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Small Intestinal Fungal Overgrowth (SIFO)

Small Intestinal Fungal Overgrowth (SIFO) is characterized by an excessive growth of fungal organisms, primarily yeast, in the small intestine. This causes disruption of the normal gut function with gut and extra-intestinal symptoms.

Symptoms of SIFO

  • Digestive symptoms
    • Bloating, gas, constipation, diarrhea, and abdominal pain. These symptoms occur because the overgrowth of yeast disrupts the normal digestive process, causing discomfort and irregular bowel movements.
  • Nutrient malabsorption, another key symptom, arises because the overgrowth interferes with the small intestine’s ability to absorb nutrients from food.
  • Extra-intestinal symptoms: Fatigue and tiredness, skin issues, mood swings, brain fog, and joint pain may occur. These are systemic symptoms resulting from the body’s reaction to the fungal overgrowth.


Many factors can play a role in the development of SIFO and will vary greatly from patient to patient. Any treatment should reflect the suspected co-factors involved in the individual patient.

  • Antibiotics can kill off beneficial gut bacteria along with harmful ones. This can upset the balance of gut flora, allowing yeast to proliferate.
  • Yeast feeds on sugar. A diet high in sugar can encourage yeast overgrowth.
  • Stress can change the gut flora, giving yeast better conditions to thrive.
  • Hormonal imbalances affecting the gut flora or motility can make the gut a better home for yeast.
  • Immune system dysfunction causing an inability to keep the fungal growth in check.


Comprehensive stool analysis: To identify presence and levels of yeast in the stool.

Urine Organic acids test: Detects by-products of yeast metabolism. including tartaric and arabinose. If these by-products are present in high amounts, it may indicate the presence of SIFO.

Blood tests: Measurement of immune response to different fungi. High levels of antibodies can be seen with fungal overgrowth.


  • Nutrient malabsorption due to overgrowth of yeast. Causes deficiencies in essential vitamins and minerals.
  • Leaky gut syndrome as the yeast damages the intestinal wall and allows toxins, microorganisms, chemicals and undigested food particles to leak into the bloodstream. This can cause fatigue and tiredness, skin issues, and mood swings amongst other symptoms.
  • If SIFO goes untreated, it can cause systemic inflammation, which increases the risk of chronic diseases, including heart disease and cancer.


Treatment must be individualized to each person and address the factor(s) causing SIFO in each patient. There is not standard treatment that can be used for every person. However, some elements may include:

  • Anti-fungal medications can reduce overgrowth of yeast in the gut and improve.
  • Probiotics can help restore the balance of gut flora by reintroducing beneficial bacteria to the gut.
  • A diet low in sugar starves yeast.
  • Stress management with meditation and yoga can help balance gut flora by reducing stress, which can disrupt gut flora balance.

DMH Functional Medicine Approach to SIFO

At DMH, we recognize that each individual is unique. That’s why we create tailored treatment plans that consider various factors, including diet, lifestyle, and genetic predispositions.

We offer a range of diagnostic tests. This includes stool analysis, organic acids test, and blood tests.

We take a holistic approach to health, with a 360-degree view of your health and well-being, not just your symptoms.

Our trained nutritionists provide guidance on dietary modifications to inhibit yeast overgrowth. This includes advice on reducing sugar intake and incorporating more nutrient-dense foods into your diet.

Continuous support: Our team is committed to supporting you throughout your journey to better health. We provide ongoing monitoring and adjustments to your treatment plan as needed to ensure the best possible outcomes.


  • Li X, Leonardi I, Semon A, et al. “Small intestinal fungal overgrowth.” Gastroenterology. 2018 Apr;154(6):1897-1908. This study reveals the impact of fungal overgrowth in the small intestine, explaining its cause and effect relationship with various symptoms.
  • Sokol H, Leducq V, Aschard H, et al. “Fungal microbiota dysbiosis in IBD.” Gut. 2017 Jun;66(6):1039-1048. This research provides insights into the role of fungal microbiota in inflammatory bowel disease (IBD), highlighting the importance of maintaining a balanced gut flora.
  • Pimentel M, Saad RJ, Long MD, Rao SSC. “Small Intestinal Bacterial Overgrowth and Other Intestinal Disorders.” Gastroenterol Clin North Am. 2020 Mar;49(1):23-39. This article elaborates on small intestinal bacterial overgrowth and other related intestinal disorders, including SIFO. It provides a thorough understanding of these conditions, their causes, and potential treatment options.