About 165 million children under the age of 5 are short for their age or suffering from stunted growth. Stunting is associated an increased risk of death before the age of 5, cognitive disability, and reduced physical and economic capacity. Children of women who were stunted in childhood are usually affected by stunting as well. The pattern creates an intergenerational cycle of illness and poverty. More than 90 percent of stunted children live in Africa and Asia. In Bangladesh, 36 percent of children under 5 are stunted.
Malnutrition and environmental enteropathy are possible factors contributing to stunted growth. A person with enteropathy has a gut that is so inflamed that it does absorb nutrients effectively. The condition is believed to be caused by frequent intestinal infections, but the definite origins are unknown.
An excessive number of bacteria in the small intestine, also known as small intestinal bacterial overgrowth (SIBO), has also been suggested as a possible cause. Like stunting, SIBO is common among developing world children.
A team of researchers, including pediatric infectious disease specialist Jeff Donowitz, examined the idea further by observing 103 2-year-old children from the Mirpur slum of Dhaka, Bangladesh. The children were followed from birth and received vaccinations, medical care, and nutritional counseling and care. Yet, despite these measures, cases of stunting increased among the participants from 9.5 percent at birth to 27.6 percent at 1-years old.
One in six children also showed signs of SIBO, as revealed by a hydrogen breath test. The odds of developing SIBO were increased by an open drain or sewer outside a child’s household. The risk of developing SIBO was also increased by a mother cutting her fingernails less than once a month and the source of a household’s drinking water being somewhere other than the municipal water supply.
The researchers ultimately found that children with SIBO had significantly worse stunting than the children without SIBO. Thus, stunting in the developing world could be caused by poor sanitation and intestinal inflammation.
"One of the things we are working on now is to see when small intestine bacterial overgrowth occurs as children grow up in urban slums and understand its contribution," Donowitz said. "We suspect that SIBO at an early age leads to malnourishment." The researchers hope the research will lead to an effective solution to prevent and treat malnourishment.
The research was published by the American Society for Microbiology in the open access journal mBio on January 12, 2016.
Sources: “Small Intestine Bacterial Overgrowth and Environmental Enteropathy in Bangladeshi Children” in mBio, University of Virginia Health System press release via EurekAlert!, Digestive Health Centre via WebMD