TABLE 2.

Studies on blood microbiota in other diseases

Study population	Material	Method	Major finding	Reference
119 diabetic and 480 nondiabetic	Whole blood	Cultured in aerobic and anaerobic broths separately	Diabetic patients have higher Klebsiella and Staphylococci	14
9‐year follow‐up of 3280 individuals without obesity or diabetes	Peripheral blood leukocytes	16S rDNA sequencing	In a 9‐year follow‐up, people with elevated 16S rDNA concentration in their blood developed diabetes regardless of other risk factors. Ralstonia spp. has a high prevalence in people who have diabetes	14
50 diabetics and 50 nondiabetic individuals	Blood plasma	16S rDNA sequencing	Diabetes patients had high 16S bacterial rRNA content, with Clostridiumcoccoides and the Atopobidum cluster being especially abundant	35
Community‐acquired (CA) Staphylococcus aureus bacteremia patients	Whole blood	From 2000 to 2011, a population‐based medical database was analyzed	CA‐SAB infection is more likely in people who have diabetes	35
58 Parkinson's disease (PD) patients and 57 healthy controls	Whole blood	16S rRNA sequencing	Genera Cloacibacterium and Isoptericola were found to be highly expressed in PD patients, while genera Paludibacterium and Saccharofermentans were found to be positively correlated with disease duration	35
20 healthy controls and 20 nondiabetic patients with chronic kidney disease (CKD)	Buffy coat samples	16S targeted metagenomic sequencing	The CKD group had higher levels of the Proteobacteria phylum, Gamma Proteobacteria class, and Enterobacteriaceae and Pseudomonadaceae families than the controls	41
50 diabetes mellitus and 100 nondiabetes Mellitus patients	Blood plasma	Next‐generation sequencing of the 16S rRNA amplicon	Bacteroides spp. were found to have a negative link with diabetes, but Sediminibacterium spp. had a positive relationship	40
10 subjects with rosacea patients and 30 healthy adults	Whole blood	16S rRNA gene sequencing	At the family level, Fusobacteriaceae and Chromatiaceae were the most common, and at the genus level, Rheinheimera was the most abundant in rosacea patients' blood	40
A total of 28 female patients and 15 age‐ and sex‐matched controls were included in the study	Blood	16S rDNA sequencing	The prevalence of the Proteobacteria phylum, genera Pelagibacterium, Halomonas, Aureimonas, Chelativorans, and others were increased in rheumatoid arthritis patients as compared to healthy	42