The Himalayan ethnic beverage tongba with therapeutic properties in high-altitude illnesses and metabolomic similarities to Japanese sake

Abstract Tongba, a millet-based fermented ethnic drink of the Limbu and other Nepalese-Tibetan communities, is consumed in the highlands of Singalila Ridge of the Himalayas and the adjoining high-altitude places of Nepal, the northern and north-eastern parts of India, and the Tibetan Plateau and is valued for its ethnomedicinal properties. In this research, the GCMS-based metabolite profiling of an authentic sample of tongba was carried out, identifying various bioactive metabolites. Several biologically active components, such as glycoside, amino acids, fatty acids, and other long-chain hydrocarbon derivatives, terpenoids and phenol, were detected in tongba, which have therapeutic properties against various high-altitude illnesses. Probable biosynthesis routes of those compounds in tongba’s broth were also studied, where many similarities were noticed with the Japanese beverage sake. The key finding of this metabolomic investigation was the detection of bioactive ethyl-α-D-glucopyranoside and cyclo(L-Leu-L-Pro) with abundant peak areas, which confirmed tongba’s therapeutic importance in high-altitude illnesses and its metabolomic similarities with sake.