First defence against bacteria & infections. Studies have shown that tea tree essential oil can inhibit the growth of the types of bacteria that cause sinus infections and respiratory problems. Help support a healthy immune system and soothe nerves. Help fight colds and flu, alleviates sore throats, tonsillitis and gum deases. It is one of the most popular essential oils because it works as a powerful disinfectant yet gentle enough to apply topically to fight skin infections and irritations.