New Paradigms for Familiar Diseases: Lessons Learned on Circulatory Bacterial Signatures in Cardiometabolic Diseases

Abstract

Despite the strongly accumulating evidence for microbial signatures in metabolic tissues, including the blood, suggesting a novel paradigm for metabolic disease development, the notion of a core blood bacterial signature in health and disease remains a contentious concept. Recent studies clearly demonstrate that under a strict contamination-free environment, methods such as 16 S rRNA gene sequencing, fluorescence in-situ hybridization, transmission electron microscopy, and several more, allied with advanced bioinformatics tools, allow unambiguous detection and quantification of bacteria and bacterial DNA in human tissues. Bacterial load and compositional changes in the blood have been reported for numerous disease states, suggesting that bacteria and their components may partially induce systemic inflammation in cardiometabolic disease. This concept has been so far primarily based on measurements of surrogate parameters. It is now highly desirable to translate the current knowledge into diagnostic, prognostic, and therapeutic approaches.This review addresses the potential clinical relevance of a blood bacterial signature pertinent to cardiometabolic diseases and outcomes and new avenues for translational approaches. It discusses pitfalls related to research in low bacterial biomass while proposing mitigation strategies for future research and application approaches.

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

“…Previously, blood contamination during collection and experiments was considered accidental. Growing evidence suggests that bacteria or LPS binding protein (LBP) or LPS in the circulation cause systemic inflammation in cardio-metabolic diseases [ 17 ]. Several studies have added scientific reasoning and findings on the existence of a healthy human blood microbiome ( Table 2 ) [ 66 ].…”

“…Several diseases, including obesity, diabetes, and cardiovascular disease, have been linked to human microbiota dysbiosis. Whole metagenome shotgun sequencing made it easy to detect the blood bacterial dysbiosis in health and disease but its use is still debated [ 17 ]. Cumulative evidence for bacterial signatures in metabolic tissues, including blood, recently opened new paths for exploring the potential impact of circulating microbiota on CMDs [ 18 , 19 , 20 , 21 ].…”