How to Test for Protein Malabsorption: The Indican Urine Test

An Indican Urine Test may detect malabsorption of proteins which may be a sign of a digestive or gastrointestinal issue. Possible conditions associated with abnormal test results range from autoimmune disease to dysbiosis and leaky gut. Restoring balance through dietary changes, appropriate supplementation if necessary, lifestyle changes, and stress management techniques will help bring those indican levels back into optimal ranges for better overall health.

What is Indican?

Through the process of digestion, bacteria residing in our intestines work to produce Indican – a metabolite derived from tryptophan. While most of it leaves our bodies during bowel movements, some is absorbed and processed by the liver and eventually released into our urine. Trace amounts are normally detected but higher than average concentrations may show a digestive or gastrointestinal issue.

Although an Indican Urine test cannot determine the specific digestive or gastrointestinal disorder, the results can still be used to point toward potential causes and treatments.

What Can a High Indican Lab Tell You?

High indican levels could suggest underlying health problems such as auto-immune disease, celiac disease, or Crohn’s – but may also be due to gut infections, dysbiosis, and overgrowth of harmful bacteria in the gut. Other potential causes include IBS, liver problems, or low stomach acidity which lead to problems absorbing protein from food sources.

Indican and Excess Dietary Protein Intake

A high level of urinary indican isn’t always a cause for concern. In some cases, a high indican might just suggest an excessive intake of protein foods. This is likely to be the case if you are eating a lot of meat, eggs, dairy, or protein powder.

Who Should Consider an Indican Test?

Antacids and Medications for GERD Affect Protein Digestion

Protein requires stomach acid to fully break down into amino acids. Many people take over-the-counter antacids or prescribed medications for gastroesophageal reflux disease or “GERD”, which could affect the digestion of protein. If a person’s ability to break down protein is in question, the indican test could be of value.

Food Allergies

When a person does not adequately break down protein into the individual amino acids, these larger proteins have greater contact with the immune system and there is greater risk for food allergies to develop. (Reference) If you have a food allergy test that indicates multiple food allergies, it’s a good idea to investigate protein digestion as well as taking measures to address leaky gut.

Unexplained Digestive Upset Could Suggest Inadequate Protein Digestion

A person may order this test if they often experience digestive symptoms and want to investigate their digestive health further. Contact your doctor or healthcare provider if you have concerns or questions about your lab results.


Any person experiencing medical symptoms should consult with a medical provider. This article does not constitute medical advice.

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About the Author

Stephanie Figon, MS, RDN, LD

Founder of NutriScape.NET. As a dietitian since 1992, Steph Figon has had experiences in consulting, 15 years in clinical, and has operated a private practice nutrition counseling office for since 2011. Connect on Linkedin