Systemic antibiotics in the surgical treatment of peri-implantitis: Impact on the salivary microbiome
Aim:  The aim was to compare shifts in the salivary microbiome composition after administration of two combined systemic antibiotic regimes used in the surgical treatment of peri-implantitis. Materials and methods: A subset of 27 patients treated surgically for peri-implantitis with an adjunctive 7-day course of systemic antibiotics were included (group A, amoxicillin and metronidazole; group B, phenoxymethylpenicillin and metronidazole). Un-stimulated saliva was collected before surgery (day 0) followed by 8 days, 14 days, 6-, and 12-months post-surgery. Microbiome profiling was performed using standardized, and automated pipelines for DNA extraction and whole genome shotgun sequencing (WGS). Results: WGS identified 407 species across 190 genera and 16 phyla, with Firmicutes and Actinobacteria being the most abundant. A distinct decrease in alpha diversity was observed at day 8 relative to baseline across both antibiotic regimens, with signs of recovery by day 14. Alpha and beta diversity analyses showed no statistically significant differences between interventions over the 12-month observation period, although there was a tendence for greater evenness and Shannon diversity in group B.  Conclusion: Both antibiotic regimens had comparable impacts on the salivary microbiome, with prolonged ecological disruptions in species abundance.   Keywords: saliva, microbiota, amoxicillin, metronidazole, penicillin V
Aim:  The aim was to compare shifts in the salivary microbiome composition after administration of two combined systemic antibiotic regimes used in the surgical treatment of peri-implantitis. Materials and methods: A subset of 27 patients treated surgically for peri-implantitis with an adjunctive 7-day course of systemic antibiotics were included (group A, amoxicillin and metronidazole; group B, phenoxymethylpenicillin and metronidazole). Un-stimulated saliva was collected before surgery (day 0) followed by 8 days, 14 days, 6-, and 12-months post-surgery. Microbiome profiling was performed using standardized, and automated pipelines for DNA extraction and whole genome shotgun sequencing (WGS). Results: WGS identified 407 species across 190 genera and 16 phyla, with Firmicutes and Actinobacteria being the most abundant. A distinct decrease in alpha diversity was observed at day 8 relative to baseline across both antibiotic regimens, with signs of recovery by day 14. Alpha and beta diversity analyses showed no statistically significant differences between interventions over the 12-month observation period, although there was a tendence for greater evenness and Shannon diversity in group B.  Conclusion: Both antibiotic regimens had comparable impacts on the salivary microbiome, with prolonged ecological disruptions in species abundance.   Keywords: saliva, microbiota, amoxicillin, metronidazole, penicillin V
Centre for Translational Microbiome Research (CTMR)