Herbal Supplement. Helps Coat and Soothe GI Tract. Slippery Elm, also known as Red Elm, Moose Elm or Indian Elm, is a small North American Tree that has been traditionally used by herbalists for over 100 years. It was reportedly used by native North Americans and early settlers as a survival food. It's bark is known for its mucilage constituents, which can help to coat and soothe the tissues of the GI tract.