Barley and their hybrids and derivatives, barley contains gluten, which makes it an unsuitable grain for consumption by people with gluten-related disorders, such as celiac disease, non-celiac gluten sensitivity and wheat allergy sufferers, among others. Nevertheless, some wheat allergy patients can tolerate barley or rye. Barley is a key ingredient in beer and whisky production. Two-row barley is traditionally used in German and English beers. Six-row barley was traditionally used in US beers, but both varieties are in common usage now. Distilled from green beer, whiskey has been made primarily from barley in Ireland and Scotland, while other countries have used
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