GLS and Cirrhosis: Glutamine is the major energy source for small intestinal enterocytes and therefore, enterocytes have high glutaminase activity and low glutamine synthetase activity, further contributing to intestinal ammonia release.[52], [53], [54] Duodenal glutaminase activity has been reported to be four-fold higher in patients with cirrhosis compared to healthy controls, probably contributing to their hyperammonaemia55 together with deficient urea synthesis.