CHILDREN in many countries are struggling to get the vitamins they need from their nutrient-poor diets. But what if bacteria could allow them to make their own?
Vitamin A deficiency affects about 250 million children worldwide. Around half a million of them go blind every year, and half of those that do die within 12 months. “It’s a serious public health issue,” says Loredana Quadro at Rutgers University in New Brunswick, New Jersey.
One attempt to tackle the problem is to genetically engineer crops such as Golden Rice, which contain high levels of compounds that the body can convert into vitamin A. But crops are susceptible to weather and can fail, says Quadro, who wants to use microbes to free us from depending on food sources.
Some bacteria produce beta-carotene, the pigment that gives carrots their orange colour. It is also a precursor chemical that our bodies use to make vitamin A. Quadro and her colleagues took the bacterial DNA that codes for this chemical and inserted it into a different strain – one that colonises mouse intestines.
After two weeks living in the guts of lab mice, the bacteria had made themselves at home and were making beta-carotene that could be detected in the gut, bloodstream and liver.
This is the first time engineered bacteria have been used to make beneficial compounds inside a living animal, says Quadro, who presented the findings at the Probiota 2015 conference in Amsterdam, the Netherlands, this week.
But her goal, a one-off probiotic treatment for children at risk of vitamin A deficiency, is still some way off. For a start, such a treatment will have to pass safety tests, and it must persist in the guts of children who may be prone to bouts of diarrhoea, says Alfred Sommer at Johns Hopkins University in Baltimore, Maryland.
This article appeared in print under the headline “Gut bugs could save children from blindness”
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