Identification and characterization of intestinal lactobacilli strains capable of degrading immunotoxic peptides present in gluten.
OBJECTIVE
Identify and characterize bacteria from the proximal gastrointestinal tract of pigs capable of degrading immunogenic gluten peptides.


RESULTS
Bacteria were cultured from the small intestine of pigs fed a 20% gluten diet and from an enrichment media with the 18-mer peptide LQLQPFPQPQLPYPQPQL. Isolates were screened for the production of specialized proteolytic enzymes and the ability to degrade and remove metastable peptides from α-gliadin (16-mer and 33-mer) and ω-gliadin (17-mer), with established roles in the aetiology of coeliac disease. Degradation was determined by ELISA and mass spectrometry (UHPLC-MS/MS in MRM mode), and hydrolysis fragments were characterized by LC-MS/MS. Four strains from the species Lactobacillus ruminis, Lactobacillus johnsonii, Lactobacillus amylovorus and Lactobacillus salivarius showed the highest peptide-degrading activities. Strains displayed different degradation rates and cleavage patterns that resulted in reduction but not complete removal of immunotoxic epitopes.


CONCLUSIONS
We employed a unique enrichment process to select for bacteria adapted to the conditions of the proximal gastrointestinal tract with the ability to partially detoxify well-characterized peptides involved in coeliac disease.


CONCLUSIONS
This study provides a basis for the selection of Lactobacillus strains for probiotic applications aimed to reduce epitope-containing gluten peptides before reaching the epithelium of the small intestine of patients with coeliac disease.
Department of Food Science and Technology, University of Nebraska, Lincoln, NE, USA; Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Canada.
R M
RM
Duar
K J
KJ
Clark
P B
PB
Patil
C
C
Hernández
S
S
Brüning
T E
TE
Burkey
N
N
Madayiputhiya
S L
SL
Taylor
J
J
Walter
D000818:Animals; D001419:Bacteria / Q000201:enzymology / Q000302:isolation & purification; D002446:Celiac Disease / Q000209:etiology; D000939:Epitopes / Q000378:metabolism; D005903:Gliadin / Q000378:metabolism; D005983:Glutens / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D007421:Intestine, Small / Q000382:microbiology*; D007778:Lactobacillus / Q000302:isolation & purification / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D019936:Probiotics; D013552:Swine
D000939:Epitopes; D010455:Peptides; D005983:Glutens; D005903:Gliadin; D010447:Peptide Hydrolases
Lactobacillus; coeliac; epitopes; gliadin; gluten; peptidase; probiotics