Randomised controlled trial of a synthetic triglyceride milk formula for preterm infants

1,3-Dioleoyl-2-palmitoyl-glycerol and 1-oleoyl-2-palmitoyl-3-linoleoyl-glycerol: Structure-function relationship, triacylglycerols preparation, nutrition value

Based on multivariate statistics, this review compared major triacylglycerols (TAGs) in animal milk and human milk fat from China and other countries. Human milk fat differs from animal milk fat in that it has longer acyl chains and higher concentrations of 1,3-dioleoyl-2-palmitoyl-glycerol (O-P-O) and 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (O-P-L). O-P-L is a significant and distinct TAG in human milk fat, particularly in China. 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) is human milk's major triglyceride molecule of O-P-L, accounting for more than 70%. As a result, OPL has piqued the interest of Chinese academics. The synthesis process and nutritional outcomes of OPL have been studied, including changes in gut microbiota, serum lipid composition, improved fatty acid and calcium absorption, and increased total bile acid levels. However, current OPL research is limited. Therefore, this review discussed enzymatic preparation of 1,3-dioleoyl-2-palmitoyl-glycerol (OPO) and OPL and their nutritional and physiological activity to direct future research direction for sn-2 palmitate and OPL.

Fat composition of milk replacer influences growth performance, feeding behavior, and plasma fatty acid profile in ad libitum-fed calves

Fat composition in milk replacers (MR) for calves differs from bovine milk fat in multiple ways. The aim of the study was to investigate the impact of different approaches of formulating fat in MR on growth, ad libitum intakes of MR and solid feeds, as well as blood metabolites in dairy calves. Upon 24 to 96 h after birth, 63 calves were acquired from dairy farms and incorporated into the study. Calves were blocked based on arrival day and randomly assigned within each block to one of 3 treatments differing in MR fat composition (n = 21 per group): VG was based on vegetable fats including 80% rapeseed and 20% coconut fats; AN was formulated with animal fats including 65% lard and 35% dairy cream; and MX with a mixture of 80% lard and 20% coconut fats. All 3 MR contained 30% fat, 24% crude protein, and 36% lactose and were formulated to have a fatty acid profile resembling that of milk fat. From arrival onward (3.1 ± 0.84 d of age; means ± standard deviation), calves were group housed and were offered an ad libitum supply of MR at 135 g/L (13.5% solids). Weaning was gradual and induced between wk 7 and 10, after which calves were fed only solid feeds. Starter feed, chopped straw, and water were offered ad libitum throughout the study. Calves were weighed, and blood was collected weekly until d 84 after arrival. Preweaning average daily gain was greater in calves fed AN (915 g/d) than other treatments (783 g/d), whereas no differences were detected in the weaning and postweaning phases. Preweaning MR intake was greater in calves fed AN than MX from wk 2 to 6 and was also higher in calves fed AN than VG in wk 5 and 6. Consistently, the number of rewarded visits during the ad libitum phase was greater in calves fed AN than MX, whereas VG showed no differences. This led to a higher preweaning total metabolizable energy intake in calves fed AN than in calves fed VG and MX. Serum cholesterol was higher, and serum albumin was lower in calves fed VG than other treatments. The proportion of high-density lipoprotein cholesterol in total plasma cholesterol was lower and that of low-density lipoprotein (LDL) cholesterol was higher in calves fed VG compared with other treatments. Overall, the fatty acid profile of plasma largely mirrored the MR fat composition during the preweaning period. Feeding AN enhanced MR intake and improved preweaning growth compared with other treatments. Feeding VG resulted in a marked increase in plasma cholesterol, particularly in the form of LDL cholesterol, which could be linked to an excessive intake of polyunsaturated fatty acids. These findings underscore the importance of formulating the fat content of MR to be similar to bovine milk fat.

Comparative evaluation of enriched formula milk powder with OPO and MFGM vs. breastfeeding and regular formula milk powder in full-term infants: a comprehensive study on gut microbiota, neurodevelopment, and growth

This study investigated the non-inferiority of feeding term healthy infants with enriched formula milk powder containing 1,3-dioleoyl-2-palmitoylglycerol (OPO) and milk fat globular membrane (MFGM), compared to breast milk, in terms of the formation of gut microbiota, neurodevelopment and growth. Infants were divided into three groups: breast milk group (BMG, N = 50), fortified formula group (FFG, N = 17), and regular formula group (RFG, N = 12), based on the feeding pattern. Growth and development information was collected from the infants at one month, four months, and six months after the intervention. Fecal samples were collected from infants and analyzed for gut microbiota using 16S ribosomal DNA identification. The study found that at the three time points, the predominant bacterial phyla in FFG and BMG were Proteobacteria, Firmicutes, and Bacteroidetes, which differed from RFG. The abundance of Bifidobacterium in the RFG was lower than the FFG (one month, p = 0.019) and BMG (four months, p = 0.007). The abundance of Methanoprebacteria and so on (genus level) are positively correlated with bone mineral density (BMD) of term infants, and have the potential to be biomarkers for predicting BMD. The abundance of beta-galactosidase, a protein that regulates lactose metabolism and sphingoid metabolism, was higher in FFG (six months, p = 0.0033) and BMG (one month, p = 0.0089; four months, p = 0.0005; six months, p = 0.0005) than in the RFG group, which may be related to the superior bone mineral density and neurodevelopment of infants in the FFG and BMG groups than in the RFG group. Our findings suggest that formula milk powder supplemented with OPO and MFGM is a viable alternative to breastfeeding, providing a practical alternative for infants who cannot be breastfed for various reasons.

Development and large-scale production of human milk fat analog by fermentation of microalgae

Background

Human milk contains a complex mixture of triacylglycerols (TAG), making it challenging to recreate using common ingredients.

Objective

The study aimed to develop an innovative fermentation technique to produce essential human milk TAG, effectively tackling a significant hurdle in infant nutrition.

Method

An in-depth analysis of the literature has been conducted to identify the specific TAG to be targeted. We used a microalgal oil production platform and a two-step procedure to modify its fatty acid and TAG composition. The palmitic acid (16:0) content has been increased by classical strain improvement techniques, followed by a step involving the expression of a lysophosphatidic acid acyltransferase (LPAAT) sequence capable of esterifying 16:0 specifically at the internal position (sn-2 palmitate) of TAG. Once the strain was stabilized, the fermentation was scaled up in a 50-L reactor to yield several kilograms of biomass. Subsequently, the oil was extracted and refined using standard oil processing conditions. Liquid chromatography-mass spectrometry was employed to monitor the TAG profile and the region specificity of 16:0 at the internal position (sn-2 palmitate) of TAG.

Results

The initial strain had a 16:0 level of 25% of total fatty acids, which was increased to 30% by classical strain improvement. Simultaneously, the oleic acid level decreased from 61% to 57% of total fatty acids. Upon expression of an exogenous LPAAT gene, the level of the 16:0 esterified in the internal position of the TAG (sn-2 palmitate) increased by a factor of 10, to reach 73% of total palmitic acid. Consequently, the concentration of oleic acid in the internal position decreased from 81% to 22% of total fatty acids, with TAG analysis confirming that the primary TAG species in the oil was 1,3-dioleoyl-2-palmitoyl-glycerol (OPO). The 50-L-scale fermentation trial confirmed the strain's ability to produce oil with a yield of >150 g of oil per liter of fermentation broth in a timeframe of 5 days, rendering the process scalable for larger-scale industrialization.

Conclusion

We have demonstrated the feasibility of producing a suitable TAG composition that can be effectively integrated into the formulations of infant nutrition in combination with other fats and oils to meet the infant feeding requirements.

Structured Lipids Engineering for Health: Novel Formulations Enriched in n-3 Long-Chain Polyunsaturated Fatty Acids with Potential Nutritional Benefits

Structured lipids (SLs) offer a promising avenue for designing novel formulations enriched in n-3 long-chain polyunsaturated fatty acids (LCPUFAs) with potential health benefits. Triacylglycerols (TAGs), the most common fats in the human diet, are both non-toxic and chemically stable. The metabolic efficiency and digestibility of TAGs are significantly influenced by the position of fatty acids (FAs) within the glycerol backbone, with FAs at the sn-2 position being readily absorbed. Over the past two decades, advancements in SL research have led to the development of modified TAGs, achieved either through chemical or enzymatic processes, resulting in SLs. The ideal structure of SLs involves medium-chain FAs at the sn-1,3 positions and long-chain n-3 LCPUFAs at the sn-2 position of the glycerol backbone, conferring specific physicochemical and nutritional attributes. These tailored SL formulations find wide-ranging applications in the food and nutraceutical industries, showing promise for dietary support in promoting health and mitigating various diseases. In particular, SLs can be harnessed as functional oils to augment TAG metabolism, thereby impeding the development of fatty liver, countering the onset of obesity, and preventing atherosclerosis and age-related chronic diseases. In scrutinising prevailing research trajectories, this review endeavours to provide an in-depth analysis of the multifaceted advantages and repercussions associated with the synthesis of SLs. It elucidates their burgeoning potential in enhancing health and well-being across a range of demographic cohorts. Specifically, the implications of SL utilisation are discussed in the context of healthcare environments and early childhood developmental support.

Human milk phospholipid analog improved the digestion and absorption of 1,3-dioleoyl-2-palmitoyl-glycerol

The present study investigated the effects of a human milk phospholipid analog (HPLA) on the digestion and absorption of 1,3-dioleoyl-2-palmitoyl-glycerol (OPO). The HPLA contained 26.48% phosphatidylethanolamine (PE), 24.64% phosphatidylcholine (PC), 36.19% sphingomyelin (SM), 6.35% phosphatidylinositol (PI), and 6.32% phosphatidylserine (PS), with 40.51% C16:0, 17.02% C18:0, 29.19% C18:1, and 13.26% C18:2. The HPLA prevented OPO from hydrolysis during the in vitro gastric phase, while it facilitated the digestion of OPO during the in vitro intestinal stage, resulting in the production of large amounts of diglycerides (DAGs) and monoglycerides (MAGs). In vivo experimental results showed that the HPLA might increase the gastric emptying rate of OPO and increase the hydrolysis and absorption of OPO at an early stage of intestinal digestion. Notably, fatty acids in the serum of the OPO group decreased to their initial value at 5 h, while the serum of the OPO + HPLA (OPOH) group still contained a high level of fatty acids indicating that the HPLA was helpful in maintaining serum lipid at a high level, which might be beneficial for sustainably providing energy for babies. The present study provides data support for the potential application of Chinese human milk phospholipid analogs in infant formulas.

Is It Time to Revise the Current Nutrient Requirements for Infant Formulas Principally Established in 1980?

Because of the production of nutrient-deficient infant formulas (IFs), the United States Congress passed regulations on the composition and production of IF, referred to as the Infant Formula Act (IFA), in 1980, which was amended in 1986. More detailed FDA rules have been created since then, specifying the ranges or minimum intakes of nutrients and providing details for the safe production and evaluation of infant formulas. Although generally effective in ensuring safe IF, recent events have made it clear that a re-evaluation of aspects of all the nutrient composition regulations for IF is needed, including consideration of adding requirements related to bioactive nutrients not mentioned in the IFA. We propose that, as principal examples, the requirement for iron content needs to be re-evaluated and that DHA and AA should be considered for addition to the nutrient requirements after scientific review by a panel such as those established by the National Academies of Sciences, Engineering, and Medicine. Additionally, there is no specific requirement in current FDA regulations for the energy density of IF, and this should be added alongside potential revisions of the protein requirement. It would also be ideal to have specific FDA rules on nutrient intakes for premature infants as these are exempted from the specific nutrient regulations of the amended IFA.

Effects of Sn-2-palmitate-enriched formula feeding on infants' growth, stool characteristics, stool fatty acid soap contents and bone mineral content: A systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis was performed to assess the effects of Sn-2-palmitate-enriched formula feeding on infants' growth, stool characteristics, stool fatty acid (FA) soap contents and bone mineral content (BMC). We searched PubMed, MEDLINE, Embase and Web of Science for randomized controlled trials published up to April 2022. Sixteen studies involving 1,931 infants were included. From each included study, weighted mean differences (WMDs) and 95% confidence intervals (CIs) for each of the above mentioned outcomes were extracted and pooled with a fixed-effects model (I2 ≤ 50%) or a random-effects model (I2 > 50%). Infants fed Sn-2-palmitate-enriched formula exhibited greater weight gains (WMD: 0.81; 95% CI: 0.23, 1.39 g/d; I2 = 0.00%), lower contents of total stool FA soaps (WMD: -3.47; 95% CI: -5.08, -1.86 mg/100 mg; I2 = 0.00%) and higher BMC (WMD: 7.08; 95% CI: 4.05, 10.10; I2 = 0.00%) than infants fed standard formula. However, no difference was observed in these outcomes between infants fed Sn-2-palmitate-enriched formula and those fed human milk. This meta-analysis demonstrated that compared with standard formula feeding, Sn-2-palmitate-enriched formula feeding could effectively promote weight gains, bone mineral accumulation and stool FA soap reduction in infants.

Effects of higher protein formula with improved fat blend on growth, feeding tolerance and nutritional biomarkers in preterm infants: A double-blind, randomized, controlled clinical trial

BACKGROUND

Preterm formulas containing greater protein:energy ratio are beneficial for non-breastfed infants, since protein is critical for promoting catch-up growth and synthesis of lean body mass. Additionally, formulas containing enriched sn-2 palmitate (sn-2) and reduced medium chain triglycerides (MCTs) may support better feeding tolerance and nutrient utilization.

METHODS

The objective of this randomized, controlled, double-blinded clinical trial is to evaluate growth, feeding tolerance and nutritional biomarkers of preterm infants with birth weight ≤2000g and gestational age ≤33wks from one neonatal unit in Vietnam receiving experimental formula (EF, n = 80) containing higher protein level of 3.4 g/100 kcal and improved fat blend with enriched sn-2 and modified level of MCTs or isocaloric control formula (CF, n = 80) containing protein level of 2.9 g/100 kcal and standard fat blend. The differences in weight gain (g/d; primary endpoint) from day 1 (D1) of full enteral feeding (FEF) until D21 between groups was evaluated for non-inferiority (margin = -2.5  g/d) and superiority (margin = 0  g/d).

RESULTS

Mean weight gain was 3.09  g/d greater in EF than CF; the lower limit of 95% CI (0.31  g/d) exceeded both non-inferiority and superiority margins. There was no significant difference in length-for-age and head circumference-for-age z-score. By D79, the mean change in weight-for-age z-scores from D1 in EF group (+0.76 SDs) surpassed the criteria for catch-up growth (+0.67 SDs). Infants in the EF group (vs. CF) tended to have softer stools (EF = 3.2 ± 0.59 vs. CF = 3.4 ± 0.58; P = 0.07) based on 5-point scale (1 = watery, 5 = hard). Difference in blood urea nitrogen and biomarkers for bone mineral status (i.e., plasma phosphorus, alkaline phosphatase and urinary calcium/phosphorus ratio) between EF and CF on FEF Day 21 reached statistical significance (P < 0.05) but all mean values stayed within normal clinical ranges for both groups.

CONCLUSION

Preterm formula with greater protein:energy ratio and new fat blend is safe, nutritionally suitable, well-tolerated, and improves catch-up weight gain of preterm infants. Clinical trial registry identifier is NCT03055052 (ClinicalTrials.gov).

Impact of Dietary Palmitic Acid on Lipid Metabolism

Palmitic acid (PA) is ubiquitously present in dietary fat guaranteeing an average intake of about 20 g/d. The relative high requirement and relative content in the human body, which accounts for 20–30% of total fatty acids (FAs), is justified by its relevant nutritional role. In particular physiological conditions, such as in the fetal stage or in the developing brain, the respectively inefficient placental and brain blood–barrier transfer of PA strongly induces its endogenous biosynthesis from glucose via de novo lipogenesis (DNL) to secure a tight homeostatic control of PA tissue concentration required to exert its multiple physiological activities. However, pathophysiological conditions (insulin resistance) are characterized by a sustained DNL in the liver and aimed at preventing the excess accumulation of glucose, which result in increased tissue content of PA and disrupted homeostatic control of its tissue concentration. This leads to an overaccumulation of tissue PA, which results in dyslipidemia, increased ectopic fat accumulation, and inflammatory tone via toll-like receptor 4. Any change in dietary saturated FAs (SFAs) usually reflects a complementary change in polyunsaturated FA (PUFA) intake. Since PUFA particularly n-3 highly PUFA, suppress lipogenic gene expression, their reduction in intake rather than excess of dietary SFA may promote endogenous PA production via DNL. Thereby, the increase in tissue PA and its deleterious consequences from dysregulated DNL can be mistakenly attributed to dietary intake of PA.

The Role of Dietary Fats in the Development and Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a significant cause of mortality and morbidity in preterm infants. The pathogenesis of NEC is not completely understood; however, intestinal immaturity and excessive immunoreactivity of intestinal mucosa to intraluminal microbes and nutrients appear to have critical roles. Dietary fats are not only the main source of energy for preterm infants, but also exert potent effects on intestinal development, intestinal microbial colonization, immune function, and inflammatory response. Preterm infants have a relatively low capacity to digest and absorb triglyceride fat. Fat may thereby accumulate in the ileum and contribute to the development of NEC by inducing oxidative stress and inflammation. Some fat components, such as long-chain polyunsaturated fatty acids (LC-PUFAs), also exert immunomodulatory roles during the early postnatal period when the immune system is rapidly developing. LC-PUFAs may have the ability to modulate the inflammatory process of NEC, particularly when the balance between n3 and n6 LC-PUFAs derivatives is maintained. Supplementation with n3 LC-PUFAs alone may have limited effect on NEC prevention. In this review, we describe how various fatty acids play different roles in the pathogenesis of NEC in preterm infants.

Obesity as a Predictor of Outcomes in Type III and Type IV Supracondylar Humerus Fractures

OBJECTIVES

To investigate the association of obesity with fracture characteristics and outcomes of operatively treated pediatric supracondylar humerus fractures.

DESIGN

Retrospective multicenter.

SETTING

Two Level I pediatric hospitals.

PATIENTS

Patients (age <18 years) with operatively treated Gartland type III and type IV fractures 2010-2014.

INTERVENTION

Closed or open reduction and percutaneous pinning of supracondylar humerus fractures.

MAIN OUTCOME MEASURE

Incidence of Gartland IV fracture, preoperative nerve palsy, open reduction and complication rates.

RESULTS

Patients in the obese group had a significantly higher likelihood of having a Gartland IV fracture (not obese: 17%; obese: 35%; P = 0.007). There was a significantly higher incidence of nerve palsy on presentation in the obese group (not obese: 20%; obese: 33%; P = 0.03). No significant differences were found between groups regarding incidence of open reduction, compartment syndrome, and rates of reoperation.

CONCLUSIONS

The present study demonstrates that obese children with a completely displaced supracondylar humerus fractures have an increased risk of Gartland type IV and preoperative nerve palsy compared with normal weight children.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

1,3-Dioleoyl-2-palmitoyl glycerol (OPO)-Enzymatic synthesis and use as an important supplement in infant formulas

1,3-dioleolyl-2-palmitate (OPO) is an important component of the human milk fat. Its unique fatty acid composition and distribution play an important role in proper infant growth and development. Owing to this, it has been attracting researchers and manufacturers to synthesize and commercialize OPO as an important human milk fat substitute added to infant formulas. In this review, the role of OPO in human milk, the benefits of OPO (sn-2 palmitate)-supplemented infant formulas over the conventional infant formulas on infant growth, and lipase-catalyzed synthesis of OPO are discussed. Over the last 20 years of research on the benefits of OPO (sn2 palmitate)-supplemented infant formulas are summarized. Similarly, studies carried out on lipase catalyzed production of OPO for the last 21 years (1999-2019) are also done focusing on the raw materials, sn1,3-regiospecific lipases, immobilization materials, and solvents used in the laboratory-scale experiments. In addition, OPO-based products currently in the market and future research trends are briefly covered in this review. PRACTICAL APPLICATIONS: This work focuses on lipase-catalyzed synthesis of 1,3-dioleoyl-2-palmitoylglycerol (the most abundant triacyl glycerol in human milk fat) and its benefits to infants when it is added in infant formulas. Over the last 20 years of published research from the literature are summarized and future research trends for efficient OPO synthesis are also covered. This will provide current and future researchers on the field with the necessary background information on OPO synthesis and design their research plans accordingly for cost-effective production of OPO and OPO-supplemented infant formulas.

Impact of an Infant Formula Containing a Novel Fat Blend (Cow's Milk Fat, Fish and Vegetable Oil) and Prebiotics on Stool Fatty Acid Soaps and Erythrocyte Fatty Acid Profiles in Full-Term Healthy Newborns

INTRODUCTION

Recently, new commercial infant formulas have been composed considering novel fat blends and oligosaccharides to better resemble the fatty acid (FA) composition and stereospecific distribution (e.g., increased amount of ß-palmitate) as well as probiotics content of human breast milk. We hypothesized that these newly composed infant formulas may decrease fecal FA soap excretion and may positively affect erythrocyte FA profiles compared with regular formulas.

METHODS

Healthy infants were randomly assigned to receive a high-sn-2-palmitate formula (>25% of the PA is esterified to the sn-2 position of the glycerol backbone, verum: n = 30) or a "standard" formula containing <10% of PA in sn-2 position and no oligosaccharides (control: n = 27); a non-randomized group of breast-fed infants served as control. Anthropometric data of the infants (body weight, recumbent length, and head circumference) were recorded at inclusion (visit 1) and 6 and 12 weeks after onset of intervention (visits 2 and 3). Blood samples for erythrocyte FA analysis (gas chromatography) were taken at visits 1 and 2; stool samples were collected at visit 2.

RESULTS

Quantitative formula intake (mL/kg body weight × day) at visit 2 (verum: 155 ± 30, control: 164 ± 30) and visit 3 (verum: 134 ± 26, control: 134 ± 21) was comparable. Six weeks after onset of intervention, stool total FA soaps, palmitate soaps, and total FAs were similar in both formula-fed groups but significantly higher than in breast-fed infants. During the 6-week intervention, erythrocyte palmitate decreased significantly from baseline in all 3 groups with no group differences (verum: 29.20 ± 1.17 to 27.12 ± 0.66, control: 29.88 ± 2.00 to 27.01 ± 0.94, breast-fed: 30.20 ± 0.86 to 26.84 ± 0.98). For selected FAs, significant changes over time in verum and control group were obvious but without formula effects. Some variations in the FA profile of breast-fed infants compared to both verum and control groups were observed.

CONCLUSIONS

In contrast to our hypothesis, feeding a newly composed infant formula based on a fat blend with 25% of PA in the sn-2 position of triacylglycerols and supplemented with a prebiotic could not decrease insoluble FA soap excretion compared with a standard product; in this respect, breastfeeding is obviously the best choice. Surprisingly, erythrocyte FA profiles were comparable in formula-fed and breast-fed infants; obvious alterations in FA composition of the respective fat sources and structure did not affect FA incorporation into membranes. Caution should be, however, exercised in drawing robust conclusions in the absence of larger, adequately powered intervention studies.

High versus low medium chain triglyceride content of formula for promoting short-term growth of preterm infants

BACKGROUND

In-hospital growth of preterm infants remains a challenge in clinical practice. The high nutrient demands of preterm infants often lead to growth faltering. For preterm infants who cannot be fed maternal or donor breast milk or may require supplementation, preterm formulas with fat in the form of medium chain triglycerides (MCTs) or long chain triglycerides (LCTs) may be chosen to support nutrient utilization and to improve growth. MCTs are easily accessible to the preterm infant with an immature digestive system, and LCTs are beneficial for central nervous system development and visual function. Both have been incorporated into preterm formulas in varying amounts, but their effects on the preterm infant's short-term growth remain unclear. This is an update of a review originally published in 2002, then in 2007.

OBJECTIVES

To determine the effects of formula containing high as opposed to low MCTs on early growth in preterm infants fed a diet consisting primarily of formula.  SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 8), in the Cochrane Library; Ovid MEDLINE Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily, and Ovid MEDLINE(R); MEDLINE via PubMed for the previous year; and Cumulative Index to Nursing and Allied Health Literature (CINAHL), on 16 September 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomized controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included all randomized and quasi-randomized trials comparing the effects of feeding high versus low MCT formula (for a minimum of five days) on the short-term growth of preterm (< 37 weeks' gestation) infants. We defined high MCT formula as 30% or more by weight, and low MCT formula as less than 30% by weight. The infants must be on full enteral diets, and the allocated formula must be the predominant source of nutrition.

DATA COLLECTION AND ANALYSIS

The review authors assessed each study's quality and extracted data on growth parameters as well as adverse effects from included studies. All data used in analysis were continuous; therefore, mean differences with 95% confidence intervals were reported. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We identified 10 eligible trials (253 infants) and extracted relevant growth data from 7 of these trials (136 infants). These studies were found to provide evidence of very low to low certainty. Risk of bias was noted, as few studies described specific methods for random sequence generation, allocation concealment, or blinding. We found no evidence of differences in short-term growth parameters when high and low MCT formulas were compared. As compared to low MCT formula, preterm infants fed high MCT formula showed little to no difference in weight gain velocity (g/kg/d) during the intervention, with a typical mean difference (MD) of -0.21 g/kg/d (95% confidence interval (CI) -1.24 to 0.83; 6 studies, 118 infants; low-certainty evidence). The analysis for weight gain (g/d) did not show evidence of differences, with an MD of 0.00 g/d (95% CI -5.93 to 5.93; 1 study, 18 infants; very low-certainty evidence), finding an average weight gain of 20 ± 5.9 versus 20 ± 6.9 g/d for high and low MCT groups, respectively. We found that length gain showed no difference between low and high MCT formulas, with a typical MD of 0.10 cm/week (95% CI -0.09 to 0.29; 3 studies, 61 infants; very low-certainty evidence). Head circumference gain also showed little to no difference during the intervention period, with an MD of -0.04 cm/week (95% CI -0.17 to 0.09; 3 studies, 61 infants; low-certainty evidence). Two studies reported skinfold thickness with different measurement definitions, and evidence was insufficient to determine if there was a difference (2 studies, 32 infants; very low-certainty evidence). There are conflicting data (5 studies) as to formula tolerance, with 4 studies reporting narrative results of no observed clinical difference and 1 study reporting higher incidence of signs of gastrointestinal intolerance in high MCT formula groups. There is no evidence of effect on the incidence of necrotizing enterocolitis (NEC), based on small numbers in two trials. Review authors found no studies addressing long-term growth parameters or neurodevelopmental outcomes.

AUTHORS' CONCLUSIONS

We found evidence of very low to low certainty suggesting no differences among short-term growth data for infants fed low versus high MCT formulas. Due to lack of evidence and uncertainty, neither formula type could be concluded to improve short-term growth outcomes or have fewer adverse effects. Further studies are necessary because the results from included studies are imprecise due to small numbers and do not address important long-term outcomes. Additional research should aim to clarify effects on formula tolerance and on long-term growth and neurodevelopmental outcomes, and should include larger study populations to better evaluate effect on NEC incidence.

Effect of milk fat-based infant formulae on stool fatty acid soaps and calcium excretion in healthy term infants: two double-blind randomised cross-over trials

Background

Palmitic acid (PA) is predominantly esterified at the SN-2 position of triacylglycerols in human milk. PA at the SN-2 position is more efficiently absorbed and results in reduced formation of PA soaps, as well as reduced fatty acid (FA) and calcium malabsorption. Bovine milk fat (MF), a natural source of SN-2-palmitate, was used in the fat blend of infant formulae (IF) in the current study to investigate its effect on stool fatty acid soaps, calcium excretion and stool characteristics.

Methods

Two double-blind, randomised cross-over trials (CS1, CS2) were conducted in parallel with healthy term, formula-fed infants aged 9-14 weeks. After a two-week run-in period, infants in CS1 (n = 17) were randomly allocated to receive either a 50% MF-based formula (50MF) or a 100% vegetable fat (VF) formula; in CS2 (n = 18), infants received either a 20% MF-based formula (20MF) or the VF formula, in a 2 × 2-week cross-over design. At the end of each two-week intervention period, stool samples were collected for FA, FA soaps and calcium excretion analysis and stool consistency was assessed according to the Amsterdam Infant Stool Scale (AISS).

Results

MF-based groups showed no significant difference in PA in stools compared to VF group, although reduced stool PA soaps (CS1: 111.28 ± 18.33 vs. 220.25 ± 29.35 mg/g dry weight, p < 0.0001; CS2: 216.24 ± 25.16 vs. 233.94 ± 35.12 mg/g dry weight, p = 0.0023), total FA soaps and calcium excretion (CS1: 46.40 ± 5.27 vs. 49.88 ± 4.77 mg/g dry weight, p = 0.0041; CS2: 46.20 ± 4.26 vs. 50.47 ± 6.71 mg/g dry weight, p = 0.0067) were observed. Furthermore, the 50MF group showed a favourable lower mean stool consistency score compared to the VF group (1.64 ± 0.49 vs. 2.03 ± 0.19, p = 0.0008).

Conclusions

While the use of bovine MF in IF did not affect PA concentrations in stool, lower excretion of palmitate soaps, total FA soaps and calcium was seen in healthy term infants. 50MF formula also showed improved stool consistency. The use of MF in IF could be an interesting approach to improve gut comfort and stool characteristics in infants, warranting further research.

Trial registration

Netherlands Trial Registry Identifier: NTR6702. Date registered: December 01, 2017.

Absorption of 1,3-dioleyl-2-palmitoylglycerol and intestinal flora profiles changes in mice

The purpose of this study was to investigate the digestion and absorption of 1,3-dioleyl-2-palmitoylglycerol (OPO) and its effects on mineral absorption and intestinal flora in vivo. Fatty acids and mineral faeces were measured using gas chromatography-mass spectrometry and inductively coupled plasma mass spectrometry, respectively. The intestinal flora composition was assessed using high-throughput 16S rRNA sequencing. After 4-week feeding experiment, the apparent absorption rate of calcium in O group (mice fed with OPO) was 48.54 ± 0.21%, which was significantly higher than that in Z group (mice fed with mixed vegetable oil), the percentage of palmitic acid in serum of the O group mice was significantly higher. Compared with Z group, the mean relative abundance of Bifidobacteriaceae and Lactobacillaceae in the O group mice was higher. These results show that OPO can promote the absorption of fat and calcium, promote the growth of beneficial bacteria.

Palm Oil and Beta-palmitate in Infant Formula: A Position Paper by the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) Committee on Nutrition

BACKGROUND

Palm oil (PO) is used in infant formulas in order to achieve palmitic acid (PA) levels similar to those in human milk. PA in PO is esterified predominantly at the SN-1,3 position of triacylglycerol (TAG), and infant formulas are now available in which a greater proportion of PA is in the SN-2 position (typical configuration in human milk). As there are some concerns about the use of PO, we aimed to review literature on health effects of PO and SN-2-palmitate in infant formulas.

METHODS

PubMed and Cochrane Database of Systematic Reviews were systematically searched for relevant studies on possible beneficial effects or harms of either PO or SN-2-palmitate in infant formula on various health outcomes.

RESULTS

We identified 12 relevant studies using PO and 21 studies using SN-2-palmitate. Published studies have variable methodology, subject characteristics, and some are underpowered for the key outcomes. PO is associated with harder stools and SN-2-palmitate use may lead to softer stool consistency. Bone effects seem to be short-lasting. For some outcomes (infant colic, faecal microbiota, lipid metabolism), the number of studies is very limited and summary evidence inconclusive. Growth of infants is not influenced. There are no studies published on the effect on markers of later diseases.

CONCLUSIONS

There is insufficient evidence to suggest that PO should be avoided as a source of fat in infant formulas for health reasons. Inclusion of high SN-2-palmitate fat blend in infant formulas may have short-term effects on stool consistency but cannot be considered essential.

Mechanisms Involved in Childhood Obesity-Related Bone Fragility

Childhood obesity is one of the major health problems in western countries. The excessive accumulation of adipose tissue causes inflammation, oxidative stress, apoptosis, and mitochondrial dysfunctions. Thus, obesity leads to the development of severe co-morbidities including type 2 diabetes mellitus, liver steatosis, cardiovascular, and neurodegenerative diseases which can develop early in life. Furthermore, obese children have low bone mineral density and a greater risk of osteoporosis and fractures. The knowledge about the interplay bone tissue and between adipose is still growing, although recent findings suggest that adipose tissue activity on bone can be fat-depot specific. Obesity is associated to a low-grade inflammation that alters the expression of adiponectin, leptin, IL-6, Monocyte Chemotactic Protein 1 (MCP1), TRAIL, LIGHT/TNFSF14, OPG, and TNFα. These molecules can affect bone metabolism, thus resulting in osteoporosis. The purpose of this review was to deepen the cellular mechanisms by which obesity may facilitate osteoporosis and bone fractures.

Dietary sn-2 palmitic triacylglycerols reduced faecal lipids, calcium contents and altered lipid metabolism in Sprague-Dawley rats

In this study, the impact of dietary sn-2 palmitic triacylglycerol (sn-2 PTAG) on faecal lipids, calcium excretion and lipid metabolic alternation was investigated in Sprague-Dawley (SD) rats fed with high-fat diet containing either palm olein (PO, sn-2 palmitic acid (PA) of 14.8%), sn-2 PTAG50 (sn-2 PA of 56.4%) or sn-2 PTAG70 (sn-2 PA of 72.4%), respectively. After 4-week feeding period, SD rats fed with sn-2 PTAGs showed reduced faecal soap fatty acids, neutral lipid and calcium excretion compared to those of PO-fed rats, whereas a significant difference was only observed for the sn-2 PTAG70-fed rats (p < .05). Moreover, dietary sn-2 PTAG70 also showed a significant effect on decreasing serum triacylglycerol (TAG) level, reducing perirenal adipocyte size and regulating lipid metabolism in small intestine and perirenal adipose tissue of SD rats. Significantly increased mRNA levels of genes involved in intestinal lipid anabolism as well as lipid catabolism were both observed in the sn-2 PTAG70-fed rats (p < .05). Meanwhile, dietary sn-2 PTAG70 also significantly up-regulated lipolysis, mitochondrial fatty acid oxidation and thermogenesis-related gene and protein levels in perirenal adipose tissue, which might be correlated with the reduced perirenal adipocyte size. Taken together, our findings indicated that sn-2 PTAG70 may have some beneficial effects on intestinal lipid utilisation and lipid metabolic activity for energy supply in visceral adipose tissue.

Effects of Plant Oil Interesterified Triacylglycerols on Lipemia and Human Health

The position of the fatty acids (sn-1, sn-2 and sn-3) (stereospecific numbering (sn)) in triacylglycerol (TAG) molecules produces a characteristic stereospecificity that defines the physical properties of the fats and influences their absorption, metabolism and uptake into tissues. Fat interesterification is a process that implies a positional distribution of fatty acids (FAs) within the TAG molecules, generating new TAG species, without affecting the FA cis-trans natural balance. The interesterified (IE) fats, frequently used in the food industry comprise fats that are rich in long-chain saturated FAs, such as palmitic acid (16:0) and stearic acid (18:0). Within the interesterified fats, a critical role is played by FA occupying the sn-2 position; in fact, the presence of an unsaturated FA in this specific position influences early metabolic processing and postprandial clearance that in turn could induce atherogenesis and thrombogenesis events. Here, we provide an overview on the role of TAG structures and interesterified palmitic and stearic acid-rich fats on fasting and postprandial lipemia, focusing our attention on their physical properties and their effects on human health.

Beta Palmitate Improves Bone Length and Quality during Catch-Up Growth in Young Rats

Palmitic acid (PA) is the most abundant saturated fatty acid in human milk, where it is heavily concentrated in the sn-2-position (termed beta palmitate, BPA) and as such is conserved in all women, regardless of their diet or ethnicity, indicating its physiological and metabolic importance. We hypothesized that BPA improves the efficiency of nutrition-induced catch up growth as compared to sn-1,3 PA, which is present in vegetable oil. Pre-pubertal male rats were subjected to a 17 days food restriction followed by re-feeding for nine days with 1,3 PA or BPA-containing diets. We measured bone length, epiphyseal growth plate height (EGP, histology), bone quality (micro-CT and 3-point bending assay), and gene expression (Affymetrix). The BPA-containing diet improved most growth parameters: humeri length and EGP height were greater in the BPA-fed animals. Further analysis of the EGP revealed that the hypertrophic zone was significantly higher in the BPA group. In addition, Affymetrix analysis revealed that the diet affected the expression of several genes in the liver and EGP. Despite the very subtle difference between the diets and the short re-feeding period, we found a small but significant improvement in most growth parameters in the BPA-fed rats. This pre-clinical study may have important implications, especially for children with growth disorders and children with special nutritional needs.

Impact of palm olein in infant formulas on stool consistency and frequency: a meta-analysis of randomized clinical trials

Background: Meta-analysis studies have documented that palm olein (PALM) predominant formulas reduce calcium and fat absorption, and bone mineralization in infants, but none have been documented for stool consistency and frequency.

Objective: The study objective was to conduct a meta-analysis of published randomized clinical trials (RCTs) on the effect of PALM-based formulas on stool consistency and frequency in infants.

Design: A literature search was conducted in BIOSIS Previews®, Embase®, Embase® Alert, MEDLINE® and Cochrane databases. PALM-based RCTs with available stool outcomes were selected and meta-analyzed. Mean rank stool consistency (MRSC, primary outcome) and stool frequency (secondary outcome) were compared between infants fed PALM-based and PALM-free formulas (NoPALM), using random effects model.

Results: Nine out of identified16 studies were meta-analyzed. The mean MRSC (scale of 1 = watery to 5 = hard) in the NoPALM-fed infants was lower (softer stools) compared to the PALM-fed infants (mean difference ‒0.355, 95% Confidence Interval [CI] of ‒0.472 to ‒0.239, p < 0.001). Difference for stool frequency was not significant (p = 0.613).

Conclusion: Meta-analysis of RCTs indicated that NoPALM-fed infants have significantly softer stools but similar stool frequencies versus PALM-fed infants, despite differences in study types and design. Future meta-analysis could benefit from including comparison with human milk-fed infants.

Characterisation of Fecal Soap Fatty Acids, Calcium Contents, Bacterial Community and Short-Chain Fatty Acids in Sprague Dawley Rats Fed with Different sn-2 Palmitic Triacylglycerols Diets

The structure of dietary triacylglycerols is thought to influence fatty acid and calcium absorption, as well as intestinal microbiota population of the host. In the present study, we investigated the impact of palmitic acid (PA) esterified at the sn-2 position on absorption of fatty acid and calcium and composition of intestinal microorganisms in rats fed high-fat diets containing either low sn-2 PA (12.1%), medium sn-2 PA (40.4%) or high sn-2 PA (56.3%), respectively. Fecal fatty acid profiles in the soaps were measured by gas chromatography (GC), while fecal calcium concentration was detected by ICP-MS. The fecal microbial composition was assessed using a 16S rRNA high-throughput sequencing technology and fecal short-chain fatty acids were detected by ion chromatograph. Dietary supplementation with a high sn-2 PA fat significantly reduced total fecal contents of fatty acids soap and calcium compared with the medium or low sn-2 PA fat groups. Diet supplementation with sn-2 PA fat did not change the entire profile of the gut microbiota community at phylum level and the difference at genera level also were minimal in the three treatment groups. However, high sn-2 PA fat diet could potentially improve total short-chain fatty acids content in the feces, suggesting that high dietary sn-2 PA fat might have a beneficial effect on host intestinal health.

Beta-palmitate - a natural component of human milk in supplemental milk formulas

The composition and function of human milk is unique and gives a basis for the development of modern artificial milk formulas that can provide an appropriate substitute for non-breastfed infants. Although human milk is not fully substitutable, modern milk formulas are attempting to mimic human milk and partially substitute its complex biological positive effects on infants. Besides the immunomodulatory factors from human milk, research has been focused on the composition and structure of human milk fat with a high content of β-palmitic acid (sn-2 palmitic acid, β-palmitate). According to the available studies, increasing the content of β-palmitate added to milk formulas promotes several beneficial physiological functions. β-palmitate positively influences fatty acid metabolism, increases calcium absorption, improves bone matrix quality and the stool consistency, and has a positive effect on the development of the intestinal microbiome.

SN2-Palmitate Reduces Fatty Acid Excretion in Chinese Formula-fed Infants

OBJECTIVES

Palmitic acid (PA) comprises 17% to 25% of human milk fatty acids, of which 70% to 75% are esterified to the SN2 position of the triglyceride (SN2-palmitate). In vegetable oils, which are commonly used in infant formulas, palmitate is primarily esterified to other positions, resulting in reduced calcium and fat absorption and hard stools. The aim of this study was to elucidate the effects of SN2-palmitate on nutrient excretion.

METHODS

In total, 171 Chinese infants were included (within 14 days of birth) in this multicenter study. Formula-fed infants were randomly assigned to receive either SN2-palmitate formula (INFAT, n = 57) or control formula (n = 57). The formulas (Biostime, China) differed only in their SN2 PA proportions. Stool was collected at 6 postnatal weeks.

RESULTS

The stool dry weight and fat content of the SN2-palmitate group were lower compared with the control group (dry weight 4.25 g vs 7.28 g, P < 0.05; fat 0.8 g vs 1.2 g, P < 0.05). The lipid component was also significantly lower for the SN2-palmitate group (0.79 g vs 1.19 g, P < 0.05). PA, representing ∼50% of the saponified fatty acids, was significantly lower in the SN2-palmitate group compared with the control group (0.3 g vs 0.7 g, P < 0.01). Breast-fed infants had a significantly lower stool dry weight, fat content, and saponified fat excretion compared with formula-fed infants (P < 0.01).

CONCLUSIONS

Similar to breast milk, the SN2-palmitate infant formula primarily reduced calcium-saponified fat excretion. The results of this study further emphasize the nutritional importance of SN2-palmitate structured fat for infants.

Growth of healthy term infants fed partially hydrolyzed whey-based infant formula: a randomized, blinded, controlled trial

Partially hydrolyzed formulas (pHF) represent a significant percentage of the infant formula market. A new whey-based, palm olein oil (PO)-free pHF was developed and a masked, randomized, parallel growth study was conducted in infants fed this formula or a commercially available whey-based pHF with PO. Infants between 0 and 8 days were to be enrolled and studied to 119 days of age. Growth and tolerance of infants were evaluated. Mean weight gain from 14 to 119 days of age was similar between groups. There were no significant differences between groups in weight, length, head circumference (HC), or length or HC gains. Infants fed the new PO-free pHF had significantly softer stools than those fed the PO-containing formula except at 119 days of age. This study demonstrates that whereas growth of infants fed different formulas during the first 4 months of life may be similar, infants may tolerate individual formulas differently.

Effects of term infant formulas containing high sn-2 palmitate with and without oligofructose on stool composition, stool characteristics, and bifidogenicity

OBJECTIVES

Levels of stool fatty acid soaps and beneficial bacteria differ between formula-fed and breast-fed infants; addition of specific formula ingredients may reduce these differences. This study evaluated the effects of a term infant formula containing high sn-2 palmitate term infant formula (sn-2) or an identical formula supplemented with oligofructose (OF) at 2 concentrations (sn-2+3 g/L OF, sn-2+5 g/L OF) on stool composition, stool characteristics, and fecal bifidobacteria.

METHODS

Healthy, term formula-fed infants 7 to 14 days old (n = 300) were randomized in a double-blind manner to receive standard formula (control), sn-2, sn-2+3 g/L OF, or sn-2+5 g/L OF for 8 weeks. Human milk (HM)-fed infants (n = 75) were studied in parallel. Stool samples were collected from all subjects at week 8 for fatty acid soaps and mineral content, and from a subset at baseline and week 8 for bifidobacteria. Stool characteristics were assessed via 3-day diary.

RESULTS

The sn-2 group had 46% less stool soap palmitate (P < 0.001) and softer stools than control (20% more mushy soft stools, P = 0.026; 50% fewer formed stools, P = 0.003). Addition of OF resulted in even fewer formed stools versus control (65% fewer for sn-2+3 g/L OF, 79% fewer for sn-2+5 g/L OF), with 5 g/L OF more closely resembling that of HM-fed infants. Both sn-2 (P < 0.05) and sn-2 with OF groups (P < 0.01) had significantly higher fecal bifidobacteria concentrations than control at week 8, not differing from HM-fed infants.

CONCLUSIONS

High sn-2-palmitate formulas led to reduced stool soaps, softer stools, and increased bifidobacteria, whereas addition of OF further improved stool consistency. Those modifications brought outcomes in formula-fed infants closer to that in HM-fed infants.

N-acetylcysteine supplementation decreases osteoclast differentiation and increases bone mass in mice fed a high-fat diet

Obesity induced by high-fat (HF) diets increases bone resorption, decreases trabecular bone mass, and reduces bone strength in various animal models. This study investigated whether N-acetylcysteine (NAC), an antioxidant and a glutathione precursor, alters glutathione status and mitigates bone microstructure deterioration in mice fed an HF diet. Forty-eight 6-wk-old male C57BL/6 mice were randomly assigned to 4 treatment groups (n = 12 per group) and fed either a normal-fat [NF (10% energy as fat)] or an HF (45% energy as fat) diet ad libitum with or without NAC supplementation at 1 g/kg diet for 17 wk. Compared with the NF groups, mice in the HF groups had higher body weight, greater serum leptin concentrations and osteoclast differentiation, and lower trabecular bone volume, trabecular number, and connectivity density (P < 0.05). NAC supplementation increased the serum-reduced glutathione concentration and bone volume and decreased osteoclast differentiation in HF-fed mice (P < 0.05). We further demonstrated that osteoclast differentiation was directly regulated by glutathione status. NAC treatment of murine macrophage RAW 264.7 cells in vitro increased glutathione status and decreased osteoclast formation. These results show that NAC supplementation increases the bone mass of obese mice induced by an HF diet through elevating glutathione status and decreasing bone resorption.

Obesity and its effects on pediatric supracondylar humeral fractures

BACKGROUND

This study evaluates the effects of childhood obesity on fracture complexity and associated injuries in pediatric supracondylar humeral fractures.

METHODS

A billing query identified all patients who were two to eleven years of age and had undergone operative treatment for extension-type supracondylar humeral fractures over a 12.5-year period. Records were reviewed for demographic data, body mass index percentile, and injury data. Complex fractures were defined as type-3 supracondylar humeral fractures, supracondylar humeral fractures with intercondylar extension, or supracondylar humeral fractures with ipsilateral upper-extremity fractures. Logistic regression analyses were used to test relationships among body mass index subgroups, fracture complexity, elbow motion, preoperative and postoperative neurovascular status, and complications.

RESULTS

Three hundred and fifty-four patients met our inclusion criteria. Forty-one children were underweight (BMI in the <5th percentile), 182 were normal weight (BMI in the 5th to 85th percentile), sixty-three were overweight (BMI in the >85th to 95th percentile), and sixty-eight were obese (BMI in the >95th percentile). There were 149 patients, eleven of whom were obese, with isolated type-2 fractures and 205 patients, fifty-seven of whom were obese, with complex fractures. Thirty-two patients had preoperative nerve palsies and twenty-eight patients had postoperative nerve palsies. Using logistic regression, obesity was associated with complex fractures (odds ratio, 9.19 [95% confidence interval, 4.25 to 19.92]; p < 0.001), preoperative nerve palsies (odds ratio, 2.69 [95% confidence interval, 1.15 to 6.29]; p = 0.02), postoperative nerve palsies (odds ratio, 7.69 [95% confidence interval, 2.66 to 22.31]; p < 0.001), and postoperative complications (odds ratio, 4.03 [95% confidence interval, 1.72 to 9.46]; p < 0.001). Additionally, obese patients were more likely to sustain complex fractures from a fall on an outstretched hand than normal-weight patients (odds ratio, 13.00 [95% confidence interval, 3.44 to 49.19]; p < 0.001).

CONCLUSIONS

Obesity is associated with more complex supracondylar humeral fractures, preoperative and postoperative nerve palsies, and postoperative complications. To our knowledge, this study is the first to assess the implications of obesity on supracondylar humeral fracture complexity and associated injuries and it validates public health efforts in combating childhood obesity.

Calcium and fat metabolic balance, and gastrointestinal tolerance in term infants fed milk-based formulas with and without palm olein and palm kernel oils: a randomized blinded crossover study

BACKGROUND

Effects of palm olein (POL) on calcium and fat metabolic balance and gastrointestinal (GI) tolerance have been clinically evaluated but its use in combination with palm kernel oil (PKO), and canola oil has not been similarly assessed in infants.

METHODS

Calcium and fat balance and GI tolerance were evaluated in 33 healthy term infants (age = 68-159 d) in a randomized, double-blinded, 14 d crossover trial at a day care center in Salvador, Brazil; followed by a 4d hospital ward metabolic balance study in 17 of the male subjects. The study compared two commercially available milk-based powdered formulas in Brazil; one containing POL (44% of total fat), PKO (21.7%) and canola oil (18.5%) as predominant fats (PALM), and the other containing none (NoPALM). Occasional human milk (HM) supplementation was allowed at home.

RESULTS

Formula and HM intakes, and growth were not different (p > 0.05). Calcium absorption (%) for infants fed NoPALM (58.8 ± 16.7%; means ± SD) was higher (p = 0.023) than those fed PALM (42.1 ± 19.2%), but was not significant (p = 0.104) when calcium intake was used as a covariate. Calcium intake was higher (p < 0.001) in NoPALM versus PALM fed infants. However, calcium retention (%) was higher in infants fed NoPALM compared to PALM with (p = 0.024) or without (p = 0.015) calcium intake as a covariate. Fat absorption (%) for NoPALM was greater than PALM fed infants (NoPALM = 96.9 ± 1.2 > PALM = 95.1 ± 1.5; p = 0.020 in Study Period I). Mean rank stool consistency was softer in infants fed NoPALM versus PALM (p < 0.001; metabolic period). Adverse events, spit-up/vomit, fussiness and gassiness were not different (p > 0.05). Formula acceptability was high and comparable for both formula feedings, regardless of HM supplementation.

CONCLUSIONS

Term infants fed PALM based formula (containing palm olein, palm kernel and canola oils) demonstrated lower calcium retention and fat absorption, and less softer stool consistency versus infants fed NoPALM based formula. Study suggested formula fat differences may affect GI function in infants.

Tandem mass spectrometric analysis of human milk triacylglycerols from normal weight and overweight mothers on different diets

The composition and structures of TAGs in the human milk from mothers with different food choices and prepregnancy body mass index were determined with two tandem mass spectrometric methods (negative APCI-MS/MS and positive UHPLC/ESI-MS/MS) at the infant's age of three months. The normal weight mothers with recommended food choices had more 18:3n-3 and less 18:0 in their milk than normal weight mothers with non-recommended food choices. A significant difference between the normal weight mothers on the non-recommended food choices and the other groups was seen in acyl carbon number: number of double bond (ACN:DB)-groups 54:6, 54:5, 54:3 and 54:2. In ACN:DB 52:7 and 52:6 the two recommended food choices-groups differed significantly from the two non-recommended food choices-groups. The regioisomerism of TAGs varied little despite differences in mother's weight and diet with sn-18:1-16:0-18:1 as the most prevalent regioisomer in the milk (13.8±2.7%). The results of this study highlight the importance of structure specific human milk substitutes and the careful selection of the MS/MS methods for analysis of mixtures of several isobaric TAGs.

Review of sn-2 palmitate oil implications for infant health

Human milk provides the optimal balanced nutrition for the growing infant in the first months after birth. The human mammary gland has evolved with unusual pathways, resulting in a specific positioning of fatty acids at the outer sn-1 and sn-3, and center sn-2 of the triacylglyceride, which is different from the triglycerides in other human tissues and plasma. The development of structured triglycerides enables mimicking the composition as well as structure of human milk fat in infant formulas. Studies conducted two decades ago, together with very recent studies, have provided increasing evidence that this unusual positioning of 16:0 in human milk triglycerides has a significant role for infant health in different directions, such as fat and calcium absorption, bone health, intestinal flora and infant comfort. This review aims to unravel the relevance of human milk triglyceride sn-2 16:0 for intestinal health and inflammatory pathways and for other post-absorption effects.

The effect of fatty acid positioning in dietary triacylglycerols and intake of long-chain n-3 polyunsaturated fatty acids on bone mineral accretion in growing piglets

Long-chain n-3 PUFA (LCPUFA) and palmitate (16:0) positioning in the triacylglycerol (TAG) of infant formula may affect calcium-uptake which could affect bone health. We investigated if a human milk fat substitute (HMFS) with a modified TAG structure holding 16:0 predominantly in the sn-2-position compared with a control (CONT) and if increasing n-3LCPUFA intake giving fish oil (FO) compared with sunflower oil (SO) would affect bone parameters in piglets in two sets of controlled 14d-interventions (n=12/group). We assessed this by dual-energy x-ray absorptiometry, and ex vivo peripheral quantitative computed tomography and mechanical strength. Bone mineral content (BMC) was higher in the FO compared to the SO-group (p=0.03). Despite similar weight gain in HMFS- and CONT-groups, body fat accumulation was higher with HMFS (p<0.001), and BMC, bone area (BA) and cortical BA in femur were lower (p=0.002, p=0.005, and p=0.02, respectively), indicating importance of both n-3LCPUFA and 16:0 TAG-positioning in infant formulas.

Dietary triacyglycerols rich in sn-2 palmitate alter post-prandial lipoprotein and unesterified fatty acids in term infants

Human milk TAG contain 20-25% 16:0, with over 70% of the 16:0 at the TAG sn-2 position. The benefits of TAG sn-2 16:0 have been ascribed to reducing 16:0 excretion as insoluble fatty acid soaps. This study builds on knowledge that infants conserve milk TG sn-2 16:0 post-absorption. Comparison of plasma lipids from 120 day old infants fed formula containing 25-27% 16:0 with 29% 16:0 or 5% 16:0 at the TAG sn-2 position showed higher formula sn-2 16:0 led to lower 18:1n-9, but higher 18:2n-6 and 22:6n-3 in the infant plasma unesterified fatty acids, higher 18:0 in LDL TAG, and higher apo B and lower apo A-1. TAG-sn-2 16:0 may provide 16:0 in remnant particles for hepatic elongation to 18:0, needed for plasma and tissue phospholipids. We suggest attention to the plasma unesterified fatty acids as possible sources of fatty acids for membrane phospholipid synthesis.

Multiscale structures of lipids in foods as parameters affecting fatty acid bioavailability and lipid metabolism

On a nutritional standpoint, lipids are now being studied beyond their energy content and fatty acid (FA) profiles. Dietary FA are building blocks of a huge diversity of more complex molecules such as triacylglycerols (TAG) and phospholipids (PL), themselves organised in supramolecular structures presenting different thermal behaviours. They are generally embedded in complex food matrixes. Recent reports have revealed that molecular and supramolecular structures of lipids and their liquid or solid state at the body temperature influence both the digestibility and metabolism of dietary FA. The aim of the present review is to highlight recent knowledge on the impact on FA digestion, absorption and metabolism of: (i) the intramolecular structure of TAG; (ii) the nature of the lipid molecules carrying FA; (iii) the supramolecular organization and physical state of lipids in native and formulated food products and (iv) the food matrix. Further work should be accomplished now to obtain a more reliable body of evidence and integrate these data in future dietary recommendations. Additionally, innovative lipid formulations in which the health beneficial effects of either native or recomposed structures of lipids will be taken into account can be foreseen.

Effect of high β-palmitate content in infant formula on the intestinal microbiota of term infants

OBJECTIVES

Palmitic acid (PA) constitutes 17% to 25% of the human milk fatty acids, and ~70% is esterified in the sn-2 position of triglycerides (β-palmitate). In the sn-2 position, PA is not hydrolyzed and thus is efficiently absorbed. The PA in palm oils, commonly used in infant formulas, is esterified in the sn-1 and sn-3 positions. In these positions, PA is hydrolyzed and forms poorly absorbed calcium complexes. The present study assessed whether high β-palmitate in infant formulas affects the intestinal flora.

METHODS

Thirty-six term infants were enrolled: 14 breast-fed (BF group) and 22 formula-fed infants who were randomly assigned to receive formula containing high β-palmitate (HBP group, n=14), or low β-palmitate (LBP group, n=8), where 44% and 14% of the PA was β-palmitate, respectively. The total amount of PA in the formulas was 19% and 22% in the LBP and HBP groups, respectively. Neither formula contained pre- or probiotics. Stool samples were collected at enrollment and at 6 weeks for the quantification of bacteria.

RESULTS

At 6 weeks, the HBP and BF groups had higher Lactobacillus and bifidobacteria counts than the LBP group (P<0.01). The Lactobacillus counts at 6 weeks were not significantly different between the HBP and BF groups. Lactobacillus counts were 1.2×10¹⁰, 1.2×10¹¹, and 5.6×10¹⁰ CFU/g for LBP, HBP, and BF groups, respectively. Bifidobacteria counts were 5.1×10⁹, 1.2×10¹¹, and 3.9×10¹⁰ CFU/g for LBP, HBP, and BF groups, respectively.

CONCLUSIONS

HBP formula beneficially affected infant gut microbiota by increasing the Lactobacillus and bifidobacteria counts in fecal stools.

High Beta-palmitate formula and bone strength in term infants: a randomized, double-blind, controlled trial

We aimed to compare the effect of 12-week feeding of commercially available infant formulas with different percentages of palmitic acid at sn-2 (beta-palmitate) on anthropometric measures and bone strength of term infants. It was hypothesized that feeding infants with high beta-palmitate (HBP) formula will enhance their bone speed of sound (SOS). Eighty-three infants appropriate for gestational age participated in the study; of these, 58 were formula-fed and 25 breast-fed infants, serving as a reference group. The formula-fed infants were randomly assigned to receive HBP formula (43 % of the palmitic acid is esterified to the middle position of the glycerol backbone, study group; n = 30) or regular formula with low-beta palmitate (LBP, 14 % of the palmitic acid is esterified to the middle position of the glycerol backbone, n = 28). Sixty-six infants completed the 12-week study. Anthropometric and quantitative ultrasound measurements of bone SOS for assessment of bone strength were performed at randomization and at 6 and 12 weeks postnatal age. At randomization, gestational age, birth weight, and bone SOS were comparable between the three groups. At 12 weeks postnatal age, the mean bone SOS of the HBP group was significantly higher than that of the LBP group (2,896 ± 133 vs. 2,825 ± 79 m/s respectively, P = 0.049) and comparable with that of the breast-fed group (2,875 ± 85 m/s). We concluded that infants consuming HBP formula had changes in bone SOS that were comparable to those of infants consuming breast milk and favorable compared to infants consuming LBP formula.

The Mediterranean diet for Polish infants: a losing struggle or a battle still worth fighting?

The Mediterranean diet is well known for its health-promoting effects. Among its key ingredients, olive oil is the most characteristic. Processing industries have been successfully manufacturing and marketing jarred baby foods with the use of vegetable oils, including olive oil, as well as other sources of visible fat. We aimed to survey manufacturer claims concerning added fat in jarred infant foods supplied to the Polish market. A total of 124 kinds of infant foods from six suppliers were analyzed. Corn, canola, and soybean oil occupied the first three positions, respectively, in rank order of vegetable oils used in jarred baby foods. In our sample, only one type of ready-to-eat jars with vegetables contained olive oil. 11% of products contained cow milk butter or cream. 61% of jarred “dinners” contained poultry or fish, which are typical sources of animal protein in the Mediterranean diet. Given that commercial baby foods currently available in the Polish market contain no olive oil, we advocate considering home preparation of infant foods with the use of visible fat. Medical professionals should encourage food manufacturers to return to the concepts of the Mediterranean diet for young consumers, aimed at long-term health.

Effects of obesity on bone metabolism

Obesity is traditionally viewed to be beneficial to bone health because of well-established positive effect of mechanical loading conferred by body weight on bone formation, despite being a risk factor for many other chronic health disorders. Although body mass has a positive effect on bone formation, whether the mass derived from an obesity condition or excessive fat accumulation is beneficial to bone remains controversial. The underline pathophysiological relationship between obesity and bone is complex and continues to be an active research area. Recent data from epidemiological and animal studies strongly support that fat accumulation is detrimental to bone mass. To our knowledge, obesity possibly affects bone metabolism through several mechanisms. Because both adipocytes and osteoblasts are derived from a common multipotential mesenchymal stem cell, obesity may increase adipocyte differentiation and fat accumulation while decrease osteoblast differentiation and bone formation. Obesity is associated with chronic inflammation. The increased circulating and tissue proinflammatory cytokines in obesity may promote osteoclast activity and bone resorption through modifying the receptor activator of NF-κB (RANK)/RANK ligand/osteoprotegerin pathway. Furthermore, the excessive secretion of leptin and/or decreased production of adiponectin by adipocytes in obesity may either directly affect bone formation or indirectly affect bone resorption through up-regulated proinflammatory cytokine production. Finally, high-fat intake may interfere with intestinal calcium absorption and therefore decrease calcium availability for bone formation. Unraveling the relationship between fat and bone metabolism at molecular level may help us to develop therapeutic agents to prevent or treat both obesity and osteoporosis. Obesity, defined as having a body mass index ≥ 30 kg/m2, is a condition in which excessive body fat accumulates to a degree that adversely affects health. The rates of obesity rates have doubled since 1980 and as of 2007, 33% of men and 35% of women in the US are obese. Obesity is positively associated to many chronic disorders such as hypertension, dyslipidemia, type 2 diabetes mellitus, coronary heart disease, and certain cancers. It is estimated that the direct medical cost associated with obesity in the United States is ~$100 billion per year.Bone mass and strength decrease during adulthood, especially in women after menopause. These changes can culminate in osteoporosis, a disease characterized by low bone mass and microarchitectural deterioration resulting in increased bone fracture risk. It is estimated that there are about 10 million Americans over the age of 50 who have osteoporosis while another 34 million people are at risk of developing the disease. In 2001, osteoporosis alone accounted for some $17 billion in direct annual healthcare expenditure. Several lines of evidence suggest that obesity and bone metabolism are interrelated. First, both osteoblasts (bone forming cells) and adipocytes (energy storing cells) are derived from a common mesenchymal stem cell and agents inhibiting adipogenesis stimulated osteoblast differentiation and vice versa, those inhibiting osteoblastogenesis increased adipogenesis. Second, decreased bone marrow osteoblastogenesis with aging is usually accompanied with increased marrow adipogenesis. Third, chronic use of steroid hormone, such as glucocorticoid, results in obesity accompanied by rapid bone loss. Fourth, both obesity and osteoporosis are associated with elevated oxidative stress and increased production of proinflammatory cytokines. At present, the mechanisms for the effects of obesity on bone metabolism are not well defined and will be the focus of this review.