SickKids study looks at the impact of micronutrient supplementation on gut health in young children in a global context

Around the world, the growth of 149 million children under the age of five is stunted due to a lack of nutrition. Malnutrition, a state of poor nutrition caused by insufficient, excessive or imbalanced consumption of nutrients, can have devastating consequences on the health and development of children. 
 
To address the growing problem of global childhood malnutrition, new research led by The Hospital for Sick Children (SickKids) in collaboration with the Aga Khan University has studied how supplementing micronutrients – like vitamins, iron and zinc – can influence the communities of microbes in the gut of young children, which have an impact on malnutrition. The study was published in Nature Communications in November 2021.  

The effect of micronutrients on young children’s gut microbiome in Pakistan

Microbes are single-celled living organisms that can be found in our bodies, including the gut. They include bacteria, viruses or fungi and have the potential to help or hinder our well-being. Looking specifically at children in Pakistan, the new study demonstrated that micronutrients can influence microbes in the developing gut of young children with specific attention on protozoa, fungi and worms, which have typically been understudied. These microbes may colonize the guts of children and affect nutrition absorption and digestive function. 
 
“Through studies such as this, we are beginning to learn how global supplementation strategies can impact the microbial communities in our guts,” says Dr. John Parkinson, Senior Scientist in the Molecular Medicine program. “In particular, we highlight an important role of eukaryotic microbes – including protozoa, fungi and worms – that have often been neglected in studies of the human gut microbiome despite many being known to be pathogenic.” 
 
The research demonstrated that micronutrient supplements can impact the developing microbiome in a young child’s gut, however certain supplements may have different impacts on the gut microbiome. Vitamins and iron-based supplements may promote the growth of potentially disruptive protozoan and fungal microbes in the guts of children, most notably in rural communities where the exposure to such microbes is elevated. The addition of zinc in a micronutrient supplement plan appears to reduce this effect. As such, further consideration should be given to new micronutrient supplementation strategies.  
 
“This study makes us rethink how we prevent or treat micronutrient deficiencies in vulnerable populations that have a damaged gut caused by frequent exposure to harmful gut microbes,” says Dr. Robert Bandsma, Principal Investigator at the SickKids Centre for Global Child Health, Staff Physician in the Division of Gastroenterology, Hepatology and Nutrition and Scientist in the Translational Medicine program at SickKids.

Improved diagnostic tool integral to study’s findings

SickKids Centre for Global Child Health collaborated with the Aga Khan University in Pakistan, where researchers profiled the microbiome (the community of microbes in a specific environment) of stool samples collected from 80 children. The children, living in Pakistan, had previously been studied to assess the impact of micronutrient supplements on growth and morbidity, at 12 and 24 months of age. 
 
The study benefited from the application of an improved diagnostic tool previously developed by Ana Popovic, a Doctoral Candidate in the Parkinson Lab at SickKids. The diagnostic is capable of rapidly surveying and capturing a diverse range of microbes in the samples. 
  
“The improved method for microbiome profiling is based on the sequencing of the ribosomal RNA genes. We previously optimized it for protozoa and microscopic worms with new DNA probes designed to target better suited genetic regions,” says Popovic. “This allowed us to more fully characterize the gut microbiomes of these children, and to uncover some surprising differences.”

More research needed to optimize nutrition interventions for malnourished children

The findings of this research show a need for new studies to uncover how global supplementation plans impact microbes in children’s guts, and how these effects might depend on contexts such as health, diet and environment. It also highlights how personalized approaches to medicine – such as tailoring micronutrient supplements – can help uphold the well-being of children worldwide.  
 
“This data points out the need for continued research on optimizing nutrition interventions in children in low- and middle-income countries using emerging tools and technologies, and assessing patho-physiological processes,” says Dr. Zulfiqar A. Bhutta, Co-Director of SickKids Centre for Global Child Health.

This study was made possible through a multidisciplinary collaboration between the Parkinson Lab, Bandsma Lab, Bhutta Lab and Dr. Lisa Pell, Program Director and Senior Research Associate at the Centre for Global Child Health, in partnership with Aga Khan University.  
 
This work was funded by an HSBC Bank Canada Catalyst Research Grant from SickKids, Canadian Institutes of Health Research, Restracomp scholarship administered by the Research Training Centre at SickKids, and a graduate scholarship from the Government of Ontario. Computing resources were provided by the SciNet High Performance Computing Consortium.