Bacteria are constantly evolving to survive. One major consequence is that many harmful microbes are becoming resistant to antibiotics and disinfectants, creating serious challenges for medicine and public health. But not all bacteria are dangerous. In fact, many are essential to keeping the human body healthy. Now, scientists are exploring whether it may be possible to influence bacterial behavior instead of simply trying to destroy bacteria outright.
Inside the human mouth, bacteria are in near constant communication. Roughly 700 bacterial species live there, and many exchange chemical messages through a process called quorum sensing. Some of these microbes communicate using signaling molecules known as N-acyl homoserine lactones (AHLs).
Researchers from the College of Biological Sciences and the School of Dentistry set out to investigate how these bacterial signals shape the oral microbiome and whether interrupting those signals could help prevent harmful plaque buildup while preserving healthy bacteria. Their findings, published in npj Biofilms and Microbiomes, could eventually influence treatments far beyond dentistry.
Scientists Target Bacterial Communication
The research team discovered several important patterns in how mouth bacteria interact: Bacteria living in dental plaque produce AHL signals in aerobic environments (such as above the gumline), and those signals can still affect bacteria in anaerobic environments (beneath the gumline). Removing AHL signals using specialized enzymes called lactonases increased populations of bacteria associated with good oral health. The findings suggest that carefully selected enzymes may be able to reshape dental plaque communities and support a healthier oral microbiome."Dental plaque develops in a sequence, much like a forest ecosystem," said Mikael Elias, associate professor in the College of Biological Sciences and senior author of the study. "Pioneer species like Streptococcus and Actinomyces are the initial settlers in simple communities -- they're generally harmless and associated with good oral health. Increasingly diverse late colonizers include the 'red complex' bacteria like Porphyromonas gingivalis, which are strongly linked to periodontal disease. By disrupting the chemical signals bacteria use to communicate, one could manipulate the plaque community to remain or return to its health-associated stage."
