Investigators have developed a technology that has the potential to prevent a mother passing on HIV to her baby during breastfeeding. HIV transmission during breastfeeding can be prevented by a strain of probiotic, Lactobacillus, in the human mouth. Researchers from Lavax and the University of Illinois at Chicago have found a way of preserving this in hot climates without the need for refrigeration. The finding was presented to last week’s 86th General Session of the International Association of Dental Research.
It is possible for an HIV-positive mother to pass on HIV to her baby during pregnancy, delivery, and by breastfeeding. The risk of this happening can be dramatically reduced by the use of antiretroviral drugs during pregnancy and labour, and by the avoidance of breastfeeding. In countries like the UK, HIV-positive mothers are advised not to breastfeed. However, in resource-limited countries hardest hit by HIV, there are no safe alternatives to breastfeeding. This means that mothers have no option but to feed their infants using a method that could involve a risk of HIV transmission.
But researchers have discovered that Lactobacillus can bind itself to HIV’s outer envelope and has the potential to prevent HIV transmission because of breastfeeding. It is also being studied in a modified form as a vaginal microbicide. The probiotic Lactobacillus belongs to the same species as those found in dairy products, such as yoghurt.
Researchers believe that once an infant has been inoculated with this Lactobacillus, it will be protected against HIV transmission until it is weaned.
But the bacillus cannot survive for long in hot climates, and there is a lack of refrigeration in settings which would benefit most from this discovery – particularly southern Africa.
Investigators therefore tried to find a long-lasting formula of this Lactobacillus, capable of surviving in hot climates.
It is already known that the sugars, sucrose and trehalose, efficiently protect Lactobacillus at temperatures between four and 20 degrees C. But after four weeks at temperatures of 33 degrees or above, Lactobacillus cells protected by these sugars die.
Now investigators have identified a new alternative. This kept the Lactobacillus strain that binds to HIV alive for twelve weeks at 33 degrees, with laboratory tests showing that it was as effective as fresh Lactobacillus at covering HIV and therefore having the potential to prevent transmission of the virus during breastfeeding.
Reference
Chang R et al. An infant formula blocking HIV transmission via breastfeeding 86th General Session of the International Association for Dental Research, Toronto, Canada, 2008.