Mechanisms by which gut microorganisms influence food sensitivities

Abstract

Finely tuned mechanisms enable the gastrointestinal tract to break down dietary components into nutrients without mounting, in the majority of cases, a dysregulated immune or functional host response. However, adverse reactions to food have been steadily increasing, and evidence suggests that this process is environmental. Adverse food reactions can be divided according to their underlying pathophysiology into food intolerances, when, for instance, there is deficiency of a host enzyme required to digest the food component, and food sensitivities, when immune mechanisms are involved. In this Review, we discuss the clinical and experimental evidence for enteric infections and/or alterations in the gut microbiota in inciting food sensitivity. We focus on mechanisms by which microorganisms might provide direct pro-inflammatory signals to the host promoting breakdown of oral tolerance to food antigens or indirect pathways that involve the metabolism of protein antigens and other dietary components by gut microorganisms. Better understanding of these mechanisms will help in the development of preventive and therapeutic strategies for food sensitivities.

Lactobacilli Degrade Wheat Amylase Trypsin Inhibitors to Reduce Intestinal Dysfunction Induced by Immunogenic Wheat Proteins

“…The role of the microbiome in gastrointestinal inflammatory and functional disorders has recently gathered great interest. 50 Here, we found that gluten plays an important role in shaping microbiota composition, which is consistent with previous studies. [51][52][53] In addition, changes in the intestinal microbiota of NOD/DQ8 mice were specific to the presence of dietary ATIs, including decreases in Lactobacillus and the Firmicutes/Bacteroidetes ratios, both of which have been described in CeD patients.…”

Evidence-based and mechanistic insights into exclusion diets for IBS

“…Designing studies with the appropriate control group to evaluate these mechanisms as well as assessing clinical efficacy is a challenge. Mechanistic studies will also yield information on which subgroups might respond to which diet to give a more precision medicine approach to treating IBS 75 . No control group is ideal, and each has strengths and weaknesses.…”

Differential Physiological Responses Elicited by Ancient and Heritage Wheat Cultivars Compared to Modern Ones

“…Pseudomonas aeruginosa, an opportunistic pathogen detected in CD patients, is able to further degrade protease-generated gluten peptides in smaller fragments with immunogenic sequences and a higher ability to translocate trough the epithelial barrier and thus interact with the gut immune system. On the other hand, Lactobacillus spp., which is highly represented in healthy subjects, is able to decrease the immunogenicity of wheat peptides generated by human or bacterial digestions [67,68]. Partially digested gluten peptides constitutes a substrate for other gut bacteria, such as Rothia spp.…”