Threonine

Threonine is an essential amino acid with a specific and underappreciated job. Mucin, the protein that forms the mucus layer lining the gut, is unusually rich in threonine, so the gut consumes a large share of dietary threonine before the rest of the body sees it.

That first-pass extraction is substantial. A meaningful fraction of what you eat is used by the intestine itself rather than entering circulation, which is why gut demand shows up in a blood result.

It also contributes to collagen and elastin, to antibody production, and to glycine and serine synthesis.

Below 70 umol/L indicates low threonine. Because the gut takes its share first, the two explanations are low intake and high gut demand, and they are hard to separate from this number alone.

Gut inflammation raises mucin turnover, which raises threonine consumption. Someone with an inflamed intestinal lining can eat adequate protein and still show a low circulating result.

Immune function is affected as well, since antibodies are threonine-rich, so a sustained shortfall touches more than digestion.

Between 70 and 360 umol/L your threonine sits inside the reference range for this panel.

Read it alongside glutamine and proline. All three are consumed by gut repair, so the group moving together points at intestinal demand rather than at any one amino acid.

Above 360 umol/L usually reflects recent high protein intake or supplementation with collagen or an amino acid complex.

Threonine is well tolerated and a high result is not concerning in itself.

As with the other amino acids on this panel, a high result in the absence of high intake is worth interpreting alongside liver and kidney function, which handle amino acid clearance.

The Western factor that acts on threonine most directly is gut irritation. Excess alcohol, frequent NSAID use and highly processed food all raise mucin turnover, which raises the amount of threonine the intestine consumes before the rest of the body gets any.

Low protein quality compounds it, since incomplete protein sources supply less threonine per gram than animal proteins do.

Complete proteins are the reliable route: eggs, poultry, fish, grass-fed meats and dairy.

Collagen-rich foods such as bone broth and slow-cooked meats are naturally high in threonine and supply it alongside the other amino acids gut repair uses.

Reducing gut irritants lowers demand, which for this marker often does more than raising intake.

Collagen peptides at 10 to 15 g daily supply threonine alongside glycine and proline, which is the combination gut lining repair draws on.

L-glutamine at around 5 g daily works on the same tissue through a different route and is commonly paired with it.

Digestive enzymes with meals are worth considering where protein digestion rather than protein intake is the limiting factor. A full amino acid complex suits the case where several amino acids read low together.