall. If your intestine were completely impermeable, you would starve. The goal is selective permeability.
When that system becomes impaired, intestinal permeability can increase.
And yes, that is essentially what people mean when they say “leaky gut.”
“Leaky Gut” Is Real—But It Is Not the Cause of Everything
The phrase leaky gut has become so overused that it is easy to dismiss.
Fatigue? Leaky gut.
Acne? Leaky gut.
Brain fog? Leaky gut.
Your neighbor is annoying? Probably leaky gut.
But intestinal barrier dysfunction is a legitimate physiological phenomenon. It has been documented in conditions including celiac disease, inflammatory bowel disease, gastrointestinal infections, critical illness, and subsets of functional gastrointestinal disorders.[2]
The real question is not whether intestinal permeability exists.
It does.
The more important questions are why it is happening, whether it is driving disease or resulting from disease, and what is interfering with recovery.
Potential contributors may include:
gastrointestinal infection
celiac disease
inflammatory bowel disease
medications
alcohol
altered motility
dysbiosis
poor sleep
chronic physiological stress
inadequate nutrition
bile or pancreatic dysfunction
food intolerances
This is where functional medicine can be useful when it avoids oversimplification.
The goal should not be to diagnose everyone with the same “leaky gut.” The goal is to figure out why this particular gut is struggling.
Your Gut Lining Is Constantly Under Construction
Your intestinal lining is not static. Cells are continually being generated, maturing, performing their jobs, and being shed. Much of the intestinal epithelium turns over within only a few days.[3]
That means the tissue responsible for separating you from trillions of microorganisms is undergoing almost constant renovation. Your gut is less like a permanent brick wall and more like the Massachusetts Turnpike. The construction never stops. And construction requires raw materials.
If you asked a crew to rebuild your house after a storm but refused to supply lumber, concrete, nails, or electricity, progress would be limited no matter how talented the contractors were.
The same principle applies biologically. Tissue repair requires amino acids, micronutrients, energy, adequate circulation, immune regulation, and an environment that is not damaging the tissue faster than the body can rebuild it.
This is where bone broth starts to make sense.
What Is Actually in Bone Broth?
Bone broth is created by simmering bones, cartilage, tendons, skin, connective tissue, and often some meat in water. During cooking, collagen-rich tissues break down and produce a broth containing protein, gelatin, amino acids, peptides, electrolytes, and minerals.
The exact composition varies substantially depending on the animal, tissues used, amount of water, cooking time, and processing method.[4] That matters because bone broth is not standardized.
One cup from your kitchen is not automatically equivalent to another brand, another recipe, or a clinical dose of collagen peptides.
Still, collagen-rich foods are notable for several amino acids, particularly:
glycine
proline
hydroxyproline
glutamine and glutamate
arginine
These nutrients participate in connective-tissue biology, antioxidant defense, immune signaling, and intestinal metabolism.[2,5]
Bone broth is therefore best understood as a functional food, not a drug.
It provides nutritional building blocks that may be useful to tissues undergoing constant repair.
Glycine Deserves More Attention
Glycine is one of the major amino acids found in collagen. It is involved not only in collagen formation but also in glutathione synthesis, creatine production, neurotransmission, and metabolic signaling.[5]
There is also growing interest in glycine and aging. In animal studies, glycine supplementation has extended lifespan, although that research should not be interpreted as proof that drinking bone broth makes humans live longer.[6]
Still, glycine is interesting for another reason.
Modern Western diets tend to emphasize muscle meat—chicken breast, steak, pork chops—while historically humans ate considerably more skin, cartilage, tendons, and connective tissue.
We eat the chicken breast. Our ancestors ate the chicken. That difference changes the balance of amino acids being consumed.
Bone broth partially restores some of the collagen-rich components that have largely disappeared from modern diets.
Glutamine Is Where the Gut Research Becomes Particularly Interesting
If there is one amino acid with a strong connection to intestinal physiology, glutamine deserves special attention. Intestinal epithelial cells use glutamine heavily for energy metabolism, cell proliferation, redox balance, and tight-junction regulation. And unlike many nutrients marketed for “gut healing,” glutamine has human clinical data.
In one randomized placebo-controlled trial, researchers studied people with postinfectious diarrhea-predominant IBS who also had objectively documented increased intestinal permeability. Participants received either placebo or 5 grams of glutamine three times daily for eight weeks. Nearly 80% of the glutamine group achieved the study's primary clinical response compared with roughly 6% of the placebo group. Symptoms, bowel frequency, stool consistency, and intestinal permeability improved.[7]
A separate trial found that adding glutamine to a low-FODMAP diet improved IBS outcomes more than diet plus placebo.[8]
That is meaningful evidence.
But there is an important distinction: the amount of glutamine in a cup of bone broth is not equivalent to 15 grams of supplemental glutamine.
A cup of broth is nutritional support. A measured dose of glutamine is a targeted intervention.
Both may have value, but they are not interchangeable.
Does Bone Broth Itself Have Research Behind It?
Yes, although direct human research is still limited. In a 2021 mouse model of ulcerative colitis, bone broth reduced intestinal tissue damage and altered several inflammatory markers, including reductions in IL-1β, IL-6, and TNF-α.[9]
That is interesting preclinical evidence. It is also a mouse study. A mouse doing well on soup does not mean a human with Crohn's disease should stop medical treatment and buy a thermos.
Animal studies can demonstrate biological plausibility and help identify mechanisms worth studying, but they do not establish clinical effectiveness in humans.
The strongest position is therefore neither “bone broth heals everything” nor “there is no evidence.” The evidence sits somewhere in the middle.
We know many of its components have relevant biological effects. We have some direct preclinical evidence. What we still need are larger, well-designed human trials testing standardized bone-broth preparations.
Thousands of years of continued use should not be dismissed as meaningless. While tradition is not a substitute for controlled clinical research, practices that persist across generations often do so because people repeatedly observe some benefit. Bone broth’s longevity as a restorative food does not prove efficacy, but it does represent a remarkably long history of real-world use—one that deserves scientific investigation rather than casual dismissal.
Why Cooked Food Sometimes Makes More Sense Than Raw Food
One point discussed in the Axe-Petrucci conversation was the use of cooked rather than raw foods during periods of significant digestive distress.[1]
That makes clinical sense.
Vegetables are healthy, but healthy does not mean equally well tolerated by every gastrointestinal tract in every circumstance. Someone with severe bloating, diarrhea, IBS, gastroparesis, visceral hypersensitivity, or active intestinal inflammation may tolerate cooked vegetables significantly better than a massive raw salad.
Imagine spraining your ankle and having your physical therapist say, “Exercise is healthy, so let's begin with a marathon.” Context matters.
Cooking softens plant tissue, changes fiber structure, and often makes foods easier to mechanically process. During a significant GI flare, some people may temporarily tolerate foods such as soups, stews, cooked vegetables, slow-cooked meats, fish, and simple whole-food carbohydrates better than large amounts of raw roughage.
The goal is not permanent restriction. The goal is giving digestion a reasonable workload while symptoms settle.
What About Lectins?
Lectins have become one of nutrition's favorite villains. Gluten held the job for a while. Seed oils are currently interviewing. Lectins are proteins found in many plant foods, especially legumes and grains. Some can clearly cause problems when consumed in high amounts in an active form. Raw kidney beans are the classic example.
But many lectin-containing foods are also highly nutritious, and soaking, fermenting, sprouting, pressure cooking, and thorough cooking can dramatically reduce lectin activity. So I do not believe everyone needs a permanently lectin-free diet.
However, a short-term reduced-lectin diet may be useful as part of a structured elimination experiment in someone with significant digestive symptoms. For perhaps 14 days, the goal might be to simplify the diet around foods that are generally easier to tolerate while temporarily reducing potential triggers.
Then you reintroduce foods.
That part matters.
If you remove 20 foods, feel better, and permanently conclude that all 20 foods were damaging your gut, you have learned almost nothing.
You have simply created a smaller diet.
Functional medicine should ideally help people tolerate more healthy foods over time, not make them afraid of dinner.
Sometimes the Gut Needs Less Work, Not More Supplements
When digestion is significantly disrupted, every meal creates work. Food has to be mechanically processed. Acid, bile, and pancreatic enzymes need to be released. Nutrients need to be absorbed. Carbohydrates reach microbes and undergo fermentation. The intestinal immune system continuously samples what is passing through.
Usually that is exactly what the gut is designed to do. But during a flare, simplifying food for a short period may reduce some of that burden.
This helps explain why nearly every culture independently developed recovery foods such as broth, rice, soup, stew, porridge, and congee.
Nobody recovering from severe diarrhea asks for the raw kale Caesar.
Bone broth fits well into this kind of temporary strategy because it provides fluid, sodium, amino acids, and some protein in a form that many people find easy to tolerate. The key word is temporary. Gut rest should not become nutritional deprivation.
Sometimes the patient does not need another cleanse, fast, or 14-bottle supplement protocol. Sometimes they need calories, protein, electrolytes, sleep, and food they can digest.
Build before you biohack.
Stress Is Part of Gut Physiology
If you want to talk seriously about gut healing, the nervous system has to be part of the conversation.
That does not mean GI symptoms are “all in your head.”
The brain and gut communicate through the autonomic nervous system, HPA axis, enteric nervous system, immune system, mast cells, and microbial signaling. In a human study, psychological stress and administration of corticotropin-releasing hormone increased intestinal permeability in susceptible participants. When mast cells were stabilized, the effect was reduced, suggesting that stress-related changes in barrier function can involve CRH and mast-cell signaling.[10]
That is measurable physiology. Stress does not affect everyone identically, and not every stressful event increases intestinal permeability. But chronic autonomic dysregulation can influence motility, visceral sensitivity, secretion, immune signaling, appetite, sleep, and the gut-brain axis.
This is why eating perfect food while chronically sleep-deprived and glued to your phone may not produce the result you expect.
Your body does not renovate the kitchen while the fire alarm is ringing.
A Free Gut Intervention: Put the Phone Down
Before your next meal, try something remarkably low-tech.
Put your phone away.
Sit down.
Look at your food.
Smell it.
Take several slow breaths.
Chew.
Do not answer an angry email while watching a video about civilization collapsing and inhaling your lunch in six minutes.
Digestion is neurologically coordinated. The sight, smell, anticipation, and chewing of food help initiate digestive responses before food even reaches the stomach.
Functional medicine works best when it recognizes that food, sleep, nervous-system state, behavior, and gastrointestinal physiology are happening in the same person.
They are not separate problems.
What About Bone Broth Fasting?
Bone-broth-supported fasting can be useful in some people, but let's use accurate language. Bone broth contains calories and amino acids. So technically, it breaks a strict fast.
True fasting alters nutrient-sensing pathways such as insulin, AMPK, and mTOR. Protein and amino acids change that environment.[11] For that reason, I would not claim that drinking bone broth produces the same autophagy response as water fasting.
But that does not make it pointless.
A bone-broth-supported fast may reduce caloric intake, simplify digestion, provide sodium and fluid, and make a short period of dietary restriction easier to tolerate. If the goal is gut simplification rather than maximizing autophagy, that may be a perfectly reasonable trade.
The Functional Medicine Question Is Bigger Than Bone Broth
The question I care about is not simply, “Does bone broth work?”
I want to know why the gut is struggling in the first place.
Is there an infection? Celiac disease? Inflammatory bowel disease? Dysbiosis? Altered motility? Alcohol exposure? Medication effects? Poor sleep? Chronic stress? Bile-acid dysfunction? Pancreatic insufficiency? Nutritional depletion?
Then I want to know what is preventing recovery.
Bone broth can provide useful nutritional support, but giving it to someone while ignoring untreated celiac disease is like putting a bucket under a leaking roof. The bucket helps.
You should still fix the roof.
This is where functional medicine earns its value. It asks not only what treatment can reduce symptoms, but also what is creating the biological environment in which those symptoms continue.
How I Would Actually Use Bone Broth for Gut Support
I would use it as one part of a broader strategy rather than as a miracle cure.
For someone appropriate for a short digestive reset, one to two servings of bone broth daily can be reasonable. There is no scientifically established therapeutic dose, so the emphasis should be on consistency and tolerance rather than pretending that a specific number of ounces is medically magical.
A short-term diet might emphasize:
bone broth
cooked vegetables
fish, eggs, and other tolerated proteins
slow-cooked meats
olive oil and other healthy fats
easy-to-tolerate whole-food carbohydrates
adequate hydration
adequate electrolytes
Depending on the clinical picture, targeted interventions such as glutamine, zinc carnosine, specific probiotics, prebiotic fibers, or treatment of an underlying GI condition may also make sense.
The key is that the intervention should follow the physiology. Not a generic gut-healing checklist.
Why I Like a 14-Day Gut Reset
Fourteen days is long enough to see whether symptoms change, but short enough to avoid unnecessary long-term restriction.
For the right person, I like the idea of simplifying food while emphasizing nutrient density, cooked foods, quality protein, healthy fats, minimal ultra-processed food, very little alcohol, reduced added sugar, adequate sleep, and slower eating. Depending on the person, foods such as high-lectin foods, high-FODMAP foods, gluten, dairy, or other suspected triggers may be reduced temporarily.
But I would not automatically eliminate everything from everyone.
The more variables you change simultaneously, the less you know about what actually helped.
Afterward, foods should be reintroduced systematically while tracking symptoms such as:
bloating
abdominal pain
gas
reflux
stool frequency and consistency
urgency
energy
brain fog
skin changes
So, Does Bone Broth Heal the Gut?
Here is where I land. Bone broth may support several of the biological processes involved in intestinal repair.
We know that intestinal epithelial cells turn over rapidly.[3] We know amino acids found in bone broth participate in barrier physiology, tissue repair, antioxidant defense, and immune signaling.[2,5] Human trials show that glutamine can improve intestinal permeability and symptoms in selected populations.[7,8] Collagen-derived peptides can survive digestion and enter circulation.[12] And animal research suggests bone broth itself can reduce intestinal inflammatory signaling.[9]
That is a respectable body of evidence.
What we do not yet have is a large human trial showing that drinking a specific amount of bone broth reliably reverses intestinal permeability.
Until someone funds the Great Chicken Soup Trial, we should be comfortable with the distinction between proven, plausible, and useful.
Bone broth has thousands of years of continued use as a restorative food. Tradition is not a substitute for controlled research, but neither is it meaningless. Practices that survive across generations often do so because people repeatedly observe some benefit. Bone broth's persistence does not prove efficacy, but it gives us a remarkably long history of real-world use that deserves scientific investigation rather than casual dismissal.
That is where I think functional medicine should be comfortable: respecting traditional wisdom, understanding modern physiology, and being precise about where the evidence is strong and where it is still emerging.
Bone broth is not magic. It does not need to be.
Sometimes food can simply be food and still be remarkably therapeutic.
Put the pot on.
References
1. Axe J, Petrucci K. The Real Reason Your Gut Won't Heal (And How Bone Broth Fixes It). The Dr. Josh Axe Show. Published August 13, 2026.
2. Matar A, Abdelnaem N, Camilleri M. Bone Broth Benefits: How Its Nutrients Fortify Gut Barrier in Health and Disease. Digestive Diseases and Sciences. 2025;70(6):1951-1961. doi:10.1007/s10620-025-08997-x.
3. van der Flier LG, Clevers H. Stem cells, self-renewal, and differentiation in the intestinal epithelium. Annual Review of Physiology. 2009;71:241-260.
4. Alcock RD, Shaw GC, Burke LM. Bone Broth Unlikely to Provide Reliable Concentrations of Collagen Precursors Compared With Supplemental Sources of Collagen Used in Collagen Research. International Journal of Sport Nutrition and Exercise Metabolism. 2019;29:265-272.
5. Li P, Wu G. Roles of dietary glycine, proline, and hydroxyproline in collagen synthesis and animal growth. Amino Acids. 2018.
6. Miller RA, Harrison DE, Astle CM, et al. Glycine supplementation extends lifespan of male and female mice. Aging Cell. 2019.
7. Zhou Q, Verne ML, Fields JZ, et al. Randomised placebo-controlled trial of dietary glutamine supplements for postinfectious irritable bowel syndrome. Gut. 2019;68(6):996-1002.
8. Rastgoo S, Ebrahimi-Daryani N, Agah S, et al. Glutamine Supplementation Enhances the Effects of a Low FODMAP Diet in Irritable Bowel Syndrome Management. Frontiers in Nutrition. 2021;8:746703.
9. Mar-Solís LM, Soto-Domínguez A, Rodríguez-Tovar LE, et al. Analysis of the Anti-Inflammatory Capacity of Bone Broth in a Murine Model of Ulcerative Colitis. Medicina. 2021;57(11):1138.
10. Vanuytsel T, van Wanrooy S, Vanheel H, et al. Psychological stress and corticotropin-releasing hormone increase intestinal permeability in humans by a mast cell-dependent mechanism. Gut. 2014;63(8):1293-1299.
11. Vendelbo MH, Møller AB, Christensen B, et al. Fasting increases human skeletal muscle net phenylalanine release and this is associated with decreased mTOR signaling. PLoS ONE. 2014;9(7):e102031.
12. Virgilio N, Schön C, Mödinger Y, et al. Absorption of bioactive peptides following collagen hydrolysate intake: a randomized, double-blind crossover study in healthy individuals. Frontiers in Nutrition. 2024;11:1416643.
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