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Study led by Afribiota investigators shows stunted growth in children is associated with gastrointestinal ‘de-compartmentalization’

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Stunting, the impaired growth and development of children, affects an estimated 155 million children per year. This represents roughly 25% of the world’s children and there exists a substantial lack of knowledge regarding the underlying causes and potential treatments. Current thinking on stunting hypothesizes that contributing factors such as inadequate psychosocial stimulation, poor nutrition, and recurrent infection are to blame. New research, however, is indicating that the microbial community of the small intestine, an organ essential for digestion and nutrient absorption, may be another contributing factor.

New data, published in PNAS by Afribiota investigators, including Microbiome Insights co-founder Dr. Brett Finlay, found that children suffering from stunting are affected by bacterial overgrowth in the small intestine and possess a microbial community made up from mainly oropharyngeal bacteria. Researchers studied duodenal and gastric samples of children with stunting, aged 2-5 years, in comparison with healthy children living in sub-Saharan Africa. Using 16S Illumina amplicon sequencing and semi-quantitative culturing methods they characterized the microbial communities of these children and found the small intestinal bacterial overgrowth in children with stunting.

The small intestines of children with stunting harboured bacterial species normally found in the oropharyngeal cavity. This overgrowth was also represented in fecal samples from the stunted children—which suggested a path toward developing non-invasive biomarkers for this condition. Furthermore, in stunted children Escherichia coli, Shigella species and Campylobacter species were more prevalent and Clostridia, well-known butyrate producers, were reduced.

These results indicate stunted children are experiencing a de-compartmentalization of the gastrointestinal tract, possibly a result of poor oral hygiene, recurrent or chronic rhino-pharyngeal infections, a hypo-chloric environment in the stomach (which weakens the natural barrier of stomach acidity), or other changes to the stomach environment which reduce its ability to kill unwanted bacteria. Importantly, these changes were seen in two geographically and nutritionally distinct populations, providing strong evidence that bacterial overgrowth is a conserved feature of the stunting condition itself.

The exact role of the oropharyngeal bacteria in intestinal inflammation, while yet to be determined, may provide vital information toward understanding the pathophysiology of stunting and potential new treatments.

Vonaesch P, Morien E, Andrianonimiadana L, et al. Stunted childhood growth is associated with decompartmentalization of the gastrointestinal tract and overgrowth of oropharyngeal taxa. Proc Natl Acad Sci U S A. 2018; 155: E8489-E8498.

Microbiome Insights co-founder Dr. Brett Finlay to speak at Institut Pasteur event

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Microbiome Insights co-founder and co-CSO Brett Finlay will be one of the distinguished speakers heading to Paris from October 15th to 16th 2018 for the Institut Pasteur meeting: Modeling the Mammalian Microbiota Host Superorganism, Current Tools and Challenges.

Knowledge about the role of microbiota and microbial metabolites in host functions and health has steadily increased over the past two decades. With mechanistic insights enabled by animal models and an increasing ability to characterize microbial communities during both development and adulthood, researchers are on the cusp of real therapeutic treatments. The Institut Pasteur meeting will bring together academic and industry leaders from this field to share new visions on host-microbiota mutualisms and parasitism, and to discuss the latest techniques and models. Along with Dr. Finlay, some exciting names on the program include Dr. Andrew Macpherson of Inselspital in Bern, Switzerland, giving the keynote address, and Marion Leclerc from the MICALIS Institute in Jouy-En-Josas, France and Philippe Sansonetti of Institut Pasteur.

Finlay will present his talk, entitled The Role of the Early Life Microbiota in Malnutrition and Environmental Enteropathy during the ‘Models of Pathogenesis’ session on Monday, October 15th. He has published over 500 papers and, as a principal investigator at the University of British Columbia he studies how microbes interact with hosts to influence health and disease. His lab developed the first animal model for the study of environmental enteropathy, a key feature of childhood malnutrition. Ongoing work with this model is now funded by the Gates Foundation in order to explore how it can better our understanding of the consequences of malnutrition. The Finlay lab also investigates the risks for childhood asthma stemming from microbiota and metabolic alterations during infancy, and were the first lab to demonstrate that early life intestinal microbiota plays a crucial role in asthma susceptibility.

By understanding how microbes colonize the small intestine and cause stunted growth and inflammation, Finlay and his collaborators hope to develop new nutritional therapies for human malnutrition. His lab’s work is essential for understanding the microbiota-host superorganism and the associations that are essential to maintain good health and development—making Finlay a “can’t miss” speaker at this prestigious meeting.