Rapid isolation of gluten-digesting bacteria from human stool and saliva by using gliadin-containing plates

Exp Biol Med (Maywood). 2015 Jul;240(7):917-24. doi: 10.1177/1535370214564748. Epub 2014 Dec 16.


The number of individuals with gluten intolerance has increased dramatically over the last years. To date, the only therapy for gluten intolerance is the complete avoidance of dietary gluten. To sustain a strictly gluten-free diet, however, is very challenging. Therefore, there is need for a non-dietary therapy. Any such treatment must appreciate that the immunogenic part of gluten are gliadin peptides which are poorly degraded by the enzymes of the gastrointestinal tract. Probiotic therapy and oral enzyme therapy containing gluten-degrading bacteria (GDB) and their gliadin-digesting enzymes are possible new approaches for the treatment of gluten intolerance, however effectively isolating GDB for these treatments is problematic. The goal of this study was to develop an easy technique to isolate GDB rapidly and efficiently with the hope it might lead to newer ways of developing either probiotics or traditional medicines to treat gluten intolerance. Several researchers have already isolated successfully GDB by using gluten minimal or limited agar plates. Although these plates can be used to isolate bacteria which can tolerate gluten, further assays are needed to investigate if the same bacteria can also digest gluten. The agar plates we developed can detect bacteria which cannot only tolerate gluten but are able to digest it as well. Therefore, we were able to combine two steps into one step. Using such technologies, we were able to isolate five GDB from saliva and stool, and identified three bacterial reference strains with gluten-degrading activity. The technique we developed to isolate bacteria with gluten-degrading activity is fast, effective, and easy to use. The GDB isolated by our technology could have potential as part of a probiotic or enzymatic therapy for people with gluten intolerance.

Keywords: Gluten intolerance; gluten; gluten-digesting bacteria; probiotics.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Bacillus / isolation & purification
  • Feces / microbiology*
  • Female
  • Gliadin / metabolism*
  • Glutens / metabolism
  • Humans
  • Male
  • Microbiological Techniques*
  • Saliva / microbiology*
  • Staphylococcus / isolation & purification
  • Streptococcus / isolation & purification


  • Glutens
  • Gliadin