Pubmed - Bovine colostrum contains immunoglobulin G antibodies against intimin, EspA, and EspB and inhibits hemolytic activity mediated by the type three secretion system of attaching and effacing Escherichia coli

Instituto de Patobiología, Instituto Nacional de Tecnología Agropecuaria, Buenos Aires, Argentina.

Abstract

Enterohemorrhagic Escherichia coli (EHEC) is the main cause of hemolytic-uremic syndrome, an endemic disease in Argentina which had an incidence in 2005 of 13.9 cases per 100,000 children younger than 5 years old. 

Cattle appear to be a major reservoir of EHEC, and a serological response to EHEC antigens has been demonstrated in natural and experimental infections. In the current study, antibodies against proteins implicated in EHEC's ability to form attaching and effacing lesions, some of which are exported to the host cell via a type three secretion system (TTSS), were identified in bovinecolostrum by Western blot analysis. Twenty-seven (77.0%) of the 35 samples examined contained immunoglobulin G (IgG) antibodies against the three proteins assayed in this study: EspA, EspB, and the carboxy-terminal 280 amino acids of gamma-intimin, an intimin subtype associated mainly with O157:H7 and O145:H- serotypes. 

Every colostrum sample was able to inhibit, in a range between 45.9 and 96.7%, the TTSS-mediated hemolytic activity of attaching and effacing E. coli. The inhibitory effect was partially mediated by IgG and lactoferrin. In conclusion, we found that early colostrum from cows contains antibodies, lactoferrin, and other unidentified substances that impair TTSS function in attaching and effacing E. coli strains. 

Bovine colostrum might act by reducing EHEC colonization in newborn calves and could be used as a prophylactic measure to protect non-breast-fed children against EHEC infection in an area of endemicity.

http://www.ncbi.nlm.nih.gov/pubmed/18562563

Pubmed - Bovine colostrum supplementation and exercise performance: potential mechanisms

School of Human Life Sciences, University of Tasmania, Launceston, Tasmania, Australia. Cecilia.Shing@utas.edu.au

Abstract

Bovine colostrum (BC) is rich in immune, growth and antimicrobial factors, which promote tissue growth and the development of the digestive tract and immune function in neonatal calves. Although the value of BC to human adults is not well understood, supplementation with BC is becoming increasingly popular in trained athletes to promote exercise performance. 

The combined presence of insulin-like growth factors (IGF), transforming growth factors, immunoglobulins, cytokines, lactoferrin and lysozyme, in addition to hormones such as growth hormone, gonadotrophin-releasing hormone, luteinizing hormone-releasing hormone and glucocorticoids, would suggest that BC might improve immune function, gastrointestinal integrity and the neuroendocrine system, parameters that may be compromised as a result of intensive training. 

A review of studies investigating the influence of BC supplementation on exercise performance suggests that BC supplementation is most effective during periods of high-intensity training and recovery from high-intensity training, possibly as a result of increased plasma IGF-1, improved intramuscular buffering capacity, increases in lean body mass and increases in salivary IgA. 

However, there are contradicting data for most parameters that have been considered to date, suggesting that small improvements across a range of parameters might contribute to improved performance and recovery, although this cannot be concluded with certainty because the various doses and length of supplementation with BC in different studies prevent direct comparison of results. Future research on the influence of BC on sports performance will only be of value if the dose and length of supplementation of a well-defined BC product is standardized across studies, and the bioavailability of the active constituents in BC is determined.

http://www.ncbi.nlm.nih.gov/pubmed/19902984