Bioactive peptides derived from animal sources have attracted growing interest in functional food and pharmaceutical research due to their diverse physiological activities and high bioavailability. Loach (Misgurnus anguillicaudatus), a protein-rich freshwater fish with low fat content, has emerged as a promising source of bioactive peptides. Recent studies have found that loach peptides have many biological effects, such as anti-oxidation, anti-fatigue, anti-bacteria, immunomodulation, anti-cancer, anti-hypertension, and anti-osteoporosis activities. In this review, the preparation, separation, purification and characterization of loach peptides were summarized. The recent progress of biological functions of loach peptides was also discussed. At present, the research of loach peptide is still in the initial stage, the relationship between the structures and functions of loach peptides, the molecular mechanisms of the function of loach peptides are needed to be further studied. In addition, this review addresses the challenges associated with the application of loach peptides and summarizes recent advances in their deep-processing and high-value utilization, aiming to provide a reference for future studies and to facilitate the continued development and broader application of loach peptides.

Dietary parboiled rice (PR) has a low risk of disease, but little is known about the contribution of PR to the prevention of hyperlipidemia. The potential role and underlying mechanisms of PR in hyperlipidemia were evaluated in this study. Male C57BL/6J mice were fed with a normal diet, high-fat diet (HFD) containing refined rice (HFDRR) or PR (HFDPR). It was found that PR intervention improved lipid accumulation in mice. Transcriptomic data analysis revealed that 27 genes were up-regulated (mostly involved in lipid breakdown) and 86 genes were down-regulated (mostly involved in inflammatory responses) in the HFDPR group compared to the HFDRR group. And 15 differentially expressed genes (DEGs) were validated by quantitative real-time PCR (RT-qPCR), while protein interaction network showed that protein tyrosine phosphatase receptor type C (PTPRC) has a central role. The gut microbiota of mice was also altered after different dietary treatments, with higher ratio of Firmicutes and Bacteroidetes, increased abundances of Ruminococcaceae, Lachnospiraceae, Christensenellaceae, Porphyromonadaceae, Rikenellaceae and Prevotellaceae, and decreased abundances of Lactobacillaceae, Peptostreptococcaceae, Erysipelotrichaceae and Actinobacteria in the HFDRR group. In addition, it was observed that PPAR signaling pathway may act as a bridge between DEGs and differential gut microbiota. These results suggested that PR can prevent hyperlipidemia by modulating liver genes and gut microbiota.