Bacteria Transplants to Fight Dental Diseases

Transplanting healthy bacteria has been successful in resolving cases of certain gut problems. The idea is to reestablish a microbiome that is more compatible with health and can proliferate and selectively eliminate pre-existing harmful bacteria. This concept has been suggested as a potential treatment and possible preventive mechanism for periodontal diseases and dental caries.

Pozhitkov and colleagues¹ noted that even patients who commit to routine dental maintenance often continue to experience progressive clinical attachment loss, dental caries, and tooth loss. Inspired by the success of fecal transplants, this group of scientists considered the possibility of using this approach for individuals with inflammatory periodontal lesions and tooth decay. The goal was to assess microbial communities from the oral cavity of subjects with periodontitis and caries to see if they differed from those with no clinical signs of disease. They hypothesized that once a disease-resistant bioflora was identified, sodium hypochlorite could be used to neutralize the previous microbial flora, then the healthy microbes could be transplanted.

They collected biofilm samples and extracted DNA from 16 healthy adults with clinical signs of periodontitis, established caries, edentulism, or oral health. They found that the oral microbiome in the subjects with periodontitis showed the greatest diversity of bacterial species compared to the other conditions. In other words, distinct microbial signatures were found in subjects with periodontitis, edentulism, or oral health, suggesting that this may lead to a prevention strategy that uses transplantation of healthy microbial flora.

A recent Wall Street Journal article discussed the subject of microbial transplantation.² Researchers at Pennsylvania State University and the University of Adelaide hypothesize that transfer of the microbiome from a healthy patient could one day significantly reduce both dental caries and inflammatory periodontal diseases. For 2 years, their teams have searched for a super donor: an individual with a balance of healthy and pathogenic oral bacteria associated with no tooth decay or inflammatory periodontal lesions. They identified one young adult, who only brushes once a day, never flosses, and hasn’t seen a dentist in 5 years. This person’s microbiome is so healthy that oral hygiene habits normally necessary to control disease are not necessary. The researchers took plaque samples from their donor and transferred them to teeth in rats. These animals showed a significant drop in their dental caries rate. Human clinical trials are set to start in 2025.

References

1. Pozhitkov AE, Leroux BG, Randolph TW, et al. Towards microbiome transplant as a therapy for periodontitis: an exploratory study of periodontitis microbial signature contrasted by oral health, caries and edentulism. BMC Oral Health. 2015;15:125.
2. Yup K. The future of everything. Wall Street Journal. October 1, 2024.

From Decisions in Dentistry. March/April 2025;11(2):6.