Digestion of human milk fat in early infancy

Interfacial composition in infant formulas powder modulate lipid digestion in simulated in-vitro infant gastrointestinal digestion

The interface structure and composition of fat globules are very important for the digestion and metabolism of fat and growth in infants. Interface composition of fat globules in infant formula (IF) supplemented with milk fat globule membranes (MFGM) and lecithin in different ways were analyzed and their effects on fat digestion properties were evaluated. The results showed that the distribution of phospholipids at the interface and structural of Concept IF1 and Concept IF2 that were more similar to those of human milk (HM) than that of conventionally processed IF3. Concept IF2 and IF3 supplemented with lecithin had larger initial particle size and more sphingomyelin (SM) (23.12 ± 0.26 %, 26.94 ± 0.34 %) than Concept IF1, and Concept IF2 had the smallest proportion of casein in the interfacial. Due to its interface composition, Concept IF2 had the highest degree of lipolysis (85.07 ± 0.76 %), the phospholipid ring structure can always be observed during gastric digestion, and a final fatty acid composition released that was more similar to HM. Concept IF1 and IF3 were different from HM and Concept IF2 in terms of structure and lipolysis rate, although superior to commercial IF4. These indicate that changes in the interfacial composition and structure of fat globules improve the digestive properties of fats in IF. Overall, the results reported herein are useful in designing new milk formulas that better simulate HM.

A Comparative Analysis of Lipid Digestion in Human Milk and Infant Formulas Based on Simulated In Vitro Infant Gastrointestinal Digestion

To investigate the lipid digestive behaviors of human and infant formulas and analyze the differences between them, we investigated the fat globule particle size distribution, lipolysis rate, and fatty acid release of infant formulas with different fat sources and human milk using an in vitro infant digestion model. The results suggested that the particle size in infant formula increased rapidly during gastric digestion and decreased significantly after intestinal digestion, whereas the particle size in human milk increased slowly during gastric digestion but increased rapidly during intestinal digestion (p < 0.05). Despite having a larger droplet size, human milk demonstrated a very high lipolysis rate due to the presence of MFGM. In terms of the distribution of fatty acids in digestion products, the proportion of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) in vegetable oil-based infant formulas was close to that of human milk. The amount of SFAs in milk fat-based infant formulas was significantly higher than that in human milk, and the content of MUFAs in all infant formulas was significantly lower than that in human milk (p < 0.05). After digestion, the most abundant fatty acid released by human milk was C18:2n6c, while the fatty acids released by infant formulas were SFAs, such as C14:0, C16:0, and C18:0.

Serial composition of human milk in preterm and term mothers

Human milk samples were collected from 86 mothers induced in the study on days 3, 7, 14 and 28 of lactation. The mothers were divided into three groups on the basis of gestation viz. group 1: 37-41 weeks (n=41), group II: 33-36 (n=23) and group III: <33 weeks gestation (n=22). All the samples were analysed for the estimation of fat, lactose and protein. The results obtained from the investigations were statistically analysed. The analysis of the results revealed a lower amount of fat and lactose in preterm milk as compared to term milk (p<0.01). These were found to increase in amount with increasing postnatal age (p<0.05). The protein levels were observed to be significantly higher in preterm than term milk (p<0.01). These were observed to decrease significantly with increase in postnatal age (p<0.01).

Ontogeny, growth and development of the small intestine: Understanding pediatric gastroenterology

Throughout our lifetime, the intestine changes. Some alterations in its form and function may be genetically determined, and some are the result of adaptation to diet, temperature, or stress. The critical period programming of the intestine can be modified, such as from subtle differences in the types and ratios of n3:m6 fatty acids in the diet of the pregnant mother, or in the diet of the weanlings. This early forced adaptation may persist in later life, such as the unwanted increased intestinal absorption of sugars, fatty acids and cholesterol. Thus, the ontogeny, early growth and development of the intestine is important for the adult gastroenterologist to appreciate, because of the potential for these early life events to affect the responsiveness of the intestine to physiological or pathological challenges in later life.

Effect of high volume intake of mother's milk with an individualized supplementation of minerals and protein on early growth of preterm infants <28 weeks of gestation

OBJECTIVE

A prospective study was designed to evaluate the effects of high volume intake of mother's milk fortified (FMM) with an individualized supplementation of minerals and protein on tolerance, short-term somatic growth, serum concentrations of calcium, phosphorus, alkaline phosphatase, and total plasma protein in healthy preterm infants below 28 weeks of gestation.

METHODS

Sixty preterm infants were included in the FMM group, for having received >80% or more of the milk volume as their own mother's milk at 3 weeks of postnatal age to 38 weeks of corrected gestational age. This group was compared with 60 preterm infants fed exclusively preterm formula milk (PF). Intended fluid volume of the FMM group was approximately 200 and 150-170 mL/kg/d in the PF group. Mother's milk was supplemented with the goal of a daily protein intake of 3.5-4 g/kg/d. Phosphorus was supplemented from 15.5 to 31 mg per 100mL mother's milk.

RESULTS

Both feeding regimes were well tolerated. At the end of the study, nutritional management in both groups resulted in a body weight between the 25th and 50th percentiles of intrauterine growth expectations. Serum values of electrolytes, alkaline phosphatase, plasma protein, blood urea nitrogen, and urinary mineral excretion did not differ significantly between the two groups at study entry as well as at the end of the investigation.

CONCLUSIONS

Mother's milk fed at higher volumes with an individualized fortification of minerals and protein provides sufficient nutrients to allow adequate growth of preterm infants <28 weeks of gestation.

Functional development of fat absorption in term and preterm neonates strongly correlates with ability to absorb long-chain Fatty acids from intestinal lumen

Our goal for this study was to determine whether the maturation of fat absorption in neonatal life is functionally related to an increased ability to hydrolyze dietary fat, to absorb long-chain fatty acids, or to do both. In 16 preterm and in eight term neonates, the intestinal ability to hydrolyze triacylglycerols and the capacity to absorb long-chain fatty acids were determined at several times between birth and 5 mo after the term age. These processes were compared with the percentage of fat absorption (formula-fed infants) or with fecal fat excretion (breast-fed infants). The functional capacity to digest triacylglycerols and to absorb the lipolytic products was evaluated by measuring serum concentrations of the lipolytic product [1-(13)C]palmitate after the enteral administration of tri-1-(13)C palmitoyl-glycerol. Long-chain fatty acids absorption (i.e. independent of lipolysis) was determined by measuring serum concentrations of [1-(13)C]stearate after its enteral administration. The efficacy of fat absorption increased in preterm infants (formula-fed) from 91.2 +/- 1.1% (mean +/- SEM) at 32.3 wk postconceptional age (PCA) to 97.3 +/- 0.6% at 53.6 wk PCA (p < 0.001), and in term infants from 91.7 +/- 1.8% (40.0 wk PCA) to 97.4 +/- 1.3% (58.9 wk PCA, p = 0.07). Both the serum concentration of [1-(13)C]stearate and that of [1-(13)C]palmitate appeared highly correlated with the efficacy of fat absorption (r = 0.82, p = 0.02; and r = 0.91, p = 0.004; respectively) and with PCA (r = 0.99, p < 0.001; and r = 0.85, p < 0.02; respectively). These results indicate that the functional development of fat absorption in preterm and term infants is related to the capacity to absorb long-chain fatty acids from the intestine.

Evidence that palmitic acid is absorbed as sn-2 monoacylglycerol from human milk by breast-fed infants

Milk fatty acids consist of about 20-25% palmitic acid (16:0), with about 70% of 16:0 esterified to the sn-2 position of the milk triacylglycerols. Hydrolysis of dietary triacylglycerols by endogeneous lipases produces sn-2 monoacylglycerols and free fatty acids, which are absorbed, reesterified, and then secreted into plasma. Unesterified 16:0 is not well absorbed and readily forms soaps with calcium in the intestine. The positioning of 16:0 at the sn-2 position of milk triacylglycerols could explain the high coefficient of absorption of milk fat. However, the milk lipase, bile salt-stimulated lipase, has been suggested to complete the hydrolysis of milk fat to free fatty acids and glycerol. These studies determined whether 16:0 is absorbed from human milk as sn-2 monopalmitin by comparison of the plasma triacylglycerol total and sn-2 position fatty acid composition between breast-fed and formula-fed term gestation infants. The human milk and formula had 21.0 and 22.3% of 16:0, respectively, with 54.2 and 4.8% 16:0 in the fatty acids esterified to the 2 position. The plasma triacylglycerol total fatty acids had 26.0 +/- 0.6 and 26.2 +/- 0.6% of 16:0, and the sn-2 position fatty acids had 23.3 +/- 3.3 and 7.4 +/- 0.7% of 16:0 in the three-month-old exclusively breast-fed (n = 17) and formula-fed (n = 18) infants, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Human gastric lipase: ontogeny and variations in children

The aim of this study was to investigate the precise origin of the acid pre-duodenal lipase during human development and to evaluate its possible changes, at the tissue level, in children with gastritis or pancreatic insufficiency. Human gastric lipase appears around the 11th week of gestation and increases slowly during pre- and postnatal development. It is localized in the fundus of the stomach without any lingual localization. Human gastric lipase reaches its adult level in the third month of life, and does not vary in relation to pancreatic insufficiency. It is only rarely impaired during gastritis.