Gut microbes hold the key to undernourishment

Malawian children playing in the village of Talia, Mangochi region. Photo: Ulla Ashorn

Malawian children playing in the village of Talia, Mangochi region. Photo: Ulla Ashorn

Professor Per Ashorn. Photo: Teemu Launis

Professor Per Ashorn. Photo: Teemu Launis

Gut microbes may yet provide an answer to the health problems encountered by undernourished children. Researchers at the University of Tampere are participating in a study directed by Washington University on the association between gut microbes and health. An article reporting the research results was published in the journal Science Translational Medicine on 25 February 2015.

“The results are important because this is one of the first studies where an association between a person’s microbiota and health is documented in children in a poor country, and, in particular, the first study that highlights the mechanisms of this association. The study is a good basis for developing efficient interventions,” says Per Ashorn, professor of international health at the University of Tampere, who participated in the study.

The research results will enable the development of more effective treatments for undernourishment by using healthy microbes in addition to a healthy diet.

“The basic idea is that undernourishment and many other health problems are caused by gene environment interaction. In this case, a child’s nutrition and gut microbes are important. The composition of human intestinal microbiota develops during the child’s first two years, and this development may potentially be directed in a desired direction. This could eventually aid healthy growth and development,” Ashorn says.

The research, which is funded by the Bill & Melinda Gates Foundation, investigated faecal samples from children in Malawi and mapped out the mechanisms through which the gut microbes affect the children’s immune system and health.

Researchers have long since established that a lack of food is not the only reason for undernourishment in children; infections and intestinal problems preventing food absorption also play a role. Earlier research conducted at Washington University in 2013 showed that a malfunction of the gut microbiota is one cause of children’s undernourishment.

The recently published study looks at the interaction between microbes and the body’s defence mechanisms.

Immunoglobulin A (IgA) is a part of this defence mechanism, especially in the gut. IgA is an antibody that is secreted in large quantities in the gastrointestinal tract. It neutralises bacteria and makes them less dangerous. IgA also helps to separate gut microbiota from the rest of the body and allows the peaceful coexistence of microbial and human cells.

The results show that IgA’s interactions with the gut microbes correlate with the development of undernourishment. Undernourished children had more IgA surrounding their E. coli bacteria than healthy children.

The main parts of the study were conducted at Washington University in St Louis, Missouri. The University of Tampere and the University of Malawi contributed by designing the research setting, collecting the biological samples and the clinical data from Malawian children, and by participating in the interpretation and publication of the research results.

Kau AL, Planer JD, Liu J, Rao S, Yatsunenko T, Trehan I, Manary MJ, Liu T-C, Stappenbeck TS, Maleta KM, Ashorn P, Dewey KG, Houpt ER, Hsief C-S, Gordon JI. Functional characterization of IgA-targeted bacterial taxa from malnourished Malawian children that produce diet-dependent enteropathy. Science Translat Med, in press.

For more information, please contact:

Per Ashorn, professor of international health, + 358 40 7280 354