The Gut Microbiome in Child Malnutrition

Undernutrition affects almost 25% of all children under the age of 5 worldwide and underlies almost half of all child deaths. Child undernutrition is also associated with long-term growth deficits, in addition to reduced cognitive potential, reduced economic potential, and elevated chronic disease risk in later life. Dietary interventions alone are insufficient to comprehensively reduce the burden of child undernutrition and fail to address the persistent infectious burden of the disease. Although the role of infections is well recognized in the pathogenesis of undernutrition, an emerging body of evidence suggests that commensal microbial communities, known as the microbiome, also play an important role. The gut microbiome regulates energy harvesting from nutrients, growth hormone signaling, colonization resistance, and immune tolerance against pathogens, amongst other pathways critically associated with healthy child growth. Hence, disturbance of the normal gut microbial ecosystem via undernourished diets or unhygienic environments, especially in the early phases of life, may perturb these critical pathways associated with child growth, thereby contributing to child undernutrition. Here we discuss the emerging evidence for the role of the gut microbiome in child undernutrition and the potential for novel gut microbiota-targeted treatments to restore healthy child growth.