Bovine lactoferrin (BLF), as an important iron-binding glycoprotein in mammalian milk, has a broad application prospect in the fields of food, medicine and nutraceuticals. This article briefly introduces the structural characteristics of BLF, and systematically summarizes its various biological functions including antibacterial, immunomodulatory, antioxidant, antiviral, antitumor and its mechanism of action. Meanwhile, it reviews the techniques currently used to extract BLF with special reference to their advantages and disadvantages. Finally, the current research hotspots and prospects of BLF are analyzed. This review provides a theoretical reference for the in-depth understanding of the biological properties of BLF and for its industrial development, thereby advancing its application in functional foods and foods for special medical purposes

Considering that vitamin deficiency is prevalent in children, the objective of this study was to evaluate the effects of hawthorn and malt as well as their combination with dietary fibers (polydextrose and xylooligosaccharide) on intestinal function in weaned mice deficient in VB₁, VB₂, VB₆ and VA. The results showed that the intestinal motility of vitamin-deficient mice was significantly promoted by high-dose hawthorn + malt alone and in combination with dietary fibers. Vitamin deficiency significantly reduced body mass gain, food intake and feed utilization in rats by 34.29%, 17.78% and 19.24% (P < 0.05), respectively, the ratio of villus height to crypt depth in jejunum and ileum by 37.30% and 36.79% (P < 0.05), and the contents of acetic acid and total short chain fatty acids (SCFA) in feces by 37.63% and 43.87% (P < 0.05), respectively, compared with the normal group. Food intake and body mass gain in vitamin-deficient rats were significantly increased by 7.84% and 14.77% in the high-dose hawthorn + malt group compared with the vitamin deficiency model group (P < 0.05), respectively. Feed utilization rate in the low-dose hawthorn + malt + dietary fiber group was significantly increased by 11.58%. The ratio of jejunal villus height and crypt depth in the high-dose hawthorn + malt and low-dose hawthorn + malt + dietary fiber groups increased significantly by 52.65% and 47.35% (P < 0.05), respectively. The contents of fecal acetic acid and total SCFAs increased by 46.86% and 78.00% in the high-dose hawthorn + malt group (P < 0.05), and by 43.74% and 44.91% in the low-dose hawthorn + malt + dietary fiber group (P < 0.05), respectively. High-dose hawthorn + malt + dietary fiber treatment led to excessive growth of Parabacteroides in the intestinal tract, thus reducing the diversity and balance of the intestinal flora. High-dose hawthorn + malt treatment could regulate the composition of the intestinal flora and increase the abundance of Lactobacillus and Akkermansia in vitamin-deficient rats. In conclusion, high-dose hawthorn + malt treatment can improve the intestinal flora of rats to some extent, and its effect is similar to that of low-dose hawthorn + malt + dietary fibers. Both of them can promote the growth of bacteria producing SCFA, increasing the intestinal content of SCFAs, improve intestinal morphology, and enhance intestinal absorption function in vitamin-deficient rats, thereby promoting the growth and development of vitamin-deficient rats. These results provide a scientific basis for the development of functional foods.

Salmonella grows better under aerobic conditions as a facultative anaerobic foodborne pathogenic bacteria. The oxygen-scavenging activity of Lactococcus lactis in the intestinal tract is a promising strategy for preventing Salmonella infection. In this study, the aerobic respiration requirement and preventive mechanism of L. lactis subsp. lactis KLDS 4.0325 in murine models infected by Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) SL1344 were investigated. Results indicate that L. lactis KLDS 4.0325 is capable of aerobic respiratory metabolism in the host intestine when exogenous heme exists, and decrease intestinal oxygen concentration, which in turn trigger autophagy of intestinal cells to reduce S. Typhimurium load, improve gut microbiota composition, alleviate intestinal barrier injury and inflammation response. These results suggest that aerobic respiration L. lactis KLDS 4.0325 can prevent S. Typhimurium infection in a new way in which by restoring intestinal cell hypoxia, maintaining immune balance and regulating intestinal flora.

Type 2 diabetes mellitus (T2DM), a chronic metabolic disease caused by an imbalance between carbohydrate intake and metabolism, is one of the most difficult metabolic diseases to treat worldwide. The main symptoms of T2DM include hyperglycemia, insufficient insulin secretion, insulin resistance, polydipsia and polyuria. T2DM is often accompanied by many complications such as atherosclerosis, renal function injury and non-alcoholic fatty liver disease. Glucagon-like peptide-1 (GLP-1) is a polypeptide composed of 31 amino acids, which is mainly used to maintain glucose homeostasis in vivo and relieve T2DM. However, its half-life is short and it is easily degraded in vivo. This article introduces probiotics and their metabolites that regulate GLP-1 in the host, and also discusses the alleviative effect of GLP-1 on T2DM, including the association between GLP-1 and T2DM, the clinical application of metformin and GLP-1 agonists, the insufficiency of GLP-1 in alleviating T2DM and the regulation of the GLP-1 content by related prebiotics. Finally, the regulatory mechanisms of probiotics and their metabolites on GLP-1, including short-chain fatty acids, bile acids (BAs), tryptophan and its derivatives and extracellular polysaccharides, are summarized in order to provide some references for studies on the regulatory effects of probiotics and their metabolites on GLP-1 production and release in the host as well as their alleviative effects on T2DM.