Low-Cost Protocol for Quantitative Measurement of Streptococcus salivarius in Human Saliva.

2025-10-31
Life (Basel, Switzerland) 15(11)

PubMed: 41302119
DOI: 10.3390/life15111695

Study Design

Type: Observational
Population: 18 healthy adult volunteers
Methods: Saliva samples were analyzed through serial dilutions and selective plating using Mitis-Salivarius Agar; CFU/mL were calculated after 24 and 48 h incubation.

Streptococcus salivarius (S. salivarius) is a prominent oral commensal bacterium with probiotic potential and relevance to both oral and systemic health. Accurate and accessible methods for quantitative measurement of this species are needed to support microbiota studies and clinical interventions. We describe a simple, low-cost, culture-based method for quantifying S. salivarius in human saliva using Mitis-Salivarius Agar. Saliva samples from 18 healthy adult volunteers were analyzed through serial dilutions and selective plating. CFU (colony forming unit)/mL were calculated after 24 and 48 h incubation. The method proved reliable for quantifying S. salivarius in concentrations ranging from 5.8 × 10⁵ to 6.1 × 10⁸ CFU/mL. Although Mitis-Salivarius Agar is a standard medium, we demonstrate its systematic validation and optimization for human saliva in a low-resource clinical setting, where molecular tools are often unavailable.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Streptococcus salivarius	—	Reduced Streptococcus salivarius Colonization	Neutral	Small	View source We describe a simple, low-cost, culture-based method for quantifying S. salivarius in human saliva using Mitis-Salivarius Agar... The method proved reliable for quantifying S. salivarius in concentrations ranging from 5.8 × 10^5 to 6.1 × 10^8 CFU/mL.