Impact of systemic probiotics as adjuncts to subgingival instrumentation on the oral-gut microbiota associated to periodontitis: a randomized controlled clinical trial.

Abstract

BACKGROUND\nThe oral-gut axis may be a route linking periodontal and systemic diseases. Probiotics could be an alternative for the treatment of microbial dysbiotic conditions, including periodontitis. This randomized placebo-controlled clinical trial evaluated the short-term efficacy of systemic probiotics adjunctive to subgingival instrumentation (SI) in promoting a better restoration of the oral-gut microbiotas and greater periodontal clinical outcome.\n\n\nMETHODS\nSystemically healthy adults with untreated periodontitis were recruited from a Dental School setting, and allocated to receive SI plus placebo (n = 24) or probiotics (n = 24), 1 capsule/day for 30 days. Subgingival biofilm and stool were obtained at baseline and 2-months post-therapy for microbiological analyses by checkerboard and 16S rRNA gene sequencing. Differences in all parameters between placebo (n = 23) and probiotics (n = 19) groups were assessed by non-parametric tests.\n\n\nRESULTS\nMost subgingival species and α-diversity decreased after therapies (p<0.05), whereas gut composition/diversity were slightly or not affected by treatments. In parallel, significant clinical improvement (p<0.05) was similar between groups, although a trend for a higher proportion of poor responders in the placebo (60.8%) than the probiotic group (31.5%) was observed (p = 0.07). Strong correlations between oral and fecal species were found (p<0.01), and distinct species related to poor response for different therapies (p<0.05). Patients were classified into 5 periodontitis oral-gut microbial clusters, which correlated differently with attachment loss after therapies (p<0.05).\n\n\nCONCLUSION\nSystemic probiotics combined to SI did not provide short-term additional clinical or microbiological benefits in the treatment of periodontitis; however, response to therapies seemed to correlate with distinct oral-gut microbial profiles. This article is protected by copyright. All rights reserved.