Decomposition does not necessarily have to occur through bacterial action. As a medical researcher, I have studied cell death in a sterile environment. Dead cells break down in various ways, depending on the type of cell death that occurred. With the type of death I suspect has occurred, I would think that the cell membranes would disintegrate and organelles would lose their structural integrity, releasing enzymes that digest cellular biomolecules. I will refrain from describing any further, out of respect for people's sensibilities. I am very curious to know what is actually happening, if breakdown products from a dead organ can penetrate into the circulatory system and so forth. I am also curious as to how long a semblance of life can be maintained in a dead body. Yes, I know this is morbid (but I'm a scientist).
I have read about young children who have had half of their brains removed because of a seizure disorder. They seem to do fine with half a brain... although I wonder if some sort of prosthetic is stuffed into their skull to keep the remaining half in place. The plasticity of a young brain is truly amazing.
My brother was on life support for a time, while his body filled up with fluids to the point he was unrecognizable.