Tuesday, 4 October 2011

Gluten, bacteria and mouthwash

Peptides. Those short-ish chains of amino acids, are interesting characters. Therapeutically, certain peptides have the propensity to do great things as exemplified by compounds such as the glucagon-like peptides and speculation on a therapeutic role in conditions like diabetes and intestinal disease.

In terms of 'disease' and ill-health, other peptides have a slightly less desirable side; something which I have been interested in for a few years speculatively in relation to conditions such as autism and schizophrenia. Peptides, such as those immunogenic epitopes derived from gluten, in relation to coeliac (celiac) disease (CD) also perhaps show a less speculative negative side in terms of effect.

What can be done about these immune-stimulating gluten peptides? Well, you could try and break them down via enzymes such as endopeptidases. There are also lots of products on the market which claim to do similar things (bearing in mind that I offer no endorsement). A recent paper by Zamakchari and colleagues* also offers another potential solution: certain enzymes produced by bacteria with the propensity to degrade gluten.

Before you go scouring the Internet for some commercial bacterial supplement, know that the authors suggested that we might already have such bacteria in our 'oral cavity' (mouth in plain speak); in our saliva and dental plaque.

The paper summary:

  • Human dental plaque and saliva were collected from willing volunteers and the various oral micro-organisms cultured. Those bacteria with gliadin-degrading activity were identified by 16S rDNA analysis, a sort of molecular fingerprinting service.
  • Various bacterial strains were added to synthetic immunogenic peptide sequences from gliadin and the subsequent effects separated and characterised by a combination of reversed-phase HPLC and mass spectrometric detection (MS/MS).
  • The results: 27 aerobic and 30 anaerobic bacterial strains capable of metabolising gluten were found. All the final anaerobic strains cultured (n=10 fastest growing) were of the Bifidobacterium genus. The final aerobic strains (n=5 fastest growing) included bacteria of the Rothia genus.
  • Several tri-peptide combinations appearing in the greatest frequency within the larger gluten peptides were broken down by individual bacterial strains. Rothia mucilaginosa and Rothia aeria seemed to come out top in terms of their hydrolysing abilities in terms of amounts and time taken. This effect was also noted when the larger immunogenic epitopes were exposed to the Rothia strains. 

There are a few important points to be taken from this research. First is the suggestion that digestion starts in the mouth and that all important motherly advice 'chew your food properly'. Masticating (or chewing to us mere mortals) is an important first step in presenting the food we eat to the rest of our hard-working gastrointestinal (GI) tract. Second is the suggestion that dental plaque (alongside saliva) might actually serve some purpose rather than just being something associated with poor oral hygiene and bad breath. I am not for one minute suggesting that we should all stop our regular tooth cleaning routine; but perhaps just step back and think about when you clean your teeth and what products you might use in your dental hygiene routine. Finally (finally!) I am already a big fan of the idea that our relationship with bacteria, some strains of bacteria, is an important one. A primary implication from this work is that 'addition' of bacteria to food or whilst eating certain foods (bearing in mind the effect of pH on these bacteria) might actually serve as another tool in the arsenal against conditions like coeliac disease, and even gluten sensitivity when it comes to degrading those very difficult gluten peptides. Please note that I am not recommending anything from this point given the slightly more negative press from these strains; just speculating.

* Zamakhchari M. et al. Identification of Rothia bacteria as gluten-degrading natural colonizers of the upper gastro-intestinal tract. PLoS ONE. September 2011.

1 comment:

  1. Yes, immune responses to gluten begin in the mucosa. Gliadin antibodies IgA + IgM can now be measured at this first stage of the gluten immune response before there is gut damage. Implementation of the gluten free diet at this stage is most beneficial.