Sterols in Infant Formulas: A Bioaccessibility Study

Infant formulae - Key components, nutritional value, and new perspectives

Breastfeeding is the most effective strategy for meeting the nutritional demands of infants, whilst infant formulae are manufactured foods that mimic human milk and can be safely used to replace breastfeeding. In this paper, the compositional differences between human milk and other mammalian milk are reviewed, and thus nutritional profiles and compositions of standard bovine milk-based formulae as well as special formulae are discussed. Differences between breast milk and other mammalian milk in composition and content affect their digestion and absorption in infants. Characteristics and mimicking of breast milk have been intensively studied with the objective of narrowing the gap between human milk and infant formulae. The functions of the key nutritional components in infant formulae are examined. This review detailed recent developments in the formulation of different types of special infant formulae and efforts for their humanization, and summarized safety and quality control of infant formulae.

Age-related reference intervals for serum phytosterols in children by gas chromatography-mass spectrometry and its application in diagnosing sitosterolemia

BACKGROUND AND AIMS

Serum phytosterol profiles are essential for the diagnosis and management of sitosterolemia. However, pediatric reference interval (RI) studies are scarce and various mass spectrometry (MS) approaches for phytosterol analysis still face multiple limitations. Therefore, an optimized gas chromatography (GC)-MS assay and age-related RIs in children are both required.

MATERIALS AND METHODS

Cholesterol and phytosterols (sitosterol, campesterol, cholestanol, stigmasterol, and sitostanol) were simultaneously determined by optimized GC-MS and performance was verified by the lower limit of quantification (LLOQ), linearity, precision, recovery, matrix effects, and method comparison. Healthy children (247 males and 263 females) were recruited, sex and age dependence were assessed using quantile regression (2.5th percentile and 97.5th percentile), and RIs were established according to Clinical and Laboratory Standards Association guideline C28-A3. These RIs were validated in 19 patients with sitosterolemia and 23 patients with hypercholesterolemia.

RESULTS

The optimized method shortened the sample processing time by approximately 60 min. Among the five phytosterols, all precision, recoveries (ranging from 89.97% to 104.94%), and relative matrix effects (%CV: ranging from 0.08% to 13.88%) met the specifications. GC-MS showed good agreement with lower cholesterol concentrations compared to conventional enzymatic methods. No significant differences between males and females were observed for all phytosterols, but age dependency was found and age-related RIs were established accordingly. Five phytosterols were significantly higher than RIs in patients with sitosterolemia.

CONCLUSION

We established age-related RIs for five phytosterols in children based on an optimized GC-MS assay, providing a screening tool for the diagnosis of sitosterolemia in children.

Dietary exposure assessment of infant formula and baby foods' oxidized lipids in the US population

Baby Foods (BFs) and Infant formulas (IFs) are the main sources of nutrition for an infant throughout the 1st year of life. Various enriched products are commercially available for parents seeking to fulfill their baby's nutritional needs. Consequently, different bioactive lipids are present in BFs and IFs, including dietary oxysterols (DOxS), whose known toxicity has been associated with mutagenicity, cancer, and other chronic diseases. In this work, we performed an exposure assessment of 25 bioactive lipids on IFs (n = 30) and BFs (n = 13) commercially available in the US. To determine dietary exposure, we used EPA's SHEDS-HT probabilistic model. Even though β-Sitosterol was the most exposed bioactive lipid with 75,410 μg/day, cholesterol was the most absorbed compound during the entire first year (19.3 mg/day). Additionally, we found 7α-hydroxycholesterol (7α-OH) as a potential DOxS biomarker of the BFs manufacturing process. This is the first time an infant's exposure assessment (including DOxS) after BFs and IFs consumption is performed, enabling much-needed information regarding these hazardous compounds and their potential effects on infants' health.

Evaluation of Pure Bile Salts in Place of Bile Extract in the Standardized INFOGEST Digestion Protocol for Quantification of Sterol Bioaccessibility

Improving standardized in vitro digestion protocols for phytosterols (PSs) is critical for understanding their bioaccessibility (BA) in food products and supplements. In this study, in vitro BA of phytosterol esters (PSEs) and free cholesterol (Ch) was compared under modified digestion conditions. The addition of Ch esterase (CE) to the INFOGEST model containing bovine bile resulted in a 70% increase in PS BA and an 18.5% reduction in Ch micellarization. Relative to the standardized INFOGEST model, substitution of pure bile salts (PBSs) did not significantly change PS BA or Ch micellarization. In the presence of CE, the substitution resulted in a 49.9% reduction in PS BA and a 13% increase in Ch micellarization. The differing results may be due to inhibitory effects of PBSs on the activity of intestinal enzymes, including CE. These results suggest that the INFOGEST model should include Ch esterase and the continued use of bile extract to evaluate PS BA.

Safety of oil from Schizochytrium sp. (strain ATCC 20889) for use in infant and follow-on formula as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of Schizochytrium sp. oil as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF which is the subject of the application is an oil rich in docosahexaenoic acid (DHA) that is produced by the microalgae Schizochytrium sp. (strain ATCC-20889). The applicant proposed to add the NF in infant formulae (IF) and follow-on formulae (FOF) at use levels in accordance with Regulation (EU) No 609/2013. The evidence provided by the applicant does not demonstrate to which species the strain Schizochytrium sp. ATCC 20889 belongs. As the source organism of the NF is not characterised at species level, no assessment for inclusion in the Qualified Presumption of Safety (QPS) list can be performed by EFSA. Marine biotoxins (including cyanotoxins) in the NF were below their limits of quantification. However, since it is unknown to which species the strain Schizochytrium sp. ATCC 20889 belongs, the concern that this strain has the potential to produce other toxins remains. No toxicological studies with the NF were provided by the applicant. Toxicological studies are available with DHA-rich algal oils produced from other strains of Schizochytrium sp. However, the Panel considers that those toxicological studies cannot be used to establish the safety of the oil produced by the strain which is under assessment in this application (Schizochytrium sp. ATCC 20889). Therefore, based on the information provided by the applicant, the Panel concludes that the safety of the NF has not been established.

Lipid profiling and dietary assessment of infant formulas reveal high intakes of major cholesterol oxidative product (7-ketocholesterol)

Approximately two-thirds of US infants receive infant formula (IF) as a primary or sole nutritional source during the first six months of life. IF is available in a variety of commercial presentations; from a manufacturing standpoint, they can be categorized as powder- (PIF) or liquid- (LIF) based formulations. Thirty commercial IFs were analyzed in their oxidative and non-oxidative lipid profiles. We identified 7-ketocholesterol - a major end-product of cholesterol oxidation - as a potential biomarker of IF manufacturing. The statistical analysis allowed a re-classification of IF based on their metabolomic fingerprint, resulting in three groups assigned with low-to-high oxidative status. Finally, we modeled the dietary intake of cholesterol, sterols, and 7-ketocholesterol in the first year of life. The database provided in this study will be instrumental for scientists interested in infant nutrition, to establish bases for epidemiological studies aimed to find connections between nutrition and diet-associated diseases, such as sitosterolemia.

Safety of oil from Schizochytrium limacinum (strain FCC-3204) for use in infant and follow-on formula as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of Schizochytrium sp. oil as a novel food (NF) pursuant to Regulation (EU) 2015/2283. Schizochytrium sp. is a single‐cell microalga. The strain FCC‐ 3204, used by the applicant (Fermentalg), belongs to the species Schizochytrium limacinum. The NF, an oil rich in docosahexaenoic acid (DHA), is obtained from microalgae after enzymatic lysis. The applicant proposed to use the NF in infant formulae (IF) and follow‐on formulae (FOF). The use level defined by the applicant was derived from Regulation (EU) 2016/127, which states the mandatory addition of DHA to IF and FOF at the level of 20–50 mg/100 kcal. The intake of DHA resulting from the use of the NF in IF and FOF is not expected to pose safety concerns. S. limacinum was attributed the qualified presumption of safety (QPS) status with the qualification ‘for production purposes only’. Data provided by the applicant demonstrated the absence of viable cells in the NF. No toxicological studies were performed with the NF. However, based on the available toxicological data on oils derived from Schizochytrium sp., the QPS status of the source of the NF, the production process, the composition of the NF and the absence of viable cells in the NF, the Panel considers there are no concerns with regard to toxicity of the NF. The Panel concludes that the NF is safe under the proposed conditions of use.

Dietary Fatty Acids and Host-Microbial Crosstalk in Neonatal Enteric Infection

Human milk is the best nutritional choice for infants. However, in instances where breastfeeding is not possible, infant formulas are used as alternatives. While formula manufacturers attempt to mimic the performance of human breast milk, formula-fed babies consistently have higher incidences of infection from diarrheal diseases than those breastfed. Differences in disease susceptibility, progression and severity can be attributed, in part, to nutritional fatty acid differences between breast milk and formula. Despite advances in our understanding of breast milk properties, formulas still present major differences in their fatty acid composition when compared to human breast milk. In this review, we highlight the role of distinct types of dietary fatty acids in modulating host inflammation, both directly and through the microbiome-immune nexus. We present evidence that dietary fatty acids influence enteric disease susceptibility and therefore, altering the fatty acid composition in formula may be a potential strategy to improve infectious outcomes in formula-fed infants.

Plant-based sterols and stanols in health & disease: "Consequences of human development in a plant-based environment?"

Dietary plant sterols and stanols as present in our diet and in functional foods are well-known for their inhibitory effects on intestinal cholesterol absorption, which translates into lower low-density lipoprotein cholesterol concentrations. However, emerging evidence suggests that plant sterols and stanols have numerous additional health effects, which are largely unnoticed in the current scientific literature. Therefore, in this review we pose the intriguing question "What would have occurred if plant sterols and stanols had been discovered and embraced by disciplines such as immunology, hepatology, pulmonology or gastroenterology before being positioned as cholesterol-lowering molecules?" What would then have been the main benefits and fields of application of plant sterols and stanols today? We here discuss potential effects ranging from its presence and function intrauterine and in breast milk towards a potential role in the development of non-alcoholic steatohepatitis (NASH), cardiovascular disease (CVD), inflammatory bowel diseases (IBD) and allergic asthma. Interestingly, effects clearly depend on the route of entrance as observed in intestinal-failure associated liver disease (IFALD) during parenteral nutrition regimens. It is only until recently that effects beyond lowering of cholesterol concentrations are being explored systematically. Thus, there is a clear need to understand the full health effects of plant sterols and stanols.

Cholesterol Content in Human Milk during Lactation: A Comparative Study of Enzymatic and Chromatographic Methods

This study validates a gas chromatography (GC) method for determining the sterol profile of human milk (HM) and compares it with an enzymatic-spectrophotometric (E-S) method. Good linearity ( r > 0.97) and low limits of detection and quantification were obtained with the GC method (<1.8 and <6 μg/100 g of HM, respectively). Suitable intra- and interassay precisions (all <18%) and satisfactory recovery percentages (80-109%) were obtained for both methods. In addition, both methodologies were used to assess cholesterol evolution in HM during lactation, showing a 50% decrease at 6 months versus colostrum. The E-S method overestimated cholesterol content by <20% versus the GC method. The results indicate that both methods may be used by the industry and in research to better understand the differences between the sterol profiles of infant formulas and HM.

Sterols in human milk during lactation: bioaccessibility and estimated intakes

Total sterol content decreased to the half throughout lactation, being their intake lower at colostrum and its bioaccessibility higher at first month.