The blood microbiome and its association to cardiovascular disease mortality: case-cohort study

Abstract

Background Little is known about the association between bacterial DNA in human blood and the risk of cardiovascular disease (CVD) mortality. Methods A case-cohort study was performed based on a 9 ½ year follow-up of the Oslo II study from 2000. Eligible for this analysis were men born in 1923 and from 1926 to 1932. The cases were men (n = 227) who had died from CVD, and the controls were randomly selected participants from the same cohort (n = 178). Analysis of the bacterial microbiome was performed on stored frozen blood samples for both cases and controls. Association analyses for CVD mortality were performed by Cox proportional hazard regression adapted to the case-cohort design. We used the Bonferroni correction due to the many bacterial genera that were identified. Results Bacterial DNA was identified in 372 (82%) of the blood samples and included 78 bacterial genera from six phyla. Three genera were significantly associated with CVD mortality. The genera Kocuria (adjusted hazard ratio (HR) 8.50, 95% confidence interval (CI) (4.05, 17.84)) and Enhydrobacter (HR 3.30 (2.01, 5.57)) indicate an association with CVD mortality with increasing levels. The genera Paracoccus (HR 0.29 (0.15, 0.57)) was inversely related. Significant predictors of CVD mortality were: the feeling of bad health; and the consumption of more than three cups of coffee per day. The following registered factors were borderline significant, namely: a history of heart failure; increased systolic blood pressure; and currently taking antihypertensive drugs now, versus previously. Conclusions The increasing levels of two bacterial genera Kocuria (skin and oral) and Enhydrobacter (skin) and low levels of Paracoccus (soil) were associated with CVD mortality independent of known risk factors for CVD.

Analysis of the blood bacterial composition of patients with acute coronary syndrome and chronic coronary syndrome

“…Several studies have documented an association between chronic infections and the risk of cardiovascular disease ( Armingohar et al., 2014 ; Lund Håheim, 2014 ; Lawrence et al., 2022 ). The circulation is a closed system, and the blood in healthy individuals was earlier believed to represent a sterile environment, which is the basis for safe blood transfusions ( Damgaard et al., 2015 ).…”

“…The accumulation of lipid bodies in the foam cells is affected by both the nutrition and gut microbiota. Bacteria are also known to form thrombi and emboli in interaction with platelets, and this is also seen as a complication of advanced lesions of atherosclerosis ( Armingohar et al., 2014 ; Lund Håheim, 2014 ; Lawrence et al., 2022 ).…”

Blood Stream Microbiota Dysbiosis Establishing New Research Standards in Cardio-Metabolic Diseases, A Meta-Analysis Study

“…The present analysis shows that eight out of 31 studies were related to circulating bacteria altered in 4795 patients with all forms of heart diseases and 477 healthy controls. The duration of studies ranges from minimum 10 days [ 55 ] to nine and half years [ 54 ]. Most studies (six out of eight) were of randomized and comparative controls and two studies by Amar et al [ 36 , 52 ] were interpretational studies.…”

Composition and changes of blood microbiota in adult patients with community-acquired sepsis: A pilot study from bench to bedside

“…A positive correlation was demonstrated between the vulnerability of the skin barrier and the abundance of Enhydrobacter genus ( Zhou et al., 2022 ). Information exists about this taxon not only as a component of the skin microbiota, but the increasing level of Enhydrobacter genus in blood microbiota was proved to be associated with cardiovascular disease mortality ( Lawrence et al., 2022 ). Knowing these correlations, it is not surprising that the blood microbiota of our septic and septic shock patients belonging to the older age group contained an increasing amount of the Enhydrobacter genus compared to the blood samples of healthy controls.…”