The P. haitanensis polysaccharide, porphyrin, was able to significantly ameliorate the learning and memory impairment in Alzheimer’s disease (AD)-model mice, to increase choline acetyltransferase (ChAT) activity, and to decrease acetylcholinesterase (AChE) activity in the cortical and hippocampal tissue of AD-model mice [46]. Here, CHAT is linked to Alzheimer disease.