Fig. 2.
Gut microbiota of Thai adult and elderly subjects at the genus level. a Genus composition data of 120 samples were subjected to PCA and ordinated in the PC1-PC2 dimension. Elderly and adult samples were plotted as closed and open circles, respectively. The five genera with the largest loadings were positioned according to the vector of loading. The ellipse covers 95% of the samples belonging to the adult and elderly groups. The vectors of the host factor fitted to the PCA ordination are displayed by arrows. Asterisk beside the name of the factor represents statistical significance with p < 0.05. The samples of the elderly group tended to be localized in the direction of the loading vector of the genus Escherichia/Shigella (p = 0.001, R2 = 0.033). The envfit analysis also indicated that age is associated with this PCA ordination, particularly the direction of the loading vector of the genus Escherichia/Shigella, whereas the other host factors, namely gender and BMI, were not statistically associated with the PCA ordination. bBox plots showing the relative abundance of the genus Escherichia/Shigella in adult and elderly groups. The genus Escherichia/Shigella was shown to have a high abundance in the elderly subjects, although there was no statistically significant difference between these two age groups