Scientists report a new way to influence the bacteria that live in the human mouth — not by killing them, but by interrupting the chemical “conversations” they use to coordinate growth. Researchers from a College of Biological Sciences and a School of Dentistry team found that dental plaque bacteria use signalling molecules called N‑acyl homoserine lactones (AHLs) to communicate, and that blocking those signals shifted plaque communities toward species associated with good oral health while reducing microbes linked to gum disease. The work, published in npj Biofilms and Microbiomes, also shows that oxygen availability above and below the gumline strongly alters how these signals work, a discovery with direct implications for periodontal treatment strategies.
The mouth hosts roughly 700 bacterial species that interact through quorum sensing — a form of chemical signalling that helps microbes coordinate behavior. The study mapped how AHL-based communication shapes those communities and tested whether disrupting signals could prevent harmful plaque formation without destroying beneficial microbes. Instead of broad-spectrum antibiotics or disinfectants, the team used specialised enzymes called lactonases to remove AHL signals and observed the community response.
Key findings include that plaque bacteria produce AHL signals in aerobic zones (above the gumline), and those signals can still influence bacteria in anaerobic pockets beneath the gums. Applying lactonases to remove AHLs increased populations of early, health-associated colonisers such as Streptococcus and Actinomyces. Conversely, adding AHLs under anaerobic conditions promoted growth of late colonisers, including members of the “red complex” like Porphyromonas gingivalis, which are strongly associated with periodontal disease.
“Dental plaque develops in a sequence, much like a forest ecosystem,” said Mikael Elias, associate professor and senior author. He explained that pioneer species establish a simpler, healthier community that can later be overtaken by more diverse, disease‑associated bacteria. Lead author Rakesh Sikdar highlighted oxygen’s role: “What’s particularly striking is how oxygen availability changes everything. When we blocked AHL signaling in aerobic conditions, we saw more health‑associated bacteria. But when we added AHLs under anaerobic conditions, we promoted the growth of disease‑associated late colonizers.”
The researchers say their approach could allow targeted modulation of the oral microbiome — maintaining protective species while preventing dysbiosis — and may eventually extend to other body sites where microbial imbalance is linked to disease. Next steps include mapping signalling differences across mouth regions and in people with varying stages of periodontal disease to refine enzyme‑based strategies for preserving oral health. (ANI)
Original Source: https://theshillongtimes.com/2026/05/10/study-finds-new-way-to-prevent-gum-disease-without-killing-good-bacteria/
Category: Features
Tags:
Publish Date: 2026-05-10 03:36:00
