Beef, Casein, and Soy Proteins Differentially Affect Lipid Metabolism, Triglycerides Accumulation and Gut Microbiota of High-Fat Diet-Fed C57BL/6J Mice.
ABSTRACT: Consumption of dietary protein at recommended levels is considered a potential strategy to promote satiety and weight management, but how protein from different dietary sources effect the obesity development, lipid metabolism, and gut microbiota is not known. This study focused on the effects of beef, casein, and soy protein diet on lipid metabolism, triglycerides accumulation, and microbial diversity in colon of C57BL/6J mice, which were given either low-fat diets (LFD, 12% Kcal) or high-fat diets (HFD, 60% Kcal) for 12 weeks. Body and liver weight increased significantly in mice fed a beef protein HFD (HFB), whereas reduced cumulative energy intake was seen in a soy protein HFD (HFS) group. HFB-fed mice showed signs of impaired glucose metabolism and insulin resistance along with a significant elevation in the concentration of triglycerides, LDL-cholesterol, total cholesterol, IL1?, TNF-?, IL-6, and leptin in serum. HFB also enhanced lipid accumulation in liver with increased activity of genes important for lipogenesis and hepatic cholesterol metabolism. A 16S rRNA gene sequencing indicated that HFD, regardless of proteins, significantly enhanced the ratio of Firmicutes to Bacteroidetes in colonic microbiota. However, HFB not only reduced the abundance of Akkermansia, compared with LFD independent of proteins, but also decreased the abundance of butyrate-producing bacteria such as Anaerotruncus, Butyricicoccus, and Lactobacillus (P < 0.05) compared with HFS and HFC. In conclusion, consumption of HFB does not only affect the gut microbiota composition but also increases the problems related to metabolic syndromes like dyslipidemia, hypercholesterolemia, and triglycerides accumulation in liver, which lead to systemic inflammation and its associated comorbidities, for example, impaired glucose metabolism and insulin resistance.
Project description:Diet influences host metabolism and intestinal microbiota; however, detailed understanding of this tripartite interaction is limited. To determine whether the nonfermentable fiber hydroxypropyl methylcellulose (HPMC) could alter the intestinal microbiota and whether such changes correlated with metabolic improvements, C57B/L6 mice were normalized to a high-fat diet (HFD), then either maintained on HFD (control), or switched to HFD supplemented with 10% HPMC, or a low-fat diet (LFD). Compared to control treatment, both LFD and HPMC reduced weight gain (11.8 and 5.7 g, respectively), plasma cholesterol (23.1 and 19.6%), and liver triglycerides (73.1 and 44.6%), and, as revealed by 454-pyrosequencing of the microbial 16S rRNA gene, decreased microbial ?-diversity and differentially altered intestinal microbiota. Both LFD and HPMC increased intestinal Erysipelotrichaceae (7.3- and 12.4-fold) and decreased Lachnospiraceae (2.0- and 2.7-fold), while only HPMC increased Peptostreptococcaceae (3.4-fold) and decreased Ruminococcaceae (2.7-fold). Specific microorganisms were directly linked with weight change and metabolic parameters in HPMC and HFD mice, but not in LFD mice, indicating that the intestinal microbiota may play differing roles during the two dietary modulations. This work indicates that HPMC is a potential prebiotic fiber that influences intestinal microbiota and improves host metabolism.
Project description:Obesity is linked to non-alcoholic fatty liver disease and risk factors associated to metabolic syndrome. Bilberry (Vaccinium myrtillus) that contains easily fermentable fiber may strengthen the intestinal barrier function, attenuate inflammation and modulate gut microbiota composition, thereby prevent obesity development. In the current study, liver lipid metabolism, fat depot, cecal and serum short-chain fatty acids (SCFAs) and gut microbiome were evaluated in rats fed bilberries in a high-fat (HFD + BB) or low-fat (LFD + BB) setting for 8 weeks and compared with diets containing equal amount of fiber resistant to fermentation (cellulose, HFD and LFD). HFD fed rats did not obtain an obese phenotype but underwent pre-obesity events including increased liver index, lipid accumulation and increased serum cholesterol levels. This was linked to shifts of cecal bacterial community and reduction of major SCFAs. Bilberry inclusion improved liver metabolism and serum lipid levels. Bilberry inclusion under either LFD or HFD, maintained microbiota homeostasis, stimulated interscapular-brown adipose tissue depot associated with increased mRNA expression of uncoupling protein-1; enhanced SCFAs in the cecum and circulation; and promoted butyric acid and butyrate-producing bacteria. These findings suggest that bilberry may serve as a preventative dietary measure to optimize microbiome and associated lipid metabolism during or prior to HFD.
Project description:BACKGROUND:Animal studies show that high fat (HF) diet-induced gut microbiota contributes to the development of obesity. Oil composition of high-fat diet affects metabolic inflammation differently with deleterious effects by saturated fat. The aim of the present study was to examine the diversity and metabolic capacity of the cecal bacterial community in C57BL/6 N mice administered two different diets, enriched respectively with coconut oil (HFC, high in saturated fat) or soy oil (HFS, high in polyunsaturated fat). The relative impact of each hypercaloric diet was evaluated after 2 and 8 weeks of feeding, and compared with that of a low-fat, control diet (LF). RESULTS:The HFC diet induced the same body weight gain and fat storage as the HFS diet, but produced higher plasma cholesterol levels after 8 weeks of treatment. At the same time point, the cecal microbiota of HFC diet-fed mice was characterized by an increased relative abundance of Allobaculum, Anaerofustis, F16, Lactobacillus reuteri and Deltaproteobacteria, and a decreased relative abundance of Akkermansia muciniphila compared to HFS mice. Comparison of cecal microbiota of high-fat fed mice versus control mice indicated major changes that were shared between the HFC and the HFS diet, including the increase in Lactobacillus plantarum, Lutispora, and Syntrophomonas, while some other shifts were specifically associated to either coconut or soy oil. Prediction of bacterial gene functions showed that the cecal microbiota of HFC mice was depleted of pathways involved in fatty acid metabolism, amino acid metabolism, xenobiotic degradation and metabolism of terpenoids and polyketides compared to mice on HFS diet. Correlation analysis revealed remarkable relationships between compositional changes in the cecal microbiota and alterations in the metabolic and transcriptomic phenotypes of high-fat fed mice. CONCLUSIONS:The study highlights significant differences in cecal microbiota composition and predictive functions of mice consuming a diet enriched in coconut vs soy oil. The correlations established between specific bacterial taxa and various traits linked to host lipid metabolism and energy storage give insights into the role and functioning of the gut microbiota that may contribute to diet-induced metabolic disorders.
Project description:Western diets high in fat and sucrose are associated with metabolic syndrome (MetS). Although the prevalence of MetS in women is comparable to that in men, metabolic adaptations in females to Western diet have not been reported in preclinical studies. This study investigates the effects of Western diet on risk factors for MetS in female mice. Based on our earlier studies in male mice, we hypothesized that dietary supplementation with extracts of Artemisia dracunculus L. (PMI5011) and Momordica charantia (bitter melon) could affect MetS risk factors in females. Eight-week-old female mice were fed a 10% kcal fat, 17% kcal sucrose diet (LFD); high-fat, high-sucrose diet (HFS; 45% kcal fat, 30% kcal sucrose); or HFS diet with PMI5011 or bitter melon for three months. Body weight and adiposity in all HFS groups were greater than the LFD. Total cholesterol level was elevated with the HFS diets along with LDL cholesterol, but triglycerides and free fatty acids were unchanged from the LFD. Over the three month period, female mice responded to the HFS diet by adaptive increases in fat oxidation energy in muscle and liver. This was coupled with increased fat storage in white and brown adipose tissue depots. These responses were enhanced with botanical supplementation and confer protection from ectopic lipid accumulation associated with MetS in female mice fed an HFS diet.
Project description:In the present study, we explored whether dietary lipid content influences the gut microbiome in adult zebrafish. Diets containing three different lipid levels (high [HFD], medium [MFD], and low [LFD]) were administered with or without the supplementation of Lactobacillus rhamnosus (P) to zebrafish in order to explore how the dietary lipid content may influence the gut microbiome. Dietary lipid content shifted the gut microbiome structure. The addition of L. rhamnosus in the diets, induced transcriptional reduction of orexigenic genes, upregulation of anorexigenic genes, and transcriptional decrease of genes involved in cholesterol and triglyceride (TAG) metabolism, concomitantly with lower content of cholesterol and TAG. Probiotic feeding also decreased nesfatin-1 peptide in HFD-P and attenuated weight gain in HFD-P and MFD-P fed zebrafish, but not in LFD-P group. Intestinal ultrastructure was not affected by dietary fat level or probiotic inclusion. In conclusion, these findings underline the role of fat content in the diet in altering gut microbiota community by shifting phylotype composition and highlight the potential of probiotics to attenuate high-fat diet-related metabolic disorder.
Project description:Understanding the importance of the gut microbiota (GM) in non-alcoholic fatty liver disease (NAFLD) has raised the hope for therapeutic microbes. We have shown that high hepatic fat content associated with low abundance of Faecalibacterium prausnitzii in humans and, further, the administration of F. prausnitzii prevented NAFLD in mice. Here, we aimed at targeting F. prausnitzii by prebiotic xylo-oligosaccharides (XOS) to treat NAFLD. First, the effect of XOS on F. prausnitzii growth was assessed in vitro. Then, XOS was supplemented or not with high (HFD, 60% of energy from fat) or low (LFD) fat diet for 12 weeks in Wistar rats (n = 10/group). XOS increased F. prausnitzii growth, having only a minor impact on the GM composition. When supplemented with HFD, XOS ameliorated hepatic steatosis. The underlying mechanisms involved enhanced hepatic ?-oxidation and mitochondrial respiration. Nuclear magnetic resonance (1H-NMR) analysis of cecal metabolites showed that, compared to the HFD, the LFD group had a healthier cecal short-chain fatty acid profile and on the HFD, XOS reduced cecal isovalerate and tyrosine, metabolites previously linked to NAFLD. Cecal branched-chain fatty acids associated positively and butyrate negatively with hepatic triglycerides. In conclusion, XOS supplementation can ameliorate NAFLD by improving hepatic oxidative metabolism and affecting GM.
Project description:Obesity is a major global lifestyle disorder associated with gut microbiota. The health benefits of eggshell membrane (ESM) have been shown in previous reports, particularly as regards gut microbiota composition. Here, we investigated whether ESM improves lipid metabolism and alters gut microbiota in high-fat diet-fed mice. A total of 20 C57BL/6J mice aged 6 weeks were given either a control diet (CON), high-fat diet (HFD), or high-fat diet + 8% ESM powder (HESM) for 20 weeks. ESM supplementation in HFD-fed mice reduced plasma triglycerides (TG) and liver total cholesterol (TC) and upregulated the expression of lipid metabolism genes carnitine palmitoyltransferase 1A and suppressor of cytokine signaling 2. Microbiota analysis showed increased relative abundance of the anti-obesity bacterium, Lactobacillus reuteri, at 4, 12, and 16 weeks and reduced the abundance of inflammation-related Blautia hydrogenotrophica, Roseburia faecis, and Ruminococcus callidus at 12 and 20 weeks. ESM-supplemented mice had increased cecal isobutyrate, negatively correlated with B. hydrogenotrophica and Parabacteroides goldsteinii abundance. The results indicate that ESM supplementation in HFD-fed mice reduced plasma TG and liver TC, possibly through alteration of lipid metabolism gene expression and gut microbiota composition, suggesting that ESM may be effective in obesity management.
Project description:BACKGROUND AND AIMS:Either lipopolysaccharide (LPS) or high-fat diet (HFD) enriched with saturated fatty acid (SFA) promotes atherosclerosis. In this study, we investigated the effect of LPS in combination with SFA-rich HFD on atherosclerosis and how LPS and SFA interact to stimulate inflammatory response in vascular endothelial cells. METHODS:Low-density lipoprotein receptor-deficient (LDLR-/-) mice were fed a low-fat diet (LFD), HFD with low palmitic acid (PA) (LP-HFD), or HFD with high PA (HP-HFD) for 20 weeks. During the last 12 weeks, half mice received LPS and half received PBS. After treatment, metabolic parameters and aortic atherosclerosis were analyzed. To understand the underlying mechanisms, human aortic endothelial cells (HAECs) were treated with LPS and/or PA and proinflammatory molecule expression was quantified. RESULTS:The metabolic study showed that LPS had no significant effect on cholesterol, triglycerides, free fatty acids, but increased insulin and insulin resistance. Both LP-HFD and HP-HFD increased body weight and cholesterol while LP-HFD increased glucose and HP-HFD increased triglycerides, insulin, and insulin resistance. Analysis of aortic atherosclerosis showed that HP-HFD was more effective than LP-HFD in inducing atherosclerosis and LPS in combination with HP-HFD increased atherosclerosis in the thoracic aorta, a less common site for atherosclerosis, as compared with LPS or HP-HFD. To understand the mechanisms, results showed that LPS and PA synergistically upregulated adhesion molecules and proinflammatory cytokines in HAECs. CONCLUSIONS:LPS and PA-rich HFD cooperatively increased atherogenesis in the thoracic aorta. The synergy between LPS and PA on proinflammatory molecules in HAECs may play an important role in atherogenesis.
Project description:The role of the liver and the endocrine pancreas in development of hyperinsulinemia in different types of obesity remains unclear. Sedentary rats (160 g) were fed a low-fat-diet (LFD, chow 13% kcal fat), high-fat-diet (HFD, 35% fat), or HFD+ 30% ethanol+ 30% fructose (HF-EFr, 22% fat). Overnight-fasted rats were culled after one, four or eight weeks. Pancreatic and hepatic mRNAs were isolated for subsequent RT-PCR analysis. After eight weeks, body weights increased three-fold in the LFD group, 2.8-fold in the HFD group, and 2.4-fold in the HF-EFr (p < 0.01). HF-EFr-fed rats had the greatest liver weights and consumed less food during Weeks 4-8 (p < 0.05). Hepatic-triglyceride content increased progressively in all groups. At Week 8, HOMA-IR values, fasting serum glucose, C-peptide, and triglycerides levels were significantly increased in LFD-fed rats compared to that at earlier time points. The greatest plasma levels of glucose, triglycerides and leptin were observed in the HF-EFr at Week 8. Gene expression of pancreatic-insulin was significantly greater in the HFD and HF-EFr groups versus the LFD. Nevertheless, insulin: C-peptide ratios and HOMA-IR values were substantially higher in HF-EFr. Hepatic gene-expression of insulin-receptor-substrate-1/2 was downregulated in the HF-EFr. The expression of phospho-ERK-1/2 and inflammatory-mediators were greatest in the HF-EFr-fed rats. Chronic intake of both LFD and HFD induced obesity, MetS, and intrahepatic-fat accumulation. The hyperinsulinemia is the strongest in rats with the lowest body weights, but having the highest liver weights. This accompanies the strongest increase of pancreatic insulin production and the maximal decrease of hepatic insulin signaling, which is possibly secondary to hepatic fat deposition, inflammation and other factors.
Project description:Untreated nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) lead to irreversible liver damage. We hypothesized that a low-fat diet (LFD) or a high-fat diet (HFD) with soy protein isolate (SPI) would be an effective intervention to halt or reverse NAFLD progression. To test these hypotheses, we conducted 2 studies. In the first study, we fed an HFD to 7-week-old C57BL/6J mice to induce NAFLD compared to an LFD (control). Hepatic steatosis was monitored by quantitative ultrasound (QUS) scans (in vivo and ex vivo). Animals were euthanized after 0, 2, 4, and 6 weeks of feeding. In the second study, 7-week-old mice were randomized onto an LFD or HFD with SPI intervention after 4 weeks of feeding HFD. Animals from each group were scanned with QUS and euthanized after 4, 9, and 12 weeks of feeding. Animals fed the HFD developed NAFLD (100%) and NASH (80%) characterized by increased liver weight, lipid accumulation, and histological scores for inflammation by 4 weeks in the first study. In the second study, the LFD ameliorated this NAFLD phenotype after 5 weeks of feeding; however, the SPI intervention failed to significantly attenuate NAFLD. QUS parameters were significantly increased with the HFDs (P < .05) and steatosis grade (P < .05) and were positively correlated with hepatic lipid concentrations. In conclusion, dietary modification may be effective at reversing NAFLD and NASH at early stages. Furthermore, QUS may become a valuable tool to track hepatic steatosis. Additional studies are needed to further evaluate the effectiveness of these interventions.