Cross-kingdom dynamics of the subgingival bacteriome and mycobiome: a pilot study on the effects of a novel HA-H₂O₂-Glycine formulation to treat periodontitis

Objectives Traditional periodontal therapy primarily focuses on bacterial biofilm control; however, recent evidence also suggests a critical role for the oral mycobiome. This study evaluated the clinical and ecological impact of a novel mouthwash formulation containing hyaluronic acid (HA), hydrogen peroxide (H 2 O 2 ), and glycine on periodontal patients Materials and Methods This prospective, randomized split-mouth trial included 13 adult participants with periodontitis treated with HA–H 2 O 2 –glycine formula (BMG0703A) used twice a day for seven days. Subgingival plaque samples were collected from periodontal pocket and healthy control sites at baseline (T0) and one-week post-treatment (T1). Microbial and fungal communities were characterized using Next-Generation Sequencing (NGS) of the 16S rRNA and ITS2 regions. Linear Mixed Models (LMM) and Spearman correlation were used to assess taxonomic shifts and cross-kingdom relationships. Results Sequencing revealed a promising ecological shift: the bacteriome shifted from anaerobic dominance ( Olsenella, Peptostreptococcus ) toward a health-associated aerobic profile, with Rothia near-doubling (11.91% to 22.68%). The mycobiome underwent a "normalization" effect: Candida abundance decreased significantly (22.8% to 9.1%), while fungal Shannon diversity in pockets returned to healthy-site levels. Inter-kingdom analysis identified antagonistic relationships between expanding commensal bacteria and opportunistic fungi, suggesting that the intervention may help re-establish a protective bacterial niche. Conclusions The HA–H 2 O 2 –glycine formulation seems to facilitate a rapid, cross-kingdom modulation of the subgingival niche. By reducing anaerobic pathogens and normalizing the mycobiome it appear to induce short-term changes, suggesting potential as adjunctive strategy in periodontal management. Clinical significance The present work underlines the possible cross-Kingdom effects of a novel compound.