Fecal total iron concentration is inversely associated with fecal Lactobacillus in preschool children

Background and Aim: Iron deficiency is associated with stunting and poor performance in children. Oral iron supplementation is widely promoted to correct iron deficiency. However, excess iron may be toxic to beneficial luminal gut bacteria and could support growth of pathobionts. The aim of this study is to analyze the fecal total iron concentration and fecal Lactobacillus levels in a cohort of stunted and normal children. Methods: The study was undertaken in two different locations. One of them is a rural area, and the other is a semi-urban-slum area; both areas are located in the Vellore district of Tamilnadu state. Twenty children (10 stunted and 10 normal growth) aged 2 to 5 years from each area were recruited. Both groups were nearly identical demographically. Fecal samples were collected. Fecal total iron was estimated, and fecal DNA was extracted and subjected to 16S rDNA-targeted real-time PCR to determine the relative predominance of Lactobacillus and Escherichia coli. Results: The fecal total iron concentration in rural children (3656 mu g/g wet wt. of feces) was significantly higher when compared with semi-urban-slum children (114.9 mu g/g wet wt. of feces, P < 0.005). Inversely, fecal Lactobacillus in rural children (median 3.18 x 10(-3) relative difference compared with total bacteria) was significantly lower when compared with semi-urban-slum children (median 59.33 x 10(-3), p < 0.005). There was no significant change observed between normal and stunted children. E. coli levels remained unaffected. Conclusion: The present study documents an inverse relationship between fecal iron concentration and fecal Lactobacillus concentration in children belonging to two different localities independent of their nutritional status.