What is SIFO or Small Intestine Fungal Overgrowth: Causes, Symptoms, Treatment, Diet, Diagnosis

SIFO or small intestinal fungal overgrowth occurs when there is an excessive amount of fungi in the intestine associated with gastrointestinal symptoms.

It mostly occurs in people with a weakened immune system but can also affect those with a healthy immune system.

A study found that 25 percent of people with unexplained GI symptoms were suffering from SIFO or small intestinal fungal overgrowth.⁽¹⁾

Most of the time the fungal growth found in SIFO or small intestinal fungal overgrowth is due to Candida species.⁽²⁾ Candida is also found in small amounts in the mouth, skin, and intestines and at low levels does not cause any problem.

If Candida grows uncontrollably, they can cause vaginal yeast infection and oral thrush. It can also upset the gut by proliferating in the intestine.

There are various factors that can increase the risk of a person to suffer from SIFO or small intestinal fungal overgrowth.

1. Excessive Proton Pump Inhibitors: Proton pump inhibitors are given to relieve the symptoms of gastroesophageal reflux. They tend to lower the level of acid in the stomach. Stomach acids are crucial for gut health as they kill the bacteria and fungi before entering the small intestine. If their level falls, bacterial growth increases.
2. Other conditions that may increase the risk of lowering the stomach acid and increasing SIFO or small intestinal fungal overgrowth risk are autoimmune conditions, anemia, and excessive use of painkillers or antacids.
3. Excessive use of antibiotics can weaken the immune system making a person more susceptible to Candida infection.
4. Taking immunosuppressant drugs put down the ability of the body to fight the fungal growth, thus increasing the risk of SIFO or small intestinal fungal overgrowth.
5. Intestinal dysmotility, which happens when the contraction of intestinal smooth muscles is impaired, is also a risk factor of SIFO. This condition can occur if suffering from any health condition such as diabetes, scleroderma, or lupus.
6. Colectomy can also increase the risk of suffering from gastrointestinal symptoms and SIFO.⁽⁴⁾
7. SIBO or small intestinal bacterial overgrowth can also increase the risk of suffering from SIFO

The symptoms of SIFO or small intestinal fungal overgrowth are very similar to those of chronic GI tract infection symptoms which include:

• Vomiting
• Gas
• Belching
• Diarrhea
• Nausea
• Abdominal pain
• Abdominal bloating

SIFO or small intestinal fungal overgrowth can also lead to more severe symptoms such as malnutrition and weight loss.⁽³⁾

The Candida species are also associated with other chronic health issues such as:

• Gastric ulcers
• Ulcerative colitis
• Crohn’s disease
• The intestinal fungi may also lead to irritable bowel syndrome.

There are numerous ways the overgrowth of microorganisms can be checked in the intestine amongst which small bowel aspirates are the only definitive way to diagnose SIFO or small intestinal fungal overgrowth. In this test, a small amount of fluid is collected from the small intestine.

It is done with the help of an instrument called endoscope which is passed through the esophagus and stomach to the intestine. The sample is then collected and sent to the laboratory for testing.

SIFO or small intestinal fungal overgrowth can also be diagnosed on the basis of clinical evidence. If the patient has digestive issues and other GI infection tests are negative, SIFO can be suspected.

Empiric treatment is a way to go ahead with the antifungal treatment if SIFO is suspected. If the symptoms start clearing up, it can be diagnosed as SIFO or small intestinal fungal overgrowth.

If the large numbers of fungi are identified in the sample, a course of antifungal drug is started. Though there may not be a complete elimination of the fungus with this drug.

Certain probiotics and herbal antimicrobials like oregano, berberine, and artemisinin are also effective as antifungal medications. Herbal antimicrobials have both antifungal and antibacterial functions and it is beneficial as half of the patients with SIFO suffer from SIBO as well.

These antimicrobials are effective in treating SIBO and abdominal pain.

An individual suffering from SIFO should focus on avoiding the following foods:

• Wheat, rye, and barley, grains which contain gluten
• Fruits high in sugar such as bananas, mangos, ad grapes
• Dairy products like cheese, creams, and milk
• Refined oils like canola, soybean, and margarine
• Sugary substitutes
• Caffeine and alcohol

A study found that Candida colonization is more common in those who consume carbohydrates and less in individuals taking a diet rich in amino acids, protein, and fatty acids.⁽⁶⁾

Many aspects of SIFO or small intestinal fungal overgrowth are yet to be understood. Although it can be treated with antifungal medicines all the symptoms are not alleviated. If having unexplained GI symptoms make sure you visit a doctor for a proper diagnosis and treatment.