Antimicrobial effects of the saliva substitute, Oralbalance®, against microorganisms from oral mucosa in the hematopoietic cell transplantation period

Goals: The commercially available saliva substitute Oralbalance® has been reported to alleviate symptoms of post-radiotherapy xerostomia in head and neck cancer patients. Oralbalance® may also be effective for xerostomia in patients undergoing hematopoietic cell transplantation (HCT) with high-dose chemotherapy and total-body irradiation. However, HCT patients are severely compromised, and saliva substitute must therefore not promote infection. This study was performed to determine the effects of Oralbalance® on microbial species identified during HCT. Patients and methods: Microbial identification of oral mucosa was performed in 28 patients undergoing HCT. The antimicrobial effects of Oralbalance® against bacteria and fungi detected in the HCT period were examined in vitro. Briefly, bacteria and fungi were spread on agar plates, and 0.1g of Oralbalance® gel was applied (about φ1cm). After incubation at 37°C for 24h, the presence of a transparent zone of inhibition around Oralbalance® was observed. Main results: Not only bacterial species constituting normal flora of the oral mucosa but also those not usually constituting normal flora, e.g., coagulase-negative Staphylococcus, were detected. A transparent zone was observed around Oralbalance® in all bacterial species examined. No transparent zone was observed for Candida albicans, but growth was inhibited in the area where Oralbalance® was applied. Conclusions: Oralbalance® does not facilitate increases in microorganisms in the HCT period. Oral care with Oralbalance® does not promote infection in patients undergoing HCT.