GI-MAP Bacterial Pathogens and Parasites: What Your Results Mean

The GI-MAP test from Diagnostic Solutions Laboratory uses quantitative PCR (qPCR) DNA technology to measure pathogens and parasites from a single stool sample. This is significantly more accurate than traditional stool cultures or microscopy-based identification, which can miss organisms at low levels and cannot distinguish between pathogenic and non-pathogenic strains.

One of the most important clinical advantages of qPCR is that it gives an exact quantity rather than simply a positive or negative result. This matters because low levels of a pathogen may be present without causing symptoms, while high levels of the same organism demand immediate attention. The GI Map bacterial pathogens report can help to understand if you need aggressive treatment or if you need to support gut health first.

The GI Map test covers a lot more pathogens and parasites compared to the standard test your doctor would run, plus it assesses intestinal health markers.

Key Takeaways

• Not every positive finding requires treatment. Quantity, symptoms, and the broader test pattern all determine clinical priority.
• Antibiotics are contraindicated for several E. coli pathotypes because they can trigger hemolytic uremic syndrome (HUS), a serious complication involving kidney damage. 
• The GI-MAP tests for six distinct E. coli gene types, each with different implications. Understanding which type is detected changes the clinical response entirely.
• Low levels of common parasites like Blastocystis and Dientamoeba may not need treatment. In the past, when tests could only show positive or negative, these were often blamed for symptoms but treatment did not always resolve them, because they were not always the primary cause.
• Viral pathogens on the GI-MAP indicate active GI infection, not past exposure. CMV and EBV in particular have significant autoimmune associations that make them clinically important findings.
• Sources of reinfection must be identified alongside treatment, or infections will recur regardless of what treatment is used.

Bacterial Pathogens

The GI-MAP includes bacterial, parasitic, and viral pathogens commonly associated with gastroenteritis. Symptoms of pathogen infection include vomiting, diarrhea, malaise, fever, and abdominal pain, though many people with positive findings will be asymptomatic. 

Immune function, overall health, the quantity detected, and the balance of beneficial bacteria all influence whether and how severely symptoms manifest.

Campylobacter

Campylobacter is one of the most common causes of foodborne illness in the US, typically contracted through fecal contamination of poultry and water. It can be infectious at very low exposures.

Clinical picture: Symptoms range from mild to severe abdominal pain and diarrhea, fever, and malaise, lasting from several days to several weeks. The vast majority of cases resolve without treatment but can be a trigger for ongoing IBS.

Treatment approach: Check calprotectin to assess the level of GI inflammation before deciding on treatment intensity. High-dose probiotics and broad-spectrum antimicrobial herbs are the first-line approach. Heavy infections can be treated with azithromycin or fluoroquinolones, though antibiotics should be a last resort given their broader impact on the microbiome.

Clostridium difficile (Toxin A and Toxin B)

An important clinical point: the GI-MAP tests for the genes that carry instructions for toxin A and toxin B, not the toxins themselves. This is why it is possible to have elevated C. difficile DNA on the test without active toxin production, and why some patients show high levels while remaining asymptomatic.

Epidemiology: Between 2 and 10% of the general population are asymptomatic carriers. Prolonged antibiotic use is the most common causative factor.

Clinical picture: Active infection causes inflammation, abdominal pain, cramping, fever, and diarrhea. Symptoms typically appear during antibiotic use and often resolve when antibiotics are stopped. GI infection can trigger reactive arthritis.

Treatment approach: Check both calprotectin and secretory IgA (SIgA) to assess inflammation and immune response.

Saccharomyces boulardii, high-dose probiotics, and broad-spectrum antimicrobial herbs address most cases as part of the 5R protocol. In asymptomatic patients where the toxin genes are positive but likely not actively expressing, immediate pharmaceutical treatment may not be necessary. However, avoiding antibiotics is prudent as they can activate toxin production. Antimicrobial herbal formulas can suppress C. diff without this risk.

E. coli: Understanding the Six Pathotypes

E. coli exists in many forms. The GI-MAP measures six distinct E. coli gene targets, each representing a different pathotype (subtype) with different clinical implications. This is one of the most nuanced sections of the pathogens panel, and the table below clarifies what each marker means.

GI-MAP Marker	Description
E. coli EPEC/EHEC (eae)	Found on either enteropathogenic (EPEC) or enterohemorrhagic (EHEC) E. coli. Interpret alongside other E. coli markers to distinguish between the two.
E. coli O157	May be found on some pathogenic strains but is not a pathogenic marker by itself. If found alone it is likely an outer membrane protein.
Enteroinvasive E. coli / Shigella	Gene found on either EIEC or Shigella.
Enterotoxigenic E. coli LT/ST	Toxin gene found on ETEC. The most common cause of traveler’s diarrhea. Around 95% of cases are self-limiting.
Shiga-like Toxin stx1	Shiga toxin gene. Caution: antibiotics are contraindicated due to HUS risk.
Shiga-like Toxin stx2	Shiga toxin gene. Caution: antibiotics are contraindicated due to HUS risk.

One or both Shiga-like Toxin genes can be present in EHEC, O157:H7, or STEC infections.

Hemolytic Uremic Syndrome (HUS): An Important Safety Note

HUS is one of the more serious potential outcomes of certain E. coli infections. It is kidney damage triggered by Shiga-like Toxin and can lead to hemolytic anemia, thrombocytopenia, kidney damage, and in severe cases, death. Risk is higher in children, during severe or prolonged infections, and when antibiotics are used. Antibiotics are contraindicated when Shiga-like Toxin genes are detected. Many practitioners extend this caution to all E. coli pathogen findings to eliminate the risk entirely.

Enterohemorrhagic E. coli (EHEC)

Epidemiology: Fecal contamination of food (undercooked beef, raw milk, unpasteurized juice) and water. Associated with hemorrhagic colitis, which may progress to HUS.

Clinical picture: Fever, abdominal cramping, fatigue, nausea, and diarrhea. Symptoms typically last up to a week.

Treatment approach: Antibiotics are contraindicated due to HUS risk. Check calprotectin and SIgA to assess inflammation and immune response. High-dose probiotics (300+ billion CFU/day) and broad-spectrum antimicrobial herbs. Bacteriophage therapy is an emerging option.

E. coli O157

Epidemiology: Fecal contamination of dairy, undercooked beef, vegetables, and juices. Associated with outbreaks of bloody diarrhea and HUS globally.

Clinical picture: Severe abdominal cramps and diarrhea. Shiga toxins inhibit protein synthesis and trigger a strong inflammatory response.

Treatment approach: Antibiotics contraindicated due to HUS risk. High-dose probiotics and broad-spectrum antimicrobial herbs. Calprotectin and SIgA results help determine treatment priority alongside the full test picture.

Enteroinvasive E. coli / Shigella

Epidemiology: Fecal contamination of ingested foods.

Clinical picture: Diarrhea (with blood and/or mucus), vomiting, fever, chills, fatigue, and abdominal cramping. Symptoms are generally self-limiting but can lead to lasting microbiome disruption. GI infection can trigger reactive arthritis.

Treatment approach: Antibiotics are generally contraindicated. High-dose probiotics and broad-spectrum antimicrobial herbs. Calprotectin and SIgA results help determine whether treatment is urgent or monitoring is appropriate.

Enterotoxigenic E. coli (ETEC) LT/ST

Epidemiology: The most common cause of traveler’s diarrhea worldwide. Fecal contamination of food and water, particularly in areas with poor sanitation. Around 95% of cases are self-limiting.

Clinical picture: Watery diarrhea is the primary symptom, caused by the heat-labile (LT) and heat-stable (ST) toxin genes.

Treatment approach: Most cases resolve without treatment. Oral rehydration, high-dose probiotics, and antimicrobial herbs where needed.

Shiga-like Toxin E. coli stx1 and stx2

Epidemiology: Fecal contamination of undercooked meat, unpasteurized milk, juice, and water.

Clinical picture: Severe abdominal cramps and diarrhea. Both toxin genes trigger a strong inflammatory response and carry HUS risk.

Treatment approach: Antibiotics and antidiarrheal medications are contraindicated as they increase the risk of HUS. High-dose probiotics and broad-spectrum antimicrobial herbs. Always treat the person, not just the test result. Some patients cannot tolerate aggressive herbal protocols at the outset and need a staged approach.

Salmonella

Epidemiology: Fecal contamination of eggs, poultry, meat, unpasteurized dairy, raw fruits, and vegetables. Exposure to reptiles, amphibians, and baby chicks is also a common source.

Clinical picture: Often asymptomatic. When symptomatic: fever, vomiting, and severe diarrhea, typically self-limiting within seven days. GI infection can trigger reactive arthritis and may be involved in ankylosing spondylitis. Systemic infections may require antibiotic treatment in some situations.

Treatment approach: Check calprotectin and SIgA. High-dose probiotics and broad-spectrum antimicrobial herbs alongside the 5R protocol. Remove and address sources of reinfection.

Vibrio cholerae

Epidemiology: Fecal contamination of raw shellfish and water. Often contracted during international travel.

Clinical picture: Can be asymptomatic or cause mild symptoms. Severe infections present with profuse watery diarrhea (historically described as rice-water stools), vomiting, rapid heart rate, low blood pressure, and loss of skin elasticity. Dehydration is the primary danger.

Treatment approach: Rehydration therapy and electrolytes are the priority. Zinc supplementation, particularly in children. High-dose probiotics and broad-spectrum antimicrobial herbs. Heavy infections may be treated with doxycycline.

Yersinia enterocolitica

Epidemiology: Fecal contamination of water, undercooked pork, meat, and dairy products.

Clinical picture: Symptoms typically develop four to seven days after exposure and are usually self-limiting. Watery or bloody diarrhea, fever, vomiting, and abdominal pain that can mimic appendicitis. Symptoms may also mimic Crohn’s disease. Can trigger autoimmune thyroiditis or inflammatory arthritis in susceptible individuals.

Treatment approach: Consider the patient’s symptoms carefully before implementing treatment — do not treat based on individual markers alone. High-dose probiotics and broad-spectrum antimicrobial herbs for most cases. Heavy infections can be treated with doxycycline combined with an aminoglycoside.

Parasitic Pathogens

Pathogenic Protozoa

The first three parasites below would ideally be negative on the GI-MAP. They are more serious pathogens that can cause systemic symptoms beyond the gut and generally require treatment when found.

I use CellCore products with my clients for parasite protocols. You can order directly using the link below

Cryptosporidium

Epidemiology: Fecal contamination of water (including swimming pools), undercooked meat, and raw milk. A common cause of traveler’s diarrhea. Can pass through standard water filtration systems.

Clinical picture: Symptoms typically last 2 to 3 weeks and are self-limiting. If symptoms persist, investigate the drinking water supply as an ongoing source. Can cause reactive arthritis.

Treatment approach: May not require treatment in mild cases. Anti-parasitic herbal treatments like the Cellcore Para 1, 2 & 3 protocol work well. Remove and address sources of fecal contamination. Heavy infections can be treated with nitazoxanide as a last resort.

Entamoeba histolytica

Epidemiology: Fecal contamination of food or water. Pets and sexual contact can also be sources.

Clinical picture: Symptoms include diarrhea, fulminating colitis (resembling ulcerative colitis), and dysentery. In extreme cases it can invade liver and lung tissue. This can be a serious parasitic infection and must be treated when found, though it is not a parasite that appears frequently.

Treatment approach: Treatment is recommended even in asymptomatic carriers given its invasive potential. Work with an experienced practitioner for this one. Mild infections can often be treated with the Cellcore products, but moderate to heavy infections tinidazole, followed by iodoquinol or paromomycin. Anti-parasitic herbal treatment and the 5R protocol to support gut recovery.

Giardia

Epidemiology: The most commonly isolated intestinal protozoan worldwide. Found in lakes, streams, and ponds, and can pass through water filtration systems. Carried by animals and common in childcare workers.

Clinical picture: Can be asymptomatic, particularly in patients with good SIgA levels and a healthy microbiome. Symptomatic cases: acute diarrhea, bloating, cramping, weight loss, intestinal malabsorption, and steatorrhea (fat in stool). Can cause urticaria and neurological symptoms including irritability, sleep disturbance, and depression. Can trigger reactive arthritis and may cause vitamin B12 deficiency and malnutrition.

Treatment approach: Check calprotectin, eosinophil activation protein, and SIgA to assess GI inflammation and immune response. Pharmaceutical options include tinidazole, nitazoxanide, metronidazole, paromomycin, furazolidone, or quinacrine. Herbal anti-parasitic formulas from Cellcore alongside gut repair and rebuild using the 5R protocol are often equally effective.

Non-Pathogenic and Commensal Protozoa

The following parasites are common findings on the GI-MAP, particularly Blastocystis hominis and Dientamoeba fragilis. Low levels may not need to be treated. In the past, when tests could only show positive or negative results, these organisms were often blamed as the cause of gut symptoms.

After treatment, however, symptoms did not always resolve, because in many cases they were not the primary driver. The pattern of the whole test, alongside the patient’s symptoms, should guide treatment decisions rather than the presence of these organisms alone.

Blastocystis hominis

Epidemiology: Fecal contamination of food or water. Found worldwide.

Clinical picture: Can cause diarrhea, abdominal pain, nausea, vomiting, fever, fatigue, and IBS-like symptoms, though many carriers are asymptomatic.

Treatment approach: Blastocystis is difficult to eradicate. Before deciding on treatment, check eosinophils on a blood test alongside calprotectin levels to determine whether active treatment is warranted. For pharmaceutical treatment: paromomycin. Herbal options: Artemisia, Coptis, or Cellcore antiparasitic herbal formulas. Assess all results and symptoms before deciding on a treatment plan, as other findings on the test may be the more pressing clinical priority.

Dientamoeba fragilis

Epidemiology: Transmission is not fully understood but is likely via fecal-oral contamination.

Clinical picture: Can be asymptomatic or cause diarrhea, abdominal pain, nausea, fever, fatigue, and weight loss.

Treatment approach: Moderate amounts of DNA that are not above the reference range can still cause symptoms and warrant treatment. Treatment options: iodoquinol, paromomycin.. High-dose probiotics and Cellcore herbal formulas alongside the 5R protocol. Identify and address sources of reinfection. Always assess other imbalances on the GI-MAP, as these may be the main cause of symptoms.

Chilomastix mesnili

Considered non-pathogenic and typically does not cause symptoms. Its presence may indicate dysbiosis or suppressed immunity. Address sources of fecal-oral contamination and support gut immunity through the 5R protocol. Assess other imbalances on the test.

Cyclospora spp.

Epidemiology: Fecal contamination of food and water. Associated with food and waterborne outbreaks. Common cause of traveler’s diarrhea, often from imported produce from tropical regions.

Clinical picture: Prolonged watery diarrhea, abdominal cramping, nausea, vomiting, and fatigue. May alternate between diarrhea and constipation. Usually self-limiting within seven days, but can persist for weeks to months in immunocompromised patients.

Treatment approach: Probiotics and broad-spectrum anti-parasitic herbal formula for most cases. Anti-parasitic pharmaceuticals (trimethoprim-sulfamethoxazole) can be considered in serious or prolonged cases. Identify and address sources of reinfection.

Endolimax nana

Considered non-pathogenic; individuals are usually asymptomatic. May indicate dysbiosis. Conservative treatment through the 5R protocol is appropriate if the clinical presentation is consistent with enteroparasitosis. Assess other markers on the GI-MAP.

Pentatrichomonas hominis

Considered harmless and non-pathogenic. Infected individuals are usually asymptomatic, though it may contribute to dysbiosis. Also colonizes dogs, cats, and other animals. If treatment is needed, consider a broad-spectrum antiparasitic herbal formula alongside probiotics. Identify and address sources of fecal contamination.

Worms

Most people are comfortable with the idea of bacteria living inside the gut, but the thought of worms is something that understandably causes more concern. The GI-MAP measures the presence of eggs that worms produce, rather than counting the worms themselves.

It is also worth noting that not all worm interactions with the human body are harmful. Helminth therapy, where someone is deliberately exposed to specific worms to help modulate immune responses in autoimmune and inflammatory conditions, is an area of active research, though it is not something used in standard practice, and not something that I would do!

Generally pharmaceutical treatments are the fastest and most effective then focus on gut healing options after this.

Hookworms (Ancylostoma duodenale and Necator americanus)

Epidemiology: Infection occurs through skin contact with soil contaminated with larvae, or ingestion of larvae. Infected cats and dogs are a source. More prevalent in southern Europe, Northern Africa, India, Asia, the Caribbean, and South America.

Clinical picture: Early symptoms include itching and rash at the site of larval penetration. Heavy infestations cause abdominal pain, diarrhea, fatigue, weight loss, iron deficiency anemia (IDA), and coughing. Many individuals are asymptomatic.

Treatment approach: Heavy infections: albendazole or mebendazole. Iron supplementation where IDA is present, though take care as iron can also feed bacterial infections,  work with your practitioner on timing and dosing. Anti-parasitic herbal treatment like the cellcore protocols can be effective but pharmaceutical treatment is often the fastest and most successful.

Roundworm (Ascaris lumbricoides)

Epidemiology: Fecal contamination of food or water. Common in international travelers and recent immigrants from Latin America and Asia.

Clinical picture: Early symptoms include fever, coughing, wheezing, and shortness of breath as larvae migrate through the lungs. Late symptoms include abdominal pain, nausea, vomiting, dry cough, and in heavy infections, appendicitis, pancreatitis, or bowel obstruction. Can cause reactive arthritis.

Treatment approach: Albendazole, mebendazole, or ivermectin. Anti-parasitic herbal treatment and the 5R protocol. Identify and remove sources of reinfection.

Whipworm (Trichuris trichiura)

Epidemiology: Fecal contamination of produce or person-to-person contact. Prevalent in Asia, Africa, South America, and rural southeastern United States.

Clinical picture: Most individuals are asymptomatic. In some cases, diarrhea with mucus and blood.

Treatment approach: Albendazole, mebendazole, or ivermectin. Iron supplementation if IDA is present. Anti-parasitic herbal treatment, gut immunity support, and probiotics. Identify and remove sources of reinfection.

Tapeworm (Taenia spp.)

Epidemiology: Fecal contamination of undercooked pork (T. solium) or beef (T. saginata). T. solium is prevalent worldwide in communities where pigs are raised and eaten; T. saginata in Africa, parts of Eastern Europe, the Philippines, and Latin America.

Clinical picture: Often asymptomatic or mild. Can cause abdominal pain, nausea, weakness, altered appetite, headache, constipation, dizziness, and diarrhea.

Treatment approach: Albendazole or praziquantel. Anti-parasitic herbal treatment and the 5R protocol. Identify and remove sources of reinfection.

Viral Pathogens

Viral gastroenteritis infections spread easily and often affect the whole household at once. They are also among the most acutely unpleasant gut infections someone can experience.

Adenovirus 40/41

Epidemiology: A common cause of diarrhea in infants and children, though it can also affect adults. Transmitted primarily via fecal-oral route.

Clinical picture: Fever and watery diarrhea, usually lasting 1 to 2 weeks. May be present in asymptomatic carriers.

Treatment approach: Handwashing and hydration are the priorities, given the volume of fluid loss with diarrhea. Antiviral herbs: cat’s claw, osha root, reishi mushroom, vitamins A, C, and D, zinc, and Echinacea. Address other GI-MAP imbalances using the 5R protocol to rebuild gut immunity.

Norovirus GI/GII

Epidemiology: Fecal contamination of food and water. One of the most common causes of non-bacterial gastroenteritis outbreaks globally.

Clinical picture: Nausea, vomiting, diarrhea, abdominal cramps, low-grade fever, muscle aches, and headache. Generally self-limiting, lasting 24 to 72 hours.

Treatment approach: Antivirals are not recommended. Hydration and mucosal support are the most important interventions. Handwashing to prevent spread. Address other GI-MAP imbalances to rebuild gut health.

Cytomegalovirus (CMV)

A positive CMV result on the GI-MAP indicates active GI infection, not past exposure,  this is an important distinction. CMV has infected approximately 60% of the population, but a positive finding on the GI-MAP means active replication in the gastrointestinal tract at the time of testing.

Clinical picture: Active infection may be asymptomatic or cause mild flu-like symptoms. Can also cause viral pneumonia, colitis, fever, and encephalitis. CMV colitis can look similar to C. difficile infection. CMV has documented associations with autoimmune diseases including lupus, systemic sclerosis, Type 1 diabetes, and rheumatoid arthritis.

Treatment approach: No treatment needed if asymptomatic. Antiviral herbs: cat’s claw, osha root, reishi and Cordyceps mushrooms, vitamins A, C, and D, zinc, Echinacea. Address GI imbalances and rebuild gut immunity with the 5R protocol.

Epstein-Barr Virus (EBV)

Similarly, a positive EBV result on the GI-MAP indicates active GI infection, not past exposure. EBV infects 90 to 95% of the global population at some point, but its presence on this test means active infection in the GI tract.

Clinical picture: Can cause infectious mononucleosis (mono): fatigue, fever, swollen lymph nodes, inflamed throat, and enlarged spleen, lasting two to four weeks in adults, with fatigue sometimes persisting for weeks or months. Found in 30 to 64% of IBD patients. EBV may increase the risk of gastric cancer, particularly when H. pylori is also present. Associated with autoimmune conditions including rheumatoid arthritis, lupus, Sjogren’s syndrome, multiple sclerosis, and autoimmune thyroid disorders.

Treatment approach: Rest and hydration during acute infection. Antiviral herbs: cat’s claw, osha root, reishi and Cordyceps mushrooms, vitamins A, C, and D, zinc, Echinacea. Follow-up blood testing including EBV Early Antigen and EBV PCR may be indicated. Rebuild gut health and immunity with the 5R protocol.

Sources of Exposure and Re-Infection

Whenever a GI-MAP comes back positive for a bacterial pathogen or parasite, the first question patients ask is: how did I get this? It is often impossible to know with certainty, but identifying likely sources is important for preventing reinfection, which is one of the most common reasons treatment fails to resolve symptoms long-term.

Most exposure occurs via fecal-oral transmission: contaminated water, raw or undercooked food, improper handwashing, and contact with infected people or animals. To reduce contamination on food, the FDA recommends washing hands first, then running cool water over fruits and vegetables while rubbing or scrubbing, and allowing them to dry before eating. (but not many people do this).

With our food often travelling from countries from around the world this can also increase the risk of infection.

During treatment, consider all possible sources of ongoing transmission: romantic partners, children in diapers, household water supply, contact with animals, and shared items such as towels and bedding. For parasitic infections in particular, whole-household or partner testing is often warranted to prevent ongoing reinfection cycles.

Frequently Asked Questions

For a complete overview of everything the GI-MAP measures, visit the Complete Guide to the GI-MAP Test. To order the test, visit the GI-MAP order page, or contact us to discuss your situation.