Season and geography induced variation in sea cucumber (Stichopus japonicus) nutritional composition and gut microbiota

Abstract

Sea cucumber (Stichopus japonicus) is considered as one of the most nutritious and luxurious seafood in Asia. This study investigated the variation in biochemical composition and gut microbes of sea cucumber related to seasons (spring and autumn) and geographical origins (Qingdao, Yantai, Weihai and Dalian) in China. In general, sea cucumber had relatively low fat and high protein. The composition variation between seasons is much more obvious than that of origins, especially for fatty acids (FA) and amino acids. Sea cucumber collected in spring contained more poly-unsaturated fatty acids (PUFA) and Asp, Glu, Leu, Phe than that of autumn. Furthermore, FA varied among origins and seasons, with the highest content of DHA found in the location of Weihai collected in spring. In addition, gut microbes changed among origins and seasons. Proteobacteria and Bacteroidetes decreased significantly from autumn to spring and Firmicutes showed the opposite trend. The variation in protein, lipid, polysaccharides, elements and gut microbes of sea cucumber between seasons and origins might be related to environmental conditions. This study may help to better understand the variation of biochemical composition and gut microbiota of sea cucumber among different origins and seasons.