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Randomized Controlled Trial
. 2013 Aug;163(2):416-23.
doi: 10.1016/j.jpeds.2013.01.024. Epub 2013 Feb 26.

Effects of different complementary feeding regimens on iron status and enteric microbiota in breastfed infants

Nancy F Krebs  1 , Laurie G Sherlock, Jamie Westcott, Diana Culbertson, K Michael Hambidge, Leah M Feazel, Charles E Robertson, Daniel N Frank
Affiliations
Randomized Controlled Trial

Effects of different complementary feeding regimens on iron status and enteric microbiota in breastfed infants

Nancy F Krebs et al. J Pediatr. 2013 Aug.

Abstract

Objective: To compare iron status in breastfed infants randomized to groups receiving complementary feeding regimens that provided iron from fortified infant cereals or meats, and to examine the development of the enteric microbiota in these groups.

Study design: Forty-five exclusively breastfed 5-month-old infants were randomized to 1 of 3 feeding groups (FGs)-commercially available pureed meats, iron- and zinc-fortified infant cereals, or iron-only fortified infant cereals-as the first and primary complementary food through 9-10 months of age. Dietary iron was determined by monthly 3-day diet records. Iron status was assessed at the end of the study by measurements of hemoglobin, serum ferritin, and soluble transferrin receptor levels. In a subsample of 14 infants, enteric microbiota were profiled in monthly stool samples (5-9 months) by 16S ribosomal RNA gene pyrosequencing.

Results: Infants in the 2 cereal FGs had 2- to 3-fold greater daily iron intakes versus the meat FG (P < .0001). More than one-quarter (27%) of the infants had a low serum ferritin level, and 36% were mildly anemic, with no significant differences by FG; more infants in the meat FG had a high soluble transferrin receptor value (P = .03). Sequence analysis identified differences by time and FG in the abundances of several bacterial groups, including significantly more abundant butyrate-producing Clostridium group XIVa in the meat FG (P = .01) CONCLUSION: A high percentage of healthy infants who were breastfed-only were iron-deficient, and complementary feeding, including iron exposure, influenced the development of the enteric microbiota. If these findings are confirmed, then reconsideration of strategies to both meet infants' iron requirements and optimize the developing microbiome may be warranted.

Keywords: FG; Feeding group; Ribosomal RNA; Soluble transferrin receptor; TDI; Total dietary iron; rRNA; sTfR.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 2
Figure 2
Longitudinal iron intakes (mg/day) by group. TDI for cereal groups significantly higher than meat group at each time point. P= 0.01, 0.002, 0.0003, and 0.0001 at 6, 7, 8, and 9 months, respectively.
Figure 4
Figure 4
Longitudinal variation in abundances of bacterial phyla in infant fecal specimens.
Figure 5
Figure 5
Age-dependent changes in relative abundances of select phyla/sub-phyla between treatment groups. X-axis: three feeding groups. Y-axis: differences in percent abundances of bacterial groups from 5 to 9 months of age (%9mo - %5mo). Statistical significance was tested by ANOVA and adjusted for the potentially confounding variable for total dietary iron (TDI). Overall P-values are indicated in upper left corners of each boxplot, and P-values less than 0.1 are noted by asterisks. The analysis of all phylum/sub-phylum categories is presented in Figure 6, online.
See this image and copyright information in PMC

References

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