Fortifying fresh human milk with commercial powdered human milk fortifiers does not affect bacterial growth during 6 hours at room temperature.

OBJECTIVE: To evaluate the growth of resident aerobic mesophilic flora and added Enterobacter sakazakii in fresh, unfortified human milk; fresh human milk fortified with two commercial powdered fortifiers differing in iron content; and infant formula prepared from powder. SUBJECTS: Eight mothers provided preterm breast milk samples. METHODS: Breast milk samples were divided into three aliquots: unfortified, fortified with fortifier containing 1.44 mg iron/14 kcal, and fortified with fortifier containing 0.4 mg iron/14 kcal. Aliquots of formula were prepared. Breast milk and formula aliquots were divided into two test samples. Half were inoculated with low amounts of E sakazakii; half were not. All test samples were maintained at room temperature (22 degrees C), serially diluted, and plated onto agars after 0, 2, 4, and 6 hours. Plates were incubated at 35 degrees C and enumerated. STATISTICAL ANALYSES: Data were analyzed using repeated measures analysis of variance. P<.05 was considered significant. RESULTS: There were no differences in colony counts of aerobic bacteria among uninoculated or among inoculated human milk samples at any time; counts did not increase significantly over 6 hours. There were no differences in colony counts of E sakazakii among inoculated human milk samples at any time; counts did not increase significantly over 6 hours. Aerobic bacteria and E sakazakii colony counts from infant formula did not increase significantly over 6 hours. CONCLUSIONS: During 6 hours at 22 degrees C, fresh human milk and formula had negligible bacterial growth; fortifying human milk with powdered fortifiers did not affect bacterial growth.

Neonatal and infant feeding: effect on bone density at 4 years.

OBJECTIVE: The aim of this study was to determine whether the type of feeding during the first 4 months of life affects bone mineral density at 4 years of age. METHODS: Healthy 4-year-old children were recruited from the offices of primary health care providers. After confirming the type of infant feeding by history, dual energy x-ray absorptiometry analysis was obtained at the University of Nebraska Medical Center and evaluated by a radiologist blinded as to feeding type. RESULTS: One hundred and seventy-eight children completed the study (58% male, 85% Caucasian; mean age, 4.5 years). All children had exclusively consumed human milk (n = 57), an infant formula containing no palm olein oil (n = 56) or an infant formula containing palm olein oil (n = 65) during the first 4 months of life. At 4 years of age, no significant differences were noted in bone mineral content or bone mineral density (P = 0.51 and 0.89, respectively) among the three feeding groups as measured by dual energy x-ray absorptiometry. Total body bone mineral content and bone mineral density varied by gender, with males having significantly higher values than females regardless of feeding type (P = 0.028 and P < 0.001, respectively). CONCLUSION: There is no association between the use of palm olein formula during the first 4 months of life and subsequent bone mineral content and bone mineral density in healthy 4-year-old children.