Figure 2. Compositions of the control, diabetic and insulin-treated diabetic microbiomes in the ileum at domain, phylum, class and order levels.

The orders Enterobacteriales (2B), Clostridiales and Bacteroidetes (2C), displaying the most striking differences, are shown in higher resolution. The abbreviated and colour-coded taxa are indicated on the right side in systematic sequence. “Other sequences” are probably those of viruses not covered in the databases used. Taxa with very low (<1%) abundances are indicated to two decimal places. A striking invasion of the genus Klebsiella was apparent in diabetes. It is noteworthy that the insulin treatment eliminated the Klebsiella invasion, but did not restore the “healthy” microbiome, and the representation of the classes Clostridia and Bacteroidia increased massively.