Common microbial signatures in blood and their amplification in clinical disorders

Blood microbiome research has emerged as a significant area of study, exploring microbial signatures within the bloodstream and their potential implications for various clinical disorders. This study aimed to identify common microbial signatures in blood across cohorts and investigate how these signatures are altered in clinical conditions. We conducted a meta-analysis of 15 publicly available studies utilizing amplicon sequencing, including 687 control and 651 case individuals with various disorders from diverse geographic locations to compare their blood microbiome profiles. The results revealed that most microbes detected in the blood originated from the gut, oral cavity, and skin, with several genera such as Corynebacterium, Streptococcus, and Lactobacillus consistently identified across studies. Furthermore, we observed a significant increase in microbial diversity and abundance in individuals with clinical disorders compared to the control group. Notably, microbial genera originating from the gut and oral cavity, including Acinetobacter, Prevotella, and Clostridium sensu stricto-1, were more prevalent in disease cohorts, suggesting a potential link between the translocation of microbial signatures and disease pathology. The study underscores the importance of considering microbial signatures as potential biomarkers in clinical settings and calls for further investigation into the role of circulating microbial DNA in immune response and disease progression.