Microbiome composition comparison in oral and atherosclerotic plaque from patients with and without periodontitis

Abstract

28There is no conclusive evidence regarding a causal relationship between periodontitis 29 and atherosclerosis. In this study, we examined the microbiome in the oral cavity and 30 atheromatous plaques from atherosclerosis patients with or without periodontitis to 31 investigate the role of oral bacteria in the formation of atheromatous plaques. We chose 32 four patients with and without periodontitis, who had undergone carotid endarterectomy.33 Bacterial samples were extracted from saliva on the tongue surface, from periodontal 34 pocket (during the oral examination), and from the atheromatous plaques. We 35 investigated the general and oral conditions from each patient and performed next-36 generation sequencing analysis for all bacterial samples. There were no significant 37 differences between both groups concerning general conditions. However, the 38 microbiome patterns of the gingival pocket showed differences depending on the absence 39 or presence of periodontitis, while those of the saliva were relatively similar. The 40 microbiome pattern of the atheromatous plaques was entirely different from that in saliva 41 present on the tongue surface and gingival pocket, and oral bacteria were seldom detected.42 However, the microbiome pattern in atheromatous plaques was different in the presence 3 43 or absence of periodontitis. These results indicated that oral bacteria did not affect the 44 formation of atheromatous plaques directly. However, the metabolic products of 45 microbiome or the host inflammatory response might indirectly influence the 46 composition of atheromatous plaques. 47