Effect of iron on the ability of enteric bacteria to induce cell damage.

<p>LDH-release (mean+SD) as a measure of cell damage of Caco-2 cells upon co-incubation with <i>S. typhimurium</i> (St, <i>n</i> = 5), <i>C. freundii</i> (Cf, <i>n</i> = 4), <i>E. coli</i> (Ec, <i>n</i> = 4), <i>E. faecalis</i> (Ef, <i>n</i> = 4), and <i>L. plantarum</i> (Lp, <i>n</i> = 2) pre-incubated with or without ferric citrate. The percentage LDH release compared to the control (no bacteria) was corrected for the number of bacteria in the medium (average between t = 0 and t = 2 h). Means within a group and without a common letter differ significantly, <i>P</i><0.05.</p

Effect of iron on bacterial adhesion to an epithelial monolayer.

<p>Adhesion (mean+SD) of enteric bacteria to a monolayer of Caco-2 cells is given as percentage of the inoculum. <b>A</b>: <i>S. typhimurium</i>, <i>n</i> = 8. <b>B</b>: <i>C. freundii</i>, <i>n</i> = 4. <b>C</b>: <i>E. coli</i>, <i>n</i> = 6. <b>D</b>: <i>E. faecalis</i>, <i>n</i> = 6. <b>E</b>: <i>L. plantarum</i>, <i>n</i> = 5. Means without a common letter differ, <i>P</i><0.05. Notably, adhesion data of <i>S. typhimurium</i> were derived from 4 separate experiments performed at 13, 15, 18 and 21 days post-seeding of Caco-2 cells. The fact that each experiment revealed the same trend is indicative for similar physiochemical properties of the monolayer at these time points.</p

Effect of iron on invasion of <i>S. typhimurium</i> into epithelial cells.

<p>Invasion (mean+SD) of <i>S. typhimurium</i> into Caco-2 cells, <i>n</i> = 2. Invasion after 3.5 h is given as percentage of the inoculum. The inoculum was removed after 2 hours of adhesion time. Means of 0–10 µmol/L ferric citrate were compared by one-way ANOVA.</p

Effect of iron on the ability of <i>S. typhimurium</i> to cross and deteriorate an epithelial monolayer.

<p>Effect of iron on the ability of <i>S. typhimurium</i> to cross an epithelial monolayer of Caco-2 cells and the integrity of this monolayer. <b>A</b>: The translocation is given as percentage of the inoculum (mean+SD), <i>n</i> = 2. Means without a common letter differ, <i>P</i><0.07. <b>B</b>: The integrity of the Caco-2 monolayer during <i>S. typhimurium</i> (St) and <i>L. plantarum</i> (Lp) translocation, monitored by TEER measurements.</p

Median levels, lower and upper quartile plus standard error, of serum hepcidin (ng/mL) by sex, measured in different subgroups.

<p>Criteria for subgroups were as follows: (<b>1</b>) total population; (<b>2</b>) no iron deficiency (ID), no anemia, and no elevated CRP concentration; (<b>3</b>) ID and anemia (IDA), but no elevated CRP concentration; (<b>4</b>) no ID and anemia, but elevated CRP concentration; (<b>5</b>) IDA and elevated CRP concentration. Cut-offs were as follows: anemia: Hb <110 g/L; ID: SF <12 ng/mL or sTfR ≥7.4 mg/L; IDA: concurrent anemia and ID; no ID: SF ≥12 ng/mL and sTfR <7.4 mg/L; elevated CRP: CRP≥4.1 mg/L. Note: all individuals with ID and no elevated CRP were anemic. Letters (a, b, c, d, e, and f) indicate significant differences at P<0.05.</p

Scatter plots and regression equations derived from the correlation of inflammation markers (A: CRP and B: IL-6) and iron markers (C: SF, D: sTfR, and E: ZPP) with serum hepcidin.

<p>Scatter plots and regression equations derived from the correlation of inflammation markers (A: CRP and B: IL-6) and iron markers (C: SF, D: sTfR, and E: ZPP) with serum hepcidin.</p

Results of linear regression analyses for serum hepcidin (ng/mL) in the total population and by gender separately.

<p>Note: Adjusted R² Total = .595; Adjusted R² Male = .553; Adjusted R² Female = .586;</p>*<p>P<0.001;</p>†<p>P<0.05. The dependent variable hepcidin and the independent variables were log-transformed before inclusion in the models. Interpretation for these betas is as follows: 1% change in the independent variable corresponds to a beta% change in the dependent variable.</p

Mean levels of cytokines and fecal calprotectin and their correlation with hepcidin and CRP.

*<p>P<0.01;</p>†<p>P<0.05.</p

Spearman correlation coefficients (rho) from iron and inflammation markers and anthropometric data of the study infants.

*<p>P<0.01;</p>†<p>P<0.05; BW = birth weight.</p