Every few days, your gut lining completely rebuilds itself from scratch.
Your liver does something similar, regenerating tissue at a pace most people never think about.
Yet there’s a specific nutrient your body needs to fuel that regeneration—one you can’t buy in a capsule, can’t order from a biohacker brand, and won’t find on any supplement shelf.
Health and nutrition educator Thomas DeLauer recently explained why a single tin of sardines might be one of the most underrated tools for gut and liver health, and the science behind it is surprisingly robust.
Jump to:
What Makes Sardines Different
It’s not the omega-3s, though they’re excellent. It’s not the calcium from the bones, the CoQ10, or even the B12.
The real magic lies in something called dietary nucleotides.
Sardines are a simple whole fish. You are eating intact cellular material, muscle, soft roe, tissue, and that is densely packed with something that is called a dietary nucleotide.
Nucleotides are the structural building blocks of DNA and RNA. When you eat whole fish—bones, skin, organs, and all—you’re consuming the literal machinery cells use to divide, repair, and regenerate.
Your body has two ways to get nucleotides: it can make them from scratch (de novo synthesis) or recycle them from food (the salvage pathway). The first method works, but it’s metabolically expensive, consuming roughly 5 to 10% of the energy used to build new tissue.
When dietary nucleotides are available, your body prefers the salvage pathway. It’s faster, cheaper, and more efficient.
Why Your Gut Depends on Nucleotides
Here’s where things get interesting.
The cells lining your intestines have a very limited capacity to make nucleotides on their own. Yet they turn over faster than almost any tissue in your body.
Research published in the journal Mucosal Immunology confirms that the entire intestinal epithelial layer is replaced every 3 to 5 days. That’s one of the fastest regeneration rates in the human body.
The cells that line your intestine have a very limited capacity to make nucleotides on their own. Yet they turn over at one of the highest rates of any tissue in your body.
This creates a unique dependency: your gut must get nucleotides from food to keep up with its own repair schedule.
A 1994 study in the journal Gut, led by researcher George Grimble, laid out the problem clearly. Intestinal cells can’t efficiently make their own building blocks, yet they rebuild constantly.
Another study from the same journal took rats with chronic diarrhea and intestinal damage, then supplemented their diet with five major nucleotides—all of which you’d find in sardines. The results were striking: better mucosal recovery, improved villus height, increased wall thickness, and overall structural integrity of the gut barrier.
When nucleotides were restricted in animal models, the gut lining literally got thinner. Bloating, food sensitivities, and immune dysfunction followed.
The Liver Regeneration Connection
Your liver also benefits dramatically from dietary nucleotides.
Researchers have studied this using a model called 70% partial hepatectomy, where 70% of a rat’s liver is surgically removed. The remaining 30% has to rebuild itself rapidly if the animal is going to survive.
A study published in the Journal of Parenteral and Enteral Nutrition found that when rats undergoing this procedure were given nucleotides, net protein catabolism was significantly reduced. The liver was better able to rebuild itself.
The liver regeneration piece is wild. In that same review, it showed that dietary nucleotide deprivation caused a loss of about 50% of liver RNA within 7 days.
Most of that RNA is ribosomal RNA—the actual machinery your liver uses to synthesize proteins. Take away nucleotides, and protein synthesis starts to collapse. Add them back, and the RNA pool is maintained.
Another study in the journal Nutrition showed that nucleotide restriction in animals triggered hepatic lipid accumulation (fat buildup in the liver) and decreased the mucosal layer of the gut.
Your liver is doing a slower, less dramatic version of this regeneration every single day. Hepatocytes turn over, repair, and regenerate constantly—especially under metabolic stress.
Why You Can’t Just Take a Supplement
Modern processed foods are essentially nucleotide-free.
Crackers, refined oils, isolated proteins, even choice cuts of meat—they don’t have the same cellular structure as whole foods. Your body is forced into the expensive de novo pathway, and many tissues simply can’t keep up.
Don’t try to find like a nucleotide supplement. It just doesn’t exist. The only way you’re going to get it is from real intact cellular structure with our food.
Whole fish, organ meats, eggs—foods where you’re chewing through actual cells—are the only reliable sources. Vegetables work too, but you need the whole food, not juices or extracts.
Sardines just happen to be the most concentrated and accessible source.
The Clinical World Has Known This for Decades
Grimble’s 1994 review specifically flagged that almost all parenteral and enteral feeding solutions used in hospitals lack nucleotides entirely. He identified this as a likely problem for critically ill patients.
The clinical community has been aware of this gap for years. It’s just difficult to implement in practice.
But for those of us eating regular diets, the fix is simple: eat real foods that have cells in them.
A Simple Weekly Protocol
DeLauer recommends a straightforward approach:
- Two to three tins of sardines per week, bones and skin intact, packed in water or olive oil
- One ounce of liver every two weeks for a balanced nutrient profile
- Whole cellular foods daily—eggs, intact muscle meat, organ meat, ground beef with gristle, vegetables like broccoli where you’re chewing through structure
The bones provide calcium with cofactor nutrients. Olive oil maximizes absorption of omega-3s and CoQ10. But the principle isn’t “eat sardines and you’re saved.”
It’s about eating real foods with intact cellular structure.
If Sardines Aren’t Your Thing
The next best options for nucleotides include:
- Liver (one of the most nutrient-dense options)
- Salmon or salmon roe (if you can handle the texture)
- Canned oysters
- Ground beef (cellular structure matters)
Avoid ultra-pasteurized, excessively blended, or high-heat processed foods. These methods break down the nucleotides you’re trying to preserve.
Why This Matters for Gut Health
If you’re dealing with bloating, food sensitivities, or digestive issues, consider your dietary nucleotide load before spending money on gut health supplements.
You can have the best probiotics in the world, but if your gut lining doesn’t have the raw materials, you’re putting good bacteria into this broken building that’s just going to drip everything out.
Your gut lining is rebuilding every 3 to 5 days. It cannot efficiently rebuild without nucleotides.
This isn’t a fringe theory. It’s backed by peer-reviewed research from the 1990s onward, published in respected journals like Gut, Nutrition, and the Journal of Parenteral and Enteral Nutrition.
The Bottom Line
Sardines deliver something most modern diets are missing: intact cellular material packed with nucleotides.
Your gut depends on these building blocks to regenerate every few days. Your liver uses them to maintain protein synthesis and repair tissue under stress.
Processed foods drain your body’s nucleotide reserves, forcing expensive metabolic workarounds. Whole foods—especially small, whole fish—provide them abundantly.
A tin or two of sardines each week, alongside eggs, organ meats, and intact muscle, might be one of the simplest ways to support long-term gut and liver health.
No capsule required.
Sources
- Grimble GK, “Dietary nucleotides and gut mucosal defence,” Gut, 1994
- Van der Flier LG, Clevers H, “Stem cells, self-renewal, and differentiation in the intestinal epithelium,” Annual Review of Physiology, 2009
- Uauy R, Stringel G, Thomas R, Quan R, “Effect of dietary nucleosides on growth and maturation of the developing gut in the rat,” Journal of Pediatric Gastroenterology and Nutrition, 1990
- Hess JR, Greenberg NA, “The role of nucleotides in the immune and gastrointestinal systems: potential clinical applications,” Nutrition in Clinical Practice, 2012
- LeLeiko NS, Bronstein AD, Baliga BS, Munro HN, “De novo purine nucleotide synthesis in the rat small and large intestine,” Pediatric Research, 1983
- Iijima S, Tsujinaka T, Kido Y, et al., “Dietary nucleotides: a necessity in TPN?” Journal of Parenteral and Enteral Nutrition, 1993
