Impact of acute undernutrition on growth, ileal morphology and nutrient transport in a murine model.

I.C Sampaio,P.A Cavalcante,A.A.M Lima,P.H.Q.S Medeiros,S.R Moore,A.M Soares,S.G.C Fonseca,F.A.P Rodrigues,G.A.C Brito,S.A Ribeiro,A Havt,J.S Oliveira,M.M.G Prata,D.V.S Costa,M.M Guedes

doi:10.1590/1414-431x20165340

Abstract

Undernutrition represents a major public health challenge for middle- and low-income countries. This study aimed to evaluate whether a multideficient Northeast Brazil regional basic diet (RBD) induces acute morphological and functional changes in the ileum of mice. Swiss mice (∼25 g) were allocated into two groups: i) control mice were fed a standard diet and II) undernourished mice were fed the RBD. After 7 days, mice were killed and the ileum collected for evaluation of electrophysiological parameters (Ussing chambers), transcription (RT-qPCR) and protein expression (western blotting) of intestinal transporters and tight junctions. Body weight gain was significantly decreased in the undernourished group, which also showed decreased crypt depth but no alterations in villus height. Electrophysiology measurements showed a reduced basal short circuit current (I sc) in the undernourished group, with no differences in transepithelial resistance. Specific substrate-evoked I sc related to affinity and efficacy (glutamine and alanyl-glutamine) were not different between groups, except for the maximum I sc (efficacy) induced by glucose. Transcription of Sglt1 and Pept1 was significantly higher in the undernourished group, while SN-2 transcription was decreased. No changes were found in transcription of CAT-1 and CFTR, while claudin-2 and occludin transcriptions were significantly increased in the undernourished group. Despite mRNA changes, SGLT-1, PEPT-1, claudin-2 and occludin protein expression showed no difference between groups. These results demonstrate early effects of the RBD on mice, which include reduced body weight and crypt depth in the absence of significant alterations to villus morphology, intestinal transporters and tight junction expression.

Highlights

Undernutrition is defined as a physiological outcome of illness and/or hunger, which subclassifies as wasting, stunting, underweight and micronutrient deficiencies
The regional basic diet (RBD) is an experimental rodent diet based on the nutritional intake of the northeastern Brazilian population and is characterized by a deficit of protein, fat and minerals, which trigger some clinical symptoms of kwashiorkor and stunting, commonly reported in this population [8,9]
Impact of RBD diet for 7 days on body weight RBD feeding triggered a significant decrease in body weight gain when compared to the nourished group during the short period of 7 days (Po0.001)

Summary

Introduction

Undernutrition is defined as a physiological outcome of illness and/or hunger, which subclassifies as wasting (an acute state), stunting (a chronic state), underweight (mixed acute and/or chronic states) and micronutrient deficiencies. This condition has a great impact on global public health, especially in middle- and low-income countries [1,2], and is the cause of 3.1 million child deaths annually. Further evaluation of childhood undernutrition-associated consequences has worrisome social implications, such as impaired school performance [4], increased economic costs [5], impaired immunity [6] and a significantly higher number of deaths due to infectious diseases [7]. The RBD promotes deleterious effects in the small intestine with altered villous height and crypt depth, reduced transmucosal resistance, increased permeability and enhanced epithelial apoptosis [12]

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