Potential prophylactic value of bovine colostrum in necrotizing enterocolitis in neonates: an in vitro study on bacterial attachment, antibody levels and cytokine production.

Necrotizing enterocolitis (NEC) is an important disease of low birth-weight neonates. The immaturity of the gut mucosa may result in close contact between the host epithelium and microorganisms which are normally confined to the gut lumen. Damage of the mucosa due to endotoxin, cytokine production or other factors is believed to then occur. The aim of this study was to determine whether spray-dried bovine colostrum demonstrated potential in vitro as a prophylactic for NEC. Antiadherence was measured using a tissue culture assay and antibody levels against Enterobacteriaceae were determined by ELISA. The effect of bovine colostrum on the production of cytokines implicated in NEC was determined by a multiplex bead assay. Enterobacter cloacae, Klebsiella oxytoca, Escherichia coli, Serratia marcescens and Klebsiella pneumoniae ssp. pneumoniae were common in both NEC positive and NEC negative infants and IgA and IgG1 antibodies to these species were present in the bovine colostrum. Pretreatment with bovine colostrum produced a significant decrease (P<0.001) in attachment of bacteria to HT-29 cells. Bovine colostrum significantly increased the production of IL-8 in HT-29 cells and IL-8, IL-6 and TNF-alpha in THP-1 cells (P<0.001). The potential of bovine colostrum to increase the production of inflammatory mediators could limit its usefulness.

Murine antigen-presenting cells are multifunctional in vitro biosensors for detecting the immunoactive potential of bovine milk products.

Antigen-presenting cells (APCs) are multifunctional components of the immune defense system. In this study, murine APCs were used as biosensors to detect immunologically active components of bovine milk and colostrum. By measuring changes in cell surface protein markers [major histocompatibility complex II, cluster designation (CD)40, CD86] and cytokines (tumor necrosis factor-alpha and interleukin-10) associated with APC activation, we identified a number of compounds that are immunoactive. The mouse macrophage cell line MH-S offered a simple and robust target for identification of immunoactives. The assay was shown to be adaptable for measuring immunoenhancing or immunosuppressive substances. Large-scale screening of milk extracts using this bioassay has the potential to identify substances that could be developed into nutraceuticals or pharmaceutical-grade immunotherapeutics.