Hyposalivation leads to changes in plaque composition that favor which organisms?

• A. Candida species, Streptococcus mutans, and Lactobacilli
• B. Staphylococcus aureus only
• C. Pseudomonas aeruginosa
• D. Viruses only

Answer: (A)

Hyposalivation shifts the oral environment toward conditions that favor acid-producing and acid-tolerant organisms. With less saliva, clearance of sugars is slower, buffering capacity drops, and antimicrobial factors in saliva are reduced. This creates an opportunity for Candida species to overgrow in the biofilm, as they thrive when salivary defenses are diminished. At the same time, key cariogenic bacteria like Streptococcus mutans and Lactobacillus species proliferate in the acidic, sugar-rich plaque environment that forms when buffering is lowered and clearance is impaired. Together, these organisms become more prominent in plaque under low saliva flow, increasing caries risk and fungal overgrowth.

Staphylococcus aureus and Pseudomonas aeruginosa are not typically enriched as the dominant organisms in caries-associated plaque linked to hyposalivation, and viruses alone do not account for the microbial shifts that drive plaque composition in this context.