Malnutrition passes down generations through gut microbiome in mouse study
Key takeaways
- A study suggests that malnutrition can be passed across generations from mother to offspring via inflammatory gut microbes.
- Harmful gut bacteria damage the intestinal lining and permanently disrupt how a child absorbs nutrients, even if they eat a healthy diet later in life.
- The findings indicate that targeting and manipulating small intestine microbes prior to or during pregnancy may break the intergenerational cycle of malnutrition.
Research has found that malnutrition and stunted growth may be passed down generations through the gut microbiome. The mouse study showed that inflammatory microbes in mothers affected the fetal growth and then the intestinal health of the babies.
The study analyzed malnourished mice using cultured bacteria from stunted children. The researchers did so by identifying the specific bacteria that cause an inflammatory chemical signal for malnutrition. These characteristics damage the intestinal lining and thereby impair nutrient absorption, they explain.
“The gut microbes in the small intestine make up a largely unexplored ecosystem — a ‘terra incognita’ — because they are difficult to sample. However, this study demonstrates how this ecosystem is important to the healthy growth and development of children,” says the study’s senior author, Jeffrey Gordon, M.D., the Dr. Robert J. Glaser Distinguished University professor at WashU Medicine, Washington, US.
Gordon is also the director at WashU Medicine’s Edison Family Center for Genome Sciences & Systems Biology.
Passing down through generations
The study, published in Nature Microbiology, suggests that blocking or mitigating the transmission of inflammatory bacterial strains from mother to fetus could be used to prevent environmental enteric dysfunction (EED) disorders — chronic inflammation, villus blunting, and decreased nutrient absorption.
EED is an inflammatory condition for children globally suffering from malnutrition and stunted growth. It damages the lining of the small intestine and thereby disrupts how nutrients are absorbed from the diet.
EED is an inflammatory condition for children globally suffering from malnutrition and stunted growth.The researchers say that the children suffering from EED also have poor immunity, cognitive development, and growth. These issues then “follow them for life” even if eating a healthy diet later on.
“The study raises the question of whether manipulating the microbes in the small intestine either prior to or during pregnancy could help foster normal pre- and postnatal growth of their offspring,” says Gordon.
“We are hopeful that this research could help us identify ways to break the vicious cycle of intergenerational malnutrition.”
The authors previously collaborated with the International Centre for Diarrhoeal Disease Research in Bangladesh, analyzing samples from 525 malnourished children. The children were on average 18 months old and were given standard therapeutic food, including eggs, milk, vitamins, and minerals.
The children that did not show signs of improvement with an increased nutritious diet underwent an endoscopy procedure — sampling the tissue lining the gut and bacteria in the upper small intestine — and identified 14 bacteria linked to inflammation and stunting.
Dividing groups
In the new study, mice were fed a diet resembling foods that are commonly eaten in the Mirpur district of Dhaka, Bangladesh, the same district where the prior clinical trial was conducted.
The mice were divided into two different groups. The first group was born under sterile conditions and did not have any gut bacteria. They were colonized with curated collections of small intestine bacteria cultured from the malnourished children. These human gut bacteria induced inflammation in the nonpregnant female mice’s intestines.
The second mouse group was given bacteria from the children without inflammation and was treated as the control group.
The scientists did not collect samples from the healthy children’s small intestines, as they stressed that performing endoscopies on healthy children is unethical.
The results revealed that inflammatory bacteria could be passed from mother to offspring, and that the harm may begin in utero and before the child’s own bacteria are present. The mouse pups that received the inflammatory bacteria developed similar problems to those suffering from malnutrition.
The study authors say they will continue their research to understand the far-reaching effects and complexity of the small intestinal gut microbiome.
