Common beans and cowpeas as complementary foods to reduce environmental enteric dysfunction and stunting in Malawian children: study protocol for two randomized controlled trials

Abstract

BackgroundInterventions to decrease the burden of childhood malnutrition are urgently needed, as millions of children die annually owing to undernutrition and hundreds of millions more are left cognitively and physically stunted. Environmental enteric dysfunction (EED), a pervasive chronic subclinical inflammatory condition among children that develops when complementary foods are introduced, places them at high risk of stunting, malabsorption, and poor oral vaccine efficacy. Improved interventions to reduce the burden of EED and stunting are expected to markedly improve the nutritional status and survival of children throughout resource-limited settings.Methods/DesignWe will conduct, in parallel, two prospective randomized controlled clinical trials to determine whether common beans or cowpeas improve growth, ameliorate EED, and alter the intestinal microbiome during a high-risk period in the lives of rural Malawian children. Study 1 will enroll children at 6 months of age and randomize them to receive common beans, cowpeas, or a standard complementary food for 6 months. Anthropometry will be compared among the three groups; EED will be assessed using a dual-sugar absorption test and by quantifying human intestinal mRNA for inflammatory messages; and the intestinal microbiota will be characterized by deep sequencing of fecal DNA, to enumerate host microbial populations and their metabolic capacity. Study 2 will enroll children 12–23 months old and follow them for 12 months, with similar interventions and assessments as Study 1.DiscussionBy amalgamating the power of rigorous clinical trials and advanced biological analysis, we aim to elucidate the potential of two grain legumes to reduce stunting and EED in a high-risk population. Legumes have potential as an affordable and effective complementary food intervention, given their cultural acceptability, nutritional content, and agricultural feasibility in sub-Saharan Africa.Trial registrationClinicaltrials.gov NCT02472262 and NCT02472301.

Micronutrient Adequacy and Dietary Diversity Exert Positive and Distinct Effects on Linear Growth in Urban Zambian Infants

“…We 347 could not investigate here whether the effect of dietary diversity on growth is mediated by the 348 gut microbiota, thus the exploration of the inter-relationships among infants' diet, the gut 349 microbiome and growth in several ongoing trials in Malawi (57) and Zimbabwe (44) is 350 timely. The beneficial effect of increased dietary diversity may also have implications in more 351 18 advantaged settings.…”

Cowpea: an overview on its nutritional facts and health benefits

“…An average cowpea grain contains 23–32% protein, 50–60% carbohydrate and about 1% fat in dry basis. The total protein content of cowpea is approximately two‐ to four‐fold greater than cereal and tuber crops . Moreover, compared to cereal grains, cowpea protein is a rich source of the amino acid lysine and is used as a natural complimentary food with cereals .…”

“…Epidemiological evidence indicates that the consumption of cowpea exerts protective effects against the development of several chronic diseases, such as gastrointestinal disorders, cardiovascular diseases, hypercholesterolemia, obesity, diabetes and several types of cancer . In addition, the literature also reports on functional ingredients in cowpea that aid in weight loss, improve digestion and strengthen blood circulation . All of these beneficial effects exerted by cowpea are attributed to the presence of phytochemicals, resistant starch, dietary fiber and a low‐fat content, along with beneficial unsaturated fatty acids.…”

Efficacy of aqueous and oil formulations of a specific Metarhizium anisopliae isolate against Aphis craccivora Koch, 1854 (Hemiptera: Aphididae) under field conditions

“…Cowpea is well adapted in the tropics because it tolerates dry weather conditions and does well even in poor soils (Bisikwa et al, ; Ddamulira, Santos, Obuo, Alanyo, & Lwanga, ; Mucheru‐Muna et al, ). Cowpea leaves are rich in proteins, carbohydrates, minerals and vitamins and have medicinal attributes (Hall, ; Trehan et al, ).…”