Small Intestinal Fungal Overgrowth, or SIFO, occurs when yeast – also known as candida – is able to grow in large quantities in the small intestine. This can lead to a number of digestive symptoms.
Other names for SIFO include chronic candidiasis and yeast syndrome(1).
Who can Have SIFO?
Limited preliminary data suggests that younger children, older adults, and individuals with weakened immune systems are more prone to getting SIFO. However, a similar study found that individuals who take PPIs (proton pump inhibitors) may be more susceptible. Anyone who has either a Blood type O, a homozygous recessive FUT2 genetic mutation, or has a Lewis A+, Lewis B- blood type – making them a non-secretor – is also more susceptible to candida overgrowth and SIFO.
Blood Types and SIFO Predisposition
Blood Type Os (about 40% of the population) and anyone who is a non-secretor (about 20% of the entire population) will always have yeast in their digestive tracts. However, it is our goal to keep this fungus at a proper level.
80% of the population are secretors, meaning that their blood cells attach their specific sugars to different substances in the body. These sugars can act as a shield, preventing other microorganisms from being able to attach themselves. For instance, these sugars normally inhibit candida from binding to the lining of our intestines. However, non-secretors don’t have this protection, giving them a higher likelihood of chronic candidiasis(2).
Other SIFO Risk Factors
Intestinal dysmotility is a common precursor to digestive disorders. We have muscles along our digestive tracts that contract, allowing substances to move through. When these contractions are altered, it can cause digestive symptoms. If the contractions are slowed down and less frequent, they can cause constipation. And if they are sped up and more frequent, it can cause diarrhea.
Patients have a higher risk of developing SIFO when they have been immunocompromised. This condition is also more likely to induce digestive symptoms in patients who have underlying diseases such as cancer.
People who have recently undergone
What SIFO Does
SIFO is a fungal – or more commonly a yeast overgrowth – inside the small intestines that can cause many symptoms similar to SIBO. One of the most notable traits of candida infection is that it can make a biofilm to protect itself from various treatments.
Generally, candida lives in our digestive tract ecosystem harmoniously with the other bacteria that make up the microbiome. When there is an overgrowth, it can deal some damage to the intestinal lining, or fight a long war with bacteria in the digestive tract. This war can cause a depletion of resources, which chronically can suppress the immune system and lead to a larger overgrowth(1).
Symptoms of SIFO
SIFO Symptoms can include classic digestive symptoms of bloating, gas, cramps, and perianal itching. Other classic symptoms can include a white coat on the tongue called oral thrush, fatigue, depression, chronic vaginal yeast infections, allergies, and skin issues. They can also include lethargy, myalgia, joint pain, and environmental sensitivities (chemicals, molds, etc).
A strange symptom that can help lead a physical to a diagnosis of SIFO is flatulence after eating a high simple carbohydrate meal or beverage(2).
Recurring SIBO or IMO symptoms that persist after proper treatment can be the result of candida overgrowth. This is mainly due to the candida organism making biofilms to protect themselves from the various treatments being given.
SIFO and SIBO have a significant overlap of symptoms. Both conditions can induce migraines, depression, fatigue, bloating, and more. About 5% of SIBO cases are SIFO. A combination of yeast overgrowth and SIBO can occur at the same time, which happens about 20% of the time.
Females are 8 times more likely to develop SIFO due to higher circulating levels of estrogen(1). Also, anybody using Antibiotics, especially for chronic for various infections have an increased risk of having SIFO.
Diagnosing SIFO
At this point in time, there is no
Esophagogastroduodenoscopy (EDG)
A test performed by a gastroenterologist
Blood Tests
Another – but less reliable – test includes checking the blood for Candida albicans (yeast) antibodies (IgG, IgA, IgM). Most major labs can perform this test. This test is best to monitor treatment for SIFO and to ensure that a patient’s SIBO/IMO symptoms are actually due to candida overgrowth. Another test called Candida Immune Complex seems to be one of the better blood tests for diagnosing SIFO.
A host of out-of-network labs can also assess various naturopathic medical lab markers. One of these markers is Beta-alanine, which is a byproduct of candida and if found to be elevated can help rule in SIFO.
We can also check the secretory IgA, which if low can indicate chronic SIFO. When this test is low because it is one of the methods the body naturally has to remove candida from itself. The last test that will sometime be investigated is D-arabinitol. This chemical is a waste product from SIFO that can be measured as well(3).
qPCR DNA Analysis
Another method offered by some labs includes a qPCR DNA analysis. Labs will analyze a stool sample. This is by far the easiest and most accessible way of diagnosing SIFO for most physicians and their patients.
An older and less sensitive and specific method is via analyzing a stool sample for candida. This is wrought with issues as candida can continue growing while the stool sample is being transported to the lab, yielding a false-positive result. There have been some advances in recent years on providing a transport solution to minimize these false-positive results but since there are other more reliable methods most physicians do not routinely use this method anymore.
Ruling Out Other Causes
Doctors need to rule out many other common causes of SIFO before making a diagnosis. These include immunodeficiencies such as AIDS and/or HIV, Autoimmune diseases such as CeD, UC, and hormone disorders such as diabetes and of course SIBO, and IMO.
Allopathic SIFO Treatment
Usually, knowledge physicians will recommend antifungal medications such as nystatin, ketoconazole, Diflucan, and/or fluconazole, but this may not completely solve the problem as the underlying reason of the SIFO must first be addressed. However, a patient who took part in a research study saw reduced quantities of fungi in the digestive system after taking a three-week course of fluconazole(6).
Natural SIFO Treatment
Dietary treatment plays a large role in helping to rebuild the digestive system. While antifungal medications can help purge the fungi, they don’t help rebuild the microbiome or the digestive system itself. Making sure the body has the proper nutrients is crucial for both recovering from an overgrowth, but also preventing it from coming back.
Most people try an anti-candida diet to short-lived success. This diet will essentially starve the yeast of the sugars they need to grow and multiply, but it is a very restrictive diet that most can not follow long-term. Avoidance of sugar, dairy, mold, and other IgG foods provoking compounds needs to be limited in this diet. But this is like running west to see the sunrise. There needs to be a consideration of why the candida is growing. Because for most people, their SIFO will return soon after they stop this diet.
The Natural Approach
One of Dr. Brody’s late teachers, Dr. James Sensenig, also taught that you need to give the body what it needs, take out the trash, and increase vitality for true healing. With the same analogy, simply removing the yeast will not induce remission (in most cases). You still need to give the body (and the yeast) what they need to thrive and be in balance in the microbiome. The vitality aspect plays a role with energy and life force, for a lack of a better word. A restrictive diet can be a drain on vitality, and it is not personalized for the patient. This can create an imbalance, upsetting the digestive tract.
Fixing a leaky gut can calm the immune system down, allowing the detoxification process of different yeast myotoxins, antigens, and other body parts are key in long-term remission prevention. Detox protocols for SIFO usually include choline, betaine, smilax, cleavers, Infrared saunas, homeopathy, and hydrotherapy treatments.
Researchers found Saccharomyces boulardii to be effective at getting rid of fungi. Researchers found this probiotic had fewer side effects than some antifungal medications in infants(7).
Naturopathic medicines include Caprylic Acid, berberine containing botanicals, garlic, oregano oil, and probiotics.
Potential SIFO Complications
The most common fungi that can infiltrate the digestive tract is the Candida species. Researchers have associated high levels of Candida with ulcerative colitis, Crohn’s disease, gastric ulcers, and potentially irritable bowel syndrome (IBS) as well. Researchers have also tied SIFO to immunodeficiency.
There is also a phenomenon called auto-brewery syndrome where a high level of yeast living inside the intestines will produce alcohol as a by-product of simple carbohydrate consumption. This alcohol can then lead to being intoxicated without ever consuming alcohol(8).
Related Bacteria
While not a bacteria, Candida tropicalis has been found in most SIFO cases. There are rare reports of candida albicans overgrowths, typically in older adults who were otherwise healthy.
References
(1.) Murray, Michael T., and Joseph E. Pizzorno. Textbook of Natural Medicine. Fourth ed., Elsevier – Health Sciences Div, 2013.
(2.) D’Adamo, Peter J., and Catherine Whitney. Eat Right For Your Type Complete Blood Type Encyclopedia. Penguin Group, 2002.
(3.) Lord, Richard S., and J. Alexander. Bralley. Laboratory Evaluations for Integrative and Functional Medicine. 2nd ed., Genova Diagnostics, 2012.
(4) Erdogan A; Rao. Small Intestinal Fungal Overgrowth. 17 Apr. 2015, pubmed.ncbi.nlm.nih.gov/25786900/.
(5) Seladi-Schulman, Jill. “SIFO: Small Intestinal Fungal Overgrowth and Your Gut Health.” Healthline, Healthline Media, 4 Dec. 2019, www.healthline.com/health/sifo.
(6) Singh, Rajdeep, and Gerard E Mullin. “A Wasting Syndrome and Malnutrition Caused by Small Intestine Fungal Overgrowth: Case Report and Review of the Literature.” Integrative Medicine (Encinitas, Calif.), InnoVision Health Media Inc., June 2017, www.ncbi.nlm.nih.gov/pmc/articles/PMC6419785/.
(7) Demirel, Gamze, et al. “Prophylactic Saccharomyces Boulardii Versus Nystatin for the Prevention of Fungal Colonization and Invasive Fungal Infection in Premature Infants.” European Journal of Pediatrics, U.S. National Library of Medicine, 24 May 2013, pubmed.ncbi.nlm.nih.gov/23703468/.
(8) Painter, Kelly. Auto-Brewery Syndrome (Gut Fermentation). 9 Oct. 2019, www.ncbi.nlm.nih.gov/books/NBK513346/.