Macronutrient content and fatty acid composition and their positional distribution in human breast milk from Zhejiang Province, China in different lactation periods

Optimizing ARA and DHA in infant formula: A systematic review of global trends, regional disparities, and considerations for precision nutrition

In the context of precision nutrition, the addition of ARA and DHA in infant formula needs to consider more factors. This study conducted a comprehensive literature review, including 112 relevant Chinese and English articles, to summarize and analyze the global levels of ARA, DHA, and the ARA/DHA ratio in breast milk. The data were correlated with local aquatic products intake and children's IQ. The results indicated that the average level of DHA in breast milk across regions is lower than that of ARA. Variations in DHA content were identified as a primary factor influencing ARA/DHA ratio fluctuations. Breast milk ARA and DHA levels decrease with prolonged lactation periods but increase over the past 22 years. Correlation analysis revealed a significant positive relationship between aquatic products intake and breast milk DHA levels (r = 0.64, p < 0.05). Breast milk DHA levels also showed a significant positive correlation with children's IQ (r = 0.67, p < 0.01). Stable breast milk ARA content did not exhibit significant correlations with aquatic products intake or children's IQ (r = 0, p > 0.05). Among 22 infant formula products available in China, only 5 had ARA levels within the range of breast milk. Most formula products had higher ARA levels than DHA, resulting in ARA/DHA ratios generally exceeding 1. The temporal and spatial variability in breast milk ARA and DHA levels may lead to diverse health outcomes in infants. Therefore, the addition of ARA and DHA in infant formula should consider this variability, including the molecular forms and positional isomerism of the added ARA and DHA. Additionally, considering the impact of different cognitive development tests and infant's gene expression on formula assessment results, there is a need to establish a more comprehensive infant health assessment system to guide the addition of ARA and DHA in formula.

Lipase-Catalyzed Synthesis of Structured Fatty Acids Enriched with Medium and Long-Chain n-3 Fatty Acids via Solvent-Free Transesterification of Skipjack Tuna Eyeball Oil and Commercial Butterfat

Human milk lipids generally have the maximum long-chain fatty acids at the sn-2 position of the glycerol backbone. This positioning makes them more digestible than long-chain fatty acids located at the sn-1, 3 positions. These unique fatty acid distributions are not found elsewhere in nature. When lactation is insufficient, infant formula milk has been used as a substitute. However, the distribution of most fatty acids ininfant formula milk is still different from human milk. Therefore, structured lipids were produced by the redistribution of medium-chain fatty acids from commercial butterfat (CBF) and n-3 and n-6 long-chain fatty acids from skipjack tuna eyeball oil (STEO). Redistribution was carried out via transesterification facilitated by Asian seabass liver lipase (ASL-L). Under the optimum conditions including a CBF/STEO ratio (3:1), transesterification time (60 h), and ASL-L unit (250 U), the newly formed modified-STEO (M-STEO) contained 93.56% triacylglycerol (TAG), 0.31% diacylglycerol (DAG), and 0.02% monoacylglycerol (MAG). The incorporated medium-chain fatty acids accounted for 18.2% of M-STEO, whereas ASL-L could incorporate 40% of n-3 fatty acids and 25-30% palmitic acid in M-STEO. The 1H NMRA and 13CNMR results revealed that the major saturated fatty acid (palmitic acid) and unsaturated fatty acids (DHA and EPA) were distributed at the sn-2 position of the TAGs in M-STEO. Thus, M-STEO enriched with medium-chain fatty acids and n-3 fatty acids positioned at the sn-2 position of TAGs can be a potential substitute for human milk fatty acids in infant formula milk (IFM).

1-Oleate-2-palmitate-3-linoleate glycerol improves lipid metabolism and gut microbiota and decreases the level of pro-inflammatory cytokines

Numerous studies have shown that 1-oleate-2-palmitate-3-linoleate (OPL) is the most abundant TAG in Chinese human milk, which is significantly different from human milk in other countries, where 1,3-oleate-2-palmitate (OPO) is the most abundant TAG. However, there have been few studies revealing the nutritional outcomes of OPL. Hence, the present study investigated the effects of an OPL supplementation diet on mice's nutritional outcomes, including liver lipid parameters, inflammation, lipidomes in the liver and serum, and the gut bacterial community. A high OPL (HOPL) diet decreased body weight, weight gain, liver TG, TC and LDL-C, and TNF-α, IL-1β, and IL-6 in mice relative to low OPL (LOPL) diet. Lipidomics results showed that HOPL feeding elevated the level of anti-inflammatory lipids, such as very long-chain Cer, LPC, PC and ether TG in the liver, and serum PC, and reduced the level of oxidized lipids (liver OxTG, HexCer 18:1;2O/22:0) and serum TG. In the gut, intestinal probiotics, including Parabacteroides, Alistipes, Bacteroides, Alloprevotella and Parasutterrlla, were enriched in the HOPL-fed group. Meanwhile, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis results showed that the HOPL diet up-regulated energy metabolism and the immune system. Correlation analysis further showed that there was a relationship among the gut bacteria, lipidome profile, and nutritional outcomes. Altogether, these results indicated that an OPL-supplemented diet improved lipid metabolism and gut bacteria, reducing the level of pro-inflammatory cytokines.

Impact of DHA from Algal Oil on the Breast Milk DHA Levels of Lactating Women: A Randomized Controlled Trial in China

Population research on the intervention of docosahexaenoic acid (DHA) supplementation in lactating women is in its infancy in China. This study investigated the effect of DHA supplementation on DHA concentrations in the breast milk of lactating women, and the intervention effect, with respect to different dietary patterns. In this trial, 160 healthy lactating women in Nanjing (30−50 days postpartum) were recruited and randomly divided into control (one placebo capsule of similar appearance per day) and supplement (one capsule with 200 mg of DHA from algal oil per day) groups for 8 weeks. Before and after the intervention, all subjects were asked to maintain basic information, maternal anthropometric parameters, breast milk (10−15 mL) sample collection, and a dietary survey using a food frequency questionnaire. The concentrations of DHA and other fatty acids in breast milk were detected using capillary gas chromatography. This study was completed by 137 subjects, with 60 in the control group and 77 in the supplement group. Compared with the DHA concentrations in the breast milk at enrollment, the absolute concentrations of the control group showed a significant decrease at the end of the trial (p = 0.037). In addition, after intervention, the absolute and relative DHA concentrations in the supplement group (10.07 mg/100 mL and 0.40%, respectively) were higher than those in the control group (7.57 mg/100 mL and 0.28%, respectively), being statistically significant (p = 0.012 and p = 0.001). Furthermore, the maternal diet in the supplement group was divided into four dietary patterns. Pattern 1 mainly included fruits and livestock meat. Pattern 2 was dominated by milk and its products, eggs, fish, shrimp and shellfish, and soybeans and its products. Pattern 3 chiefly comprised cereal and beans other than soybeans, potatoes, and nuts. Pattern 4 was high in poultry meat and low in cooking oils. The change in the absolute concentration of DHA in Pattern 3 was lower than that in other patterns (p < 0.05). In conclusion, DHA supplementation in lactating mothers increased breast milk DHA concentrations. The dietary pattern mainly characterized by cereal and beans other than soybeans, potatoes, and nuts may contribute to the poor intervention effect.

Maternal Factors Affecting the Macronutrient Composition of Transitional Human Milk

This study investigated the influence of selected maternal factors on the macronutrient composition and energy of human milk (HM). The study enrolled 159 breastfeeding mothers from five postpartum care centers in Seoul, Korea. Their gestational weeks were 37−42 weeks, they had no complications before and after childbirth, and were at 7−14 days postpartum. They provided data using structured questionnaires on general characteristics, stress, sleep quality, spousal support, and dietary intake. Breastfeeding assessment (LATCH) was investigated by qualified nurses, and each mother provided one sample of HM. The HM composition was analyzed using the Miris® HM analyzer. The relationships between variables were analyzed using Pearson’s correlation analysis, and a linear regression analysis was performed to verify the main variables. It was found that maternal dietary intake was related to HM composition as the %energy from carbohydrates (β = 0.86, p < 0.01) and %energy from fat (β = 0.77, p < 0.05) showed positive relationships with HM energy. The LATCH score was positively related to HM energy (β = 0.17, p < 0.05). In contrast, postpartum stress, sleep quality, and spousal support were not associated with HM macronutrient composition. In conclusion, HM macronutrients and energy content were associated with maternal dietary intake and LATCH scores, but not with postpartum stress, sleep quality, and spousal support.