Small intestinal fungal overgrowth (SIFO) is characterized by a high quantity of fungi (such as yeast) in the small intestine, while SIBO is caused by elevated numbers of bacteria. Despite the conditions sounding similar, their risk factors, symptoms, and treatments differ.
Prescription antacids and altered gut motility may increase the risk of developing SIBO, but they aren’t associated with SIFO.[1]
Studies have foundthat the rates of unexplained GI symptoms are similar in participants regardless of fungal colonization, which contrasts with the relationship between bacterial overgrowth and GI distress.
Also, while SIBO is conventionally treated with antibiotics, SIFO requires antifungal medications.[2] Probiotics may prevent or suppress intestinal overgrowth of Candida (a type of yeast), but they don’t prevent SIBO.[3][4]
However, in both cases, emerging research suggests that the composition of the fungi or bacteria — not simply a higher number of either — has a greater impact on whether the overgrowth might lead to symptoms.[5][6]