Study: Breast Feeding No Better Than Bottle Feeding For Kids’ Health

[pnwmom]

39. Link please? I've searched for anything backing up your theory, and haven't found it.

You said: "And the baby's digestive tract breaks down mom's antibodies after about 3 months. " According to the source below, "like many other host resistance factors in human milk, Lysozyme is relatively resistant to proteolysis and to denaturation resulting from the high acidity within the stomach."

http://books.nap.edu/openbook.php?record_id=1577&page=134

Many of the whey proteins in human milk have direct protective effects against infection. Lactoferrin, one of the dominant whey proteins in human milk throughout lactation (Table 6-5) (Butte et al., 1984a; Goldman et al., 1982, 1983a,b), inhibits the multiplication of siderophilic (iron-absorbing) bacteria by competing with these microorganisims for ferric iron (Bullen et al., 1978; Stephens et al., 1980).

SNIP

Lysozyme is a protein in human milk that affords protection in two different ways: it breaks down susceptible bacteria by cleaving peptidoglycans from their cell walls (Chipman and Sharon, 1969), and it acts in concert with other components in human milk to kill microbial pathogens. High concentrations of this protein are found in human milk throughout lactation (Butte et al., 1984b; Goldman et al., 1982, 1983a,b), whereas concentrations in cow's milk are very much lower. Like many other host resistance factors in human milk, lysozyme is relatively resistant to proteolysis and to denaturation resulting from the high acidity within the stomach.

http://pediatrics.aappublications.org/content/119/5/941.full

The protection conferred by breastfeeding was related to the levels of IgA class enterovirus antibodies in breast milk, which seemed to be more important than transplacentally acquired antibodies. This is logical, because the primary replication of enteroviruses occurs in gut mucosa, where breast milk antibodies can directly neutralize the virus in the intestine and prevent its subsequent spread to the circulation. The protective effect was related to exclusive breastfeeding rather than total breastfeeding, suggesting that there may be a dose-effect related to the greater amount of breast milk ingested by exclusively breastfed infants. In addition, protection correlated with enterovirus IgA levels, supporting true biological effect rather than the influence of potential confounding factors, like family size or socioeconomic status.

http://adc.bmj.com/content/78/3/235.full

We have shown that mothers maintain a steady output of IgA throughout the first year of lactation, that there is a difference in the concentration of IgA secreted by each breast, and there is a variation throughout the year according to season. The seasonal changes are due more to fluctuations in milk IgA concentrations than the weights of milk ingested. These findings confirm and extend those of other studies of lactating mothers in both the developing and developed world,4-6 and underline the potential value of prolonged breast feeding in infancy. Human milk has been shown to confer protection against several enteric and respiratory infections,2 8 and in circumstances of poor hygiene and high risk of infection it is likely to be of significant importance to the suckling infant.

IgA acts at the mucosal surface of the gastrointestinal tract to protect against potentially harmful microbial and food antigens. Although the infants continued to ingest a constant amount of IgA each day, the amount relative to body weight decreased. The length of the small intestine increases by 56% during the first year of postnatal life, in parallel with an increase in body weight of 55% and length of 50%.9 IgA survives passage through the gastrointestinal tract10 and its detection in the faeces of breast fed infants throughout the first year suggests that the amounts ingested remain sufficient to provide mucosal protection in spite of the increasing surface area of the gastrointestinal tract.