Is the so-called fragrant baby derived from people's love or does it truly have its fragrance? On the 21st, a small study in Communication Chemistry analyzed for the first time the differences in the chemical composition of body odor between infants and adolescents. Research has shown that there are two unpleasant compounds that only exist in adolescent body odor samples, and they smell like sweat, urine, musk, and sandalwood. The team from the University of Erlangen Nuremberg in Germany compared the chemical composition of mixed body odor samples from 18 infants (0-3 years old) and 18 adolescents (14-18 years old). The samples were taken from cotton pads sewn under the armpits of cotton T-shirts and baby jumpsuits, and the subjects wore these clothes overnight. Parents of adolescent and infant participants were asked to avoid consuming strongly flavored foods and using fragrances and cleaning agents within 48 hours prior to the study. The research team found that although the chemical composition of the two groups of body odors was similar, samples collected from teenagers contained more carboxylic acid 3-methylbutyric acid, 2-methylheptanoic acid, octanoic acid, 4-ethyloctanoic acid, lauric acid, and myristic acid, as well as berberine and an unknown odor. They described the smell of carboxylic acid as "cheese flavor", "fruit flavor and dry plum flavor", "musty flavor, coriander flavor and grease flavor", "goat flavor", "wax flavor and soap flavor", and "earth flavor, grass flavor and green pepper flavor", while the unknown smell has the flavor of "sandalwood and fragrance", and Baiqiu plum has the flavor of "earth". The team identified two steroid compounds, androstenone, which only exist in samples from adolescents. They reported that these two substances have "sweat, urine, and musk flavors" and "sandalwood and musk flavors" respectively. And a pleasant smelling α- Isomethylionone, with a "violet like odor" and "soap and fragrance odor", has a higher level in infant body odor samples. Researchers believe that the appearance of higher levels of carboxylic acids and steroids may be due to differences in the activity of sebaceous and apocrine glands between adolescents and infants. They concluded that because there were no unpleasant steroid odors in the baby's body odor samples and the carboxylic acid levels were low, it may lead people to believe that the baby has a very pleasant and fragrant odor. (Lai Xin She)