The total composition of the Sun, by mass, is probably exactly the same as the total bulk composition of the entire heliosphere, with the obvious necessary accelerated nuclear changes brought about in that life-giving, compressed compost heap by fusions, fissions, and whatnot over great expanses of time.
Maybe the lifespan before expanding and swallowing the Earth might be a quite a bit sooner than the estimated 5 billion years if Sun is somehow all made out of fuel.