: Grain food consumption is a trigger of gluten related disorders: celiac disease, non-celiac gluten sensitivity (NCGS) and wheat allergy. They demonstrate with non-specific symptoms: bloating, abdominal discomfort, diarrhea and flatulence. Aim: The aim of the review is to summarize data about pathogenesis, symptoms and criteria of NCGS, which can be helpful for physicians. : The PubMed and Google Scholar databases were searched in January 2019 with phrases: 'non-celiac gluten sensitivity', non-celiac gluten sensitivity', non-celiac wheat gluten sensitivity', non-celiac wheat gluten sensitivity', and gluten sensitivity'. More than 1000 results were found. A total of 67 clinical trials published between 1989 and 2019 was scanned. After skimming abstracts, 66 articles were chosen for this review; including 26 clinical trials. Results: In 2015, Salerno Experts' Criteria of NCGS were published. The Salerno first step is assessing the clinical response to gluten free diet (GFD) and second is measuring the effect of reintroducing gluten after a period of treatment with GFD. Several clinical trials were based on the criteria. : Symptoms of NCGS are similar to other gluten-related diseases, irritable bowel syndrome and Crohn's disease. With Salerno Experts' Criteria of NCGS, it is possible to diagnose patients properly and give them advice about nutritional treatment.