By whose recommendation should one of these chains be changed at 100,000 KM? This is NOT a BELT! If you are changing your oil frequently, you should never have to change this chain until time to service the engine for some other reason.
As said by ILUVMILS, check it if you are suffering from timing chain phobia, but there is absolutely no reason to change it for the heck of it. There are many people who have suffered catastrophic timing belt failure and some that have suffered catastrophic timing chain failure, but chains don't break due to normal wear like belts do.
Actually timing chains rarely fail on their own. They fail because of some other problem, usually a broken rail.
On the V8's you need to pay particularly close attention to the rails, and on some of the inlines you have to take some extra steps, but if you're properly maintaining your engine with frequent oil and filter changes, changing the chain at 100,000 km intervals will probably increase your odds of having a problem. Going in there and doing things introduces the risk of something not put together right, something forgotten to be tightened, etc., etc.,
I would not be surprised that more timing chain related failures are due to mistakes during replacement, than failure of an undisturbed chain, assuming again that the car is properly maintained.
Check it for stretch and inspect the rails.