Oral probiotics have been recently gaining much attention owing to their potential to inhibit the progression of dental caries by controlling the cariogenic effects ofStreptococcus mutans. We isolated and genotypically identified 77 lactic acid bacteria including 12Limosilactobacillus fermentumprobiotic candidates from the oral cavity of healthy volunteers. Among the 12L. fermentumisolates, nine isolates effectively inhibited the growth ofS. mutansvia hydrogen peroxide (H2O2) production. The others neither suppressed the growth ofS. mutansnor produced H2O2. Eight out of the nine H2O2-producingL. fermentumisolates exhibited strong adherence to oral epithelial KB cells while inhibiting the adherence ofS. mutansto KB cells. The eight H2O2-producing isolates were neither haemolytic based on a blood-agar test, cytotoxic according to lactate dehydrogenase assay, nor resistant to eight antibiotics represented by the European Food Safety Authority guideline, indicating that the isolates have potential to suppress the cariogenesis driven byS. mutanswhile providing general probiotic benefits.