SRI International has received a US$ 1 lakh Grand Challenges Explorations grant from the Bill & Melinda Gates Foundation as a support to an innovative global health research project, titled "Vitamin A-Secreting Probiotics to Activate Mucosal Immunity." The study is conducted by Douglas Watson, protein biochemist in SRI's Center for Advanced Drug Research (CADRE).

Watson's project is one of 78 grants announced by the Gates Foundation in the fourth funding round of Grand Challenges Explorations, an initiative to help scientists around the world explore bold and largely unproven ways to improve health in developing countries. The grants were provided to scientists in 18 countries on six continents.

To receive funding, Watson showed in a two-page application how his idea falls outside current scientific paradigms and might lead to significant advances in global health. The initiative is highly competitive, receiving almost 2,700 proposals in this round.

Through metabolic engineering, SRI researchers are developing therapies to address diarrhoeal diseases, which lead annually to as many as 5 million childhood deaths. In areas such as sub-Saharan Africa and Southeast Asia, severe vitamin A deficiency contributes to poor gut mucosal immunity, which increases susceptibility to acute and chronic diarrhoea. Vitamin A supplementation can reduce childhood mortality by 30 percent; however, studies have shown that fewer than 60 percent of children in affected areas receive the recommended dose.

To facilitate delivery of vitamin A to children who may not otherwise receive enough of it, SRI researchers will plan to engineer a probiotic bacterium that produces vitamin A for direct delivery to mucosal immune cells in the gastrointestinal tract. If successful, this therapy could restore protective mucosal immunity while simultaneously combating other consequences of vitamin A deficiency, including blindness and susceptibility to measles and malaria. The new therapy, which should reduce the duration of symptoms while also reducing the impact of future infections, could be developed for distribution during clinic visits for the treatment of diarrhoea.

"Creative new approaches are urgently needed to combat many global health issues, including deadly diarrhoeal diseases," said Krishna Kodukula, executive director of SRI's Center for Advanced Drug Research. "We are hopeful that our idea to use metabolically engineered probiotics will lead to a treatment that will also restore the body's immunity and combat the consequences of vitamin A deficiency. Approaches such as these may also be useful for the development of new remedies against other diarrheal diseases."

"The winners of these grants show the bold thinking we need to tackle some of the world's greatest health challenges," said Dr Tachi Yamada, president of the Gates Foundation's Global Health Program. "I'm excited about their ideas and look forward to seeing some of these exploratory projects turn into life-saving breakthroughs."

Silicon Valley-based SRI International is one of the world's leading independent research and technology development organizations.