Toward the Elucidation of the Biological Mechanism for the Pleasant and Unpleasant Taste of Fatty Acids

Abstract

Evidences have been accumulated that the taste organ is involved in the detection of fats since ~2000, because several molecules have been found to detect fatty acids in taste systems. The authors reported expression and function of GPR40 (FFAR1) and GPR120 (FFAR4) in mouse tongue to transmit fatty acid information to the brain. Particularly, GPR120 is involved in neural information pathway that plays role in distinguishing fatty acid taste from other primary tastes. The function of GPR120 was first reported to be involved in appetite and feeding control in the intestine through secretion of intestinal peptides, GLP-1. Recently, GPR120 is also reported in gastric ghrelin-expressing cells to suppress ghrelin secretion by fatty-acid stimulation. Taste information of fatty acids is suggested to be induce cephalic phase responses before food has reached the digestion, priming the body for an incoming fats or oils. As for the relationship between taste and disease, due to poor taste sensitivity, obese and/or diabetic patients have a risk of taking too much lipids and seasonings. In conclusion, it is important to elucidate mechanisms for the pleasant and unpleasant taste of fats because taste is closely related to feeding behavior connecting to lifestyle-related diseases.