3.3.2 Effect of GP on bacterial community structure
We analyzed the differences in bacterial abundance in rats before and
after GP administration at the phylum
and genus levels, and the heatmaps are shown in Figures 3B and C.
Compared with the blank group, the abundance of Gram-positive Firmicutes
bacteria in the model group decreased significantly,
while the abundance of Gram-negativeBacteroidetes, Verrucomicrobia, Proteobacteria, Tenericutes,
Cyanobacteria, and Deferribacteres increased significantly
(Qin et al., 2010). The abundance of
Gram-negative bacteria decreased significantly after GP administration.
Next, Grapeland was used to construct a hierarchical tree of the
composition of the sample population at each classification level to
explore the dominant microbial groups (Fig.3D). The results showed that
the dominant species at the phylum level were Firmicutes,
Bacteroidetes, Verrucomicrobia and Proteobacteria, and the dominant
species at the genus level were Akkermansia, Allobaculum, andOscillospira . It is suggested that the above bacteria can be used
as a characteristic index for future fecal microbiota transplantation.
Community composition analyses at the taxonomic levels of phylum and
genus have preliminarily proved that the bacterial community structure
before and after GP treatment is significantly different. We further
used principal component analysis (PCA) to analyze the overall structure
of the flora before and after the occurrence of intestinal inflammation
and under the intervention of GP, which also proved that there were
significant differences between the three groups (Fig. 3E).