Add-On: KOH Preparation for Yeast

This is a single-marker test detecting yeast. It is available as an add-on to the GI Effects® profiles.

What is the Add-On: KOH Preparation for Yeast By Genova Diagnostics?

This test is an add-on to the full GI Effects profile.  This add-on test specifically looks for the presence of yeast.

The Potassium Hydroxide (KOH) test involves mixing a small amount of stool with a solution of potassium hydroxide, which serves to dissolve any organic matter while leaving fungal elements intact. 

The sample is then observed under a microscope, where the fungal elements, if present, become visible due to their resistance to the potassium hydroxide solution. Specifically, the test aims to identify the characteristic budding yeast cells or hyphae structures that are indicative of fungal overgrowth or infection in the digestive system. 

Overall, the KOH test provides a rapid and reliable means of detecting yeast overgrowth in stool samples, aiding in the timely diagnosis and management of fungal-related gastrointestinal disorders.

How is the Add-On: KOH Preparation for Yeast By Genova Diagnostics Clinically Relevant?

Intestinal yeast including Candida, Saccharomyces, and Malassezia is a normal part of the human mycobiome.  However, in some instances certain types of yeast may begin to overpopulate the human GI tract, causing digestive and systemic issues.  

Digestive conditions including Chron’s disease, Ulcerative Colitis, and ulcers have all been linked with Candida albicans overgrowth.  [4.]  It has also been suggested that in the presence of leaky gut, gastrointestinal Candida can migrate into the bloodstream, causing a potentially deadly systemic Candida infection.  [1.]

Other symptoms associated with yeast overgrowth include migraines, fatigue, depression, bloating, chronic fatigue syndrome, and more.  [2., 9.]  Chronic candidiasis has also been linked with chronic or recurrent vaginal yeast infections, oral, skin and nail infections.  [3., 6., 8.]

Who Can Benefit From the Add-On: KOH Preparation for Yeast by Genova Diagnostics?

Immunocompromised individuals: People with conditions such as leukemia, lymphoma, or those undergoing cancer cytotoxic chemotherapy, which compromise the immune system, are at increased risk of candidiasis due to reduced immunity and compromised mucosal barriers.  [7.] 

Antibiotic users: Antibiotic usage disrupts the balance of bacteria in the gastrointestinal tract, allowing fungal commensals like Candida to proliferate and potentially cause opportunistic infections.  [7.] 

HIV patients: Individuals with HIV/AIDS are highly susceptible to candidiasis, with more than 90% of patients presenting with oral candidiasis due to their compromised immune system.  [7.] 

Individuals with diabetes mellitus: colonization of Candida increases in individuals with diabetes mellitus, predisposing them to candidiasis.  [7.] 

Pregnant women: Pregnancy can lead to hormonal changes that increase the risk of vaginal candidiasis.  [7.]

Individuals with nutritional deficiencies: Deficiencies in vitamins such as A and B6, as well as iron, can weaken the immune system and predispose individuals to candidiasis.  [7.] 

Individuals with xerostomia: Dry mouth, often associated with conditions like Sjögren's syndrome or as a side effect of medications, can increase the risk of oral candidiasis due to reduced levels of protective antifungal proteins.  [7.] 

Elderly individuals: Older adults may be more susceptible to candidiasis due to factors such as weakened immune function, underlying health conditions, and the presence of dentures, which can harbor fungal growth.  [7.] 

Infants: Infants, particularly those on antibiotics or with underlying health conditions, are at increased risk of candidiasis, especially oral thrush.  [7.] 

Individuals with chronic medical conditions: Conditions such as tuberculosis, myxedema, hypoparathyroidism, Addison's disease, and chronic smoking can weaken the immune system and increase susceptibility to candidiasis. Additionally, individuals with poorly maintained dentures, IV tubes, catheters, or heart valves may be at increased risk of fungal infections.  [7.] 

Collection and Shipping 

This test is an add-on, and it will be assessed in the sample provided by the patient for the full GI Effects profile.  Click here for Collection and Shipping Instructions.  

Additional Resources for Practitioners

Article: Using the GI Effects Test in Clinic

Video: Clinical Pearl 3: Culture, KOH Prep, and PCR to Evaluate Yeast

Video: Interpreting the GI Effects Profile

References

[1.] Alonso-Monge R, Gresnigt MS, Román E, Hube B, Pla J. Candida albicans colonization of the gastrointestinal tract: A double-edged sword. PLoS Pathog. 2021 Jul 22;17(7):e1009710. doi: 10.1371/journal.ppat.1009710. PMID: 34293071; PMCID: PMC8297749.

[2.] Cater RE 2nd. Chronic intestinal candidiasis as a possible etiological factor in the chronic fatigue syndrome. Med Hypotheses. 1995 Jun;44(6):507-15. doi: 10.1016/0306-9877(95)90515-4. PMID: 7476598. 

[3.] Darwazeh AMG, Darwazeh TA. What Makes Oral Candidiasis Recurrent Infection? A Clinical View. Journal of Mycology. 2014;2014:1-5. doi:https://doi.org/10.1155/2014/758394

‌[4.] Kumamoto CA. Inflammation and gastrointestinal Candida colonization. Curr Opin Microbiol. 2011 Aug;14(4):386-91. doi: 10.1016/j.mib.2011.07.015. Epub 2011 Jul 28. PMID: 21802979; PMCID: PMC3163673.

[5.] Mohanty A, Gupta P, Arathi K, Rao S, Rohilla R, Meena S, Singh A, Kaistha N, Rath RS, Varshney S. Evaluation of Direct Examination, Culture, and Histopathology in the Diagnosis of Mucormycosis: Reiterating the Role of KOH Mount for Early Diagnosis. Cureus. 2021 Nov 10;13(11):e19455. doi: 10.7759/cureus.19455. PMID: 34926028; PMCID: PMC8654087.

[6.] Nucci M, Anaissie E. Revisiting the source of candidemia: skin or gut? Clin Infect Dis. 2001 Dec 15;33(12):1959-67. doi: 10.1086/323759. Epub 2001 Nov 8. PMID: 11702290.

[7.] R AN, Rafiq NB. Candidiasis. [Updated 2023 May 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560624/

[8.] Rosati D, Bruno M, Jaeger M, ten Oever J, Netea MG. Recurrent Vulvovaginal Candidiasis: An Immunological Perspective. Microorganisms. 2020;8(2):144. doi:https://doi.org/10.3390/microorganisms8020144

[9.] Singh R, Mullin GE. A Wasting Syndrome and Malnutrition Caused by Small Intestine Fungal Overgrowth: Case Report and Review of the Literature. Integr Med (Encinitas). 2017 Jun;16(3):48-51. PMID: 30881247; PMCID: PMC6419785.