Fullscript Academy

Stool testing offers a comprehensive analysis of gastrointestinal (GI) health, focusing on several key categories of markers. As an essential diagnostic aid for GI assessment, it provides a detailed snapshot of the gut's functional status, helping to identify underlying causes of GI symptoms and guiding targeted therapeutic interventions.

Digestive and absorption markers

Comprehensive stool tests can help assess the efficiency of digestion and nutrient absorption. Key markers include elastase, steatocrit, and short-chain fatty acids (SCFAs).

Elastase

Elastase is a pancreatic enzyme crucial for the digestion of proteins. Low levels of elastase indicate exocrine pancreatic insufficiency (EPI), which can lead to malnutrition and GI symptoms like diarrhea, bloating, and weight loss. A score of less than 200 mcg per gram is considered moderate pancreatic insufficiency, with a score of less than 100 mcg per gram considered severe. (Phillips 2021)

Pancreatic insufficiency may be caused by:

• Autoimmune pancreatitis
• Celiac disease
• Chronic pancreatitis
• Cystic fibrosis
• Diabetes
• Gallstones
• GI surgery, such as gastric bypass or pancreatic resection
• Inflammatory bowel disease (IBD)
• Pancreatic tumor/cancer
• Zollinger-Ellison syndrome (NIDDK 2023)

Short-chain fatty acids

SCFAs are produced by the fermentation of dietary fibers by gut microbiota. They play a vital role in colon health and systemic metabolism. Imbalances in SCFAs can reflect dysbiosis or inadequate fiber intake, impacting bowel function and systemic health. (Venegas 2019)

Steatocrit

Steatocrit measures the fat content in stool, serving as an indicator of fat malabsorption. Elevated steatocrit levels suggest steatorrhea, often seen in conditions such as chronic pancreatitis, celiac disease, and small intestinal bacterial overgrowth (SIBO). (Azer 2023)

Stool testing is an essential tool for assessing gastrointestinal health and targeting specific symptoms.

Inflammatory and immunological markers

Inflammatory and immunological markers provide insights into gut inflammation and immune function. Important markers include calprotectin, lactoferrin, and secretory IgA (sIgA).

Calprotectin

Calprotectin is a protein found in neutrophils and serves as a marker for intestinal inflammation. Elevated levels are associated with inflammatory bowel diseases like Crohn's disease and ulcerative colitis, as well as infections and neoplasms. (Pathirana 2018)

Levels of calprotectin between 100–200 mcg per gram and higher are considered serious and a referral for a colonoscopy may be warranted. For levels between 50–100 mcg per gram, the expert recommendation is to follow up with a repeat calprotectin test in a few weeks to monitor levels. (Bjarnason 2017)

Lactoferrin

Lactoferrin is another marker of inflammation, specifically linked to neutrophil activity. High levels suggest active inflammation, often seen in IBD, infections, and colorectal cancer. Alongside measuring other inflammatory markers like calprotectin, lactoferrin helps differentiate between inflammatory and non-inflammatory GI conditions. Levels above 7.25 mcg per gram are considered to be high and may require further evaluation. (Abraham 2018)

Secretory IgA

sIgA is the primary immunoglobulin in mucosal secretions, playing a crucial role in immune defense within the gut. Low levels of sIgA can indicate a weakened immune response in the gut, making individuals more susceptible to infections, chronic inflammation, and food sensitivities. Conversely, high levels of sIgA suggest an ongoing immune response, often linked to chronic infections, autoimmune reactions, or significant gut inflammation. Altered sIgA levels may require addressing underlying infections, reducing inflammatory triggers, and supporting gut barrier integrity to restore balance and improve gut health. (Conrey 2023)

Microbiota and dysbiosis markers

This category examines the balance of commensal and pathogenic microorganisms in the gut, including bacteria, yeast/fungi, and parasites.

Commensal bacteria

Stool testing evaluates the diversity and abundance of beneficial bacteria. A healthy microbiota is crucial for maintaining gut integrity, immune function, and metabolic processes. Imbalances in commensal bacteria can lead to dysbiosis, contributing to conditions like irritable bowel syndrome (IBS), IBD, and metabolic syndrome. (Petersen 2014)

Akkermansia muciniphila

A deficiency in Akkermansia muciniphila can affect the gut mucosal layer, leading to weakened gut barrier function and increased susceptibility to metabolic disorders like obesity and insulin resistance. (Rodrigues 2022)

Bifidobacterium species

Low Bifidobacterium levels can compromise immune function, making individuals more susceptible to infections and chronic inflammation. This species is crucial for modulating the immune system and maintaining gut health. (Gavzy 2023)

Faecalibacterium prausnitzii

This beneficial bacterium is known for its anti-inflammatory properties. Low levels of Faecalibacterium prausnitzii are linked to increased inflammation and have been associated with conditions such as Crohn's disease and ulcerative colitis. (Martin 2023)

Lactobacillus species

Reduced levels of Lactobacillus can lead to digestive issues such as bloating, gas, constipation, or diarrhea. This species helps maintain a healthy gut barrier and its deficiency is often associated with IBS. (Sharma 2023)

Prevotella species

Low levels of Prevotella can influence metabolic health and are often associated with a diet low in fiber. This imbalance can contribute to metabolic disorders and inflammation. (Abdelsalam 2023)

Pathogenic bacteria, yeast/fungi, and parasites

The presence of pathogenic organisms can cause or exacerbate GI symptoms and diseases. (Nagao-Kitamoto 2016) Identifying and quantifying these pathogens is essential for diagnosing infections and guiding antimicrobial therapies. Conditions like candidiasis and parasitic infections can be identified through pathogenic stool analysis. (Hsieh 2010) (Otašević 2018)

Campylobacter species

Campylobacter is a common cause of bacterial gastroenteritis, leading to symptoms like diarrhea, abdominal pain, fever, and nausea. It's often associated with foodborne illness and can necessitate antibiotic treatment and supportive care. (WHO 2020)

Candida species

Overgrowth of Candida, a type of yeast, can lead to GI symptoms such as bloating, gas, and diarrhea. (Kreulen 2023) It can also contribute to systemic symptoms like fatigue and brain fog. (Cater 1995) Treatment often involves antifungal medications and dietary changes to reduce sugar intake and support the growth of beneficial bacteria. (Jawhara 2023)

Clostridium difficile

This bacterium can cause severe diarrhea and colitis, particularly after antibiotic use. Infection with Clostridium difficile (C. diff) often requires prompt medical treatment, including antibiotics and possibly fecal microbiota transplantation (FMT) to restore healthy gut flora. (Mada 2024)

Escherichia coli pathogenic strains

Certain strains of Escherichia coli (E. coli), such as E. coli O157, can produce toxins leading to severe GI distress, including bloody diarrhea and hemolytic uremic syndrome (HUS). Treatment focuses on hydration and, in severe cases, may require hospitalization. (Ameer 2024)

Giardia lamblia

This protozoan parasite causes giardiasis, leading to symptoms such as diarrhea, cramps, and nausea. It's typically treated with antibiotic medications and supportive care to manage dehydration. (Dunn 2024)

Salmonella species

Infection with Salmonella can result in severe GI symptoms, including diarrhea, fever, and abdominal cramps. This pathogen is typically acquired through contaminated food or water and may require antibiotic therapy in severe cases. (CDC n.d.)

Shigella species

Shigella infection, or shigellosis, causes dysentery, characterized by diarrhea (often bloody), fever, and stomach pain. Treatment involves antibiotics and rehydration therapy to manage dehydration and electrolyte imbalances. (Aslam 2024)

Test preparation

Proper preparation is crucial for getting accurate stool testing results. Review the instructions included with the specific test being administered, but some general considerations are listed below.

Ensure that patients are aware of any preparation instructions for the specific test they're taking. 

Dietary guidelines

Generally, patients should continue eating their regular diet before the test without making any drastic changes. This helps provide the most accurate image of their health status, factoring in any dietary considerations. However, certain tests do have specific food interferences. Review test instructions for any specific foods that can interfere with results. (HealthLink BC n.d.)

Medication and supplement restrictions

Antibiotics and antifungals can affect stool test results. If taking any, patients should complete the course 1–2 weeks before the test to avoid alterations in results. Patients should also avoid using any laxatives or antidiarrheal medications prior to testing, if possible. Check the instructions of the specific test for an optimal time frame. (HealthLink BC n.d.)

Probiotic supplements, including those in food form (like yogurt with added probiotics), may need to be discontinued at least three days before the test. Digestive enzymes shouldn’t impact the result of digestive function markers, but some laboratory companies recommend discontinuing digestive enzyme supplements for a few days before the test. (National Library of Medicine n.d.)

Sample collection

Inform patients of the specific sample collection instructions provided with the test kit to ensure proper handling and storage of the stool samples. Always consult with laboratory company instructions related to their health condition.

Other considerations

Both solid and liquid stool can be collected, though alternative collection methods may be required for liquid stool. Testing should also be avoided during menstruation, as blood contamination from menstruation can affect results. (HealthLink BC n.d.)

Integrating results into treatment strategies

When interpreting stool test results, it’s important to consider each patient's specific symptoms and medical history. Based on the panel's findings, personalized treatment plans can be developed to help address specific imbalances and deficiencies.

Dietary interventions

Recommend a diet that supports digestion, enhances nutrient absorption, and promotes a healthy microbiota. This may include increasing fiber intake, eliminating food triggers, and incorporating probiotics. A high-fiber diet has been linked to a decreased risk of metabolic syndrome and cardiovascular disease. Probiotics can encourage the development of healthy bacteria and help restore balance to the gut microbiome. (Aziz 2024)

Using digestive enzyme and pancreatic enzymes may be beneficial in supporting digestive function and addressing deficiencies. (Ianiro 2016) Prebiotics, such as inulin or fructo-oligosaccharides (FOS), play a crucial role in promoting the growth of beneficial gut bacteria. (Davani-Davari 2019) Probiotics, including strains like Lactobacillus and Bifidobacterium, are essential for replenishing beneficial bacteria in the gut, helping to restore microbial balance. Incorporating these into a patient’s treatment plan can help alleviate IBS symptoms and support a healthy gut. (National Institutes of Health n.d.)

Antimicrobials like berberine are also effective in targeting pathogenic organisms within the gut. They work by eliminating harmful microbes while sparing beneficial flora, aiding in the resolution of dysbiosis without disrupting the overall gut ecosystem. (Zhang 2021)

Omega-3 fatty acids, curcumin, and immunoglobulins may be a good option for reducing inflammation and supporting immune function. (Bland 2022)(Hewlings 2017)(Paraschiv 2024) Additionally these can aid in supporting the healing of the mucosal barrier. (Ghosh 2018)(Soares 2020)

Stool test interpretation for greater health outcomes

Stool testing is a powerful tool for healthcare providers, providing detailed insights into GI health. By understanding and interpreting these markers, practitioners can develop personalized and effective treatment plans, addressing the root causes of GI issues and promoting overall health.