There is some chicken in chicken bouillon but not actually the chicken meat.
Instead the chicken bouillon contains chicken fat and chicken protein which gives the chicken bouillon the chicken flavor.
Chicken Bouillon is made from things such as dehydrated vegetables, meat stock, a small portion of fat, MSG, salt, and seasonings, shaped into a small cube.
So the chicken bouillon does contain some chicken but mostly the fat and some chicken meat stock and seasonings to make it taste like chicken.