This study assessed the improvements yielded by Lactobacillus curvatus HY7602-fermented antlers (FA) in dexamethasone-induced muscle atrophy and the effects of bioactive compounds increased by fermentation. Dexamethasone-treated C2C12 myoblast cells were treated with FA and non-fermented antlers (NFA). FA showed inhibitory effects on muscle protein degradation in the C2C12 cells. Hsb:ICR mice were orally administered saline (control(CON) and dexamethasone only (DEX)), oxymetholone (DEX+OXY), NFA (DEX+NFA), and FA (DEX+FA) via gavage. Before the end of the experiment, dexamethasone was intraperitoneally (IP) injected into the mice, except in the control group, to induce muscle atrophy. Compared with the DEX group, the DEX+FA group exhibited a significant prevention in the reduction of hindlimb strength, calf thickness, calf muscle weight, and the cross-sectional area of muscle fibers (p < 0.05). The FA-induced improvements in muscle atrophy were associated with a decreased gene expression of protein degradation and growth inhibition, and an increased gene expression of protein synthesis and growth factors. Sialic acid, a bioactive compound associated with muscles, was increased by 51.41% after fermentation and suppressed the expression of protein degradation genes in the C2C12 cells. L. curvatus HY7602-fermented antlers with increased sialic acid after fermentation may therefore be useful for preventing and improving muscle atrophy.

People on vegan diets are at risk of being deficient in varied nutrients such as vitamin B₁₂ and certain amino acids. In this study, we investigated vitamin B₁₂-producing lactic acid bacteria (LAB) as well as the probiotic and antioxidant properties. Lactiplantibacillus plantarum HY7720 was screened from 22 strains of LAB that were isolated from different plant foods, and its growth ability and extracellular vitamin B₁₂-producing capacity in vitamin B₁₂-deficient medium were investigated. To determine whether HY7720 functions as a probiotic, survival rate in the simulated gastrointestinal tract and adhesion property to human intestinal epithelial cells of HY7720 were compared with positive control, Lacticaseibacillus rhamnosus GG (LGG). Moreover, the results showed that HY7720 recovered the gene expression levels of tight junction-associated proteins (TJPs), including TJP1, TJP2, occludin (OCLN), and claudin-1 (CLDN1) and inhibited the secretion levels of pro-inflammatory cytokines, including interleukin (IL)-6 and IL-8, in tumor necrosis factor (TNF)-α-stimulated Caco-2 cells. Furthermore, we verified that HY7720 exhibit the antioxidant potential, by showing its intracellular reactive oxygen species (ROS) scavenging ability in hydrogen peroxide (H₂O₂)-stimulated Caco-2 cells. The ability of HY7720 to ameliorate H₂O₂-induced cytotoxicity in Caco-2 cells was inhibited by mitogen-activated protein kinase (MAPK) inhibitors, indicating that its antioxidant responses are related to extracellular signal-regulated kinase (ERK) and c-JUN N-terminal kinase (JNK). This study also investigated the nutritional qualities of three plant-based materials (brown rice, white rice, and soy milk) fermented using HY7720. Collectively, HY7720 could be used as a promising probiotic strain for the prevention of nutritional deficiencies among people on vegetarian diets.

Inflammatory bowel disease (IBD) involves chronic inflammation and disruption of the intestinal barrier, often accompanied by alterations in gut microbiota composition. This study examined the protective potential of a prebiotic mixture extract (PME) prepared from Vigna radiata (mung bean), Vigna angularis (red bean), and Foeniculum vulgare (fennel) using the HT-29 cell and colitis animal model. PME exhibited concentration-dependent antioxidant activity, with greater radical-scavenging capacity in the ABTS assay than in the DPPH assay. In LPS-stimulated HT-29 epithelial cells, PME reduced the mRNA expression of inflammation-associated genes (TNF-α, IL-1β, NF-κB) and upregulated tight junction markers (CLDN1 and OCLN), demonstrating its anti-inflammatory and supportive effects on the intestinal barrier. Vitexin, a C-glycosylated flavonoid, was detected in PME and is expected to mediate these protective effects. In a DSS-induced colitis mouse model, PME administration alleviated disease severity by increasing colon length, reducing serum levels of inflammatory cytokines and COX-2/PGE2, and restoring intestinal permeability. Furthermore, PME modulated the gut microbiota by enhancing beneficial bacteria such as Bifidobacterium and Faecalibaculum while suppressing inflammation-associated taxa, including Escherichia, Bacteroides, and Mucispirillum. These improvements collectively suggest that PME reinforces epithelial barrier integrity and promotes intestinal homeostasis through both anti-inflammatory and microbiota-regulating actions.