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.

RESUMENEl 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% del ácido palmítico en la posición sn-2. Las fórmu-las con base láctea presentaron la mayor concentración de ácido palmítico en la posición sn-2. Palabras clave: ácido palmítico, triacilgliceroles, posición sn-2, fórmulas lácteas, lactantes. SUMMARYThe 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.

The effect of daily consumption of a yogurt containing Lactobacillus reuteri CRL 1098 on the lipid profile of hypercholesterolemic subjects was evaluated by performing a prospective, randomized, double-blind, cross-over placebo controlled clinical study. Participants consumed daily a yogurt containing L. reuteri CRL 1098 or a placebo for four weeks, separated by a wash-out period. Total cholesterol, triacylglycerol, high-density (HDL) and low-density (LDL) lipoprotein levels were assessed at the beginning and at the end of each period. We found a statistically significant reduction of total (−7.86 g/dl) and LDL (−7.02 g/dl) cholesterol in absolute changes (before-after) as well as a decreasing trend in the group receiving the yogurt containing L. reuteri with respect to the placebo group, without detecting changes in HDL-cholesterol and triacylglycerol levels. Our results suggest that low amounts of yogurt (125 g/day) and low doses of the CRL 1098 strain (10 6 CFU) are sufficient to reduce total and LDL-cholesterol levels in hypercholesterolemic subjects.

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.