Are Veillonella species early colonizers, bridging species, or late colonizers?

• A. Early colonizers
• B. Late colonizers
• C. Bridging species
• D. Unknown

Answer: (C)

Veillonella act as bridging species in the development of dental biofilms. They don’t initiate colonization; early colonizers such as Streptococcus attach first and produce lactate. Veillonella cannot ferment sugars themselves but thrive on that lactate, so they appear after the initial colonizers. By consuming lactate, they help modulate the local environment and create avenues for other, more anaerobic late colonizers to establish, effectively linking the early and late phases of the biofilm. They can also coaggregate with both early and late organisms, reinforcing their role as a connector between stages of the community.