FO improved body weight, muscle thickness, weight, and fiber size of gastrocnemius and strength in a muscle atrophy induced mouse model. Bodyweight was decreased by Dexa/Saline but increased by GABA, lactate, GABA+lactate, and FO treatment (a). The muscle thickness of gastrocnemius (b–d) and muscle weight of gastrocnemius (b,d) were decreased by Dexa/Saline but increased by GABA, lactate, GABA+lactate, and FO treatment (c,d). The mean CSA of gastrocnemius muscle fiber was decreased Dexa/Saline but increased by GABA, lactate, GABA+lactate, and FO treatment. Scale bar = 1 cm (e,f). The grip strength was decreased Dexa/Saline but increased by GABA, lactate, GABA+lactate, and FO treatment. Scale bar = 100 μm (g). Different letters a–g indicate significant differences among the group as determined by multiple comparisons (Mann-Whitney U test); p < 0.05. BW, body weight; cross-sectional area (CSA); fermented oyster extracts (FO); γ-aminobutyric acid (GABA); gastrocnemius (gastroc.).