Fecal Lactoferrin Interpreter

Lactoferrin is a protein released by certain white blood cells (mainly neutrophils) that rush into your gut when your intestines are inflamed (red, swollen, or irritated). When there is more inflammation, more of these cells release lactoferrin, and it shows up in your stool (poop). A stool test measures how much is there. The result is reported as a number in micrograms per gram (µg/g). A higher number usually means more inflammation in the gut. Because it comes from the same kind of cells, lactoferrin gives similar information to another common stool test called calprotectin.

This test is a clue, not a diagnosis. Your doctor reads it together with your symptoms, exam, and other tests. Different labs use slightly different cut-offs, so always follow the ranges your own doctor and lab use. As a general guide, many labs use a value of about 7.25 µg/g as the line between "negative" and "positive":

• Below 4.0 µg/g — usually normal. Inflammation in the gut is unlikely. This is a strong reason to feel reassured, especially if you were being checked for inflammatory bowel disease (IBD). A normal lactoferrin is one of the more reliable ways to say active gut inflammation is unlikely.
• 4.0 to 7.25 µg/g — borderline. This "grey zone" is neither clearly normal nor clearly raised. Your doctor may repeat the test, watch the trend over time, or combine it with other results.
• Above 7.25 µg/g — raised. Inflammation is more likely. Your doctor may want more tests, such as a look inside the bowel (colonoscopy). A raised number does not by itself confirm a specific disease — other things can push it up too.

A normal lactoferrin is very good at making IBD unlikely. It is not a test for irritable bowel syndrome (IBS): a normal result cannot "prove" IBS, and a raised result does not rule IBS out.

If you already have IBD (such as Crohn's disease or ulcerative colitis), this test is useful for tracking how you are doing over time. A single number matters less than the direction it is moving:

• A falling number often means your treatment is working and inflammation is calming down.
• A stable low number suggests your disease is well controlled.
• A rising number can be an early warning of a flare, sometimes before you feel worse. Your doctor may act on this before symptoms return.

Lactoferrin can naturally vary from day to day and even between different poops on the same day, so one small change is not always meaningful.

• Follow the exact instructions from your lab or the test kit.
• Collect the sample as directed and get it to the lab or store it as told. Lactoferrin is stable at room temperature for only a couple of days and is generally less stable than calprotectin, so getting the sample to the lab promptly matters.
• If you can, avoid NSAID pain relievers (like ibuprofen) before testing unless your doctor says otherwise, since they can raise the number.
• Tell your doctor if you have a stomach bug or infection, or are on your period, as these can affect the result.

• What does my number mean for me specifically?
• Does this change my diagnosis or my treatment?
• Should I repeat the test, and if so, when?
• Do I need a colonoscopy or other tests?
• Which of my medicines could be affecting this result?

Healthy young children, especially babies and toddlers, can normally have higher lactoferrin than adults. Children's results should always be interpreted by a pediatric doctor using age-appropriate ranges.