Aflatoxin Exposure, Child Stunting, and Dysbiosis in the Intestinal Microbiome among Children in Guatemala

Recent literature suggests that intestinal microbiome may play a mediating role between aflatoxin exposure and the height-for-age of children. We tested the hypothesis that among children in Guatemala, aflatoxin exposure was associated with intestinal microbiome dysbiosis and lower height-for-age. De-identified data were acquired from local health officials for 35 children who attended a health clinic in Totonicapán, Guatemala, and had potentially been exposed to aflatoxin through their maize-based food supply. Microbial differences were assessed for children grouped by height, diarrhea, age, and aflatoxin exposure. Furthermore, two subgroups were identified - one healthy (n = 12) and one unhealthy/dysbiotic (n = 9) - based upon clustering of the children's microbiomes and morbidity data. Odds ratios were computed to assess the likelihood of a child having a healthy or dysbiotic microbiome based on the classification of height, diarrhea, age, or aflatoxin exposure. The results of the study supported significant differences in beta diversity between the intestinal microbiomes of children who were shorter (less than or equal to -2.54 standard deviation; SD) versus taller (greater than -2.54 SD), those who were older (>14 months of age) versus younger (<14 months of age), and those that had reported diarrhea in the past 2 weeks versus not. Most importantly, children whose aflatoxin-contaminated diet resulted in the consumption of >10 ng of aflatoxin/kg of body weight/day had 24 times higher odds of having a dysbiotic intestinal microbiome. The results build upon available literature and support the need for more in-depth studies concerning the interactions among aflatoxin exposure, the intestinal microbiome, and child stunting.