Bacterial-Based Strategies to Hydrolyze Gluten Peptides and Protect Intestinal Mucosa

Abstract

Gluten is a mixture of proteins highly resistant to hydrolysis, resulting in the emergence of toxic peptides responsible for gluten-related disorders. Currently, a gluten-free diet (GFD) is the unique proven therapy for celiac disease (CD). Several research groups and pharmaceutical companies are developing new nondietetic therapeutic strategies for CD. Probiotics are viable microorganisms thought to have a healthy effect on the host. The proteolytic mechanism of lactic acid bacteria comprises an extracellular serine protease, di- and oligopeptide-specific transport systems, and several intracellular peptidases that might affect gluten degradation. Therefore, probiotic supplementation is an attractive therapy because of its possible anti-inflammatory and immunomodulatory properties. Several studies have been performed to assess the effectiveness of various specific probiotic strains, showing positive effects on immune-modulation (inhibition of pro-inflammatory cytokine TNF-α) restoring gut microbiota and decrease of immunogenic peptides. The present review aims to summarize the current knowledge on the ability of probiotic strain (single or mixtures) to digest gliadin peptides in vitro and to modulate the inflammatory response in the gut.

Keywords: celiac disease; gluten digestion; gluten hydrolysis; microbiota; probiotics.

Figure 1

α-gliadin structure and toxic epitopes (33-mer and p31-43). A, B, C represent the peptides hydrolyzed by a different mixture of probiotic strains. (A) Hydrolyzed by a mixture of L. paracasei, L. plantarum, Bifidobacterium animalis subsp. lactis, B. breve Bbr8, B. breve BL10 (18). (A, B) Hydrolyzed by a mixture of L. alimentarius, L. brevis, L. sanfranciscensis, L. hilgardii (15); mixture of Streptococcus thermophilus, L. plantarum, L. acidophilus, L. casei, L. delbrueckii subsp. bulgaricus, Bifidobacterium breve, B. infantis, B. longum (16). (A–C) Hydrolyzed by a mixture of L. casei, L. delbrueckii subsp. bulgaricus, L. paracasei LPC01 and BGP2, L. plantarum BGP12, LP27, LP35, LP40, LP47, and SP1 (17).