Ox bile is typically secreted from the liver and mimics our bile - those who had gallbladder removed cannot concentrate large amounts of bile so when eating a meal (specially high in fat) supplementing with bile can help digest the fats.
Most digestive enzymes are typically secreted from the pancreas - however vegetarian based enzymes will also be usable to break down food (or supplementing with animal based like pancreatin).

You need strong digestion to break down foods to absorb nutrients while at the same time reducing metabolic waste.
Weak digestion means less nutrients absorbed and more waste accumulation.
Since the body needs to work extra hard to detoxify the extra metabolic wastes it would need even more nutrients to do the job but without strong digestion it can't perform and overtime, toxicity arises.

So strngthening digestion is the basis for health - Betain HCL, bile, enzymes can all help if taken in right proportions, but even better is to provide nutrients that require no digestion so that they can be absorbed and the body make whatever it needs.
Mike