UCSD immunology researchers, working with contributors from around the United States and Zambia, published a study Aug. 15 that sheds further light on the advantages of breast-feeding.

The study, published in the American Journal of Clinical Nutrition, found a compound active in breast milk that protects against HIV spreading from mother to infant. It was found that a higher concentration of the compound in breast milk correlates with lower rates of transmission.

The compound — human milk oligosaccharide (HMO) — is a carbohydrate that, once ingested, resides in the infant’s intestinal tract. HMO is thought to help culture important bacteria in the intestine, and it has also shown anti-inflammatory properties that may bolster immune response.

The group initiated the study to determine why only 10 to 15 percent of infants feeding from infected mothers were contracting the virus.

“In developing countries, HIV-infected mothers are faced with the decision of whether or not to breast-feed their babies,” Laura Bode, assistant professor in UCSD’s Department of Pediatrics, said. “Breast-feeding exposes the baby to the virus and increases the risk of the baby dying from the HIV infection, but not breast-feeding increases the risk for the baby to die from other intestinal or respiratory infections.”

In a longitudinal study, researchers collected 200 samples of breast milk from HIV-infected mothers throughout Lusaka, the capital city of Zambia, and then followed the women and children for 24 months.

  The researchers concluded that further research into HMO might be effective in an effort to develop a better defense against HIV contraction.