The contribution of environmental enteropathy to the global problem of micronutrient deficiency

Abstract

Sometimes referred to as hidden hunger, micronutrient deficiencies persist on a global scale. For some micronutrients this appears to be due to inadequate intake, for others intake may not match increased requirements. However, for most micronutrient deficiencies there is uncertainty as to the dominant driver, and the question about the contribution of malabsorption is open. Environmental enteropathy (EE), formerly referred to as tropical enteropathy and also referred to as environmental enteric dysfunction, is an asymptomatic disorder of small intestinal structure and function which is very highly prevalent in many disadvantaged populations. Recent studies of the pathology and microbiology of this disorder suggest that it is driven by very high pathogen burdens in children and adults living in insanitary environments and is characterised by major derangements of the epithelial cells of the intestinal mucosa. Transcriptomic data suggest that it may lead to impaired digestion and absorption of macronutrients. Given the very high prevalence of EE, marginal malabsorption could have large impacts at population scales. However, the relative contributions of inadequate soil and crop micronutrient contents, inadequate intake, malabsorption and increased requirements are unknown. Malabsorption may compromise attempts to improve micronutrient status, but with the exception of zinc there is currently little evidence to confirm that malabsorption contributes to micronutrient deficiency. Much further research is required to understand the role of malabsorption in hidden hunger, especially in very disadvantaged populations where these deficiencies are most prevalent.

Global acute malnutrition is associated with geography, season and malaria incidence in the conflict-affected regions of Ouham and Ouham Pendé prefectures, Central African Republic

“…Characterised by blunted microvilli and in ammation in the small intestine, altered gut permeability and microbiota, environmental enteropathy leads to reduced absorptive capacity for drugs and nutrients, and micronutrient de ciencies and is thought to be a causal factor in malnutrition and stunting [49,50].…”

Micronutrient malnutrition across the life course, sarcopenia and frailty

“…Although good quality diets are important for growth in children and health in adults, of all ages, many societal and economic issues mean this is not achieved. That micronutrient deficiencies affect about one third of the world's population, persisting despite economic growth such as in South Asia, and are prevalent in high income countries, is a huge concern (1,(8)(9)(10)(11) . Around 45% of deaths among children under 5 years of age are linked to undernutrition, mostly occurring in low-and middle-income countries.…”

“…Professor Paul Kelly, gave his Keynote Lecture from Lusaka, and continued to address the issue of Hidden Hunger, suggesting that one cause may be the condition of environmental enteropathy that leads to malabsorption of nutrients (10) . Environmental enteropathy, previously known as tropical enteropathy, also referred to as environmental enteric dysfunction, is an asymptomatic disorder of small intestinal structure and function.…”

“…This is likely caused by the very high pathogenic burden in children and adults living in insanitary environments. New research using transcriptomic techniques suggests that damage to the epithelial cells of the gut mucosa has effects on nutrient transporters and enzymes responsible for nutrient absorption, so leading to impaired digestion and absorption nutrients including zinc (10) .…”

“…The majority of micronutrient deficiencies do not exist alone with individuals frequently subject to one or more deficiencies; even in the UK 48% of those over 50 years of age have at least one micronutrient deficiency (21) . Given the physiological interactions between these nutrients greater understanding of the multiple micronutrient deficiencies is needed, as are the interactions between obesity, medications and the environment (10) . Although much of our understanding of the physiological mechanisms of micronutrients for maintaining health was elicited some time ago, the newer research for vitamin E and magnesium presented, indicates there remains more to learn (15,16) .…”