Bovine milk with variant β-casein types on immunological mediated intestinal changes and gut health of mice

• Published in: Frontiers in nutrition (Lausanne) 2022-09, Vol.9, p.970685-970685
• Main Authors: Liu, Bin, Qiao, Weicang, Zhang, Minghui, Liu, Yanpin, Zhao, Junying, Chen, Lijun
• Format: Article
• Language: English
• Subjects: gut microbiome; immune factors; inflammation; morphology; Nutrition; SCFAs; β-casein
• ISSN: 2296-861X; 2296-861X
• DOI: 10.3389/fnut.2022.970685

Dietary proteins provide bioactive peptides, which are important for host gastrointestinal functions. We hypothesized that A2-type β-casein could provide gastrointestinal benefits and improve the immune and gut health. This study was conducted to investigate those effects and mechanisms. Thirty BALB-c mice (3–4 weeks old) were fed with either a control diet (control), a diet supplemented with bovine milk containing A1 and A2 type β-casein (A1A2, contains 63.62% A2 β-casein of total β-casein) or a diet containing A2 type β-casein (A2A2, contains 95.96% A2 β-casein of total β-casein) (10 ml/kg body weight) for 4 weeks. Immunoglobulin and inflammation factors were measured in serum, and histological variations were measured in duodenal and ileum, and stool 16S rRNA and short-chain fatty acids (SCFAs) contents were measured in fecal samples. Results showed that consumption of A2-type β-casein milk could improve proximal small intestine villus and crypt morphology ( p < 0.05), increase IgG and IgE responses, and modulate the composition and diversity of gut microbiota by increase the relative abundance of phylum Proteobacteria, class Clostridia , family Ruminococcaceae and species Lactobacillus animalis ( p < 0.05). There were also significant associations between gut microbes, immune response, and SCFAs, especially isobutyric acid ( p < 0.05), which may potentially regulated gastrointestinal benefits. Moreover, intake of A2-type β-casein milk had no impact on inflammation. These findings explained potential benefits of consumption of A2-type β-casein milk on host immune system and gut health outcomes, and provide insights to the future application of nutritional modulation.