Predictive value of gut microbiota in long-term blood pressure control: a cross-sectional study

Figures

• 

  Fig. 1. Flow chart of 16 s deoxyribonucleic acid assay for intestinal flora. PCR polymerase chain reaction, DNA deoxyribonucleic acid. In the raw data obtained from sequencing, there is a certain amount of interference data. To obtain high-quality sequencing data to improve the accuracy of the subsequent bioinformatics analysis, first, the original data needed to be spliced; then, they were quality controlled and filtered to obtain valid data

• 

  Fig. 2. Multilevel species composition of faecal flora in the two groups of patients. This figure Shows the loop of the faecal flora phylum-level composition of the two groups of patients; the overall upper half is the classification of the phylum level of intestinal flora, and the lower half is the patient's intestinal flora specimen. The first circle (from the outside to the inside) represents the uncontrolled group, controlled group and the names of the phylum-level flora classification: Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, Verrucomicrobia, Fusobacteria and Bacteria (unclassified). The second circle represents the number of each specimen in the two groups and the number of the phylum level of the flora. The third circle represents the percentage of phylum level in the two groups of specimens and the total percentage of the two groups. The linked line in the innermost circle shows the specific distribution of the phylum within the group

• 

  Fig. 3. Comparison of faecal flora composition at the phylum level in the two groups of patients. F/B: Firmicutes–Bacteroidetes ratio, which is an important indicator of intestinal flora balance. The higher the F/B value, the worse the balance of the flora and the more serious the disorder of the flora [37]: Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, Fusobacteria, Verrucomicrobia, Bacteria (unclassified). *P < 0.05, ** P < 0.01

• 

  Fig. 4. Comparison of intestinal flora abundance and diversity index in the two groups of patients. The Chao1 and ACE indices are mainly concerned with the species richness information of the samples and estimate the number of species contained in a colony, while the Shannon and Simpson indices mainly comprehensively reflect the diversity and evenness of species, i.e., high ACE and Chao1 indices indicate a high number of species in the samples, and high Shannon and Simpson indices indicate high species abundance and evenness

• 

  Fig. 5. Comparison of the β diversity of the intestinal flora in the two groups of patients. PCoA principal coordinate analysis. During PCoA sorting, other distance/non-similarity matrices can be selected, and thus, the interrelationships between objects can be represented in two-dimensional coordinates. NMDS non-metric multidimensional scale analysis. This differs in that NMDS is no longer a characteristic root sorting technique and no longer aims to sort the bearings to load more variance; therefore, NMDS-sorted graphs can be arbitrarily rotated, centred and inverted. With the same number of axes, NMDS tends to obtain relationships between objects with less distortion than PCoA. The results of an NMDS analysis are measured by stress, which is generally considered to be represented by a two-dimensional point plot of NMDS when stress < 0.2 and its graph has some interpretative significance. When stress < 0.1, it can be considered a good ranking; when stress < 0.05, it is well-represented

• 

  Fig. 6. Differential analysis of the genus levels of intestinal flora in the two groups of patients. Each colour represents a group of samples. The bar on the left indicates the flora with significantly different abundance in the two groups of samples and the average relative abundance in the two groups, respectively. The graph on the right indicates the difference in relative abundance, separated by a dashed line in the middle; the left side of the dashed line indicates flora with higher relative abundance in one group, while the right side of the dashed line indicates flora with higher relative abundance in the other group; hence, each side of the dashed line is in a different colour. Streptococcus, Paraprevotella, Akkermansia and Bifidobacterium

• 

  Fig. 7. Receiver operating characteristic curves of factors of intestinal flora differences in the two groups of patients