Postbiotics derived from wine grape seed extract and whey with lactic acid bacteria alleviate muscle atrophy by modulating genes involved in inflammation, myogenesis, and bone metabolism

A postbiotic product (WDG), derived from the bioconversion of wine grape seed flour extract (GSE) and branched-chain amino acid-rich whey using Lentilactobacillus kefiri DH5 (DH5), may synergistically improve bioavailability and bioactivity to alleviate muscle atrophy. The left hindlimbs of C57BL/6J mice were immobilized for 2 wk, and the mice were randomly divided into 5 groups fed a high-fat (HF) diet (CON), 5% grape seed flour (G), whey (W), W + DH5 (WD), or 2.5% G + W + DH5 + GSE (WDG). The WDG group showed the most significant improvements in holding impulse time, muscle mass, and expression of genes related to muscle growth markers (MyoD, Igf-1, Atrogin-1), with its antisarcopenic effects being superior to those of G or WD alone. The RNA-sequencing analysis revealed that WDG positively regulated genes related to anti-inflammation, phagocytosis, angiogenesis, myogenesis, bone metabolism, and brown adipose tissue development. These findings suggest that WDG may be a potent natural functional product for the management of sarcopenia.