Presented by: Michelle Darr February 5, 2013

Transcription

1 Total calcium absorption is similar from infant formulas with and without prebiotics and exceeds that in human milk-fed infants Penni D Hicks1, 2,3*, Keli Hawthorne1, 2, Carol L Berseth3, John D Marunycz3, James E Heubi4 and Steven A Abrams1, 2 Presented by: Michelle Darr February 5, 2013

2 Introduction ² Prebiotics are non-digestible food ingredients that help beneficial bacteria grow in the digestive tract ² Human milk serves as a natural source of prebiotics for infants ² Prebiotics are sometimes added to infant formulas ² In infants, prebiotics are thought to help intestinal development by: promoting growth of healthy and beneficial bacteria, protecting against infection, promoting intestinal adaptation outside the uterus, and supporting the immaturity of infant intestine ² Prebiotics have been previously shown to increase calcium absorption in adolescents

3 Purpose ² To evaluate calcium absorption in infants fed a formula with prebiotics and one formula without prebiotics ² To compare the calcium absorption from the formulas with/without prebiotics with the calcium absorption from human milk

4 Methods ² Infants fed the prebiotic (PF) and control (CF) formulas were from five hospitalsà double blind randomized ² Infants fed the human milk (HM) were from one of the study sitesà non-randomized ² HM infants consumed breast milk plus daily vitamin drops (A,C,D) ² Infants consumed the PF and CF between days of life ² PF contained galactooligosaccharides and polydextrose at 1:1 per 4g/L ² Calcium absorption was measured during a 24 hour impatient hospital stay ² Calcium absorption was measured by using a dual tracer stable isotope ² 3 mg 44 Ca was given orally in 60 ml PF, CF, and HM ² 46 Ca was given as intravenously as 0.01 mg chloride salt

5 Methods

6 Results Fractional absorption = ratio of oral tracer: intravenous tracer recovered in urine x 100à % absorbed Total Calcium Absorbed 20ng/mL 247±27mg/d > 20ng//mL 327±11mg/d Fractional Calcium Absorption 20ng/mL 50.3 ±4.3% > 20ng//mL 59.9±1.7%

7 Results ² Calcium intake, fractional calcium absorption and total calcium absorption were similar in infants fed the prebiotic and control formulas ² Calcium intake (p<0.001), fractional calcium absorption (p<0.001) and total calcium absorption(p<0.001) were significantly different from the HM and formula fed infants ² Serum calcium was significantly higher in the prebiotic fed infants than the control fed infants but not clinically significant ² No significant differences in serum phosphorus or alkaline phosphatase activity in formula fed infants ² Serum 25-OHD was not found to be significantly different between PF and CF infants (p=0.42) ² Formula fed infants with 25-OHD levels 20 ng/d had a significantly lower total calcium absorption than those with levels >20ng/d (p=0.01) ² Differences not seen between HM infants with levels 20 ng/d or >20ng/d (p=0.91)

8 Discussion/Conclusion ² Higher net calcium absorption observed in the cow milk based infant formulas (prebiotics or without) compared to HM ² Prebiotics did not significantly impact calcium bioavailability/ No effect of prebiotics on calcium absorption was found ² Calcium absorption seen in adolescents may be due to a different gastrointestinal ph or a different prebiotic(s) ² Not possible to directly compare the relative bioavailability of calcium in breast milk to formulas because concentrations of calcium in infant formulas exceed those in human milk ² Further study is needed to evaluate the relationship between low 25-OHD levels and calcium absorption in infants

9 Questions?