This invention discloses a *
Lactococcus faecium* strain, YS-IM01. This strain can efficiently hydrolyze sheep
colostrum proteins and specifically release a large amount of
leucine. This invention also provides a
polypeptide composition comprising multiple active peptides with potential for
muscle synthesis, immunomodulation, and
antioxidant activity. This invention further provides a fermented sheep
colostrum product obtained by fermenting sheep
colostrum with the aforementioned *
Lactococcus faecium*. This invention also provides a method for preparing the fermented sheep colostrum product, comprising steps including
fermentation, low-temperature vacuum concentration, and vacuum freeze-
drying. Simultaneously, this invention also provides a method for preparing a
drug using *
Lactococcus faecium* and the
polypeptide composition to prevent and / or improve age-related
muscle loss.