Question: what causes bacteria to deteriate the body?

Andrew McKinley answered on 18 Nov 2014:

Bacteria are always at work in our body – you will have heard of “friendly bacteria” – these are ones which live naturally in our body and actually help us in life. It is when we die and our body stops renewing itself and flushing out the toxins that makes the situation change. The bacteria multiply with nothing to keep them in check, and new cells do not replace those consumed by the bacteria.
Essentially it is a balance – when we die, we stop our side of the balance, so the bacteria take over.