Grapefruit seed extract is a highly concentrated fungal and microbial balancing extract. Grapefruit seed extract exerts these effects within the gastrointestinal (GI) tract, promoting healthy microflora and gut ecology. A preliminary clinical trial reported that grapefruit seed extract supplements helped support healthy GI function and comfort. An in vitro study using human skin fibroblast cells indicated that grapefruit seed extract promoted healthy gram-positive and gram-negative balance. Other studies support these findings, citing that grapefruit seed extract promotes a healthy environment when exposed to a wide range of bacterial biotypes.