Climate-based variability in the essential fatty acid composition of soybean oil.

BACKGROUND: Soybean oil is a major dietary source of the essential fatty acids linoleic acid (LA) and α-linolenic acid (ALA); however, high-daytime temperatures during seed development reduce desaturase activity in soybeans. The resultant reduction in LA and ALA levels is a phenomenon well-known to soybean breeders, although the impact of this interaction between plants and environment on human nutrition is poorly understood. OBJECTIVES: Using data from the literature, we developed a model for soybean essential fatty acid composition. Combining this model with contemporary agricultural and meteorological data sets, we determined whether insufficiency of essential fatty acids could result from geographic, intrayear, or interyear variability. METHODS: We modeled this change using 233 data points from 16 studies that provided fatty acid composition data from plants grown under daytime high temperatures ranging from 15°C to 40°C. RESULTS: As temperature increased, LA and ALA concentrations decreased from 55% to 30% and 13% to 3.5%, respectively. Application of the model to daytime high temperatures from 2 growth periods over 6 y showed significant regional, interyear, and intrayear variation in essential fatty acid content (P < 0.05). Using county yield data, we developed oil fatty acid models for the 3 top-producing regions of the United States. From this work, it was determined that soybean oil manufactured from soybeans in the southern United States may contain insufficient ALA to meet human nutritional needs because of high-daytime temperatures. CONCLUSIONS: This work suggests that climate-based variation may result in many human populations not achieving an adequate daily intake of ALA.

Effects of Blanching, Freezing and Canning on the Carbohydrates in Sweet Corn.

Sweet corn is frequently consumed in the US and contains carbohydrates as major macronutrients. This study examined the effects of blanching, freezing, and canning on carbohydrates in sweet corn. Fresh bi-color sweet corn was picked in the field and processed immediately into frozen and canned samples. Simple sugars, starch, and dietary fiber (DF) (including total DF (TDF), insoluble DF (IDF) and two fractions of soluble DF (SDF)) were measured according to the AOAC methods. Additional glycomic analysis including oligosaccharides, monosaccharide composition of total polysaccharides (MCTP) and glycosidic linkage of total polysaccharides (GLTP) were analyzed using UHPLC-MS. Sucrose is the major simple sugar, and IDF is the main contributor to TDF. Sucrose and total simple sugar concentrations were not altered after blanching or freezing but were significantly reduced in canned samples. Kestose was the only oligosaccharide identified in sweet corn and decreased in all heat-treated or frozen samples. Starch content decreased in frozen samples but increased in canned samples. While two SDF fractions did not differ across all samples, blanching, freezing and canning resulted in increases in TDF and IDF. Six monosaccharides were identified as major building blocks of the total polysaccharides from MCTP analysis. Glucose and total monosaccharide concentrations increased in two canned samples. GLTP was also profoundly altered by different food processing methods. This study provided insights into the changes in the content and quality of carbohydrates in sweet corn after food processing. The data are important for accurate assessment of the carbohydrate intake from different sweet corn products.

Metabolomic Alterations in Mammary Glands from Pubertal Mice Fed a High-Fat Diet.

Dietary malpractice is a risk factor for obesity. This study tested the hypothesis that consumption of a high-fat diet alters mammary metabolome in pubertal mice. We performed untargeted metabolomic analysis of primary metabolism on mammary glands from pubertal mice fed the AIN93G standard diet or a high-fat diet (HFD) for 3 weeks. We identified 97 metabolites for statistical comparisons. The HFD altered the amino acid metabolism considerably. This included elevated expression of branched-chain amino acids, non-essential amino acids (aspartic acid and glutamic acid), and methionine sulfoxide (oxidized methionine) and an alteration in the aminoacyl-tRNA biosynthesis pathway. Furthermore, elevations of fumaric acid and malic acid (both are citrate cycle intermediates) and glyceric acid (its phosphate derivatives are intermediates of glycolysis) in HFD-fed mice suggest an acceleration of both citrate cycle and glycolysis. Lower expression of glycerol, oleic acid, and palmitoleic acid, as well as decreased mammary expression of genes encoding lipid metabolism (Acaca, Fads1, Fasn, Scd1, and Srebf1) in HFD-fed mice indicate an attenuated lipid metabolism in the presence of adequate dietary fat. In conclusion, consumption of the HFD for 3 weeks alters metabolic profile of pubertal mammary glands. This alteration may affect mammary development and growth in pubertal mice.

Effects of maternal HF diet and absence of TRPC1 gene on mouse placental growth and fetal intrauterine growth retardation (IUGR).

Placental tissue intracellular calcium (Ca2+) regulates placental development and growth. Maternal high-fat diet (HFD) results in placental lipid accumulation, increased inflammation, reduced nutrient transport expression, and intrauterine growth restriction (IUGR). Currently, whether maternal HFD differentially affects placental and fetal growth and development under reduced Ca2+ influx is not yet known. We hypothesized that maternal HFD feeding decreases placental growth and development resulting in IUGR and that reduction of Ca2+ influx in the placenta worsens maternal HFD-induced placental dysfunction and IUGR. Three-week-old female B6129SF2/J wild type (WT) and transient receptor potential canonical 1 (TRPC1) protein deficient (KO) mice were fed normal fat (NF, 16 kcal % fat) and high fat (HF, 45 kcal % fat) diets for 12 weeks prior to mating with NF diet fed male mice. Fetuses and placentae were examined at mid- (D12) and late- (D18) gestation. At D12, maternal HFD had no effects on placental or fetal weight changes in WT and TRPC1 KO mice while absence of TRPC1 resulted in decreased placental and fetal weights. At D18, maternal HFD increased placental weights in both TRPC1 KO and WT mice, in part, by moderately increasing placental tissue triacylglyceride (TAG, P=.0632). At D12, mRNA expression of key placental growth factors including IGF1, PLGF, and VEGF were increased in WT compared to TRPC1 KO mice while IGF2 and VEGF mRNA expression were increased at D18. Results presented in our study demonstrated that maternal HFD increased placental weight, in part, due to increased lipid concentration resulting in IUGR and via an additive adverse effect of genotype and maternal HFD. Future studies are needed to determine the signaling mechanism underlying Ca2+ influx reduction-induced placental dysfunction and IUGR.

Identification of oncogenic signatures in the inflammatory colon of C57BL/6 mice fed a high-fat diet.

Adoption of an obesogenic diet such as a high-fat diet (HFD) results in obesity, bacterial dysbiosis, chronic inflammation, and cancer. Gut bacteria and their metabolites are recognized by interleukin-1 (IL-1R)/toll-like receptors (TLRs) which are essential to maintain intestinal homeostasis. Moreover, host extracellular microRNAs (miRNAs) can alter bacterial growth in the colon. Characterization of the underlying mechanisms may lead to identifying fecal oncogenic signatures reflecting colonic health. We hypothesize that an HFD accelerates the inflammatory process and modulates IL-1R/TLR pathways, gut microbiome, and disease-related miRNA in the colon. In this study, 4-week-old C57BL/6 mice were fed a modified AIN93G diet (AIN, 16% energy fat) or an HFD (45% energy fat) for 15 weeks. In addition to increased body weight and body fat composition, the concentrations of plasma interleukin 6 (IL-6), inflammatory cell infiltration, ß-catenin, and cell proliferation marker (Ki67) in the colon were elevated > 68% in the HFD group compared to the AIN group. Using a PCR array analysis, we identified 14 out of 84 genes with a ≥ 24% decrease in mRNA content related to IL-1R and TLR pathways in colonic epithelial cells in mice fed an HFD compared to the AIN. Furthermore, the content of Alistipes bacteria, the Firmicutes/Bacteroidetes ratio, microRNA-29a, and deoxycholic and lithocholic acids (secondary bile acids with oncogenic potential) were 55% greater in the feces of the HFD group compared to the AIN group. Collectively, this composite, a multimodal profile may represent a unique HFD-induced fecal signature for colonic inflammation and cancer in C57BL/6 mice.

Quantifying Sphingomyelin in Dairy through Infusion-Based Shotgun Mass Spectrometry with Lithium-Ion-Induced Fragmentation.

Quantifying sphingomyelin (SM) species by infusion-based mass spectrometry (MS) is complicated by the presence of isobaric phosphatidylcholine (PC) species, which generate a common m/z 184 product ion in the presence of ammonium ions as a result of the phosphocholine headgroup. Lithium ion adducts of SM undergo a selective dehydration [Li + H2O + (CH3)3NC2H4PO4] with a corresponding neutral loss of -207 Da. This neutral loss was employed to create a SM-selective method for identifying target species, which were quantitated using multiple reaction monitoring (MRM). SM-selective fragments in MS3 were used to characterize the sphingosine base and acyl chain. These methods were used to identify 50 individual SM species in bovine milk ranging from SM 28:1 to SM 44:2, with d16:1, d17:1, d18:1, d19:1, and d20:1 bases, and acyl fatty acids ranging from 10 to 25 carbons and 0-1 desaturations. Spiked SM standards into milk had a recovery of 99.7%, and endogenous milk SM had <10% coefficient of variation for both intra- and interday variability, with limits of detection of 1.4-5.55 nM and limits of quantitation of 11.8-178.1 nM. This MS-MRM method was employed to accurately and precisely quantify SM species in dairy products, including bovine-derived whole milk, half and half, whipping cream, and goat milk.

Alteration in Plasma Metabolome in High-Fat Diet-Fed Monocyte Chemotactic Protein-1 Knockout Mice Bearing Pulmonary Metastases of Lewis Lung Carcinoma.

Both clinical and laboratory studies have shown that monocyte chemotactic protein-1 (MCP-1) is involved in cancer spread. To understand the role of MCP-1 in metabolism in the presence of metastasis, we conducted an untargeted metabolomic analysis of primary metabolism on plasma collected from a study showing that MCP-1 deficiency reduces spontaneous metastasis of Lewis lung carcinoma (LLC) to the lungs in mice fed a high-fat diet (HFD). In a 2 × 2 design, wild-type (WT) or Mcp-1 knockout (Mcp-1 -/-) mice maintained on the AIN93G standard diet or HFD were subcutaneously injected with LLC cells to induce lung metastasis. We identified 87 metabolites for metabolomic analysis from this study. Amino acid metabolism was altered considerably in the presence of LLC metastases with the aminoacyl-tRNA biosynthesis pathways as the leading pathway altered. The HFD modified lipid and energy metabolism, evidenced by lower contents of arachidonic acid, cholesterol, and long-chain saturated fatty acids and higher contents of glucose and pyruvic acid in mice fed the HFD. These findings were supported by network analysis showing alterations in fatty acid synthesis and glycolysis/gluconeogenesis pathways between the 2 diets. Furthermore, elevations of the citrate cycle intermediates (citric acid, fumaric acid, isocitric acid, and succinic acid) and glyceric acid in Mcp-1 -/- mice, regardless of diet, suggest the involvement of MCP-1 in mitochondrial energy metabolism during LLC metastasis. The present study demonstrates that MCP-1 deficiency and the HFD altered plasma metabolome in mice bearing LLC metastases. These findings can be useful in understanding the impact of obesity on prevention and treatment of cancer metastasis.

Corrigendum: Lipidomic Analysis of TRPC1 Ca2+-Permeable Channel-Knock Out Mouse Demonstrates a Vital Role in Placental Tissue Sphingolipid and Triacylglycerol Homeostasis Under Maternal High-Fat Diet.

[This corrects the article DOI: 10.3389/fendo.2022.854269.].

Metabolomes of Lewis lung carcinoma metastases and normal lung tissue from mice fed different diets.

Metastasis is a devastating aspect of cancer. This study tested the hypothesis that metabolome of metastases differs from that of host organs by using the spontaneous metastasis model of Lewis lung carcinoma (LLC). In a 2 × 2 design, male C57BL/6 mice with or without a subcutaneous LLC inoculation were fed the standard AIN93G diet or a high-fat diet (HFD) for 12 weeks. Lung metastases from injected mice and the lungs from non-injected mice were harvested at the end of study for untargeted metabolomics of primary metabolism by using gas chromatography time-of-flight mass spectrometry. We identified 91 metabolites for metabolomic analysis. The analysis demonstrated that amino acid and energy metabolism were altered the most in LLC metastases compared to the lungs. A 60% decrease in glutamine and a 25-fold elevation in sorbitol were observed in metastases. Cholesterol and its metabolite dihydrocholesterol were 50% lower in metastases than in the lungs. The HFD elevated arachidonic acid and its precursor linoleic acid in the lungs from noncancer-bearing mice, reflecting the dietary fatty acid composition of the HFD. This elevation did not occur in metastases from HFD-fed LLC-bearing mice, suggesting alterations in lipid metabolism during LLC metastatic progression. Understanding the differences in metabolome between pulmonary LLC metastases and the normal healthy lungs can be useful in designing targeted studies for prevention and treatment of cancer spread using this LLC spontaneous metastasis model.

Lipidomic Analysis of TRPC1 Ca2+-Permeable Channel-Knock Out Mouse Demonstrates a Vital Role in Placental Tissue Sphingolipid and Triacylglycerol Homeostasis Under Maternal High-Fat Diet.

The transient receptor potential canonical channel 1 (TRPC1) is a ubiquitous Ca2+-permeable integral membrane protein present in most tissues, including adipose and placenta, and functionally regulates energetic homeostasis. We demonstrated that elimination of TRPC1 in a mouse model increased body adiposity and limited adipose accumulation under a high fat diet (HFD) even under conditions of exercise. Additionally, intracellular Ca2+ regulates membrane lipid content via the activation of the protein kinase C pathway, which may impact placental membrane lipid content and structure. Based upon this we investigated the effect of HFD and TRPC1 elimination on neutral lipids (triacylglycerol and cholesteryl ester), membrane lipids (phosphatidylcholine and phosphatidylethanolamine), and other multifunctional lipid species (unesterified cholesterol, sphingomyelins, ceramides). The concentration of unesterified cholesterol and sphingomyelin increased with gestational age (E12.5 to E 18.5.) indicating possible increases in plasma membrane fluidity. Diet-dependent increases ceramide concentration at E12.5 suggest a pro-inflammatory role for HFD in early gestation. TRPC1-dependent decreases in cholesterol ester concentration with concomitant increases in long-chain polyunsaturated fatty acid -containing triacylglycerols indicate a disruption of neutral lipid homeostasis that may be tied to Ca2+ regulation. These results align with changes in lipid content observed in studies of preeclamptic human placenta.

Identification of High and Low Branched-Chain Fatty Acid-Producing Phenotypes in Holstein Cows following High-Forage and Low-Forage Diets in a Crossover Designed Trial.

BACKGROUND: Branched-chain fatty acids (BCFAs) are rumen-derived fatty acids comprising ∼2% of bovine-milk fatty acids. BCFAs possess anti-inflammatory properties and enriching the BCFA content of bovine milk may provide human health benefits. OBJECTIVE: We determined whether forage content impacts the BCFA content of milk from Holstein cows and identified fatty acid phenotypes in high vs. low BCFA-containing milks. METHODS: Holstein cows (n = 62), fed for 67 d in a crossover design, consumed a diet with high forage and low concentrate (HF:C) and a diet with low forage and high concentrate (LF:C). Milk samples were collected at the end of each treatment period and fatty acid content determined. Paired t-tests, 1-factor ANOVA, sparse partial least-squares discriminant analysis (sPLSDA), and Pearson's correlation analysis were used to analyze the data. RESULTS: The total milk fatty acid concentration for cows fed the HF:C diet was greater than that of cows fed the LF:C diet (4.2 ± 0.7 g/100 mL vs. 3.9 ± 0.9 g/100 mL). sPLSDA demonstrated separation of the dietary treatments, with BCFAs and odd-chain fatty acids as primary determinants. Total BCFA content in milk fat was elevated by HF:C intake compared with LF:C intake (1.80 vs. 1.68%). Quintile separation of high vs. low BCFA milks resulted in 4 groups: HF:C /low BCFAs, HF:C /high BCFAs; LF:C /low BCFAs, and LF:C /high BCFAs. Milks from the high BCFA quintiles had lower palmitic acid content (29.6% vs. 34.4%) but higher oleic acid content than milks from the low BCFA quintiles (19.7% vs. 17.0%). Some cows were identified as high BCFA producers or low BCFA producers regardless of diet. CONCLUSIONS: BCFA content of milk is diet-sensitive but variation in responses exists. The potential to produce milk with high BCFA content and lower SFA content needs further study.

Mammary Tumorigenesis and Metabolome in Male Adipose Specific Monocyte Chemotactic Protein-1 Deficient MMTV-PyMT Mice Fed a High-Fat Diet.

Male breast cancer, while uncommon, is a highly malignant disease. Monocyte chemotactic protein-1 (MCP-1) is an adipokine; its concentration in adipose tissue is elevated in obesity. This study tested the hypothesis that adipose-derived MCP-1 contributes to male breast cancer. In a 2x2 design, male MMTV-PyMT mice with or without adipose-specific Mcp-1 knockout [designated as Mcp-1-/- or wild-type (WT)] were fed the AIN93G standard diet or a high-fat diet (HFD) for 25 weeks. Mcp-1-/- mice had lower adipose Mcp-1 expression than WT mice. Adipose Mcp-1 deficiency reduced plasma concentrations of MCP-1 in mice fed the HFD compared to their WT counterparts. Mcp-1-/- mice had a longer tumor latency (25.2 weeks vs. 18.0 weeks) and lower tumor incidence (19% vs. 56%), tumor progression (2317% vs. 4792%), and tumor weight (0.23 g vs. 0.64 g) than WT mice. Plasma metabolomics analysis identified 56 metabolites that differed among the four dietary groups, including 22 differed between Mcp-1-/- and WT mice. Pathway and network analyses along with discriminant analysis showed that pathways of amino acid and carbohydrate metabolisms are the most disturbed in MMTV-PyMT mice. In conclusion, adipose-derived MCP-1 contributes to mammary tumorigenesis in male MMTV-PyMT. The potential involvement of adipose-derived MCP-1 in metabolomics warrants further investigation on its role in causal relationships between cancer metabolism and mammary tumorigenesis in this male MMTV-PyMT model.

Azoxymethane Alters the Plasma Metabolome to a Greater Extent in Mice Fed a High-Fat Diet Compared to an AIN-93 Diet.

Consumption of a high-fat diet (HFD) links obesity to colon cancer in humans. Our data show that a HFD (45% energy fat versus 16% energy fat in an AIN-93 diet (AIN)) promotes azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) formation in a mouse cancer model. However, the underlying metabolic basis remains to be determined. In the present study, we hypothesize that AOM treatment results in different plasma metabolomic responses in diet-induced obese mice. An untargeted metabolomic analysis was performed on the plasma samples by gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). We found that 53 of 144 identified metabolites were different between the 4 groups of mice (AIN, AIN + AOM, HFD, HFD + AOM), and sparse partial least-squares discriminant analysis showed a separation between the HFD and HFD + AOM groups but not the AIN and AIN + AOM groups. Moreover, the concentrations of dihydrocholesterol and cholesterol were inversely associated with AOM-induced colonic ACF formation. Functional pathway analyses indicated that diets and AOM-induced colonic ACF modulated five metabolic pathways. Collectively, in addition to differential plasma metabolomic responses, AOM treatment decreases dihydrocholesterol and cholesterol levels and alters the composition of plasma metabolome to a greater extent in mice fed a HFD compared to the AIN.

Adequacy of calcium and vitamin D reduces inflammation, ß-catenin signaling, and dysbiotic Parasutterela bacteria in the colon of C57BL/6 mice fed a western-style diet.

Adoption of an obesogenic diet low in calcium and vitamin D (CaD) leads to increased obesity, colonic inflammation, and cancer. However, the underlying mechanisms remain to be elucidated. We tested the hypothesis that CaD supplementation (from inadequacy to adequacy) may reduce colonic inflammation, oncogenic signaling, and dysbiosis in the colon of C57BL/6 mice fed a Western diet. Male C57/BL6 mice (4-weeks old) were assigned to 3 dietary groups for 36 weeks: (1) AIN76A as a control diet (AIN); (2) a defined rodent "new Western diet" (NWD); or (3) NWD with CaD supplementation (NWD/CaD). Compared to the AIN, mice receiving the NWD or NWD/CaD exhibited more than 0.2-fold increase in the levels of plasma leptin, tumor necrosis factor α (TNF-α) and body weight. The levels of plasma interleukin 6 (IL-6), inflammatory cell infiltration, and ß-catenin/Ki67 protein (oncogenic signaling) were increased more than 0.8-fold in the NWD (but not NWD/CaD) group compared to the AIN group. Consistent with the inflammatory phenotype, colonic secondary bile acid (inflammatory bacterial metabolite) levels increased more than 0.4-fold in the NWD group compared to the NWD/CaD and AIN groups. Furthermore, the abundance of colonic Proteobacteria (e.g., Parasutterela), considered signatures of dysbiosis, was increased more than four-fold; and the α diversity of colonic bacterial species, indicative of health, was decreased by 30% in the NWD group compared to the AIN and NWD/CaD groups. Collectively, CaD adequacy reduces colonic inflammation, ß-catenin oncogenic signaling, secondary bile acids, and bacterial dysbiosis in mice fed with a Western diet.

Identification of Phenotypic Lipidomic Signatures in Response to Long Chain n-3 Polyunsaturated Fatty Acid Supplementation in Humans.

Background Supplementation with long chain n-3 polyunsaturated fatty acids is used to reduce total circulating triacylglycerol (TAG) concentrations. However, in about 30% of people, supplementation with long chain n-3 polyunsaturated fatty acids does not result in decreased plasma TAG. Lipidomic analysis may provide insight into this inter-individual variability. Methods Lipidomic analyses using targeted, mass spectrometry were performed on plasma samples obtained from a clinical study in which participants were supplemented with 3 g/day of long chain n-3 in the form of fish oil capsules over a 6-week period. TAG species and cholesteryl esters (CE) were quantified for 130 participants pre- and post-supplementation. Participants were segregated into 3 potential responder phenotypes: (1) positive responder (Rpos; TAG decrease), (2) non-responder (Rnon; lacking TAG change), and (3) negative responder (Rneg; TAG increase) representing 67%, 18%, and 15% of the study participants, respectively. Separation of the 3 phenotypes was attributed to differential responses in TAG with 50 to 54 carbons with 1 to 4 desaturations. Elevated TAG with higher carbon number and desaturation were common to all phenotypes following supplementation. Using the TAG responder phenotype for grouping, decreases in total CE and specific CE occurred in the Rpos phenotype versus the Rneg phenotype with intermediate responses in the Rnon phenotype. CE 20:5, containing eicosapentaenoic acid (20:5n-3), was elevated in all phenotypes. A classifier combining lipidomic and genomic features was built to discriminate triacylglycerol response phenotypes and reached a high predictive performance with a balanced accuracy of 75%. Conclusions These data identify lipidomic signatures, TAG and CE, associated with long chain n-3 response p henotypes and identify a novel phenotype based upon CE changes. Registration URL: https://www.ClinicalTrials.gov; Unique Identifier: NCT01343342.

Simple, Rapid Lipidomic Analysis of Triacylglycerols in Bovine Milk by Infusion-Electrospray Mass Spectrometry.

Bovine milk is a complex mixture of lipids, proteins, carbohydrates, and other factors of which lipids comprise 3-5% of the total mass. Rapid analysis and characterization of the triacylglycerols (TAG) that comprise about 95% of the total lipid is daunting given the numerous TAG species. In the attached methods paper, we demonstrate an improved method for identifying and quantifying TAG species by infusion-based "shotgun" lipidomics. Because of the broad range of TAG species in milk, a single internal standard was insufficient for the analysis and required sectioning the spectrum into three portions based upon mass range to provide accurate quantitation of TAG species. Isobaric phospholipid interferences were removed using a simple dispersive solid-phase extraction step. Using this method, > 100 TAG species were quantitated by acyl carbon number and desaturation level in a sample of commercially purchased bovine milk.

Time-restricted feeding mice a high-fat diet induces a unique lipidomic profile.

Time-restricted feeding (TRF) can reduce adiposity and lessen the co-morbidities of obesity. Mice consuming obesogenic high-fat (HF) diets develop insulin resistance and hepatic steatosis, but have elevated indices of long-chain polyunsaturated fatty acids (LCPUFA) that may be beneficial. While TRF impacts lipid metabolism, scant data exist regarding the impact of TRF upon lipidomic composition of tissues. We (1) tested the hypothesis that TRF of a HF diet elevates LCPUFA indices while preventing insulin resistance and hepatic steatosis and (2) determined the impact of TRF upon the lipidome in plasma, liver, and adipose tissue. For 12 weeks, male, adult mice were fed a control diet ad libitum, a HF diet ad libitum (HF-AL), or a HF diet with TRF, 12 hours during the dark phase (HF-TRF). HF-TRF prevented insulin resistance and hepatic steatosis resulting from by HF-AL treatment. TRF-blocked plasma increases in LCPUFA induced by HF-AL treatment but elevated concentrations of triacylglycerols and non-esterified saturated fatty acids. Analysis of the hepatic lipidome demonstrated that TRF did not elevate LCPUFA while reducing steatosis. However, TRF created (1) a separate hepatic lipid signature for triacylglycerols, phosphatidylcholine, and phosphatidylethanolamine species and (2) modified gene and protein expression consistent with reduced fatty acid synthesis and restoration of diurnal gene signaling. TRF increased the saturated fatty acid content in visceral adipose tissue. In summary, TRF of a HF diet alters the lipidomic profile of plasma, liver, and adipose tissue, creating a third distinct lipid metabolic state indicative of positive metabolic adaptations following HF intake.

Metabolome of Mammary Tumors Differs from Normal Mammary Glands But Is Not Altered by Time-restricted Feeding Under Obesogenic Conditions.

BACKGROUND/AIM: Time restricted feeding (TRF) mitigates the high-fat diet-enhanced mammary tumorigenesis in a MMTV-PyMT breast cancer model. MATERIALS AND METHODS: We performed untargeted metabolomic and targeted transcriptomic analyses on mammary tumors from MMTV-PyMT mice fed a standard AIN93G diet, a high-fat diet (HFD), or HFD with TRF (12 h, dark phase) and mammary glands from wild-type mice fed the AIN93G diet. RESULTS: The metabolic profile of mammary tumors differed from that of mammary glands; there was no impact of TRF upon tumor metabolome. TRF did reduce elevated expression of Hmgcr, Srebp1, Fads2, and Ppard in mammary tumors, indicating a down-regulation of lipid metabolism. CONCLUSION: The null effect of TRF on the metabolomic profile does not rule out changes in more refined intracellular signaling pathways. It suggests that the protection of TRF against mammary tumorigenesis may rely upon its action on the host rather than a direct effect on tumor metabolism.

Advanced liver steatosis accompanies an increase in hepatic inflammation, colonic, secondary bile acids and Lactobacillaceae/Lachnospiraceae bacteria in C57BL/6 mice fed a high-fat diet.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western countries, and the gut-liver axis is implicated in liver disease pathogenesis. We hypothesize that advanced liver steatosis accompanies an increase in hepatic inflammation, colonic secondary bile acids (BAs) and secondary BA-producing bacteria in mice fed a high-fat (HF) diet model of obesity. Four-week old male C57BL/6 mice were fed an HF (45% energy) or a low-fat (LF) (10% energy) diet for 21 weeks. At the end of the study, body weight and body fat percentage in the HF group were 0.23- and 0.41-fold greater than those in the LF group, respectively. Similarly, the HF group exhibited an increase in hepatic lipid droplets, inflammatory cell infiltration, inducible nitric oxide synthase, and hepatocellular ballooning (but without hepatic Mallory bodies) which are key histological features of advanced hepatic steatosis. Furthermore, RNA sequencing, qPCR and immunohistological methods found that nicotinamide n-methyltransferase and selenoprotein P, two inflammation-related hepatic genes, were upregulated in the HF group. Consistent with the hepatic inflammation, the levels of proinflammatory plasma-cytokines (TNF-α and IL6), colonic secondary BAs (LCA, DCA) and secondary BA producing bacteria (e.g., lactobacillaceae/Lachnospiraceae) were at least 0.5-fold greater in the HF group compared with the LF group. Taken together, the data demonstrate that advanced liver-steatosis is concurrent with an elevated level of hepatic inflammation, colonic secondary bile acids and their associated bacteria in mice fed an HF diet. These data suggest a potential gut-liver crosstalk at the stage of advanced liver-steatosis.

Concurrent validity of skin carotenoid status as a concentration biomarker of vegetable and fruit intake compared to multiple 24-h recalls and plasma carotenoid concentrations across one year: a cohort study.

BACKGROUND: Biological markers of vegetable and fruit (VF) intake are needed both for nutrition surveillance and for the evaluation of nutrition interventions. Optically assessed skin carotenoid status (SCS) has been proposed as a marker of intake but there are few published validity studies to date. Therefore, the objective of the study was to examine the concurrent validity of multiple methods of assessing VF intake cross-sectionally and seasonally over one year and to discuss the relative merits and limitations of each method. METHODS: Fifty-two 40-60 y old women completed a 1-year longitudinal study that included 1) SCS assessment using resonance Raman spectroscopy (RRS) and using pressure-mediated reflection spectroscopy (RS) at 12 timepoints, 2) thirty-six 24-h recalls using the Automated Self-Administered 24-Hour Dietary Assessment Tool (ASA24; total 1866 recalls), and 3) plasma carotenoid concentrations measured every 3 months. Pearson correlation coefficients and mixed linear models were used to estimate pairwise correlations between RRS, RS, ASA24, and plasma carotenoids. RESULTS: RS and RRS were strongly correlated at baseline and over the year (r = 0.86 and 0.76; respectively, P < 0.001). RS was strongly correlated with plasma carotenoids at baseline (r = 0.70) and moderately across the year (r = 0.65), as was RRS (r = 0.77 and 0.69, respectively, all P < 0.001). At baseline, self-reported VF was weakly correlated with RRS (r = 0.33; P = 0.016), but not with RS or plasma carotenoids. Across the year, self-reported VF intake was weakly correlated with both RS (r = 0.37; P = 0.008), RRS (r = 0.37; P = 0.007), and with plasma carotenoids (r = 0.36; P < 0.008). CONCLUSIONS: SCS as measured by RS and RRS is moderately to strongly correlated with plasma carotenoid concentrations both cross-sectionally and longitudinally, indicating that it can be a powerful tool to assess carotenoid-rich VF intake in populations. CLINICAL TRIAL REGISTRY: This trial was registered at ClinicalTrials.gov as NCT01674296.