Are there links between oral microbiota and early childhood caries?

Early childhood caries (ECC) is tooth decay in children under six years old. It is one of the most common chronic childhood diseases worldwide, affecting between 17% and 57% of children in African studies ⁴. The mouth is home to a large community of bacteria, fungi, and other microbes called the oral microbiota. A growing body of research shows that changes in this microbial community, especially during infancy and early childhood, are closely tied to whether a child develops ECC ²⁵⁶. The short answer is yes, there are links, but the picture is more complex than the old idea that one or two bad bacteria simply cause cavities.

What the research says

The traditional view was that ECC is caused mainly by sugar and acid-producing bacteria like Streptococcus mutans. A newer framework describes ECC as the result of a disrupted developmental ecology of the infant oral ecosystem, where host, microbe, and environmental factors interact from before birth through the first 1,000 days of life ². In this model, maternal microbial transmission, how the infant microbiome assembles, breastfeeding, complementary feeding, diet, tooth eruption, and biofilm maturation all shape whether a child's oral ecosystem stays balanced or shifts toward disease ². This means the link between microbiota and ECC starts very early, not just when a cavity appears.

What to ask your doctor

• What does my child's current oral bacteria profile or plaque level suggest about their caries risk?
• How do feeding choices, including breastfeeding and when we introduce other foods, affect the bacteria in my child's mouth?
• Are there specific bacteria or microbial tests that could help predict my child's risk for early childhood caries?
• What preventive steps, such as fluoride or sealants, are recommended for my child's age and risk level?
• Could my child's oral health be affecting other parts of their body, like their kidneys?