Table 3 Included studies examining the association between cardiovascular risk/disease and the oral microbiome

Boaden, 2017

Saliva, buccal mucosa, tongue, gingiva and hard palate

Describe the bacterial profile of the oral flora during the first two weeks following a stroke, examining changes in the condition of the oral cavity and infections

Patients with stroke (n = 50)

20% current, 30% prior-smokers

16S

V1–V9

[75]

Fåk et al., 2015

Whole mouth swab

Elucidate whether the oral microbiota composition differed between patients with asymptomatic and symptomatic atherosclerosis

Asymptomatic atherosclerosis (n = 35), symptomatic atherosclerosis (n = 27), control (n = 30), total (n = 92)

Current smokers: 9% asymptomatic atherosclerosis, 23% symptomatic atherosclerosis, 21% control

16S

V1–V2

[70]

Gordon et al., 2019

Subgingival plaque

Characterize and compare the oral microbiome between four study groups based on BP status in postmenopausal women

Normal BP (n = 179), stage I hypertension (n = 106), Stage II hypertension (n = 42), patients on hypertension medications, irregardless of BP (n = 119), total (n = 446)

Current 4.5%, former 39.7% normal BP; current 2.8%, former 47.2% stage I; current 2.4%, former 40.5% Stage II, current 2.5%, former 45.4% patients on hypertension medications

16S

V3–V4

[69]

Leskelä et al., 2020

Saliva

Investigate associations of specific oral bacteria and LPS neutralizing capacity in a case–control study of ischemic stroke

Controls (n = 100), Patients with stroke (n = 98), total (n = 198)

Current smokers: 12% controls, 28% patients with stroke

Targeted qPCR sequencing

N/A

[63]

Liljestrand et al., 2018

Subgingival plaque

Study the association between periodontal pathogen burden, saliva and serum LPS activity and how periodontitis and coronary artery disease interrelate with them

Control (n = 123), stable CAD (n = 184), ACS (n = 169), ACS-like, no CAD (n = 29); total (n = 505)

Ever smokers: 46.3% control, stable CAD, ACS, ACS-like, no CAD; 52.9% total

DNA hybridization

N/A

[64]

Kannosh et al., 2018

Subgingival plaque

Assess temporal changes in the frequency of periodontal bacteria in the subgingival plaque and in atherosclerotic blood vessels of patients with atherosclerosis

Patients with atherosclerosis (n = 100)

Smokers: 55% of total sample

Targeted 16S sequencing

N/A

[67]

Koren et al., 2011

Oral cavity swab

Aimed to address: Is there a core atherosclerotic plaque microbiota? Are bacteria present in the plaque also detectable in the oral cavities or guts of the same individuals? Is an altered oral or fecal microbiota associated with atherosclerosis?

Controls (n = 15), patients with atherosclerosis (n = 15); total (n = 30)

Current smoker: 0%, controls, 40% patients with atherosclerosis

16S

V1–V2

[74]

Mahalakshmi et al., 2017

Subgingival plaque

Determine the incidence of anaerobic periodontopathic bacterial co-occurrences in periodontitis and atherosclerosis

Control patients without periodontitis or systemic disease (n = 100), patients with atherosclerosis (n = 65); patients with periodontitis but no systemic disease (n = 59); total (n = 224)

Current or past smokers were excluded from the study

Targeted 16S sequencing

N/A

[71]

Nikolaeva et al., 2019

Subgingival plaque

Characterize composition of subgingival biofilm with periodontopathogenic bacteria species and endothelium-dependent vasodilation in patients with chest pain and concomitant periodontitis

Patients with angina pectoris (n = 15); patients with acute myocardial infarction (n = 15); Patients with chest pain but no coronary artery disease (n = 15); total (n = 45)

Current smokers: 80% patients with angina pectoris; 60% patients with acute myocardial infarction; 47% patients with chest pain but no coronary artery disease

Targeted 16S sequencing

N/A

[72]

Perry et al., 2020

Saliva

Establish how oral bacteria are related to cough sensitivity and pneumonia in a clinical stroke population

Patients with atherosclerosis (n = 100)

Not reported

Targeted qPCR

N/A

[76]

Serra e Silva Filho et al., 2014)

Subgingival plaque

Assess microbial diversity of the subgingival environment and atheroma plaques of patients with periodontitis and obstructive coronary artery atherosclerosis

Patients with periodontitis and atherosclerosis (n = 18)

Smokers: 55.6% of total sample

16S

V1–V9 (27f/ 1492r primers)

[68]

Su et al., 2019

Tongue dorsum

Study the association between oral bacteria on the tongue dorsum and factors associated with oral health and systemic disease in middle-aged and elderly patients

Total sample (n = 70)

Smokers: 11% of total sample

Targeted PCR sequencing

N/A

[73]

Ziebolz, Jahn, et al., 2018

Subgingival plaque

Detect periodontal pathogens DNA in atrial and myocardial tissue, and to investigate periodontal status and their connection to cardiac tissue inflammation

Patients undergoing surgery for aortic valve stenosis (n = 30)

Smoking history was present in only 8 patients: average of 27.2 ± 21.8 pack/years in that subset

Targeted PCR sequencing

N/A

[66]

Ziebolz, Rost, et al., 2018

Subgingival plaque

Detect correlations of microbiological DNA, inflammatory proteins, and infection parameters in patients with periodontal disease and valvular heart disease

Patients undergoing surgery for aortic valve stenosis (n = 10)

Smokers: 30% of total sample

Targeted PCR sequencing

N/A

[65]