Lactoferrin protects the body against viruses and bacteria. Doctors may recommend a fecal lactoferrin test to check whether a person has intestinal inflammation. This test measures lactoferrin levels in the stool.

Lactoferrin is a protein present in mammals’ milk, including that of humans. It is also in saliva, tears, and mucus.

High lactoferrin levels in stool samples may indicate that an individual has inflammation in the gastrointestinal (GI) tract. A fecal lactoferrin test can help doctors diagnose a condition before symptoms arise.

In this article, we explain the significance of lactoferrin in stool and how doctors test for it. We also look at the meaning of different fecal lactoferrin levels and the benefits of fecal lactoferrin testing over other tests.

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Fecal lactoferrin testing can detect inflammation in the intestines, which can help doctors provide a diagnosis for people with abdominal pain and diarrhea.

There are various possible causes of abdominal-related symptoms, including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and infections.

The test can determine whether there is a need for a gastroenterologist referral, which may apply to those with chronic symptoms.

IBD can affect people of any age, but most diagnoses occur between the ages of 15 and 35 years.

If the stool has a high lactoferrin level, this may mean that the individual has inflammation in their GI tract. However, the test cannot specify the cause, so a person may need to undergo an endoscopy exam as a follow-up test.

Low lactoferrin levels suggest that there is no inflammation.

Lactoferrin levels can also be moderate, meaning that some inflammation may be present. If a doctor performs another test that shows an increase in lactoferrin levels, the condition may have worsened.

Fecal lactoferrin testing may be a better option than other tests for some people.

Testing during pregnancy

Endoscopies, CT scans, and MRI exams can help healthcare professionals determine whether a person has IBD.

However, the authors of a 2020 study explain that an endoscopy procedure may not be safe during pregnancy, as it might increase the risk of preterm birth or low gestational weight. A CT scan can also increase the chance of congenital anomalies.

Fecal lactoferrin testing is not expensive, and it can help monitor IBD during pregnancy.

Testing in children

An older research article states that lactoferrin and calprotectin are the “most reliable” fecal biomarkers. The levels of these proteins correlate with inflammation in IBD.

The author notes that stool testing is less invasive than a colonoscopy, as it does not involve tube insertion. This may make it the preferred option for children.

Testing in the case of a possible flare-up

Individuals with recurring symptoms may have IBD flare-ups. A fecal biomarker test cannot determine whether someone has IBD. However, if the test is negative, it indicates no sign of inflammation or infection.

People with positive results may need to undergo further evaluation. While tests are ongoing, the medical team may not prescribe anti-inflammatory medications.

The authors of a 2020 study suggest that fecal biomarkers can help doctors monitor their patients with IBD and predict disease progression.

In people with IBD, stool testing can take place at any stage of the disease.

According to a 2018 article, an ileocolonoscopy may be helpful for those who have just received a diagnosis of IBD, as it can indicate the location of the inflammation. However, fecal lactoferrin testing may still be helpful, as it can monitor the inflammation and give an indication of the severity of the disease.

Doctors may not recommend lactoferrin testing when a person is breastfeeding, as human breast milk contains about 8–10 milligrams of lactoferrin.

Fecal lactoferrin tests can be helpful for individuals with IBD symptoms, such as:

The Crohn’s & Colitis Foundation lists the following tests that may help doctors diagnose IBD:

  • Blood tests: These can help check whether the individual has anemia, which develops if there are not enough red blood cells carrying oxygen to bodily tissues. Blood tests can also determine whether a person requires further testing.
  • Colonoscopy: During this procedure, a doctor uses a thin tube with a camera to view the colon. They may also take tissue samples and send them to a laboratory for analysis.
  • Sigmoidoscopy: A doctor will use a tube with a camera on it to examine the colon’s left side. This test, which usually takes place without sedation, can indicate how the body is responding to treatment.
  • Pouchoscopy: Endoscopists may recommend undergoing a pouchoscopy, which is a procedure that allows them to look closely at the lining of the small bowel. It may take about 10 minutes and can help check for ulcers, inflammation, and polyps.
  • CT scan: This imaging test takes several X-rays of the internal organs from different angles. The authors of a 2016 study explain that a CT scan provides images of the pelvis and entire abdomen in just a few seconds and that it can detect problems associated with the bowel wall.

IBD can cause diarrhea, rectal bleeding, and skin rash. A lactoferrin stool test can help determine whether a person has intestinal inflammation, which can help diagnose IBD.

A lactoferrin stool test may be a good option for children, as they may feel uncomfortable undergoing a colonoscopy, which requires the insertion of a tube into the colon.

It may be useful during pregnancy, as some imaging exams, such as CT scans, may increase the risk of pregnancy complications or congenital anomalies.

Doctors may also use other tests to check for IBD, including a pouchoscopy, a blood test, or a sigmoidoscopy.