Aug 31st, 2020

There are tons of commensal or symbiotic bacteria found in oral saliva. Now we see research that one species can break down gluten compounds that cause an exaggerated immune response that is autoimmune for celiac disease or not traditionally described autoimmune for the non-celiac gluten sensitivity. Gluten peptides are typically resistant to the pancreatic digestive enzymes that mammals produce making humans more susceptible to immune reactions to intact gluten peptide fragments that leak into the sub endothelial space of the gut.

Dr. Wei and colleagues from Boston University isolated gluten-degrading enzymes, subtilisins, from Rothia mucilaginosa, an oral microbe.
From the paper, the Rothia subtilisins and two subtilisins from Bacillus licheniformis, subtilisin A and the food-grade Nattokinase, efficiently degraded the immunogenic gliadin-derived 33-mer peptide and the immunodominant epitopes recognized by the R5 and G12 antibodies. This study identified Rothia and food-grade Bacillus subtilisins as promising new candidates for enzyme therapeutics in celiac disease. (Wei at. al. 2016) The Rothia species can also have a beneficial effect on iron absorption and thus iron stores and potentially vaccine response. (Uranga et. al. 2020)

When we study this microbe further, we find more interesting data. "Rothia mucilaginosa has been found at high abundance on oral leukoplakia (OLK). The ability of clinical isolates to produce acetaldehyde (ACH) from ethanol has not been investigated. Analysis of R.mucilaginosa genome shows that this species does not normally encode acetaldehyde dehydrogenase (ALDH) required for detoxification of ACH.... These levels were demonstrated to induce oxidative stress in cultured oral keratinocytes. This study shows that R. mucilaginosa can generate ACH from ethanol in vitro at levels which can induce oxidative stress. This organism likely contributes to oral ACH levels following alcohol consumption and the significance of the increased abundance of R. mucilaginosa in patients with potentially malignant disorders requires further investigation. (Amer et. al. 2020)

Here we find a different reality for this bacteria. In the presence of alcohol, the bacteria produces damaging acetaldehyde chemicals. Clearly, a bacteria can be a friend or a foe depending on what we are doing personally.

Once again we see a clear indication that lifestyle choices can drive a change for our benefit or our detriment. Not surprising that alcohol, a toxin, would cause a negative response, where gluten, a historically normal protein, would have a positive response.

Very cool science,
Dr. M


Wei J of Physiology
Uranga Msystems
Amer J Microbiology