How Bacteria Is Tied To Stunted Growth In Malnourished Children

How Bacteria Is Tied To Stunted Growth In Malnourished ChildrenChildren in the Kutupalong refugee camp in Cox's Bazar, Bangladesh receive screening and treatment for malnutrition. (Credit: Maggie Moore/USAID/Flickr)

Malnutrition can lead to stunted growth. A new study of children in Bangladesh implicates 14 types of bacteria in the small intestine.

Many children who receive treatment for malnutrition in developing countries never fully recover. They can also experience immune system dysfunction and poor cognitive development that typically cause long-term health issues into adulthood.

The bacteria in question contribute to disease in the lining of the small intestine—a condition called environmental enteric dysfunction—which impairs the absorption of nutrients from food and suppresses growth factors necessary for healthy development.

The research, published in The New England Journal of Medicine, may help scientists design new therapies for malnourished children who remain stunted and underweight even after receiving therapeutic foods, researchers say.

In an editorial that accompanies the study, Ramnick J. Xavier, of Massachusetts General Hospital and the Broad Institute of MIT and Harvard, called the new research “reminiscent of the identification of Helicobacter pylori as a cause of ulcers.”

According to Xavier, the work ties a disease to a group of bacteria that colonizes a specific region of the gut and illustrates the benefits of integrating global health with basic mechanistic studies of the causes of disease.

Small intestine’s vital role

The gut microbiome has a symbiotic relationship with its human host. Evidence is emerging about its critical contributions during the early years of life to healthy growth and development. Much research involving the gut microbiome has focused on bacteria measured in fecal samples, which are not necessarily representative of the microbial communities living in different regions along the length of the gastrointestinal tract.

 Get The Latest From InnerSelf

For the new study, researchers focused on the upper small intestine—the region of the gut immediately following the stomach—because it is largely unstudied and because there were hints that it could play an important role in malnutrition.

“Much of the body’s nutrient absorption takes place in the small intestine,” says senior author Jeffrey I. Gordon, professor and director of the Edison Family Center for Genome Sciences & Systems Biology at the Washington University School of Medicine in St. Louis. “The small intestine is lined with finger-like projections called villi, which increase the absorptive surface area of the gut.

“In environmental enteric dysfunction, these villi are damaged and collapse, causing inflammation in the wall of the gut and reducing its ability to absorb nutrients. This disorder has been very difficult to diagnose, and its cause is enigmatic as is its relationship to the many manifestations of malnutrition, including short stature (stunting).

“Our study was designed to address these questions. The results have helped us to decipher disease mechanisms and also provide a rationale for developing new therapies that target the small intestinal microbiome.”

Stunting and malnutrition

For the new study, researchers began with a nutritional intervention for 525 malnourished children, who averaged 18 months of age and had stunted growth. They received a standard nutritional supplement that included milk, eggs, minerals, and vitamins.

The investigators received permission from the parents of each of the 110 children who did not show improvement with this treatment to perform an endoscopy on their child. The procedure allowed the researchers to obtain tissue biopsies and collect microbial samples from the children’s upper small intestines.

“In the past, it was hoped that providing more nutritious food and improved sanitation would be sufficient to overcome stunting,” says first author Robert Y. Chen, a doctoral student in Gordon’s lab. “But that approach hasn’t worked for many children.

“In this study, we were able to look more closely at molecules and microbes in the small intestine to understand in more detail what is happening in these children that makes their condition so resistant to nutritional interventions.”

The researchers focused on 80 of the 110 children for whom they also had blood samples and in whom they had found evidence of environmental enteric dysfunction via intestinal biopsies. They measured the abundances of thousands of proteins in blood samples and in the small intestinal biopsy samples.

The results revealed lower than normal levels of proteins involved in various aspects of growth, higher levels of proteins resulting from breakdown of the lining of the gut, and hyperactivation of the gut immune system. Samples of the microbial content of the same region of the small intestine revealed a group of 14 types of bacteria; the higher the levels of these organisms, the more severe the stunting. The researchers also linked the levels of these organisms to the levels of intestinal proteins involved with inflammation, which can damage the gut.

“This core group of 14 bacteria were present in 80% of the malnourished stunted children,” Chen says. “What is quite striking is that these bacteria were highly correlated with proteins that cause a pro-inflammatory state and with stunting. The inflammatory markers also could be measured in blood, which could help us identify these problems in children without doing an endoscopy.”

A ‘largely unexplored wilderness’

The researchers found that they could detect these 14 bacterial strains in fecal samples from these children and that their levels differed from those in the fecal samples of healthy children.

The researchers also noted that none of the 14 strains are typically viewed as disease-producing pathogens. Gordon and his colleagues couldn’t directly compare the bacterial samples from the upper small intestines of the malnourished children to those of healthy children in Bangladesh because it would not have been ethical to perform endoscopies on healthy children.

To establish whether the 14 bacterial strains in the upper small intestine play a causal role in environmental enteric dysfunction—and are not an effect of malnutrition, for example—the researchers studied germ-free mice fed a diet representative of the diets of the Bangladeshi children in the study.

The germ-free mice, born and raised under sterile conditions with no microbiomes of their own, were given a collection of microbes from the malnourished children—including the strains linked to stunted growth. They also fed control mice with normal mouse gut microbes the same diet. Those that received the gut microbes from the upper small intestines of the malnourished children developed disruption of the lining of the small intestine and inflammatory changes characteristic of environmental enteric dysfunction.

“Our study provides strong evidence that there is more to stunting than the conventional culprits that we traditionally blame for the problem—food scarcity, poor sanitation, or a contaminated water supply, for example,” says coauthor Michael J. Barratt, executive director of Washington University’s Center for Gut Microbiome and Nutrition Research.

Adds Gordon, “The small intestinal microbiota has been a largely unexplored wilderness’—a ‘terra incognita.’ These new findings provide evidence for the important contributions of the small intestine’s microbial community to the healthy growth of children, and how perturbations in its composition and function can result in malnutrition.

“Much more needs to be done, but our team’s findings, including the creation of an animal model that portrays important features of environmental enteric dysfunction in children, pave the way for new methods to diagnose this disease and new treatments that repair the gut microbial community. These treatments—whether therapeutic foods or probiotics, for example—would seek to reduce the levels and impact of these damaging bacteria in the small intestines of malnourished children.”

Tahmeed Ahmed of the International Centre for Diarrhoeal Disease Research in Dhaka, Bangladesh, collaborated on the study. The Bill & Melinda Gates Foundation funded the work.

Original Study

Related Books

The Human Swarm: How Our Societies Arise, Thrive, and Fall

by Mark W. Moffett
0465055680If a chimpanzee ventures into the territory of a different group, it will almost certainly be killed. But a New Yorker can fly to Los Angeles--or Borneo--with very little fear. Psychologists have done little to explain this: for years, they have held that our biology puts a hard upper limit--about 150 people--on the size of our social groups. But human societies are in fact vastly larger. How do we manage--by and large--to get along with each other? In this paradigm-shattering book, biologist Mark W. Moffett draws on findings in psychology, sociology and anthropology to explain the social adaptations that bind societies. He explores how the tension between identity and anonymity defines how societies develop, function, and fail. Surpassing Guns, Germs, and Steel and Sapiens, The Human Swarm reveals how mankind created sprawling civilizations of unrivaled complexity--and what it will take to sustain them.   Available On Amazon

Environment: The Science Behind the Stories

by Jay H. Withgott, Matthew Laposata
0134204883Environment: The Science behind the Stories is a best seller for the introductory environmental science course known for its student-friendly narrative style, its integration of real stories and case studies, and its presentation of the latest science and research. The 6th Edition features new opportunities to help students see connections between integrated case studies and the science in each chapter, and provides them with opportunities to apply the scientific process to environmental concerns. Available On Amazon

Feasible Planet: A guide to more sustainable living

by Ken Kroes
0995847045Are you concerned about the state of our planet and hope that governments and corporations will find a sustainable way for us to live? If you do not think about it too hard, that may work, but will it? Left on their own, with drivers of popularity and profits, I am not too convinced that it will. The missing part of this equation is you and me. Individuals who believe that corporations and governments can do better. Individuals who believe that through action, we can buy a bit more time to develop and implement solutions to our critical issues. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you,, and at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.



follow InnerSelf on


 Get The Latest By Email



The Day Of Reckoning Has Come For The GOP
by Robert Jennings,
The Republican party is no longer a pro-America political party. It is an illegitimate pseudo-political party full of radicals and reactionaries whose stated goal is to disrupt, destabilize, and…
Why Donald Trump Could Be History's Biggest Loser
by Robert Jennings,
Updated July 2, 20020 - This whole coronavirus pandemic is costing a fortune, maybe 2 or 3 or 4 fortunes, all of unknown size. Oh yeah, and, hundreds of thousands, maybe a million, of people will die…
Blue-Eyes vs Brown Eyes: How Racism is Taught
by Marie T. Russell, InnerSelf
In this 1992 Oprah Show episode, award-winning anti-racism activist and educator Jane Elliott taught the audience a tough lesson about racism by demonstrating just how easy it is to learn prejudice.
A Change Is Gonna Come...
by Marie T. Russell, InnerSelf
(May 30, 2020) As I watch the news on the events in Philadephia and other cities in the country, my heart aches for what is transpiring. I know that this is part of the greater change that is taking…
A Song Can Uplift the Heart and Soul
by Marie T. Russell, InnerSelf
I have several ways that I use to clear the darkness from my mind when I find it has crept in. One is gardening, or spending time in nature. The other is silence. Another way is reading. And one that…