Bacillus subtilis has been intensively studied and widely used in biotechnology, known as the best characterized of the low GC Gram-positive bacterial species. This rod-shaped bacterium produces endospores that allow it to undergo a series of extreme environmental conditions like heat, gastric hydrochloric acid, pancreatic enzymes, and bile. Bacillus subtilis has demonstrated the ability to produces many enzymes that support metabolism, protect intestinal cells against oxidant-mediated tissue damage and loss of barrier function, and increase the immune reaction of intestinal cells. Additionally, this spore-form bacterium produces several fungicidal compounds, which control fungal pathogens such as Candida.