Human Colostrum and Breast Milk

Source: SAGE journals

This study proved traces of TRAIL ( known anti-cancer agent) in human breast milk

" To our knowledge, this is the first time that TRAIL has

been measured in colostrum and human breast milk. This

study has revealed much higher TRAIL concentrations in

colostrum and breast milk compared to the levels of circulating

serum TRAIL. Although previous studies have

shown that breast cells express TRAIL,

 it was unexpected

that the mean level of soluble TRAIL detected in colostrum

reached 48.6 ng/mL, approximately 2-fold higher than the level

previously reported in the conjunctival sac fluid

approximately 40-fold greater than the level measured in

human saliva,

and > 400-fold greater than the level found

in human serum. Although we observed a significant

decline in levels of TRAIL in human breast milk measured

at day 4 or 5, these concentrations were still much higher

than those usually found in human serum/plasma and were

in the range of concentrations that are able to kill cancer

cells.

 Conversely, TRAIL was not detected in ready-tofeed

infant formulas.

It is well known that human milk is more than simple

food for infants, representing a complex biological liquid

containing many immunoactive agents. In the context of

our study, the important role of breastfeeding in the prevention

of certain childhood cancers, such as lymphoblastic

leukemia, Hodgkin’s disease, and neuroblastoma, has been

previously demonstrated,

and the presence in human milk

of substances with antitumor activity, such as human alphalactalbumin

made lethal to tumor cells (HAMLET), has

been reported.

However, in consideration of the strong

anticancer activity of TRAIL, which is currently used as a

recombinant protein in many clinical trials against a variety

of human cancers,

endogenous soluble TRAIL represents

a strong candidate to explain the overall biological effect of

breastfeeding against cancer. In this respect, it has recently

been shown that certain

Lactobacillus strains induce

TRAIL production and facilitate natural killer activity

against cancer cells.

Thus, our hypothesis is that high concentrations of soluble

TRAIL present in human colostrum and breast milk

might play a key role in mediating the anticancer activity of

human milk."

Abstract
Background:

TNF-related apoptosis inducing ligand (TRAIL) is a pleiotropic cytokine, which plays a key role in the immune

system as well as in controlling the balance of apoptosis and proliferation in various organs and tissues.

Objective:

To investigate the presence and levels of soluble TRAIL in human colostrum and milk.

Methods:

The levels of soluble human TRAIL were measured in human colostrum (day 2 after delivery) and breast milk (day

5 after delivery). The presence of TRAIL was also measured in infant formula.

Results:

Levels of soluble TRAIL in the colostrum and mature human milk were, respectively, at least 400 and 100 fold higher

than those detected in human serum. No TRAIL was detected in formula.

Conclusion:

Human soluble TRAIL is present at extremely high levels in human colostrum and human milk and might have

a significant role in mediating the anti-cancer activity of human milk.