Background: Based on the 16S rDNA sequence, intestinal flora changes in
atrial fibrillation (AF) patients were monitored, the correlation between the
changes and CHADS-VAS score was analyzed, and the possible
related factors affecting the changes of intestinal flora were investigated.
Methods: According to the inclusion criteria, 53 AF patients were
selected as atrial fibrillation group (Group AF), detection of C-reactive protein
(CRP), homocysteine (Hcy), total bile acid (TBA), brain
natriuretic peptide (BNP), High-sensitivity cardiac troponin (Hs-cTn) and left
ventricular ejection fraction (LVEF) were accomplished. A total of 29 healthy
subjects who underwent physical examination with matched gender and age were
selected as the healthy group (Group H), and the same examinations as in Group AF
were handled. Structural composition of intestinal flora was detected and
analyzed by 16S rRNA sequencing technology. Flora differences between Group AF
and Group H were counted, and the correlation analysis among age, Hs-cTn, CRP,
TBA, Hcy, BNP and LVEF were explored. Meanwhile, CHADS-VAS
score of 53 AF patients was fulfilled, then patients were divided into three
subgroups according to different scores, namely: 0 point (AF-0, n = 9), 1 point
(AF-1, n = 15), 2 points (AF-2, n = 29). Finally, the
correlation of intestinal flora differences and CHADS-VAS
scores were analyzed. Results: In terms of Alpha
diversity, compared with the control group, the abundance and diversity of flora
in Group AF were observably reduced. However, at phylum and class level, there
was no notable difference in community structure between Group AF and Group H
(p 0.05). Further statistics revealed that the composition and
abundance of intestinal flora in Group AF were prominently different from those
in Group H at phylum, class, order and family levels, which were correlated with
CRP and LVEF. Additionally, bioinformatics analysis comparison was performed on
three CHADS-VAS score subgroups of Group AF with Group H. It
was reported that at phylum level, the relative abundance of Firmicutes in Group
AF-2 and Chloroflexi in Group H was higher. At class level, the relative
abundance of Sphingobacteriia, Flavobacteriia and Alphaproteobacteria was higher
in group H. At order level, the relative abundance of Sphingobacteriales,
Micrococcales, Flavobacteriales, Sphingobacteriales and Rhizobiales in group H
was higher. At family level, the relative abundance of Sphingobacteriaceae,
Flavobacteriaceae and Clostridiaceae in group H was higher. At genus level, the
relative abundance of Sphingobacterium in group H,
Clostridiumsensustricto-1 in Group AF-2, Dialister and
Allisonella in Group AF-1, and Prevotella-9 in Group AF-0 were
higher. Conclusions: There were changes in the relative abundance of
intestinal flora at phylum, class, order and family levels, which was concerned
with LVEF and CRP value, whereas Alpha diversity index of the flora decreased.
The composition and relative abundance of intestinal flora varied in AF patients
with CHADS-VAS scores of 0, 1, and 2.