Glutamate mother liquor bioconversion slurry enhances antioxidant performance in mice by modifying gut microbiota and ascorbic acid metabolism
The global breeding industry currently faces a critical shortage of protein supplies. Glutamate mother liquor bioconversion slurry (GMLBS), a high amino acid protein slurry, is a proteinal soybean meal alternative. However, the safety and commercial value of GMLBS as a novel protein feed require validation. This study aimed to assess the safety of GMLBS and investigate its effects on the health of mice when replacing various proportions of soybean meal in their diet, along with the underlying regulatory mechanisms. The study began by monitoring the behavior and growth of mice after administering different ratios of GMLBS. Different GMLBS ratios replaced soybean meal in the diet, where growth performance and nutrient digestibility were observed. Our findings confirm the safety of GMLBS, showing no adverse effects. Although GMLBS did not markedly enhance the weight of mice, it increased the activities of enzymes like catalase, superoxide dismutase, and glutathione peroxidase, along with levels of immunoglobulin A, G, and M. It also reduced the malondialdehyde content and concentrations of pro-inflammatory cytokines like interleukin-6, tumor necrosis factor-a, and interleukin-1 b. GMLBS increased the relative abundance of Saccharomyces and Wickerhamomyces while reducing Staphylococcus. Meanwhile, it affects the ascorbate and aldarate metabolism pathways. GMLBS effectively enhances the health of mice, particularly when it replaces 60% of soybean meal in the basal diet. These results demonstrate the viability and benefits of GMLBS as a novel protein feed, offering a potential solution to monosodium glutamate wastewater pollution and the global shortage of protein resources.