The crosstalk between gut microbiota, intestinal epithelial cells, and innate and adaptive immune system governs the maintenance of the intestinal homeostasis. Any interference in this tight dialogue and in the processes preserving cellular homeostasis (e.g., autophagy) may dysregulate the immune response and impair the clearance of harmful bacteria favoring the dysbiotic alteration of the microbic flora that leads to chronic inflammation. Gut dysbiosis is strongly associated with gastrointestinal inflammatory disorders, among them the inflammatory bowel disease (IBD). This review discusses the current knowledge on IBD, from the genetic background of high-risk patients to the molecular mechanisms underlying the disease, the contribution of the microbic flora, and the role of autophagy in intestinal epithelial cells and provides the state of art regarding the targeted-nutritional approaches aimed to restore the beneficial crosstalk between an “anti-inflammatory” microbiota and the host. Analysis of the molecular pathogenesis of IBD will help identify genetic and diet-associated risk factors and thus suggest personalized strategies to prevent and manage the disease to improve quality of life with long-term maintenance of the remission phase.

Celiac disease (CD) is a permanent intolerance to dietary protein, gluten, from wheat rye and barley. It occurs in about 1% worldwide population, in genetically predisposed individuals bearing human leukocyte antigen (HLA) DQ2/DQ8. Gut epithelial cell stress and innate immune activation are responsible for breaking oral tolerance to gliadin, the gluten component. To date, the only treatment available for CD is a long-term gluten-free diet. Several evidences show that an altered composition of the intestinal microbiota (dysbiosis) could play a key role in the pathogenesis of CD, through the modulation of intestinal permeability and the regulation of the immune system. Here we show that gliadin induces a chronic ER stress condition in the small intestine of a CD mouse model and that the co-administration of probiotics efficiently attenuates both UPR and gut inflammation. Moreover, the composition of probiotics formulations might differ in their activity at molecular level, especially toward the three axes of the UPR. Therefore, rebalancing the gut microbiota composition by probiotics administration might rep-resent a new strategy to treat CD affected patients.