The fat deposition and lipid composition directly influence meat quality and feed efficiency during pork production. Glutamate (GLU) is a major component of proteins and has been widely utilized in livestock production. However, the role of GLU in regulating lipid deposition and the lipo-nutritional quality of porcine fat remains unclear. This study aimed to investigate the effects of GLU on fatty acid composition and lipid profiles in subcutaneous fat (SF) and perirenal fat (PF) from Shaziling pigs. Forty-eight finishing pigs aged 150 days (31.56 ± 0.95 kg) were divided into the control (CON) group and the GLU-supplemented group (1% GLU), each consisting of 6 pens (4 pigs per pen). After 51 days, 6 pigs (1 pig/pen) from each group were slaughtered for analysis. Fatty acid analysis detected 46 species in SF and 40 in PF. In SF, 1% GLU significantly increased the content of C18:3n3 (P < 0.05), which was accompanied by an increase in n3 PUFA deposition (P < 0.05) and a decreased n6/n3 ratio (P = 0.06). In PF, GLU supplementation reduced the levels of C18:1n9t, C24:1, C22:6n3, and others (P < 0.05). The content of monounsaturated fatty acids (MUFAs) and n9 unsaturated fatty acids (UFAs) was significantly decreased in the GLU group (P < 0.05). Similarly, GLU significantly reduced the n6/n3 PUFA ratio in PF (P < 0.05). Lipidomics profiling identified 2264 unique lipids in fat tissues. GLU had minimal effects on lipid composition in SF but significantly reduced ceramides (Cer), phosphatidylserine (PS), and phosphatidylinositol (PIP) contents in PF (P < 0.05) compared to the CON group. Additionally, GLU influenced the acyl chain saturation degree, fatty acyl chain length, and individual acyl chain composition in glycerophospholipid (GP) pools of PF. These results demonstrate the regulatory role of GLU on lipid dynamics in porcine fat and provide insights into regulating fat deposition and liponutritional quality in indigenous Chinese pig breeds.

Evidence indicates hypervitaminosis A may be attributed to overconsumption of natural preformed vitamin A (VA) and overlapping VA intervention strategies. Hypervitaminosis A can disrupt metabolic processes; however, the extent and mechanisms of these impacts are not well understood. This study aims to assess metabolic differences related to hypervitaminosis A and VA supplementation by performing metabolomics analysis. A subsample of South African preschoolers participating in the country’s VA supplementation programme was selected. Participants were divided into two groups: adequate VA (n 15; 0·59–0·99 µmol/g total liver reserve and high VA (n 15; ≥ 1·0 µmol/g total liver reserve). Serum samples were collected at baseline and 28 d after consuming a 200 000 IU VA supplement. Lipidomics and oxylipins assays were conducted using ultraperformance LC-MS. At baseline, unsaturated lysophosphatidylcholines and unsaturated phosphatidylcholines were significantly lower in the high VA group (P < 0·05). A group-by-time interaction with VA supplementation was observed for polyunsaturated lysophosphatidylcholines and polyunsaturated phosphatidylcholines (P < 0·05). Additionally, a group effect was noted for oxylipins, and a time effect in response to VA supplementation was seen with decreased arachidonic acid and lipoxygenase- and non-enzymatically derived oxylipins (P < 0·05). Hypervitaminosis A is associated with modifications in lipids involved in cell structure and signalling, particularly unsaturated lysophosphatidylcholines and phosphatidylcholines. Further research is needed to identify the mechanisms behind these modifications, their physiological effects and their potential as biomarkers of elevated vitamin A status.

This study aimed to assess how Bacillus subtilis and Enterococcus faecium co-fermented feed (FF) affects the antioxidant capacity, muscle fibre types and muscle lipid profiles of finishing pigs. In this study, a total of 144 Duroc × Berkshire × Jiaxing Black finishing pigs were randomly assigned into three groups with four replicates (twelve pigs per replication). The three treatments were a basal diet (0 % FF), basal diet + 5 % FF and basal diet + 10 % FF, respectively. The experiment lasted 38 d after 4 d of acclimation. The study revealed that 10 % FF significantly increased the activity of superoxide dismutase (SOD) and catalase (CAT) compared with 0 % FF group, with mRNA levels of up-regulated antioxidant-related genes (GPX1, SOD1, SOD2 and CAT) in 10 % FF group. 10 % FF also significantly up-regulated the percentage of slow-twitch fibre and the mRNA expression of MyHC I, MyHC IIa and MyHC IIx, and slow MyHC protein expression while reducing MyHC IIb mRNA expression. Lipidomics analysis showed that 5 % FF and 10 % FF altered lipid profiles in longissimus thoracis. 10 % FF particularly led to an increase in the percentage of TAG. The Pearson correlation analysis indicated that certain molecular markers such as phosphatidic acid (PA) (49:4), Hex2Cer (d50:6), cardiolipin (CL) (72:8) and phosphatidylcholine (PC) (33:0e) could be used to indicate the characteristics of muscle fibres and were closely related to meat quality. Together, our findings suggest that 10 % FF improved antioxidant capacity, enhanced slow-twitch fibre percentage and altered muscle lipid profiles in finishing pigs.

Gestational diabetes mellitus (GDM) is the most common medical complication of pregnancy and a severe threat to pregnant people and offspring health. The molecular origins of GDM, and in particular the placental responses, are not fully known. The present study aimed to perform a comprehensive characterisation of the lipid species in placentas from pregnancies complicated with GDM using high-resolution MS lipidomics, with a particular focus on sphingolipids and acylcarnitines in a semi-targeted approach. The results indicated that despite no major disruption in lipid metabolism, placentas from GDM pregnancies showed significant alterations in sphingolipids, mostly lower abundance of total ceramides. Additionally, very long-chain ceramides and sphingomyelins with twenty-four carbons were lower, and glucosylceramides with sixteen carbons were higher in placentas from GDM pregnancies. Semi-targeted lipidomics revealed the strong impact of GDM on the placental acylcarnitine profile, particularly lower contents of medium and long-chain fatty-acyl carnitine species. The lower contents of sphingolipids may affect the secretory function of the placenta, and lower contents of long-chain fatty acylcarnitines is suggestive of mitochondrial dysfunction. These alterations in placental lipid metabolism may have consequences for fetal growth and development.

Lipid metabolism has been an area of increased interest in psychosis research, not only due to its link to metabolic comorbidities, but also due to its putative role in the pathophysiology of psychosis. Lipid disturbances are observed already in the period preceding the onset of psychosis. For example, we performed mass spectrometry based lipidomics in a cohort of individuals at clinical high risk for psychosis (the EU-GEI study) and found that the individuals who transitioned to psychosis within a 2-year follow-up period displayed decreased levels of ether phospholipids. This finding may be of direct (patho)physiological relevance, as ether phospholipids (particularly plasmalogens, a major subgroup of ether phospholipids) are highly enriched in the brain, are supplied to the brain by the liver, have many structural and functional roles, and may act as endogenous antioxidants. Accumulating evidence also suggests that lipid disturbances play a crucial role in the development of metabolic comorbidities associated with psychotic disorders. Our lipidomic studies have shown that psychotic patients who rapidly gain weight during follow-up have elevated triglycerides (TGs) with low double bond count and carbon number at baseline. These TGs are known to be associated with non-alcoholic fatty liver disease (NAFLD) and with increased risk of type 2 diabetes. In conclusion, although the mechanisms linking dysregulation of lipid metabolism with the pathophysiology of psychosis are currently poorly understood, findings by us and others suggest that metabolic abnormalities are evident in people who are vulnerable to psychosis, and to the associated metabolic comorbidities.

In this work we report a lipidomics approach to study the effects of two diet systems on the composition of ovine milk. Milk from two groups of Sarda sheep grazing on 40% (P40) and 60% (P60) of pasture were analyzed by a UHPLC-QTOF-MS analytical platform and data submitted to multivariate statistical analysis. Pairwise partial least square discriminant analysis of the lipid profile of the data was carried out to classify samples and to find discriminant lipids. The two dietary groups were characterized by differences in triacylglycerols, phosphocholines and phosphatidylethanolamines levels. Discriminants of the P40 group were TG and PC containing in their backbone saturated medium chain FA thus suggesting greater de novo fatty synthesis in the mammary gland. On the other hand, the P60 group was characterized by TG and PC formed by unsaturated long chain FA originating from the diet or from lipid mobilization.

Lifestyle intervention may be effective in reducing type 2 diabetes mellitus incidence and cardiometabolic risk. A more personalised nutritional approach based on an individual or subgroup-based metabolic profile may optimise intervention outcome. Whole body insulin resistance (IR) reflects defective insulin action in tissues such as muscle, liver, adipose tissue, gut and brain, which may precede the development of cardiometabolic diseases. IR may develop in different organs but the severity may vary between organs. Individuals with more pronounced hepatic IR have a distinct plasma metabolome and lipidome profile as compared with individuals with more pronounced muscle IR. Additionally, genes related to extracellular modelling were upregulated in abdominal subcutaneous adipose tissue in individuals with more pronounced hepatic IR, whilst genes related to inflammation as well as systemic low-grade inflammation were upregulated in individuals with primarily muscle IR. There are indications that these distinct IR phenotypes may also respond differentially to dietary macronutrient composition. Besides metabolic phenotype, microbial phenotype may be of importance in personalising the response to diet. In particular fibres or fibre mixtures, leading to a high distal acetate and SCFA production may have more pronounced effects on metabolic health. Notably, individuals with prediabetes may have a reduced response to diet-induced microbiota modulation with respect to host insulin sensitivity and metabolic health outcomes. Overall, we need more research to relate metabolic subphenotypes to intervention outcomes to define more optimal diets for individuals with or predisposed to chronic metabolic diseases.

Cardiometabolic diseases exhibit changes in lipid biology, which is important as lipids have critical roles in membrane architecture, signalling, hormone synthesis, homoeostasis and metabolism. However, Developmental Origins of Health and Disease studies of cardiometabolic disease rarely include analysis of lipids. This short review highlights some examples of lipid pathology and then explores the technology available for analysing lipids, focussing on the need to develop imaging modalities for intracellular lipids. Analytical methods for studying interactions between the complex endocrine and intracellular signalling pathways that regulate lipid metabolism have been critical in expanding our understanding of how cardiometabolic diseases develop in association with obesity and dietary factors. Biochemical methods can be used to generate detailed lipid profiles to establish links between lifestyle factors and metabolic signalling pathways and determine how changes in specific lipid subtypes in plasma and homogenized tissue are associated with disease progression. New imaging modalities enable the specific visualization of intracellular lipid traffic and distribution in situ. These techniques provide a dynamic picture of the interactions between lipid storage, mobilization and signalling, which operate during normal cell function and are altered in many important diseases. The development of methods for imaging intracellular lipids can provide a dynamic real-time picture of how lipids are involved in complex signalling and other cell biology pathways; and how they ultimately regulate metabolic function/homoeostasis during early development. Some imaging modalities have the potential to be adapted for in vivo applications, and may enable the direct visualization of progression of pathogenesis of cardiometabolic disease after poor growth in early life.

The circadian system temporally coordinates daily rhythms in feeding behaviour and energy metabolism. The objective of the present paper is to review the mechanisms that underlie circadian regulation of lipid metabolic pathways. Circadian rhythms in behaviour and physiology are generated by master clock neurons in the suprachiasmatic nucleus (SCN). The SCN and its efferent targets in the hypothalamus integrate light and feeding signals to entrain behavioural rhythms as well as clock cells located in peripheral tissues, including the liver, adipose tissue and muscle. Circadian rhythms in gene expression are regulated at the cellular level by a molecular clock comprising a core set of clock genes/proteins. In peripheral tissues, hundreds of genes involved in lipid biosynthesis and fatty acid oxidation are rhythmically activated and repressed by clock proteins, hence providing a direct mechanism for circadian regulation of lipids. Disruption of clock gene function results in abnormal metabolic phenotypes and impaired lipid absorption, demonstrating that the circadian system is essential for normal energy metabolism. The composition and timing of meals influence diurnal regulation of metabolic pathways, with food intake during the usual rest phase associated with dysregulation of lipid metabolism. Recent studies using metabolomics and lipidomics platforms have shown that hundreds of lipid species are circadian-regulated in human plasma, including but not limited to fatty acids, TAG, glycerophospholipids, sterol lipids and sphingolipids. In future work, these lipid profiling approaches can be used to understand better the interaction between diet, mealtimes and circadian rhythms on lipid metabolism and risk for obesity and metabolic diseases.

Ageing is associated with a prolonged and exaggerated postprandial lipaemia. This study aimed to examine the contribution of alterations in chylomicron synthesis, size and lipid composition to increased lipaemia. Healthy older (60–75 years; n 15) and younger (20–25 years; n 15) subjects consumed a high-fat breakfast. Chylomicron dynamics and fatty acid composition were analysed for 5 h in the postprandial state. Plasma TAG levels were elevated following the meal in the older subjects, relative to younger subjects (P<0·01). For older subjects compared with younger subjects, circulating chylomicron particle size was smaller (P<0·05), with greater apoB content (P<0·05) at all postprandial time points. However, total chylomicron TAG concentration between the groups was unaltered post-meal. Compared with younger subjects, the older subjects exhibited a greater proportion of oleic acid in the TAG and phospholipid (PL) fraction (P<0·05), plus lower proportions of linoleic acid in the TAG fraction of the chylomicrons (P<0·01). Thus, following the ingestion of a high-fat meal, older individuals demonstrate both smaller, more numerous chylomicrons, with a greater total MUFA and lower PUFA contents. These data suggest that the increased postprandial lipaemia of ageing cannot be attributed to increased chylomicron TAG. Rather, ageing is associated with changes in chylomicron particle size, apoB content and fatty acid composition of the chylomicron TAG and PL fractions.

The association between consumption of full-fat dairy foods and CVD may depend partly on the nature of products and may not apply to low-fat dairy foods. Increased circulating levels of inflammatory biomarkers after consumption of dairy product-rich meals suggest an association with CVD. In the present study, we tested the effects of low-fat and full-fat dairy diets on biomarkers associated with inflammation, oxidative stress or atherogenesis and on plasma lipid classes. Within full-fat dairy diets, we also compared fermented v. non-fermented products. In a randomised cross-over study, twelve overweight/obese subjects consumed during two 3-week periods two full-fat dairy diets containing either yogurt plus cheese (fermented) or butter, cream and ice cream (non-fermented) or a low-fat milk plus yogurt diet, with the latter being consumed between and at the end of the full-fat dairy dietary periods. The concentrations of six inflammatory and two atherogenic biomarkers known to be raised in CVD were measured as well as those of plasma F2-isoprostanes and lipid classes. The concentrations of six of the eight biomarkers tended to be higher on consumption of the low-fat dairy diet than on that of the fermented dairy diet and the concentrations of two plasmalogen lipid classes reported to be associated with increased oxidisability were also higher on consumption of the low-fat dairy diet than on that of the fermented dairy diet (P< 0·001), although plasma F2-isoprostane concentrations did not differ on consumption of any of the diets. On the other hand, the concentrations of plasma sphingomyelin and IL-6 were significantly higher on consumption of the non-fermented dairy diet than on that of the low-fat dairy diet (P< 0·02). In conclusion, short-term diets containing low-fat dairy products did not lead to a more favourable biomarker profile associated with CVD risk compared with the full-fat dairy products, suggesting that full-fat fermented dairy products may be the more favourable.

The biological membranes of Trypanosoma brucei contain a complex array of phospholipids that are synthesized de novo from precursors obtained either directly from the host, or as catabolised endocytosed lipids. This paper describes the use of nanoflow electrospray tandem mass spectrometry and high resolution mass spectrometry in both positive and negative ion modes, allowing the identification of ~500 individual molecular phospholipids species from total lipid extracts of cultured bloodstream and procyclic form T. brucei. Various molecular species of all of the major subclasses of glycerophospholipids were identified including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol as well as phosphatidic acid, phosphatidylglycerol and cardolipin, and the sphingolipids sphingomyelin, inositol phosphoceramide and ethanolamine phosphoceramide. The lipidomic data obtained in this study will aid future biochemical phenotyping of either genetically or chemically manipulated commonly used bloodstream and procyclic strains of Trypanosoma brucei. Hopefully this will allow a greater understanding of the bizarre world of lipids in this important human pathogen.