Foods that are gluten free are all foods that do not contain any wheat (including spelt), rye, barley and oats, or any derivative ingredients made from these four grains. Always check ingredient lists and Allergens statements on packaging of products for these grains or their derivatives.
Yes, gluten is a naturally occurring protein found in some grains including Wheat (and spelt), Rye, Barley and Oats.
A food is ‘gluten-free’ if it does not contain any gluten. Gluten is naturally present in some grains: Barley, Rye, Oats and Wheat (including Spelt, Kamut and Freekeh); or any processed food ingredients that are derived from the same grains. In Australia and New zealand ‘gluten-free’ food must not contain any detectable gluten, in other countries the allowable threshold is 20 ppm.