Figure 1.

Differences and similarities of germ-free (axenic) and broad-spectrum antibiotic-treated mice (decimation of microbes). While both techniques result in the aberrant enlargement of the cecum, GF mice are less susceptible for colonic inflammation, and present elongated villus structures compared to antibiotic treated animals. In both the animal models, absence of gut microbiota alters protein expression levels in the liver. In the bone marrow, the two mouse models present both reduced granulocytes, monocytes and progenitor cells, but higher T cell levels. On the other hand, while B cells in GF animals are increased, in antibiotic-treated counterparts they were reported to be decreased. Both the complete absence and the decimation of the gut microbiota influences vascular physiology and have an effect on vascular disease. Neointimal hyperplasia, a proliferation and inflammation response to arterial injury, was increased in antibiotic treated rats. Antibiotic treatment leads to a diminished development of aortic root lesion. Additionally, germ-free mice were protected from cardiac inflammation and arterial thrombus growth.