Small Intestinal Fungal Overgrowth
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Small intestinal fungal overgrowth (SIFO) is characterized by the presence of excessive number of fungal organisms in the small intestine associated with gastrointestinal (GI) symptoms. Candidiasis is known to cause GI symptoms particularly in immunocompromised patients or those receiving steroids or antibiotics. However, only recently, there is emerging literature that an overgrowth of fungus in the small intestine of non-immunocompromised subjects may cause unexplained GI symptoms. Two recent studies showed that 26 % (24/94) and 25.3 % (38/150) of a series of patients with unexplained GI symptoms had SIFO. The most common symptoms observed in these patients were belching, bloating, indigestion, nausea, diarrhea, and gas. The underlying mechanism(s) that predisposes to SIFO is unclear but small intestinal dysmotility and use of proton pump inhibitors has been implicated. However, further studies are needed; both to confirm these observations and to examine the clinical relevance of fungal overgrowth, both in healthy subjects and in patients with otherwise unexplained GI symptoms. Importantly, whether eradication or its treatment leads to resolution of symptoms remains unclear; at present, a 2–3-week course of antifungal therapy is recommended and may be effective in improving symptoms, but evidence for eradication is lacking.
KeywordsSmall intestine Fungal overgrowth Symptoms Duodenal culture Diagnosis Treatment Review
We acknowledge the technical and secretarial assistance of Ms. Helen Smith.
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Conflict of Interest
Askin Erdogan and Satish S.C. Rao declare that they have no conflict of interest.
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This article does not contain any studies with human or animal subjects performed by any of the authors. Among cited articles where one of the authors of the current report were authors, local Institutional Review Board approval was obtained and maintained for studies where human (or animal) subjects research was performed.
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- 3.Micames CG, Bentley R, Onken J. Clinical challenges and images in GI. Invasive candidal enterocolitis. Gastroenterology. 2007;133(2):391, 731. doi: 10.1053/j.gastro.2007.06.051.
- 10.••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;37(11):1103–11. doi: 10.1111/apt.12304. This is the first study investigating the prevalence of SIFO in patients with persistent GI symptoms, evaluating the symptoms of patients and showing that dysmotility and proton pomp use are independent risk factors for SIFO/SIBO. This study also showed that symptoms are poor predictors of SIFO and testing is essential.PubMedCentralPubMedCrossRefGoogle Scholar
- 26.••Iliev ID, Funari VA, Taylor KD, Nguyen Q, Reyes CN, Strom SP, et al. Interactions between commensal fungi and the C-type lectin receptor Dectin-1 influence colitis. Science. 2012;336(6086):1314–7. doi: 10.1126/science.1221789. This study found that fungi in colonic tissue are abundant, closely located with commensal bacteria, and commensal fungi are recognized by Dectin-1. The authors also showed that Dectin-1 deficiency leads to increased susceptibility to colitis. Although 7/20 of most common fungi were found in mice food, this only represented for 1.5 % of fungi in the intestine indicating that those species mostly found in the gut are native to the gut. Furthermore, treatment of colitis with fluconazole reduced weight loss and caused milder histological disease findings indicating the effect of fungi on gut health.PubMedCentralPubMedCrossRefGoogle Scholar
- 39.••Gong YB, Zheng JL, Jin B, Zhuo DX, Huang ZQ, Qi H, et al. Particular Candida albicans strains in the digestive tract of dyspeptic patients, identified by multilocus sequence typing. PLoS ONE. 2012;7(4):e35311. doi: 10.1371/journal.pone.0035311. This study shows that Candida albicans colonizes oral flora as well as gastric flora of dyspeptic patients; overall C. albicans was isolated from 97.8 % of the Candida-positive subjects from oral/gastric samples in the dyspeptic group, but from only 56.3 % in the healthy group (P, 0.001). This study suggests that Candida albicans can survive in gastric acidity.PubMedCentralPubMedCrossRefGoogle Scholar
- 40.•Banerjee P, Kaur R, Uppal B. Study of fungal isolates in patients with chronic diarrhea at a tertiary care hospital in north India. J Mycol Med. 2013;23(1):21–6. doi: 10.1016/j.mycmed.2012.12.002. This study was carried out in patients suffering from chronic diarrhea and aimed to find the rate of isolation of yeast from stool and also antifungal susceptibility of opportunistic pathogens. Of total, 26.7 % of stool specimens grew fungal organisms and most were found to be sensitive to antifungal agents including fluconazole. This study shows that opportunistic yeast may cause symptoms like chronic diarrhea.PubMedCrossRefGoogle Scholar
- 42.Pfaller MA, Jones RN, Messer SA, Edmond MB, Wenzel RP. National surveillance of nosocomial blood stream infection due to species of Candida other than Candida albicans: frequency of occurrence and antifungal susceptibility in the SCOPE Program. SCOPE Participant Group. Surveillance and Control of Pathogens of Epidemiologic. Diagn Microbiol Infect Dis. 1998;30(2):121–9.PubMedCrossRefGoogle Scholar
- 44.Phillips P, Shafran S, Garber G, Rotstein C, Smaill F, Fong I, et al. Multicenter randomized trial of fluconazole versus amphotericin B for treatment of candidemia in non-neutropenic patients. Canadian Candidemia Study Group. Eur J Clin Microbiol Infect Dis Off Publ Eur Soc Clin Microbiol. 1997;16(5):337–45.CrossRefGoogle Scholar
- 45.Rex JH, Pappas PG, Karchmer AW, Sobel J, Edwards JE, Hadley S, et al. A randomized and blinded multicenter trial of high-dose fluconazole plus placebo versus fluconazole plus amphotericin B as therapy for candidemia and its consequences in nonneutropenic subjects. Clin Infect Dis Off Publ Infect Dis Soc Am. 2003;36(10):1221–8. doi: 10.1086/374850.CrossRefGoogle Scholar
- 46.Jiang L, Yong X, Li R, Peng Y, Liu W, Qin Q, et al. Dynamic analysis of oral Candida carriage, distribution, and antifungal susceptibility in HIV-infected patients during the first year of highly active antiretroviral therapy in Guangxi, China. J Oral Pathol Med Off Publ Int Assoc Oral Pathol Am Acad Oral Pathol. 2014. doi: 10.1111/jop.12192.Google Scholar
- 47.Pfaller MA, Jones RN, Doern GV, Fluit AC, Verhoef J, Sader HS, et al. International surveillance of blood stream infections due to Candida species in the European SENTRY Program: species distribution and antifungal susceptibility including the investigational triazole and echinocandin agents. SENTRY Participant Group (Europe). Diagn Microbiol Infect Dis. 1999;35(1):19–25.PubMedCrossRefGoogle Scholar
- 54.••Pappas PG, Kauffman CA, Andes D, Benjamin Jr DK, Calandra TF, Edwards Jr JE, et al. Clinical practice guidelines for the management of candidiasis: 2009 update by the Infectious Diseases Society of America. Clin Infect Dis Off Publ Infect Dis Soc Am. 2009;48(5):503–35. doi: 10.1086/596757. This infectious disease society guideline provides comprehensive information on the various drugs, their mechanism of action and profile and indication for treatment of candidiasis.CrossRefGoogle Scholar