A substance in human breast milk seems to reduce the risk of mother-to-child transmission of H.I.V., scientists have reported.
Researchers working in Zambia collected breast milk samples from 81 H.I.V.-positive women who transmitted the virus to their infants during breast-feeding, 86 H.I.V.-positive women who did not transmit, and 36 uninfected women. The scientists analyzed the samples for concentrations of a carbohydrate called human milk oligosaccharides. There is growing evidence that the substance contains immunologically active components that may minimize the risk of viral transmission.
The study, published online Aug. 15 in The American Journal of Clinical Nutrition, found that women whose breast milk held concentrations of human milk oligosaccharides above the median were less than half as likely to have transmitted the infection to their babies as those with concentrations below the median.
In resource-poor countries, the risk of H.I.V. transmission from breast milk is outweighed by its various benefits, so infected women are encouraged to breast-feed while taking antiretroviral drugs.
"People talk about proteins and lipids that are important in human milk, but oligosaccharides are something people don't appreciate as much," said Lars Bode, the lead author of the study and an assistant professor of pediatrics at the University of California, San Diego.
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