In a two-stage digestion system (multistage), different digestion vessels are optimised to bring maximum control over the bacterial communities living within the digesters.

To dilute the bile, water and electrolytes from the digestion system are added.

The implementation of an anaerobic digestion system rectified the problem.

Ruminants have a digestion system whereby micro-organisms in the rumen produce enzymes breaking down and thereby making available phosphorus from plant material.

Faulty genomes can also occur - for example, norns which can not see or hear, or immortal norns due to a hyper-efficient digestion system.