In Vivo Study on the Salivary Kinetics of Two Probiotic Strains Delivered via Chewing Gum

Probiotics are increasingly used to promote oral health, with <i>Lacticaseibacillus rhamnosus</i> demonstrating proven effectiveness. Additionally, <i>Heyndrickxia coagulans</i> shows promising potential in this field. Chewing gum has recently been proposed as an innovative delivery method for probiotics. This study aimed to evaluate the kinetics in saliva of <i>Heyndrickxia coagulans SNZ1969</i>^® and <i>Lacticaseibacillus rhamnosus GG</i> in microencapsulated and non-microencapsulated forms (LGG^®) following their administration via sugar-free chewing gums. A randomized cross-over trial was conducted involving 10 volunteers. Participants chewed gums containing one of the probiotic strains for 10 min. Saliva samples were collected at baseline (T₀) and six subsequent time points over 2 h (T₁-T₆). Colony-forming units (CFUs) were identified and quantified. The Tukey's range test was applied to make pairwise comparisons between different probiotics at every time point, between different time points of the same probiotic, and between the area under the curve describing the kinetics of different probiotics in saliva. At T₁, all probiotics exhibited peak counts, followed by a gradual decline until T₆. <i>H. coagulans</i> SNZ1969^® achieved the highest counts at T₁, T₂, and T₃ (mean log₁₀ CFU/mL: 6.1 ± 0.5; 5.8 ± 0.5; 5.6 ± 0.5, respectively), while the non-microencapsulated form of LGG^® peaked at T₄, T₅, and T₆ (mean log₁₀ CFU/mL: 4.0 ± 0.7; 3.8 ± 0.9; 3.3 ± 1.3, respectively). The participants reported no adverse effects. Probiotics were detectable in saliva up to 2 h post-administration via chewing gum, indicating its suitability as a delivery vehicle. However, significant variability was observed among participants.