Oat vary among oat varieties. Also, oats products are frequently cross-contaminated with other gluten-containing cereals during grain harvesting, transport, storage or processing. Pure oats contain less than 20 parts per million of gluten from wheat, barley, rye, or any of their hybrids. Use of pure oats in a gluten-free diet offers improved nutritional value from the rich content of oat protein, vitamins, minerals, fiber, and lipids, but remains controversial because a small proportion of people with celiac disease react to pure oats. Some cultivars of pure oat could be a safe part of a gluten-free diet, requiring knowledge of the oat
Non-celiac gluten sensitivity in gluten and gluten-containing cereals (wheat, rye, barley, and their derivatives) may have a role in the development of symptoms. FODMAPs are present in gluten-containing grains and have recently been identified as a possible cause of gastrointestinal symptoms in NCGS patients, but do not justify extra-digestive symptoms. For these reasons, NCGS is a controversial clinical condition and some authors still question it. It has been suggested that "non-celiac wheat sensitivity" is a more appropriate term, without forgetting that other gluten-containing cereals are implicated in the development of symptoms. NCGS is the most common syndrome of gluten-related disorders with prevalence rates