Diet-induced Change Research Articles

Temporal changes in soluble angiotensin-converting enzyme 2 associated with metabolic health, body composition, and proteome dynamics during a weight loss diet intervention: a randomized trial with implications for the COVID-19 pandemic

Angiotensin-converting enzyme 2 (ACE2) serves protective functions in metabolic, cardiovascular, renal, and pulmonary diseases and is linked to COVID-19 pathology. The correlates of temporal changes in soluble ACE2 (sACE2) remain understudied. We explored the associations of sACE2 with metabolic health and proteome dynamics during a weight loss diet intervention. We analyzed 457 healthy individuals (mean±SD age: 39.8±6.6 y) with BMI 28-40kg/m2 in the DIETFITS (Diet Intervention Examining the Factors Interacting with Treatment Success) study. Biochemical markers of metabolic health and 236 proteins were measured by Olink CVDII, CVDIII, and Inflammation I arrays at baseline and at 6 mo during the dietary intervention. We determined clinical and routine biochemical correlates of the diet-induced change in sACE2 (ΔsACE2) using stepwise linear regression. We combined feature selection models and multivariable-adjusted linear regression to identify protein dynamics associated with ΔsACE2. sACE2 decreased on average at 6 mo during the diet intervention. Stronger decline in sACE2 during the diet intervention was independently associated with female sex, lower HOMA-IR and LDL cholesterol at baseline, and a stronger decline in HOMA-IR, triglycerides, HDL cholesterol, and fat mass. Participants with decreasing HOMA-IR (OR: 1.97; 95% CI: 1.28, 3.03) and triglycerides (OR: 2.71; 95% CI: 1.72, 4.26) had significantly higher odds for a decrease in sACE2 during the diet intervention than those without (P≤0.0073). Feature selection models linked ΔsACE2 to changes in α-1-microglobulin/bikunin precursor, E-selectin, hydroxyacid oxidase 1, kidney injury molecule 1, tyrosine-protein kinase Mer, placental growth factor, thrombomodulin, and TNF receptor superfamily member 10B. ΔsACE2 remained associated with these protein changes in multivariable-adjusted linear regression. Decrease in sACE2 during a weight loss diet intervention was associated with improvements in metabolic health, fat mass, and markers of angiotensin peptide metabolism, hepatic and vascular injury, renal function, chronic inflammation, and oxidative stress. Our findings may improve the risk stratification, prevention, and management of cardiometabolic complications.This trial was registered at clinicaltrials.gov as NCT01826591.

The association of soluble ACE2 change with metabolic health, body composition and proteome dynamics during a weight loss diet intervention: implications for the COVID-19 pandemic

Abstract Background Angiotensin-converting enzyme 2 (ACE2) serves protective functions in metabolic, cardiovascular, renal and pulmonary diseases and is linked to COVID-19 pathology. We explored the association between soluble AC2 (sACE2) and metabolic health and proteome dynamics during a weight loss diet intervention. Methods We analyzed 457 healthy individuals (mean age 39.8±6.6) with BMI 28–40 kg/m2 who participated in the Diet Intervention Examining the Factors Interacting with Treatment Success (DIETFITS). Biochemical markers of metabolic health and 236 proteins measured by Olink CVD II, CVD III and Inflammation arrays were available at baseline and 6 months following dietary intervention. We determined clinical and routine biochemical correlates of the diet-induced change in sACE2 (ΔsACE2) using stepwise linear regression. We then combined feature selection models and multivariable-adjusted linear regression to identify protein dynamics associated with ΔsACE2. Results sACE2 decreased significantly on average at 6-months in the diet intervention. A stronger decline in sACE2 during the diet intervention was independently associated with female sex, lower HOMA-IR and LDL cholesterol at baseline, and a stronger decline in HOMA-IR, triglycerides, HDL-cholesterol and fat mass. In line, participants with decreasing HOMA-IR and triglycerides had significantly higher odds for a decrease in sACE2 during the diet intervention than those who did not (P≤0.0073 for both). Feature selection models linked ΔsACE2 to changes in AMBP, E-selectin, HAOX1, KIM-1, MERTK, PGF, thrombomodulin and TRAIL-R2. ΔsACE2 remained independently associated with these protein changes in multivariable-adjusted linear regression. Conclusion Decrease in sACE2 during a weight loss diet intervention was associated with improvements in metabolic health, fat mass and markers of angiotensin peptide metabolism, vascular injury, renal function, chronic inflammation and oxidative stress. Our findings may improve the risk stratification, prevention, and management of cardiometabolic and COVID-19-related complications. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NIHResearch Foundation Flanders

Omega 3 fatty acids stimulate thermogenesis during torpor in the Arctic Ground Squirrel

Omega 3 polyunsaturated fatty acids (PUFAs) influence metabolism and thermogenesis in non-hibernators. How omega 3 PUFAs influence Arctic Ground Squirrels (AGS) during hibernation is unknown. Prior to hibernation we fed AGS chow composed of an omega 6:3 ratio approximately 1:1 (high in omega 3 PUFA, termed Balanced Diet), or an omega 6:3 ratio of 5:1 (Standard Rodent Chow), and measured the influence of diet on core body temperature (Tb), brown adipose tissue (BAT) mass, fatty acid profiles of BAT, white adipose tissue (WAT) and plasma as well as hypothalamic endocannabinoid and endocannabinoid-like bioactive fatty acid amides during hibernation. Results show feeding a diet high in omega 3 PUFAs, with a more balanced omega 6:3 ratio, increases AGS Tb in torpor. We found the diet-induced increase in Tb during torpor is most easily explained by an increase in the mass of BAT deposits of Balanced Diet AGS. The increase in BAT mass is associated with elevated levels of metabolites DHA and EPA in tissue and plasma suggesting that these omega 3 PUFAs may play a role in thermogenesis during torpor. While we did not observe diet-induced change in endocannabinoids, we do report altered hypothalamic levels of some endocannabinoids, and endocannabinoid-like compounds, during hibernation.

The Role of Gut Hormones in Diet-Induced Weight Change: A Systematic Review.

Gut hormones are known to play an important role in long-term weight loss maintenance after bariatric surgery. However, the interplay between gut hormones and diet-induced weight changes remains unclear. Our aims were to evaluate the alterations of gut hormones in diet-induced weight loss, weight maintenance, and weight regain periods. Available studies were searched on MEDLINE, EMASE, ClinicalTrials.gov, the Cochrane Library, and Web of science from inception to October 2016. After selection, 16 studies with 656 participants were included. Based on current evidence, we found significant alterations of gut hormones induced by different diets. In weight-loss diets, decreased fasting total PYY, GLP-1, CCK, GIP, PP, and amylin along with increased ghrelin levels were observed in most studies. After weight loss, the persistent decreases of fasting total PYY and GLP-1 levels as well as increased appetite were reported, suggesting the profound impact of altered gut hormones on later weight regain after dietary intervention. The differences between diet-induced changes in gut hormones and other treatments such as bariatric surgery and exercise are also discussed in this review. Although significant alterations of gut hormones were found during weight changes, huge heterogeneity exists in methods and populations. More large-scale studies with elaborate design addressing the gut hormone alterations in dietary weight regulation are required in the future.

Caloric restriction protects livers from ischemia/reperfusion damage by preventing Ca2+-induced mitochondrial permeability transition

Caloric restriction (CR) promotes lifespan extension and protects against many pathological conditions, including ischemia/reperfusion injury to the brain, heart and kidney. In the liver, ischemia/reperfusion damage is related to excessive mitochondrial Ca2+ accumulation, leading to the mitochondrial permeability transition. Indeed, liver mitochondria isolated from animals maintained on CR for 4 months were protected against permeability transition and capable of taking up Ca2+ at faster rates and in larger quantities. These changes were not related to modifications in mitochondrial respiratory activity, but rather to a higher proportion of ATP relative to ADP in CR liver mitochondria. Accordingly, both depletion of mitochondrial adenine nucleotides and loading mitochondria with exogenous ATP abolished the differences between CR and ad libitum (AL) fed groups. The prevention against permeability transition promoted by CR strongly protected against in vivo liver damage induced by ischemia/reperfusion. Overall, our results show that CR strongly protects the liver against ischemia/reperfusion and uncover a mechanism for this protection, through a yet undescribed diet-induced change in liver mitochondrial Ca2+ handling related to elevated intramitochondrial ATP.

Effect of probiotic yoghurt on animal-based diet-induced change in gut microbiota: an open, randomised, parallel-group study.

Diet has a significant influence on the intestinal environment. In this study, we assessed changes in the faecal microbiota induced by an animal-based diet and the effect of the ingestion of yoghurt supplemented with a probiotic strain on these changes. In total, 33 subjects were enrolled in an open, randomised, parallel-group study. After a seven-day pre-observation period, the subjects were allocated into three groups (11 subjects in each group). All of the subjects were provided with an animal-based diet for five days, followed by a balanced diet for 14 days. Subjects in the first group ingested dairy in the form of 200 g of yoghurt supplemented with Bifidobacterium longum during both the animal-based and balanced diet periods (YAB group). Subjects in the second group ingested yoghurt only during the balanced diet period (YB group). Subjects who did not ingest yoghurt throughout the intervention were used as the control (CTR) group. Faecal samples were collected before and after the animal-based diet was provided and after the balanced diet was provided, followed by analysis by high-throughput sequencing of amplicons derived from the V3-V4 region of the 16S rRNA gene. In the YB and CTR groups, the animal-based diet caused a significant increase in the relative abundance of Bilophila, Odoribacter, Dorea and Ruminococcus (belonging to Lachnospiraceae) and a significant decrease in the level of Bifidobacterium after five days of intake. With the exception of Ruminococcus, these changes were not observed in the YAB group. No significant effect was induced by yoghurt supplementation following an animal-based diet (YB group vs CTR group). These results suggest that the intake of yoghurt supplemented with bifidobacteria played a role in maintaining a normal microbiota composition during the ingestion of a meat-based diet. This study protocol was registered in the University Hospital Medical Information Network: UMIN000014164.

Fish oil replacement in feeds for juvenile Florida Pompano: Composition of alternative lipid influences degree of tissue fatty acid profile distortion

Replacing long-chain polyunsaturated fatty acid (LC-PUFA)-rich fish oil with alternative lipids in Florida Pompano Trachinotus carolinus feeds is likely to cause tissue LC-PUFA depletion in a manner similar to that observed in other species; however, there is little information available regarding fish oil sparing in this species. Moreover, it is unknown whether alternative lipids with different levels of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), or C18 polyunsaturated fatty acids (C18 PUFAs) are equally suitable in this context. Accordingly, we assessed the production performance and tissue composition of juvenile Florida Pompano (43.4±0.2g) fed diets containing menhaden fish oil (FISH) or 25:75 blends of fish oil and standard soybean oil (C18 PUFA SOY), MUFA-enriched soybean oil (MUFA SOY), SFA-enriched soybean oil (SFA SOY), palm oil (PALM), or poultry fat (POULTRY). After 8weeks, all diets were well accepted, and weight gain (228±20%, grand mean±SE) and specific growth rate (2.2±0.1% body weight/day) were unaffected by dietary treatment. Feed conversion ratio, feed intake, and hepatosomatic index varied among treatments; however, the ranges of values observed were relatively narrow (FCR=1.33–1.61, feed intake=3.09–3.65% body weight/day, HSI=1.1–1.5) and pairwise comparisons revealed few differences among treatments. Fatty acid profiles of the fillet, liver, and eye tissues generally mirrored dietary fatty acid composition, whereas the brain tissue was more resistant to dietary influence. Compared to those fed the FISH diet, fillets of fish fed the reduced fish oil diets had lower levels of n-3 fatty acids and LC-PUFAs, and greater levels of the fatty acids that were abundant in the alternative lipids. These trends were observed, albeit to a lesser extent in liver and eye tissues, but not in brain tissue, which was relatively resistant to diet-induced compositional change. In general, tissue fatty acid profile distortion was greatest among fish fed the MUFA SOY and C18 PUFA SOY diets, least overt among fish fed the SFA SOY diet, and intermediate among fish fed the PALM and POULTRY diets. All alternative lipids appeared effective as partial substitutes for menhaden fish oil, but fully hydrogenated, SFA-rich soybean oil may offer some strategic advantage in terms of limiting diet-induced modification of tissue fatty acid profile in Florida Pompano. Statement of relevanceAs there are few studies addressing lipid nutrition of Trachinotus spp. and there is scarce information regarding the influence of different alternative lipid source on tissue levels of LC-PUFAs in these species, this study is relevant to aquafeed manufacturers and those culturing Florida Pompano and other Trachinotus spp. The present results provide valuable information regarding alternative lipids in marine carnivorous finfish feeds and their effects on fish performance and tissue fatty acid composition. Further, these findings highlight the promising potential of fully hydrogenated, SFA-rich soybean oil in aquafeeds.

Neuropeptide Y genotype, central obesity, and abdominal fat distribution: the POUNDS LOST trial

Neuropeptide Y is a key peptide affecting adiposity and has been related to obesity risk. However, little is known about the role of NPY variations in diet-induced change in adiposity. The objective was to examine the effects of NPY variant rs16147 on central obesity and abdominal fat distribution in response to dietary interventions. We genotyped a functional NPY variant rs16147 among 723 participants in the Preventing Overweight Using Novel Dietary Strategies trial. Changes in waist circumference (WC), total abdominal adipose tissue, visceral adipose tissue, and subcutaneous adipose tissue (SAT) from baseline to 6 and 24 mo were evaluated with respect to the rs16147 genotypes. Genotype-dietary fat interaction was also examined. The rs16147 C allele was associated with a greater reduction in WC at 6 mo (P < 0.001). In addition, the genotypes showed a statistically significant interaction with dietary fat in relation to WC and SAT (P-interaction = 0.01 and 0.04): the association was stronger in individuals with high-fat intake than in those with low-fat intake. At 24 mo, the association remained statistically significant for WC in the high-fat diet group (P = 0.02), although the gene-dietary fat interaction became nonsignificant (P = 0.30). In addition, we found statistically significant genotype-dietary fat interaction on the change in total abdominal adipose tissue, visceral adipose tissue, and SAT at 24 mo (P = 0.01, 0.05, and 0.04): the rs16147 T allele appeared to associate with more adverse change in the abdominal fat deposition in the high-fat diet group than in the low-fat diet group. Our data indicate that the NPY rs16147 genotypes affect the change in abdominal adiposity in response to dietary interventions, and the effects of the rs16147 single-nucleotide polymorphism on central obesity and abdominal fat distribution were modified by dietary fat.

Effects of Dietary Energy Sources on Post Mortem Glycolysis, Meat Quality and Muscle Fibre Type Transformation of Finishing Pigs.

Dietary energy source can influence muscle glycogen storage at slaughter. However, few studies have demonstrated whether the diet-induced change of muscle glycogen is achieved by the transformation of muscle fibre type. This study investigated the effects of dietary energy sources on meat quality, post mortem glycolysis and muscle fibre type transformation of finishing pigs. Seventy-two barrows with an average body weight of 65.0 ± 2.0 kg were selected and were allotted to three iso-energetic and iso-nitrogenous diets A, B or C, and each treatment consisted of three replicates (pens) of eight pigs each. Diet A contained 44.1% starch, 5.9% crude fat and 12.6% neutral detergent fiber (NDF); diet B contained 37.6% starch, 9.5% crude fat and 15.4% NDF; and diet C contained 30.9% starch, 14.3% crude fat and 17.8% NDF. The duration of the experiment was 28 days. After feed withdrawal 12 h, 24 pigs (eight per treatment) were slaughtered, samples from M. longissimus lumborum (LL) were collected for subsequent analysis. The results showed that pigs fed diet C had lesser average daily gain, average daily feed intake and back fat depth than those fed diet A (P<0.05). Diet C increased pH45min (P<0.05) and decreased drip loss (P<0.05) in LL muscles compared with diet A. Meat from pigs fed diet A showed increased contents of lactate and greater glycolytic potential (GP) compared with those fed diet C (P<0.05). Greater mRNA expression of myosin heavy-chain (MyHC)-I and IIa and lesser expression of MyHC-IIx and IIb (P<0.05) in LL muscles were found in pigs fed diet C, than in pigs fed diet A. In addition, pigs fed diet C resulted in downregulation of miR23a and upregulation of miR409 and miR208b (P<0.05), associated with conserved changes of their corresponding targets. These findings indicated that diets containing low starch and high fibre were beneficial in reducing muscle glycolysis, improving meat quality of finishing pigs. This reduction of GP may be partially associated with the improvement of oxidative fibre composition in LL muscle, and the change in myofibre type may be correlated with the change in the miRNA expression.

Visualized macrophage dynamics and significance of S100A8 in obese fat

Chronic low-grade inflammation of adipose tissue plays a crucial role in the pathophysiology of obesity. Immunohistological microscopic analysis in obese fat tissue has demonstrated the infiltration of several immune cells such as macrophages, but dynamics of immune cells have not been fully elucidated and clarified. Here, by using intravital multiphoton imaging technique, to our knowledge for the first time, we analyzed and visualized the inflammatory processes in adipose tissue under high-fat and high-sucrose (HF/HS) diet with lysozyme M-EGFP transgenic (LysM(EGFP)) mice whose EGFP was specifically expressed in the myelomonocytic lineage. Mobility of LysM(EGFP)-positive macrophages was shown to be activated just 5 d after HF/HS diet, when the distinct hypertrophy of adipocytes and the accumulation of macrophages still have not become prominent. Significant increase of S100A8 was detected in mature adipocyte fraction just 5 d after HF/HS diet. Recombinant S100A8 protein stimulated chemotactic migration in vitro and in vivo, as well as induced proinflammatory molecules, both macrophages and adipocytes, such as TNF-α and chemokine (C-C motif) ligand 2. Finally, an antibody against S100A8 efficiently suppressed the HF/HS diet-induced initial inflammatory change, i.e., increased mobilization of adipose LysM(EGFP)-positive macrophages, and ameliorated HF/HS diet-induced insulin resistance. In conclusion, time-lapse intravital multiphoton imaging of adipose tissues identified the very early event exhibiting increased mobility of macrophages, which may be triggered by increased expression of adipose S100A8 and results in progression of chronic inflammation in situ.

Soluble CD163 Is Associated With CD163 mRNA Expression in Adipose Tissue and With Insulin Sensitivity in Steady-State Condition but Not in Response to Calorie Restriction

Soluble CD163 (sCD163) was suggested as a biomarker of insulin sensitivity and CD163 mRNA expression representing macrophage content in adipose tissue (AT). The aim of this study was to investigate, in cross-sectional and prospective design, the relationship between sCD163 circulating levels and CD163 mRNA expression in adipose tissue and insulin sensitivity assessed by euglycemic-hyperinsulinemic clamp. Two cohorts of subjects were examined in the study. Cohort 1 included 42 women with a wide range of body mass index (17-48 kg/m(2)); cohort 2 included 27 obese women who followed a dietary intervention consisting of 1 month of a very low-calorie diet and 5 months of a weight-stabilization period. Serum levels of CD163 and mRNA expression of CD163 and CD68 in sc and visceral (visc) AT were determined, and insulin sensitivity [expressed as glucose disposal rate (GDR)] was measured in cohort 1. In cohort 2, serum levels of CD163, mRNA expressions of CD163, CD68, and CD163-shedding factors [TNF-α-converting enzyme (TACE) and tissue inhibitor of metalloproteinase (TIMP3)] in sc AT were examined and GDR was measured before and during dietary intervention. In cohort 1, circulating sCD163 correlated with CD163 mRNA levels in both sc and visc AT. sCD163 and CD163 mRNA expression in both fat depots correlated with GDR. In cohort 2, the diet-induced changes of sCD163 levels did not correlate with those of CD163, CD68, TACE, and TIMP3 mRNA levels. Although the pattern of the diet-induced change of sCD163 paralleled that of GDR, there was no correlation between the changes of these two variables. sCD163 correlates with CD163 mRNA expression in sc and visc AT and with whole-body insulin sensitivity in the steady-state condition. These associations are not observed with respect to the diet-induced changes during a weight-reducing hypocaloric diet.

Diet-induced metabolic change induces estrogen-independent allometric mammary growth

Lifetime breast cancer risk reflects an unresolved combination of early life factors including diet, body mass index, metabolic syndrome, obesity, and age at first menses. In parallel, the onset of allometric growth by the mammary glands around puberty is widely held to be estrogen (E)-dependent. Here we report that several physiological changes associated with metabolic syndrome in response to a diet supplemented with the trans-10, cis-12 isomer of conjugated linoleic acid lead to ovary-independent allometric growth of the mammary ducts. The E-independence of this diet-induced growth was highlighted by the fact that it occurred both in male mice and with pharmacological inhibition of either E receptor function or E biosynthesis. Reversal of the metabolic phenotype with the peroxisome proliferator-activated receptor-γ agonist rosiglitazone abrogated diet-induced mammary growth. A role for hyperinsulinemia and increased insulin-like growth factor-I receptor (IGF-IR) expression during mammary growth induced by the trans-10, cis-12 isomer of conjugated linoleic acid was confirmed by its reversal upon pharmacological inhibition of IGF-IR function. Diet-stimulated ductal growth also increased mammary tumorigenesis in ovariectomized polyomavirus middle T-antigen mice. Our data demonstrate that diet-induced metabolic dysregulation, independently of ovarian function, stimulates allometric growth within the mammary glands via an IGF-IR-dependent mechanism.

Su1991 Diet-Induced Change in Gastrointestinal Transit Significantly Alters Distal Gut Microbial Communities

Su1991 Diet-Induced Change in Gastrointestinal Transit Significantly Alters Distal Gut Microbial Communities

Role of the Gut in Visceral Fat Inflammation and Metabolic Disorders

Role of the Gut in Visceral Fat Inflammation and Metabolic Disorders

Changes in lipoprotein(a), oxidized phospholipids, and LDL subclasses with a low-fat high-carbohydrate diet

Low-fat diets have been shown to increase plasma concentrations of lipoprotein(a) [Lp(a)], a preferential lipoprotein carrier of oxidized phospholipids (OxPLs) in plasma, as well as small dense LDL particles. We sought to determine whether increases in plasma Lp(a) induced by a low-fat high-carbohydrate (LFHC) diet are related to changes in OxPL and LDL subclasses. We studied 63 healthy subjects after 4 weeks of consuming, in random order, a high-fat low-carbohydrate (HFLC) diet and a LFHC diet. Plasma concentrations of Lp(a) (P < 0.01), OxPL/apolipoprotein (apo)B (P < 0.005), and OxPL-apo(a) (P < 0.05) were significantly higher on the LFHC diet compared with the HFLC diet whereas LDL peak particle size was significantly smaller (P < 0.0001). Diet-induced changes in Lp(a) were strongly correlated with changes in OxPL/apoB (P < 0.0001). The increases in plasma Lp(a) levels after the LFHC diet were also correlated with decreases in medium LDL particles (P < 0.01) and increases in very small LDL particles (P < 0.05). These results demonstrate that induction of increased levels of Lp(a) by an LFHC diet is associated with increases in OxPLs and with changes in LDL subclass distribution that may reflect altered metabolism of Lp(a) particles.

Are purines mediators of the anticonvulsant/neuroprotective effects of ketogenic diets?

Abnormal neuronal signaling caused by metabolic changes characterizes several neurological disorders, and in some instances metabolic interventions provide therapeutic benefits. Indeed, altering metabolism either by fasting or by maintaining a low-carbohydrate (ketogenic) diet might reduce epileptic seizures and offer neuroprotection in part because the diet increases mitochondrial biogenesis and brain energy levels. Here we focus on a novel hypothesis that a ketogenic diet-induced change in energy metabolism increases levels of ATP and adenosine, purines that are critically involved in neuron-glia interactions, neuromodulation and synaptic plasticity. Enhancing brain bioenergetics (ATP) and increasing levels of adenosine, an endogenous anticonvulsant and neuroprotective molecule, might help with understanding and treating a variety of neurological disorders.

Fatty acid composition, growth and morphological deformities in juvenile cyprinid, Scardinius erythrophthalmus fed formulated diet supplemented with natural food

Response of a freshwater cyprinid fish Scardinius erythrophthalmus juveniles (initial age 195 days, initial weight 0.82 ± 0.06 g) to supplementation of a formulated commercial dry diet with natural food was examined. A 90-day experiment at 25 °C consisted of two periods. During 60 days three feeding groups were studied: the group F received the dry diet Futura exclusively, the group FC was fed Futura supplemented with frozen larvae of Chironomidae, and the group C received exclusively chironomids. This was followed by a 30 days “recovery period” during which all fish received larval chironomids, only. No mortality occurred during the experiment. The poorest growth was found in the F group, in the supplemented group FC growth was intermediary, and the best growth took place in the C group. The highest condition coefficient was in the group F, the lowest one in the group C. In the group F incidence of spinal curvatures was the highest (77.8% on day 60), in the group FC it was intermediary (42.2%) while no body deformities were found in the group C. After a month exclusively on chironomids (day 90) percentage of deformed fish declined to 66.3 and 31.3, respectively, for the groups F and FC. The proportions of fatty acids in Futura were typical of a formulated diet based on n−3 rich oils: a high concentration of n−3 PUFA (26.9% of total fatty acids, predominantly docosahexaenoic acid DHA, C22:6 n−3), and a low concentration of n−6 PUFA (4.9%). In contrast, chironomids contained only 5.9% n−3 PUFA, and a high concentration of n−6 PUFA (28.8%, mainly linoleic acid LA, C18:2 n−6 and arachidonic acid AA, C20:4 n−6), which compares well with natural food of freshwater fish. Fatty acid composition of fish whole body lipids reflected the fatty acid profiles of the respective diets, while chironomid supplementation to Futura resulted in intermediary values. Diet-induced change in the fatty acid profiles seems to be a relatively slow process. Supplementation of formulated dry diets deficient in n−6 fatty acids with natural invertebrate food could be regarded as a technique to mitigate body deformities in freshwater fish juveniles. We suggest that the diets manufactured for freshwater juveniles should resemble their natural invertebrate prey.

Endocannabinoid Dysregulation in the Pancreas and Adipose Tissue of Mice Fed With a High‐fat Diet

In mice, endocannabinoids (ECs) modulate insulin release from pancreatic beta-cells and adipokine expression in adipocytes through cannabinoid receptors. Their pancreatic and adipose tissue levels are elevated during hyperglycemia and obesity, but the mechanisms underlying these alterations are not understood. We assessed in mice fed for up to 14 weeks with a standard or high-fat diet (HFD): (i) the expression of cannabinoid receptors and EC biosynthesizing enzymes (N-acyl-phosphatidyl-ethanolamine-selective phospholipase D (NAPE-PLD) and DAGLalpha) and degrading enzymes (fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL)) in pancreatic and adipose tissue sections by immunohistochemical staining; (ii) the amounts, measured by liquid chromatography-mass spectrometry, of the ECs, 2-AG, and anandamide (AEA). Although CB(1) receptors and biosynthetic enzymes were found mostly in alpha-cells, degrading enzymes were identified in beta-cells. Following HFD, staining for biosynthetic enzymes in beta-cells and lower staining for FAAH were observed together with an increase of EC pancreatic levels. While we observed no diet-induced change in the intensity of the staining of EC metabolic enzymes in the mesenteric visceral fat, a decrease in EC concentrations was accompanied by lower and higher staining of biosynthesizing enzymes and FAAH, respectively, in the subcutaneous fat. No change in cannabinoid receptor staining was observed following HFD in any of the analyzed tissues. We provide unprecedented information on the distribution of EC metabolic enzymes in the pancreas and adipose organ, where their aberrant expression during hyperglycemia and obesity contribute to dysregulated EC levels.

Reduction of tissue transglutaminase autoantibody levels by gluten-free diet is associated with changes in subsets of peripheral blood lymphocytes in children with newly diagnosed coeliac disease

Tissue transglutaminase (tTG) autoantibodies decline after gluten-free diet in patients with coeliac disease. We tested the hypothesis that gluten-free diet-induced change in tTG autoantibody levels affects subsets of peripheral blood lymphocytes. Peripheral blood was obtained from 20 children with biopsy-proven active coeliac disease. Gluten-free diet was initiated and the children examined again after three and six months. tTG autoantibodies were measured in radioligand binding assays and lymphocyte subsets by flow cytometry. IgA-tTG levels at diagnosis, 2204 U/ml (median, range 113-24990), were reduced over six months to 76 U/ml (median, range 1-1261) (P < 0.001). At six months, 12/20 (60%) children had reduced their IgA-tTG levels to < 100 U/ml and these children showed a decrease in B cells (mean change -3.8%, P = 0.014), CD4+ T cells (mean -4.32%, P = 0.011) and CD4+ T cells expressing CD25high (mean change -0.62%, P = 0.036). In contrast, the CD4+CD25(high)CCR4+ T cell population increased during the same period (mean change 11.5%, P = 0.0036). The decline in IgA-tTG levels correlated to the decrease in B cells (r = 0.56, P = 0.01), CD4+ T cells (r = 0.66, P = 0.004) as well as CD4+CD25high T cells (r = 0.59, P = 0.01). A negative correlation was found between the decline in IgA-tTG and CD4+CD25high T cells expressing CD45RO (r = -0.49, P = 0.03) and CCR4 (r = -0.54, P = 0.01). This is the first observational study on the effect of gluten-free diet on concurrent changes of tTG autoantibodies and specific peripheral blood lymphocyte subsets. Our data suggest that flow cytometry may be a useful complement to tTG autoantibodies when studying the effects of gluten-free diet in children with coeliac disease.

Study of Diet-Induced Changes in Lipoprotein Metabolism in Two Strains of Golden-Syrian Hamsters

The objective of this study was to characterize two strains of Golden-Syrian hamsters for use in the study of diet-induced changes in lipoprotein metabolism. In Experiment 1, the time course and response to dietary saturated fat was investigated for serum lipoprotein profiles and aortic lesion formation in Golden-Syrian hamsters from Charles River Laboratories, Wilmington, MA (CR) and Bio Breeders, Watertown, MA (F(1)B). Hamsters were fed a nonpurified diet containing 10 g/100 g saturated fat and 0.1 g/100 g dietary cholesterol. After 12 wk, CR hamsters had significantly lower serum total and non-HDL cholesterol (TC and nHDL-C) levels, but higher aortic cholesteryl ester (CE) than the F(1)B hamsters (P < 0.05). In Experiment 2, CR hamsters were fed a nonpurified diet containing 10 g/100 g saturated fat and 0.1, 0.5 or 1 g/100 g dietary cholesterol. After 10 wk of dietary intervention, TC and nHDL-C levels were significantly higher in the 0.5 and 1.0 g/100 g cholesterol groups than in the 0.1 g/100 g cholesterol group. These levels declined after 20 wk of dietary intervention in all groups, potentially reflecting the toxic effect of high cholesterol intakes. CR hamsters fed a 10 g/100 g saturated fat containing 0.1 g/100 g dietary cholesterol for 10 wk appear to be a good model for investigating diet-induced change in plasma lipids.