Bovine colostrum applications in sick and healthy people: A systematic review 

This comprehensive review published in 2021 evaluated evidence relating to the clinical use of exogenous supplemental bovine colostrum in human health. 24 full text studies were selected and reviewed regarding intestinal and respiratory recovery. The mechanism of action seemed to suggest bovine colostrum modulates the immune response and may increase sIgA.  

References:

Guberti, M., Botti, S., Capuzzo, M. T., Nardozi, S., Fusco, A., Cera, A., Dugo, L., Piredda, M., & De Marinis, M. G. (2021). Bovine Colostrum Applications in Sick and Healthy People: A Systematic Review. Nutrients, 13(7), 2194. https://doi.org/10.3390/nu13072194