Diagnosis and Treatment of SIBO and SIFO

Microbial overgrowth in the small intestine, specifically SIBO (small intestinal bacterial overgrowth), is associated with a range of comorbid conditions. Restoring balance to gut flora through customized lifestyle interventions and nutritional changes can significantly improve health, especially immune function, which relies on a healthy intestinal microbiome.

Comorbidities associated with SIBO include irritable bowel syndrome (IBS), inflammatory bowel disease, motility problems, chronic pancreatitis, cirrhosis, and immunodeficiency conditions.

Similar to SIBO, small intestinal fungal overgrowth, or SIFO, is associated with a range of systemic symptoms including bloating, fatigue, migraines, and depression. Motility disorders and reduced stomach acid from overuse of proton-pump inhibitors are risk factors for both SIBO and SIFO.

With symptoms that overlap with SIFO, SIBO can be difficult to diagnose. The American College of Gastroenterology 2020 clinical guidelines recommend small bowel aspirate and culture, along with breath testing for patients with IBS.

Dietary changes may improve symptoms for sufferers of both SIBO and SIFO, while antibiotics and probiotics can be useful treatments for SIBO and antifungal therapy for SIFO.

The Institute for Functional Medicine’s 5R framework for treatment of GI issues, including both SIBO and SIFO, is: Restore, Replace, Re-inoculate, Repair, and Rebalance. Dietary approaches to improve gut health include interventions that reduce fermentation of carbohydrates and removal of inflammation trigger foods.