Environmental Enteric Dysfunction and the Fecal Microbiota in Malawian Children

Abstract

Environmental enteric dysfunction (EED) is often measured with a dual sugar absorption test and implicated as a causative factor in childhood stunting. Disturbances in the gut microbiota are hypothesized to be a mechanism by which EED is exacerbated, although this supposition lacks support. We performed 16S ribosomal RNA gene sequencing of fecal samples from 81 rural Malawian children with varying degrees of EED to determine which bacterial taxa were associated with EED. At the phyla level, Proteobacteria abundance is reduced with severe EED. Among bacterial genera, Megasphaera, Mitsuokella, and Sutterella were higher in EED and Succinivibrio, Klebsiella, and Clostridium_XI were lower in EED. Bacterial diversity did not vary with the extent of EED. Though EED is a condition that is typically believed to affect the proximal small bowel, and our focus was on stool, our data do suggest that there are intraluminal microbial differences that reflect, or plausibly lead to, EED.

Conflict of interest statement

Phillip I. Tarr is on the Scientific Advisory Board of MediBeacon, and is the coinventor of a novel technology to measure gut permeability.

© The American Society of Tropical Medicine and Hygiene.

Figures

Figure 1.

Circos plot and table showing associations between six genera abundance (% of total bacteria) and each category of lactulose:mannitol (L:M). The circus plot is a circular representation of the association of the different genera labeled A–G and the environmental enteric dysfunction (EED) status (no EED, moderate EED, and severe EED), labeled H–J. The inner circle shows the percentage of genera abundance multiplied by 1,000, the outer circle the relative abundance of the genera among the six genera. The lines indicate the association of each genera with the EED status: no EED is blue, moderate EED is purple, and severe EED is pink.

Figure 2.

Microbial community variation represented by principal coordinates plot (PCoA, genus-level Brady–Curtis dissimilarity). There are no significant differences in the community structures of children based on their environmental enteric dysfunction (EED) status (P > 0.05).