Small intestinal fungal overgrowth (SIFO) is a condition characterized by an excessive population of fungal microorganisms inhabiting the small intestine (SI).1 SIFO exhibits a broad range of symptoms to include gas, diarrhea (leading to nutrient deficiencies), belching, indigestion, and bloating.1(1) Left unmitigated, such symptoms can negatively effect individuals’ quality of life and health. However, detection and management of SIFO is possible through the use of appropriate tests and dietary interventions, respectively. The following will consider detection and management of SIFO in greater detail.

SIFO is largely characterized by overgrowth of a specific fungus known as Candida; a microorganism considered opportunistic in nature and one that colonizes the mucosal and skin and surfaces of the body.1(3) Generally, cell-mediated and humeral immunological responses control the levels of fungus along the SI.1(3) However, any form of damage to the walls of the SI or the microbiome at large might enable SIFO to proliferate. Such mucosal damage along the intestinal tract could emanate from antibiotic use, chemotherapy, inflammatory processes (i.e., gluten sensitivity), immune molecule activation, and epithelial repair disruption.1(3) As such, it is critical to control the growth the growth of Candida.

SIFO can be confirmed (in conjunction to symptoms) by the use of urine tests seeking the presence of D-arabinitol; a metabolite, organic acid, and biomarker for pathogenic candida species.2 If an individual is positive for fungal overgrowth, the next step is developing nutritional interventions (and medications when appropriate) to down-regulate the proliferation of such species. Research has indicated that Candida tends to grow aggressively when enveloped by particular nutrient mediums.2(387) As such, a nutrition regimen which denies a favorable growth medium for Candida is warranted.

Jeziorek et al.3 stated that diet can significantly influence the activity and composition of intestinal microbiota, to include fungi. Furthermore, particular nutrients affect the metabolic (energy-producing) activity of microbes, and macronutrients such as carbohydrates, proteins, and fats have been frequently studied in for their effects upon Candida. Of particular interest is the aggressive growth rate of fungus in carbohydrate-rick mediums.3(4) Equally intriguing is the inhibition of Candida growth and proliferation when exposed to saturated fatty acids. The following will consider said macronutrients, and other foods which control fungal growth, in greater detail.

Generally, individuals positive for Candida spp. cultures consumed processed carbohydrates such as cereals cereal from purified than from whole-grain flour sources. Individuals with negative Candida spp. cultures more often included healthier wheat flour substitutes (e.g. rye flour, oat flour, buckwheat flour).3(4) Additionally, research has indicated that medium and short-chain fatty acids, such as those found in coconut oil, tended to inhibit the growth of fungus and killsaid microorganism.3(4) Thus, it can be concluded that if SIFO prefers carbohydrates as a food source, lowering starchy and refined carbohydrates in the diet might be a useful intervention in controlling both the symptoms and the growth of fungus. Layering such an approach with a diet rich in saturated fat might also be indicated, especially from sources such as coconut oil.

Although manipulating macronutrient ratios in the diet has been shown to control SIFO, other interventions exist that are equally simple and non-invasive, such as the use of spices. Since a high degree of antifungal resistance (nystatin, clotrimazole, fluconazole, itraconazole, and amphotericin B) have been reported in Candida species, any and all nutritional strategies are warranted. Latti et al.4 conducted a study analyzing the effectiveness of cinnamon bark, cumin, dried black pepper fruits, and dried Indian bay leaves upon the growth rates of Candida albicans (often found in the oral cavity and intestinal tract). Interestingly, the four extracts demonstrated significant antimicrobial activity; cinnamon demonstrated the highest anti-fungal properties.4(3)

In conclusion, SIFO is a condition characterized by an excessive overgrowth of fungal microorganisms inhabiting the SI. SIFO exhibits a broad range of symptoms to include gas, diarrhea (leading to nutrient deficiencies), belching, indigestion, and bloating. However, simple dietary interventions, in conjunction to pharmacological approaches where indicated, such as lowering refined/starchy carbohydrates intake, increasing medium/short chain saturated fatty acids such as coconut oil, and increasing the use of certain spices like cinnamon/curcumin/bay leaves/black pepper fruit can have measurable and beneficial changes to gut health and fungal control. Ultimately, such non-invasive and cost-effective approaches strategies can help liberate individuals from illness and improve health, performance, and longevity.


1. Erdogan A, Rao SSC. Small intestinal fungal overgrowth. Curr Gastroenterol Rep. 2015; 17(4):1-7. doi:10.1007/s11894-015-0436-2.
2. Lord RS, Bralley, JA. Laboratory Evaluations for Integrative and Functional Medicine. 2 nd ed. Duluth, GA: Genova Diagnostics; 2012.
3. Jeziorek M, Frej-Mądrzak M, Choroszy-Król I. The influence of diet on gastrointestinal candida spp. colonization and the susceptibility of candida spp. to antifungal drugs. Rocz Panstw Zakl Hig. 2019;70(2):195-200. doi: 10.32394/rpzh.2019.0070.
4. Latti P, Ramanarayanan S, Prashant GM. Antifungal efficacy of spice extracts against Candida albicans: An in vitro study. Indian J Community Med. 2019;44(5):77-80.

-Michael McIsaac