Although probiotics aren’t likely to prevent invasive fungal infections, it appears that they can reduce the risk of Candida colonization in premature babies and critically ill children.[1][2]
Vitamin D supplementation may be effective for reducing the prevalence of Candida colonization as well as systemic Candida infection (as measured by blood and urine levels of Candida).
Some studies have also investigated medium-chain triglycerides (MCT) with and without vitamin D. These results are promising, but preliminary.[3][4]
Certain compounds extracted from oregano, pine, cinnamon, and coffee suppress Candida growth in cell culture models and denture stomatitis (mild oral inflammation due to thrush), but these haven't been studied in the human GI tract.[5][6][7]