NEW YORK (Reuters Health) - Colonizing an infant’s digestive tract with mannose-binding Lactobacillus may protect them from HIV present in breast milk, according to a presentation at the American Society for Microbiology general meeting in New Orleans.
Because maternal treatment before delivery prevents vertical transmission, breastfeeding now represents the major source of infant infections in Africa, causing approximately 800,000 new infections annually, Dr. Lin Tao told Reuters Health.
Because conventional prophylaxis with antiretrovirals, microbicides, or vaccines cannot be used in infants, “we sought to block HIV transmission from mother to child using a more innovative approach,” added Dr. Tao, of the University Illinois at Chicago College of Dentistry. Lactobacillus, a common commensal in the GI tract and the vagina of adults, seemed to be such an option.
The researchers obtained saliva samples from more than 100 healthy volunteers, from which they isolated 170 Lactobacillus strains. Nine were capable of binding to mannose in Saccharomyces cerevisiae, which was used as a surrogate for HIV.
The strain with the highest affinity for the yeast, L. fermentum OLB-19a, also binds to HIV glycoproteins and to T and B lymphocytes and dendritic cells, the investigators found. The bacteria prevented immune cell infection by HIV.
Because “the stomach and intestine is where active absorption of milk takes place, it will be very important to have the bacteria in the oral cavity and throughout the intestinal tract,” Dr. Tao explained. To that end, his group is attempting to develop lyophilized Lactobacillus that can be administered to infants.
Their current research was funded by the National Institutes of Health, the researcher noted. The group’s challenge now is to find a sponsor to fund the next steps in developing a product. Because the intent is to distribute the Lactobacillus preparation in underdeveloped countries, it is unlikely that a pharmaceutical company will be interested in investing in a product unlikely to earn a profit, Dr. Tao said.
But if this approach works, freeze-dried Lactobacillus has the potential to prevent half a million infections annually, he added.
MeSH Headings:Environment and Public Health: Health: Health Occupations: Medicine: Population Characteristics: Preventive Medicine: Public Health: Specialties, Medical: Disease Transmission, Vertical: Disease Transmission: Biological Sciences: Health CareCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
