Reported breast milk lipid concentrations may vary with geographical region, postnatal age and year of sample collection. In this review, we summarized data on the concentrations of total fat, total phospholipids, cholesterol and fatty acids in human milk worldwide and their variation according to lactation stage, study area and sample collection year. A systematic literature search was performed using the PubMed, Embase, Web of Science and Medline databases for English language papers and Wanfang and China National Knowledge Infrastructure databases for Chinese language papers. A total of 186 studies evaluating the human milk lipid profiles were included. According to random effects models based on worldwide data, the summarized means (95% confidence intervals) as percentages of total fat were 42.2% (41.1%, 43.3%) for saturated fatty acids (SFAs), 36.6% (35.6%, 37.5%) for monounsaturated fatty acids (MUFAs) and 21.0% (19.3%, 22.7%) for polyunsaturated fatty acids (PUFAs). However, the study heterogeneity was high for most types of fatty acids (I² > 99%). Human milk from western countries had higher concentrations of MUFAs and 18:1n-9, but lower concentrations of PUFAs, 18:2n-6, 20:4n-6, 18:3n-3, 20:5n-3, 22:6n-3 and total n-6PUFA in compared with those from non-western countries (P: <0.001–0.011). Significant lactation stage differences were observed for total fat and some individual fatty acids. The concentrations of SFAs and 16:0 were significantly negatively correlated with sampling year (P < 0.001–0.028). In contrast, a significant positive correlation between the concentrations of 18:2n-6 and 18:3n-3 and sampling year was observed (P < 0.001–0.035). Our results suggest that the pooling of data on human milk lipid profiles in different studies should be done with caution due to the high between-study heterogeneity. The concentration of lipids, including total fat, cholesterol and specific fatty acids, differs in human milk according to lactation stage, geographical region and year of sample collection.

Phytonutrients are natural bioactive components present in the daily diet that can exert a positive impact on human health. Studies have shown that phytonutrients may act as antioxidants and improve metabolism after being ingested, which help to regulate physiological processes and prevent metabolic disorders and diseases. However, their efficacy is limited by their low bioavailability. The gut microbiota is symbiotic with humans and its abundance and profile are related to most diseases. Interestingly, studies have shown that the gut microbiota is associated with the metabolism of phytonutrients by converting them into small molecules that can be absorbed by the body, thereby enhancing their bioavailability. Furthermore, phytonutrients can modulate the composition of the gut microbiota, and therefore improve the host's health. Here, we focus on uncovering the mechanisms by which phytonutrients and gut microbiota play roles in health, and the interrelationships between phytonutrients and gut microbiota were summarized. We also reviewed the studies that reported the efficacy of phytonutrients in human health and the future directions.

Nutritional disorders have become a major public health issue, requiring increased targeted approaches. Personalized nutrition adapted to individual needs has garnered dramatic attention as an effective way to improve nutritional balance and maintain health. With the rapidly evolving fields of genomics and nutrigenetics, accumulation of genetic variants has been indicated to alter the effects of nutritional supplementation, suggesting its indispensable role in the genotype-based personalized nutrition. Additionally, the metabolism of nutrients, such as lipids, especially omega-3 polyunsaturated fatty acids, glucose, vitamin A, folic acid, vitamin D, iron, and calcium could be effectively improved with related genetic variants. This review focuses on existing literatures linking critical genetic variants to the nutrient and the ways in which these variants influence the outcomes of certain nutritional supplementations. Although further studies are required in this direction, such evidence provides valuable insights for the guidance of appropriate interventions using genetic information, thus paving the way for the smooth transition of conventional generic approach to genotype-based personalized nutrition.

The glycaemic index (GI) is a food metric that ranks the acute impact of available (digestible) carbohydrates on blood glucose. At present, few countries regulate the inclusion of GI on food labels even though the information may assist consumers to manage blood glucose levels. Australia and New Zealand regulate GI claims as nutrition content claims and also recognize the GI Foundation’s certified Low GI trademark as an endorsement. The GI Foundation of South Africa endorses foods with low, medium and high GI symbols. In Asia, Singapore’s Healthier Choice Symbol has specific provisions for low GI claims. Low GI claims are also permitted on food labels in India. In China, there are no national regulations specific to GI; however, voluntary claims are permitted. In the USA, GI claims are not specifically regulated but are permitted, as they are deemed to fall under general food-labelling provisions. In Canada and the European Union, GI claims are not legal under current food law. Inconsistences in food regulation around the world undermine consumer and health professional confidence and call for harmonization. Global provisions for GI claims/endorsements in food standard codes would be in the best interests of people with diabetes and those at risk.

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.