The immune system of old mice is restored by transplanting gut microbes from young mice
A new study on mice shows that the gut microbiome is responsible for at the very least a part of the decline in the immune system as we age.
The microbiome of the gut
The microbiome is a diverse community of bacteria, archaea and viruses living in our intestines. 98% of intestinal microbiome is made up of four bacterial groups: Firmicutes (Bacteroidetes), Proteobacteria (Proteobacteria), and Actinobacteria.