The digestion of dietary and blood proteins. Explanation:Circumstances that increase serum ammonia levels tend to aggravate or precipitate hepatic encephalopathy. The largest source of ammonia is the enzymatic and bacterial digestion of dietary and blood proteins in the GI tract. Ammonia from these sources increases as a result of GI bleeding (ie, bleeding esophageal varices, chronic GI bleeding), a high-protein diet, bacterial infection, or uremia.