Beneficial Effect of Olive Leaf Extract as an Adjunct to Standard Antifungal Therapy in Treating Candida-Related Oral Diseases

The aim of this study was to evaluate whether combined administration of olive leaf extract (OLE) with standard antifungal therapy—nystatin (NYS) or miconazole (MIC) could be a more efficient alternative in reducing the number of Candida colonies, the presence of oral signs and symptoms and changes in salivary IL-17A level compared to standard therapy alone. The study included 59 subjects with a positive microbiological Candida colony number greater than 600 CFU/mL and at least one oral sign or symptom present. Subjects were randomly divided into four groups depending on applied therapy: OLE + NYS group (n = 15), OLE + MIC group (n = 15), NYS group (n = 14), MIC group (n = 15). Therapy duration and clinical monitoring were standardized across all groups. There was no significant difference between the tested groups in Candida spp. colony number or salivary IL-17A levels. In the OLE + NYS group, a significant increase in salivation rate was observed, while a significant decrease in tongue burning was reported in the OLE + MIC group. A significant reduction in burning of the oral mucosa and tongue was observed in the MIC group. No significant differences were found in other clinical signs or symptoms among treatment groups. OLE, as an adjunct to standard antifungal therapy, did not significantly reduce Candida spp. colony number or salivary IL-17A levels. However, in combination with NYS it increased salivation rate, while in combination with miconazole, it significantly decreased tongue burning. Both symptoms are common clinical findings in oral Candida-related disease and suggest that OLE may have supportive potential in the clinical management of these conditions. Further research is needed to explore its potential therapeutic benefits on oral health.