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Microbiome Certain types of bacteria can help prevent malnutrition in children
About one quarter of children worldwide are malnourished. As a result, they are more susceptible to disease and unable to develop healthily. Malnutrition is one of the leading causes of child mortality. One study now showed that certain types of bacteria could help fight the problem.
Every year, millions of children die from malnutrition
Child malnutrition claims millions of deaths every year. According to the World Health Organization (WHO), it is one of the leading causes of child mortality worldwide. In addition, they prevent healthy development and make them more susceptible to diseases. Long-term consequences of malnutrition can be, for example, cardiovascular diseases and metabolic disorders such as diabetes mellitus. According to the WHO, in 2011 about 165 million children were not age-appropriate in terms of body growth. An international study showed that underweight and too small children carry other types of bacteria in the intestine than normally developed peers.
Picture: fotoliaxrender - fotolia Inadequate diet with serious consequences
According to a news agency dpa, administering certain bacterial species to mice has been shown to prevent the consequences of malnutrition, such as limited growth or low weight. However, the team of scientists led by Laura Blanton of Washington University, St. Louis, Missouri, pointed out that it is still unclear how an inadequate diet will cause the grave consequences. In addition to limited growth, this included metabolic disorders and mental impairment. The researchers now publish their findings in the journal "Science".
More calories alone are not enough
Several years ago, scientists from this university reported that more calories in malnutrition are not enough to combat malnutrition and the associated underweight in the long term. For the current study, the researchers first studied stool samples of children from Malawi, to examine whether the microbiome of the intestine - ie the community of the bacteria living there - has something to do with the identified deficiencies. In it, they identified the bacterial species and based on this, created a model from which it can be seen which types of bacteria belong to a healthy microbiome at which age. They then showed to a group of Malawi infants that the microbiome of malnourished children appears to be underdeveloped. According to the information, it was more like the younger children.
Insufficient for a healthy development
In the next step, the researchers took stool samples from 19 healthy and malnourished children aged six and 18 months, and transferred the samples to two groups of five-week-old mice that had grown germ-free by then. The animals were given a diet that is typical of many children in Malawi and inadequate for healthy development. After just four to five weeks, there was a clear difference. Thus, mice given intestinal bacteria to malnourished children had significantly less weight and lean mass than mice given the bacteria of healthy children. In addition, her metabolism and her bone structure were abnormally changed.
"Growth needs satisfied at different ages"
When the scientists brought the animals of both groups together a few days after such stool transplants, these differences did not occur. Because the rodents also eat feces, they apparently had exchanged the beneficial bacteria with each other. As the researchers showed in further experiments, only two types of bacteria - Ruminococcus gnavus and Clostridium symbiosum - can trigger the growth brake. "Our results show that the development of the microbiome in healthy children is optimized to meet the different growth needs at different ages," the study authors said. Now further investigations would have to clarify whether supplemented therapeutically an age-appropriate microbiome can be built up in malnourished children and this could stop the consequences of malnutrition.
Metabolism in organs normalized
Also with significant involvement of the Washington University team researchers describe in another study similar experiments. They examined the influence of certain sugars in breast milk on the microbiome of mice and piglets. First, they found that the milk of mothers of healthy babies contains significantly more sialic acid-containing sugars than mothers of malnourished babies. When they administered these special sugars to mice or piglets with a gut microbiota of malnourished children, the animals grew better. As the scientists in the journal "Cell" reported, the animals not only put on lean mass, but also the metabolism in the liver, muscles and brain normalized.
Influence of intestinal bacteria on our health
Eventually, they identified those bacteria responsible for these effects, and discovered a veritable food web in the gut. It turned out that some types of bacteria digested the sialic acid-containing sugars, while others lived off the resulting metabolic products. "This ability to accurately analyze how food is distributed among members of the microbial community and how its metabolic performance can affect human biology is part of our ongoing research program," study leader Jeffrey Gordon said in a statement from his university. It is conceivable to one day optimize infant formula or therapeutic foods for the treatment of malnutrition with sialic acid-containing sugars. The influence of intestinal bacteria on health has often been the focus of scientific research in the past. Recently, US researchers reported in the journal Nature that Western eating habits reduce valuable intestinal bacteria. Accordingly, the diversity and number of intestinal bacteria in low-fiber diets are decreasing from generation to generation. (Ad)