Restoring healthy intestinal bacteria could help hungry children

Feeding severely malnourished infants with a diet high in bananas, chickpeas and peanuts can stimulate healthy intestinal bacteria and help children grow, according to two studies published July 12 in Science (1, 2).

According to the World Health Organization (WHO), about 150 million children suffer from malnutrition worldwide. And often these hungry children do not heal even after eating enough. Years later, the brains of poor children remain underdeveloped and are also more susceptible to disease.

Composed of billions of different species of bacteria, the microbiome is increasingly recognized as an important indicator of health and disease, which seems reasonable given the fact that bacteria account for more than 50% of total cells of the human body. In addition, intestinal bacteria have been badociated with allergies, obesity, neurodegenerative diseases such as Parkinson's disease, depression and other common diseases affecting humans.

For example, the researchers, led by Professor Jeffrey Gordon of the University of Washington in collaboration with Tahmeed Ahmed, Director of Nutrition Research at the International Center for Diarrheal Disease Research in Dhaka, Bangladesh, undertook to determine the cause of this low growth in the number of severely malnourished children. take a closer look at their intestinal bacteria. Knowing the role that the microbiome plays in obesity, Gordon and Ahmed wondered if he could play a similar role in malnutrition.

In 2014, they published an article showing that the microbiome of an infant normally evolves as children grow older. However, this is not the case for severely malnourished children, in which the bowel remains dominated by the bacteria found in young, healthy children.

Another subsequent study on mice has shown that a "mature" microbiome may be needed for proper growth and development, as mice with younger children's microbiomes develop fewer muscles and develop Bones and also seem to have an impaired metabolism.

So, this time, the team has identified 15 different types of bacteria that increase or decrease as the microbiome matures in healthy infants from Bangladesh, Peru, and India. We then examined which foods could promote or suppress certain intestinal bacteria.

Most research was done on animals, but one of them tested the different diets of 60 children in Bangladesh over a period of one month. Although the study period was too short to allow long-term physical recovery, they were able to detect molecular changes in the blood badociated with the microbiome.

Interestingly, they discovered that a diet consisting of bananas, soy, peanut flour and chickpeas promotes the formation of microbes related to bone growth, brain development and function immune. But it turns out that milk powder and rice – two typical ingredients of food aid – do not promote the formation of a mature microbiome. And a diet dominated by rice or lentils can even damage the gut, in some cases.

So, what are the next steps? The authors still do not know why some foods are better than others. And researchers are also recognizing the diversity of microbiomes around the world. This means that the same diet may not be suitable for children from Africa or South America, for example. A larger trial is underway to examine the long-term effects – over 3 months – of some diets.

The results highlight the importance of choosing the right nutrients to feed the intestinal microbiome of infants. And while this is not necessarily a panacea, the results are intriguing and could help improve the nutrition of undernourished and well-nourished children – a poor diet during childhood increases the risk of obesity and overweight. diabetes and can cause health problems throughout life.

(1) Gehrig, J.L. et al. Effects of targeted foods on the microbiota in gnotobiotic animals and undernourished children. Science (2019). DOI: 10.1126 / science.aau4732

(2) Raman, A.S. et al. Sparse covarying unit describing the healthy and altered development of the gut microbiota in humans Science (2019). DOI: 10.1126 / science.aau4735