Specialty Testing Guide › GI-MAP Gut Testing
To read a GI-MAP report, start with the findings that could need prompt medical care, then work down to the microbes and markers that are only interesting. Each line shows an amount, a lab reference range and sometimes a "High" or "Low" flag. A flag tells you a number sits outside the lab's range. It does not tell you that you have an infection or that anything needs treating.
The most common mistake is treating every flagged line as a problem. This guide walks through the report in a sensible order and explains why "detected" is not the same as "infected."
Key takeaways
- Read blood, inflammation and true pathogen results first, because those are the ones that can change care quickly.
- A flagged organism means its DNA was found above the lab's cutoff, not that it is alive or causing your symptoms.
- Many organisms on the report, including some parasites, are common in people who feel well.
- Your symptoms and history decide which findings matter, so the report is a starting point for a conversation rather than a diagnosis.
First, understand the format
Most microbe results are reported as genome equivalents per gram of stool and written in scientific notation, where 1.00e3 means 1,000.1 A result of "<dl" means the target was below the detectable limit.
The reference ranges are the lab's own. They were set by the lab for its own assays, so they cannot be compared directly with numbers from a different stool test. The intestinal health markers use ordinary units such as micrograms per gram.
Read the report in priority order
A clinician usually sorts results by how much they could matter, not by where they sit on the page:
- 1. Possible bleeding or inflammation. A positive occult blood result or a high calprotectin, especially with weight loss, rectal bleeding, anemia or night-time symptoms, points toward a gastroenterologist, not a supplement plan.
- 2. Pathogens that match your symptoms. A pathogen such as Giardia in someone with ongoing diarrhea deserves attention. The same finding in someone with no gut symptoms is harder to interpret.
- 3. H. pylori. A positive result should be handled according to treatment guidelines, which usually means confirmation and standard therapy. See H. pylori on a GI-MAP.
- 4. Digestion and gut immune markers. Low elastase or high fat in stool can point to a digestive problem worth checking with standard tests.
- 5. Bacterial balance, yeast and protozoa. These are the most talked-about sections and usually the least certain.
Why "detected" is not "infected"
The test finds DNA. DNA can come from organisms that are dead, passing through, or living quietly without causing harm. The lab itself notes that not everyone with a positive pathogen finding will have symptoms.2
C. difficile is a good example. A GI-MAP can report C. difficile toxin genes, but infectious disease guidelines say the preferred group for C. difficile testing is people with unexplained, new-onset diarrhea of three or more unformed stools in 24 hours.13 The same guidelines advise against testing stool from people without symptoms.3
Protozoa work the same way. Blastocystis is a frequent "positive" on stool panels. In one study of healthy adults using a sensitive PCR test, Blastocystis was present in 56% of the people sampled.4 Finding it does not, by itself, explain symptoms. Our article on parasites on a stool test covers when treatment is debated.
A section-by-section guide
| Section | What a flag may mean | Typical next step |
|---|---|---|
| Pathogens | DNA of a known gut pathogen was found above the cutoff | Weigh against symptoms; standard testing or a doctor visit if you are ill |
| H. pylori | H. pylori DNA found, with gene results for virulence and drug resistance | Guideline-based confirmation and treatment |
| Commensal bacteria | Higher or lower than the lab's range for common resident bacteria | Context only; diet and recent antibiotics often explain it |
| Dysbiotic and overgrowth bacteria | Organisms that are normal in small amounts were found at higher levels | Interpret with symptoms; rarely urgent |
| Fungi and protozoa | Yeast or protozoa DNA above the lab's cutoff | Often found in healthy people; treat cautiously |
| Intestinal health markers | Signs of inflammation, bleeding, poor digestion or immune activity | High calprotectin or blood: medical follow-up first |
For the dysbiotic bacteria, the lab's own description says most sources consider many of these microbes normal in stool, causing problems mainly at high levels in vulnerable people.2 For the markers, see calprotectin explained and our guide to secretory IgA and the other stool markers.
Patterns matter more than single lines
One mildly high number rarely means much. A clinician looks for findings that fit together and fit you: diarrhea plus a pathogen plus raised calprotectin tells a clearer story than a single flagged bacterium in someone who feels fine.
Dr. Kenneth Varano, the clinic's medical director, notes that some patients test positive for dysbiosis without any symptoms. That is a reason to treat the person, not the printout. It is also why retesting after treatment only makes sense when there was a clear finding to recheck.
Your next step
A report is most useful when someone who knows your history reads it with you. Our article on what happens after your GI-MAP results explains how a results visit works and how a plan is built. Pennsylvania patients can have that visit in person in Conshohocken or by telehealth. Every article on the test is collected on the GI-MAP hub.
Frequently asked questions
My report has several "High" flags. Is my gut seriously unbalanced?
Not necessarily. Flags mark numbers outside the lab's range, and many flagged microbes are common in people without symptoms. What matters is whether the findings match how you feel and whether any of them point to bleeding, inflammation or a true infection.
Should I treat every organism the report finds?
No. Treating harmless findings can mean courses of antimicrobials you did not need. A clinician should decide which findings, if any, are worth acting on.
Can I compare my numbers with a friend's report or another lab's test?
Not reliably. Reference ranges are specific to the lab and its methods, and one person's normal varies with diet, medicines and timing.
Related reading
This article is for general education and is not medical advice. Decisions about testing and treatment should be made with your clinician. If you have severe symptoms, call 911. For a suspected poisoning, call Poison Control at 1-800-222-1222.
