Red blood cell membrane fatty acid composition in infants fed formulas with different lipid profiles.

BACKGROUND: There is growing interest in the fatty acid composition of breast milk and substitute formulas used to replace or complement infant breastfeeding. AIM: The aims of this study were to assess the impact of two follow-up infant formulas based on cow milk fat, vegetable oils and different docosahexaenoic (DHA) and arachidonic (ARA) acid content on red blood cell membrane fatty acid composition, and determine the percent saturated fatty acid (SFA) incorporation into the membrane. STUDY DESIGN: This was a double-blind, randomized, controlled, parallel-group clinical trial. Infants received treatment or control product for at least four months before the age of six months. The control group (n=25) received standard infant formula (FA) and the treatment group (n=24) received the same formula supplemented with higher DHA and ARA content (FB). The reference group (n=47) consisted of normal healthy exclusively breastfed infants. OUTCOME MEASURE: Red blood cell membrane fatty acid composition was determined by capillary gas chromatography. RESULTS: Ninety-six infants completed the study (FA, 25; FB, 24; reference, 47). Higher DHA content reflected higher DHA percentage in the red blood cell membrane. Breast milk and FB did not show any significant differences in DHA content. ARA percentage was higher in breastfed infants and palmitic acid percentage was higher in FB- compared with FA-fed infants. CONCLUSION: DHA and palmitic acid percent distributions were higher in the red blood cell membrane of infants receiving FB. DHA percent distribution was not significantly different in FB-fed and breastfed infants. SFA percent distribution was not significantly different when comparing both formulas with breast milk.

[Profile of triacylglycerols and percentage of palmitic acid at the sn-2 in breast milk substitutes]. / Perfil de triacilgliceroles y porcentaje de ácido palmítico en la posición sn-2 en sustitutos de leche materna.

The aim of this study was to analyze the percentage of palmitic acid at sn-2 position on triacylglycerols in infant formulas. We studied 6 infant formulas in the Argentinean market that are used as breast-milk substitutes during the first six months after delivery: 2 formulas with vegetable oils as basic source of lipids (F1, F2); 1 formula with milk fat and vegetable oils (F3); 1 formula with structured lipids and vegetable oils (F4); 2 formulas for pre-term infants, one with milk fat and other oils (F5), and the other with vegetable oils (F6). Results showed that F1, F2, F3 and F4 presented 14.6%, 14.8%, 48.1% and 44.5%, respectively, of palmitic acid at sn-2 position, whereas formulas F5 and F6 had 49.5% and 14.6%, respectively, of palmitic acid at sn-2 position. Milk-based infant formulas had the highest concentration of palmitic acid at sn-2 position.

Perfil de triacilgliceroles y porcentaje de ácido palmítico en la posición sn-2 en sustitutos de leche materna / Profile of triacylglycerols and percentage of palmitic acid at the sn-2 in breast milk substitutes

El objetivo del presente trabajo es analizar el porcentaje de ácido palmítico en la posición sn-2 de los triacilgliceroles en sustitutos de la leche materna. Se analizaron 6 productos del mercado argentino que se presentan como sustitutos de la leche materna durante el primer semestre de vida: 2 fórmulas con aceites vegetales como fuente básica de lípidos (F1 y F2); 1 fórmula con grasa láctea como base y aceites vegetales (F3); 1 fórmula con lípidos estructurados y aceites vegetales (F4); 2 fórmulas para prematuros, una con grasa láctea como base y otros aceites (F5) y otra con aceites vegetales (F6). Los resultados muestran que F1, F2, F3 y F4 presentaron 14,6%, 14,8%, 48,1% y 44,5% del ácido palmítico en la posición sn-2, respectivamente. Por su parte, las fórmulas F5 y F6 presentaron 49,5% y 14,6% delácido palmítico en la posición sn-2. Las fórmulas con base láctea presentaron la mayor concentración de ácido palmítico en la posición sn-2.

The aim of this study was to analyze the percentage of palmitic acid at sn-2 position on triacylglycerols in infant formulas. We studied 6 infant formulas in the Argentinean market that are used as breast-milk substitutes during the frst six months after delivery: 2 formulas with vegetable oils as basic source of lipids (F1, F2); 1 formula with milk fat and vegetable oils (F3); 1 formula with structured lipids and vegetable oils (F4); 2 formulas for pre-term infants, one with milk fat and other oils (F5), and the other with vegetable oils (F6). Results showed that F1, F2, F3 and F4 presented 14.6%, 14.8%, 48.1% and 44.5%, respectively, of palmitic acid at sn-2 position, whereas formulas F5 and F6 had 49.5% and 14.6%, respectively, of palmitic acid at sn-2 position. Milk-based infant formulas had the highest concentration of palmitic acid at sn-2 position.

Effect of probiotic supplementation on immunoglobulins, isoagglutinins and antibody response in children of low socio-economic status.

BACKGROUND: Antigen exposure is one of the major exogenous factors modulating human immunocompetence acquisition. Decline in family size and improvements in public health and hygiene in developed countries, may deprive the immune system of appropriate antigen input by diminishing infectious stimuli. Probiotics are a large group of microorganisms defined by their beneficial effects on human health and with stimulating effects on different functions of the immune system. AIM OF THE STUDY: We conducted a double-blind, placebo-controlled trial to determine if probiotics maintain their immune-stimulating effects in a population of 162 children with a high index of natural exposure to microorganisms. Children were to ingest for at least 4 months one of two products, low-fat milk fermented by Streptococcus thermophilus (control product) or low-fat milk fermented by S. thermophilus and Lactobacillus casei, with Lactobacillus acidophilus, oligofructose and inulin added after the fermentation process (test product). According to their age, children were vaccinated with DTP-Hib vaccine or a 23-valent anti-pneumococcal vaccine. RESULTS: Final analysis of results was done in 70 children in each group, showing that the rate of immunoglobulin and isoagglutinin acquisition was similar in both groups. There was no difference between groups in antibody levels neither before nor after vaccination. Days of fever and number of episodes of infection were not statistically different in either group. CONCLUSIONS: Supplementation of standard fermented milk with additional probiotics was not of benefit. The high natural rate of early microbial exposure in infants and children from a population of low socio-economic status living in a "less hygienic environment" may account for the absence of an additional immune-stimulating effect by supplementary probiotics.