Salivary Peptide Protects Against E. Coli Diarrhea

MedicalResearch.com Interview with:

Esther Bullitt, Ph.D. Associate Professor Dept. of Physiology & Biophysics Boston University School of Medicine Boston, MA  02118-2526

Dr. Bullitt

Esther Bullitt, Ph.D.
Associate Professor
Dept. of Physiology & Biophysics
Boston University School of Medicine
Boston, MA  02118-2526 

MedicalResearch.com: What is the background for this study?

Response:      We know that saliva has properties that allow us to swallow easily, and to help prevent gum disease and infections in the mouth. But is that really the only use for the 1-2 liters (1-2 quarts) of saliva we produce every day?  We decided to test whether a component of saliva, Histatin-5, can help prevent diarrheal disease (Traveler’s Diarrhea by Enterotoxigenic Escherichia coli (ETEC)) that is caused by bacteria commonly found in contaminated food and water.

ETEC are bacteria that have hundreds of thin hair-like fibers on their surface, called pili. These bacteria bind specifically to the surface of the gut using these pili, and the bacteria need to stay bound long enough to initiate disease. Studies by Mike Levine’s group in the 1970’s showed that pili are necessary for enterotoxigenic Escherichia coli (ETEC) to cause disease. No adhesion, no disease.

One aid to remaining bound is the unwinding and rewinding of the pili. These helical fibers can unwind up to 8 times their original length, acting as shock absorbers during fluid flow.  

MedicalResearch.com: What are the main findings? 

Schematic illustrates how the salivary peptide possibly alters pili on the bacteria surface.

Schematic illustrates how the salivary peptide possibly alters pili on the bacteria surface.

Response:     After adding the saliva peptide Histatin-5 to ETEC bacteria, binding of the bacteria to organoids grown from a section cut out of a person’s gut small intestine is significantly reduced. We also see, using an electron microscope, that the pili become more rigid in the presence of the saliva peptide. Without the ability of pili to unwind and rewind, bacteria may still bind briefly in the gut, but without their natural shock absorbers (pili) they cannot stay bound. When bacteria are washed away, they cannot cause disease.

MedicalResearch.com: What should readers take away from your report? 

Response: Saliva has a much bigger role in preventing disease than has been known – the saliva peptide Histatin-5 reduces binding to gut tissue by bacteria that cause Traveler’s Diarrhea. Without adhesion there is no disease, so we have a new path forward for therapeutics to help prevent getting sick from eating contaminated food. 

MedicalResearch.com: What recommendations do you have for future research as a result of this work?

Response:  Our group has investigated one component from saliva (Histatin-5), against one type of bacteria that causes disease (ETEC that cause Traveler’s Diarrhea). Saliva has many other components that might work against other disease-causing bacteria, and we hope that there will be future research to test these possibilities. 

MedicalResearch.com: Is there anything else you would like to add?

Response: We already produce and swallow Histatin-5 every day in our saliva. Therefore, the potential for using Histatin-5 to develop a non-toxic therapeutic is high. We anticipate that added Histatin-5 can increase the number of bacteria that can’t bind, after eating contaminated food. No adhesion, no disease!

This work was funded primarily by the NIH, Boston University School of Medicine, and Washington University; no authors have any conflicts of interest. 

Citations:

A Role for Salivary Peptides in the Innate Defense Against Enterotoxigenic Escherichia coli

Jeffrey W Brown Arwa Badahdah Micah Iticovici Tim J VickersDavid M Alvarado Eva J Helmerhorst Frank G Oppenheim Jason C MillsMatthew A Ciorba James M Fleckenstein Esther Bullitt

The Journal of Infectious Diseases, jiy032, https://doi.org/10.1093/infdis/jiy032

 

The information on MedicalResearch.com is provided for educational purposes only, and is in no way intended to diagnose, cure, or treat any medical or other condition. Always seek the advice of your physician or other qualified health and ask your doctor any questions you may have regarding a medical condition. In addition to all other limitations and disclaimers in this agreement, service provider and its third party providers disclaim any liability or loss in connection with the content provided on this website.

 

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.