Selection of Gut-Resistant Bacteria and Construction of Microbial Consortia for Improving Gluten Digestion under Simulated Gastrointestinal Conditions.

UNLABELLED

This work aimed to define the microbial consortia that are able to digest gluten into non-toxic and non-immunogenic peptides in the human gastrointestinal tract.

METHODS

131 out of 504 tested and lactic acid bacteria, specifically (64), lactobacilli (63), (1), and (3), showed strong gastrointestinal resistance and were selected for their PepN, PepI, PepX, PepO, and PepP activities toward synthetic substrates. Based on multivariate analysis, 24 strains were clearly distinct from the other tested strains based on having the highest enzymatic activities. As estimated by RP-HPLC and nano-ESI-MS/MS, 6 cytoplasmic extracts out of 24 selected strains showed the ability to hydrolyze immunogenic epitopes, specifically 57-68 of α9-gliadin, 62-75 of A-gliadin, 134-153 of γ-gliadin, and 57-89 (33-mer) of α2-gliadin. Live and lysed cells of selected strains were combined into different microbial consortia for hydrolyzing gluten under gastrointestinal conditions. Commercial proteolytic enzymes ( E1, E2, Veron HPP, and Veron PS proteases) were also added to each microbial consortium. Consortium activity was evaluated by ELISA tests, RP-HPLC-nano-ESI-MS/MS, and duodenal explants from celiac disease patients.

RESULTS

two microbial consortia (Consortium 4: (.) DSM33363 and DSM33364, (.) DSM33373, DSM33298, and DSM33301; and Consortium 16: . DSM33363 and DSM33364, . DSM33373, DSM33374, DSM33300, DSM33297 and DSM33355), containing commercial enzymes, were able to hydrolyze gluten to non-toxic and non-immunogenic peptides under gastrointestinal conditions.

CONCLUSIONS

the results of this study provide evidence that selected microbial consortia could potentially improve the digestion of gluten in gluten-sensitive patients by hydrolyzing the immunogenic peptides during gastrointestinal digestion.