SIFO: Small Intestinal Fungal Overgrowth
Content
1. What is SIFO?
1.1 Fungi in the Gut
2. Causes for SIFO
3. Treatment of SIFO
4. Summary
1. What is SIFO?
In addition to SIBO (small intestinal bacterial overgrowth), also known as small intestine dysbiosis, there is another condition called SIFO (small intestinal fungal overgrowth). In SIFO, fungi multiply excessively in the small intestine, which can cause gastrointestinal (gi) symptoms (1). Patients might experience symptoms like include belching, bloating, nausea, and diarrhea (1). SIFO is less common than SIBO and can be difficult to diagnose, as the symptoms are often similar.
1.1 Fungi in the Gut
The presence of fungi, such as Candida, in the gut is normal and does not cause issues as long as they do not overgrow. For example, Candida species, which belong to the yeast family, are found in around 70% of healthy adults (2). However, if fungal overgrowth occurs, it can be detected in stool or urine samples.
Fungal overgrowth can be identified through a stool test, though this primarily reflects the large intestine. Another diagnostic method involves urine testing: Candida produces D-arabinitol as a metabolic byproduct, which is excreted in the urine (3,4). However, an elevated arabinitol level only confirms the presence of Candida overgrowth, without distinguishing whether it originates in the small intestine or large intestine. Each test has its advantages and limitations, but combined, they can provide a clearer diagnosis.
2. Causes for SIFO
The risk factors for small intestinal fungal overgrowth (SIFO) include various factors that disrupt the balance of the gut microbiome or promote fungal overgrowth in the small intestine. These factors include:
· A weakened immune system
· Use of immunosuppressive medications
· Excessive antibiotic use
· Age (newborns and elderly are more susceptible)
· Use of proton pump inhibitors (PPIs)
· Dietary habits
· Reduced small intestine motility (1,5,6).
Antibiotics can reduce beneficial bacteria in the gut, promoting fungal overgrowth. Proton pump inhibitors (PPIs) lower stomach acid production, weakening the body’s natural defense against microorganisms. A diet high in sugar and carbohydrates can encourage fungal growth, as these serve as a preferred energy source for fungi.
Additionally, pre-existing digestive disorders, such as chronic inflammatory bowel diseases or gastrointestinal surgeries, can increase the risk. Older adults and newborns are particularly vulnerable due to weaker immune function or frequent medication use. A combination of these factors significantly raises the risk of developing SIFO.
3. Treatment of SIFO
The treatment of Small Intestinal Fungal Overgrowth (SIFO) aims to reduce excessive fungal colonization, address underlying causes, and stabilize the gut microbiome. Therapy typically involves multiple approaches. Antifungal medications can be used to treat SIFO, while oregano oil (7) serves as a natural alternative. The effectiveness of the treatment may also be enhanced by following a diet low in simple sugars (8). To prevent recurrent fungal overgrowth, a balanced diet and a healthy lifestyle are recommended. In cases of recurring symptoms, regular monitoring and adjustments to the treatment plan are necessary. SIFO therapy should always be carried out in collaboration with a doctor or naturopath.
4. Summary
In summary, current knowledge about SIFO is still limited (as of November 2024). Further studies are needed to better understand its health implications and improve diagnostic and treatment approaches.
References
- Erdogan A, Rao SS. Small intestinal fungal overgrowth. Curr Gastroenterol Rep. 2015 Apr;17(4):16. doi: 10.1007/s11894-015-0436-2. PMID: 25786900.
- Schulze J, Sonnenborn U. Yeasts in the gut: from commensals to infectious agents. Dtsch Arztebl Int. 2009 Dec;106(51-52):837-42. doi: 10.3238/arztebl.2009.0837. Epub 2009 Dec 18. PMID: 20062581; PMCID: PMC2803610.
- Pitarch A, Nombela C, Gil C. Diagnosis of Invasive Candidiasis: From Gold Standard Methods to Promising Leading-edge Technologies. Curr Top Med Chem. 2018;18(16):1375-1392. doi: 10.2174/1568026618666181025093146. PMID: 30360714.
- Roboz J. Diagnosis and monitoring of disseminated candidiasis based on serum/urine D/L-arabinitol ratios. Chirality. 1994;6(2):51-7. doi: 10.1002/chir.530060203. PMID: 8204415.
- Jacobs C, Coss Adame E, Attaluri A, Valestin J, Rao SS. Dysmotility and proton pump inhibitor use are independent risk factors for small intestinal bacterial and/or fungal overgrowth. Aliment Pharmacol Ther. 2013 Jun;37(11):1103-11. doi: 10.1111/apt.12304. Epub 2013 Apr 10. PMID: 23574267; PMCID: PMC3764612.
- Banaszak M, Górna I, Woźniak D, Przysławski J, Drzymała-Czyż S. Association between Gut Dysbiosis and the Occurrence of SIBO, LIBO, SIFO and IMO. Microorganisms. 2023 Feb 24;11(3):573. doi: 10.3390/microorganisms11030573. PMID: 36985147; PMCID: PMC10052891.
- Hacioglu M, Oyardi O, Kirinti A. Oregano essential oil inhibits Candida biofilms. Z Naturforsch C J Biosci. 2021 Apr 29;76(11-12):443-450. doi: 10.1515/znc-2021-0002. PMID: 33915040.
- Otašević S, Momčilović S, Petrović M, Radulović O, Stojanović NM, Arsić-Arsenijević V. The dietary modification and treatment of intestinal Candida overgrowth – a pilot study. J Mycol Med. 2018 Dec;28(4):623-627. doi: 10.1016/j.mycmed.2018.08.002. Epub 2018 Aug 27. PMID: 30166063.
