Phosphatidylcholines (PC) are a class of phospholipids with choline as the head group. is a chemical found in eggs, soy, mustard, sunflower and other foods. It is naturally present in all cells of the body. They are a major component of biofilms. Dipalmitoylphosphatidylcholine (aka lecithin) is a major component of lung surfactants and is usually used in L/S ratios to calculate fetal lung maturity. Although phosphatidylcholines are found in all plant and animal cells, they are absent from the cell membranes of most bacteria. Phosphatidylcholines are used in ulcerative colitis. There is some scientific research to support this use, and phosphatidylcholine is also used to treat memory loss, Alzheimer’s disease, and liver disease, but there is no good scientific evidence to support these uses.