Lipolysis and thermogenesis in adipose tissues as new potential mechanisms for metabolic benefits of dietary fiber

Silencing of dopamine receptor D5 inhibits the browning of 3T3-L1 adipocytes and ATP-consuming futile cycles in C2C12 muscle cells

BACKGROUND

As a part of the catecholamines, dopamine receptors (DRs) have not been extensively studied like β3-AR in the thermogenesis process. The present study investigates the effect of DRD5 in browning events and ATP-consuming futile cycles.

METHODS

siRNA technology, qPCR, immunoblot analysis, immunofluorescence, and staining methods were used to investigate the effect of DRD5 on 3T3-L1 and C2C12 cells.

RESULTS

siDdr5 increased lipogenesis-associated effectors, and adipogenesis markers while reducing the expression of beige fat effectors. ATP-consuming futile cycle markers were also reduced following the siDrd5. On the contrary, pharmacological activation of DRD5 stimulated these effectors. Our mechanistic studies elucidated that DRD5 mediates fat browning via the cAMP-PKA-p38 MAPK signalling pathway in 3T3-L1 cells as well as the cAMP-SERCA-RyR pathway for the ATP-consuming futile cycles in both cells.

CONCLUSIONS

siDrd5 positively regulates browning and ATP-consuming futile cycles, and understanding its functions will provide insights into novel strategies to treat obesity.

Associations of Ultra-Processed Food Intake with Body Fat and Skeletal Muscle Mass by Sociodemographic Factors

BACKGRUOUND

The effects of excessive ultra-processed food (UPF) consumption on body composition measures or sociodemographic disparities are understudied in Korea. We aimed to investigate the association of UPF intake with percent body fat (PBF) and percent appendicular skeletal muscle mass (PASM) by sociodemographic status in adults.

METHODS

This study used data from the Korea National Health and Nutrition Examination Survey 2008-2011 (n=11,123 aged ≥40 years). We used a NOVA system to classify all foods reported in a 24-hour dietary recall, and the percentage of energy intake (%kcal) from UPFs was estimated. PBF and PASM were measured by dual-energy X-ray absorptiometry. Tertile (T) 3 of PBF indicated adiposity and T1 of PASM indicated low skeletal muscle mass, respectively. Multinomial logistic regression models were used to estimate odds ratios (OR) with 95% confidence interval (CI) after adjusting covariates.

RESULTS

UPF intake was positively associated with PBF-defined adiposity (ORper 10% increase, 1.04; 95% CI, 1.002 to 1.08) and low PASM (ORper 10% increase, 1.05; 95% CI, 1.01 to 1.09). These associations were stronger in rural residents (PBF: ORper 10% increase, 1.14; 95% CI, 1.06 to 1.23; PASM: ORper 10% increase, 1.15; 95% CI, 1.07 to 1.23) and not college graduates (PBF: ORper 10% increase, 1.06; 95% CI, 1.02 to 1.11; PASM: ORper 10% increase, 1.07; 95% CI, 1.03 to 1.12) than their counterparts.

CONCLUSION

A higher UPF intake was associated with higher adiposity and lower skeletal muscle mass among Korean adults aged 40 years and older, particularly in those from rural areas and with lower education levels.

Acute activation of adipocyte lipolysis reveals dynamic lipid remodeling of the hepatic lipidome

Adipose tissue is the site of long-term energy storage. During the fasting state, exercise, and cold exposure, the white adipose tissue mobilizes energy for peripheral tissues through lipolysis. The mobilization of lipids from white adipose tissue to the liver can lead to excess triglyceride accumulation and fatty liver disease. Although the white adipose tissue is known to release free fatty acids, a comprehensive analysis of lipids mobilized from white adipocytes in vivo has not been completed. In these studies, we provide a comprehensive quantitative analysis of the adipocyte-secreted lipidome and show that there is interorgan crosstalk with liver. Our analysis identifies multiple lipid classes released by adipocytes in response to activation of lipolysis. Time-dependent analysis of the serum lipidome showed that free fatty acids increase within 30 min of β3-adrenergic receptor activation and subsequently decrease, followed by a rise in serum triglycerides, liver triglycerides, and several ceramide species. The triglyceride composition of liver is enriched for linoleic acid despite higher concentrations of palmitate in the blood. To further validate that these findings were a specific consequence of lipolysis, we generated mice with conditional deletion of adipose tissue triglyceride lipase exclusively in adipocytes. This loss of in vivo adipocyte lipolysis prevented the rise in serum free fatty acids and hepatic triglycerides. Furthermore, conditioned media from adipocytes promotes lipid remodeling in hepatocytes with concomitant changes in genes/pathways mediating lipid utilization. Together, these data highlight critical role of adipocyte lipolysis in interorgan crosstalk between adipocytes and liver.

Screening of Genes Related to Fat Deposition of Pekin Ducks Based on Transcriptome Analysis

Subcutaneous fat deposition is an important index with which to evaluate meat-producing ducks, and affects their meat quality and feed conversion rate. Studying the differentially expressed genes in subcutaneous fat will help to comprehensively understand the potential mechanisms regulating fat deposition in ducks. In this study, 72 Nankou 1 Pekin Ducks and 72 Jingdian Pekin Ducks (half male and half female) at 42 days of age were selected for slaughter performance and transcriptome analysis. The results showed that the breast-muscle yield of Nankou 1 ducks was significantly higher than that of Jingdian ducks, but that the abdominal fat yield and subcutaneous fat yield were higher than that of Jingdian ducks. Thousands of DEGs, including many important genes involved in fat metabolism regulation, were detected by transcriptome. KEGG enrichment analysis showed that the DEGs were significantly enriched on pathways such as regulation of lipolysis in adipocytes, primary bile acid biosynthesis, and biosynthesis of unsaturated fatty acids. SCD, FGF7, LTBP1, PNPLA3, ADCY2, and ACOT8 were selected as candidate genes for regulating subcutaneous fat deposition. The results indicated that Nankou 1 had superior fat deposition ability compared to Jingdian ducks, and that the candidate genes regulated fat deposition by regulating fat synthesis and decomposition.

The Effect of Dietary Oat Consumption and Its Constituents on Fat Storage and Obesity

This review is to summarize and analyze the currently available knowledge concerning the action of oat (Avena sativa L.) consumption on obesity, as well as possible constituents and extra- and intracellular mediators responsible for its anti-obesity effect. The oat constituents could reduce fat storage via several mediatory mechanisms - brain centers regulating appetite, gastrointestinal functions, gut bacteria, fat synthesis and metabolism and maybe via changes in oxidative processes, steroid hormones receptors and adipose tissue vascularization. Several oat constituents (starch, fiber and beta-glucan) could have anti-obesity properties, whilst one oat constituent (starch or fiber) could affect fat storage via several mechanisms of action.

Dopamine receptor D4 (DRD4) negatively regulates UCP1- and ATP-dependent thermogenesis in 3T3-L1 adipocytes and C2C12 muscle cells

The activation of beige fat and muscle tissues is an interesting and encouraging target for therapeutic intervention in obesity owing to their remarkable lipolytic activity and energy-consuming futile cycles. This study examined the effect of dopamine receptor D4 (DRD4) on lipid metabolisms as well as UCP1- and ATP-dependent thermogenesis in Drd4-silenced 3T3-L1 adipocytes and C2C12 muscle cells. Silencing of Drd4, followed by quantitative real-time PCR, immunoblot analysis, immunofluorescence, and staining methods, were applied to evaluate the effects of DRD4 on diverse target genes and proteins of both cells. The findings showed that DRD4 was expressed in the adipose and muscle tissues of normal and obese mice. Furthermore, the knockdown of Drd4 upregulated the expression of brown adipocyte-specific genes and proteins while downregulating lipogenesis and the adipogenesis marker proteins. Drd4 silencing also upregulated the expression of key signaling molecules involved in ATP-dependent thermogenesis in both cells. This was further elucidated by mechanistic studies showing that a Drd4 knockdown mediates UCP1-dependent thermogenesis via the cAMP/PKA/p38MAPK pathway in 3T3-L1 adipocytes and UCP1-independent thermogenesis via the cAMP/SLN/SERCA2a pathway in C2C12 muscle cells. In addition, siDrd4 also mediates myogenesis via the cAMP/PKA/ERK1/2/Cyclin D3 pathway in C2C12 muscle cells. Silencing of Drd4 promotes β3-AR-dependent browning in 3T3-L1 adipocytes and α1-AR/SERCA-based thermogenesis through an ATP-consuming futile process in C2C12 muscle cells. Understanding the novel functions of DRD4 on adipose and muscle tissues in terms of its ability to enhance energy expenditure and regulate whole-body energy metabolism will aid in developing novel obesity intervention techniques.

Therapeutic effects of atorvastatin on doxorubicin-induced hepatotoxicity in rats via antioxidative damage, anti-inflammatory, and anti-lipotoxicity

Doxorubicin (DOX), is a high efficiency anthracycline antitumor drug. However, the clinical application of DOX is limited mainly by dose-related adverse drug reactions. Currently, the therapeutic effects of Atorvastatin (ATO) on DOX-induced hepatotoxicity were studied in vivo. The results indicated that DOX impaired hepatic function, as measured by an increased levels of liver weight index and serum concentrations of aspartate transaminase and alanine transaminase, as well as alteration of hepatic histology. In addition, DOX increased the serum levles of triglyceride (TG) and nonestesterified fatty acid. ATO prevented these changes. Mechanical analysis revealed that ATO restored the changes of malondialdehyde, reactive oxygen radical species, glutathione peroxidase and manganese superoxide dismutase. Additionally, ATO inhibited the increased expression levels of nuclear factor-kappa B and interleukin 1β, hence suppressing inflammation. Meanwhile, ATO inhibited cell apoptosis by dramatically decreasing the Bax/Bcl-2 ratio. In addition, ATO mitigated the lipidtoxicity by inhibiting the adipolysis of TG and accelerating hepatic lipid metabolism. Taken together, the results suggest ATO has therapeutic effect on DOX-induced hepatotoxicity via inhibition of oxidative damage, inflammatory and apoptosis. In addition, ATO attenuates DOX-induced hyperlipidemia via modulation of lipid metabolism.

Effect of quercetin and Abelmoschus esculentus (L.) Moench on lipids metabolism and blood glucose through AMPK-α in diabetic rats (HFD/STZ)

Phosphoenolpyruvate carboxykinase (PEPCK) is a key enzyme in the glyconeogenesis pathway. The AMP-activated protein kinase alpha (AMPK-α) pathway regulates PEPCK, which itself is activated by the AMP/ATP ratio and liver kinase B1 (KB1). The Abelmoschus esculentus (L.) Moench (okra) plant contains a large amount of quercetin that can function as an agonist or an antagonist. The aim of this study was to examine the effects of quercetin flavonoid and A. esculentus extract on the level of AMPK-α expression and associated metabolic pathways. The findings demonstrate that metformin, quercetin, and okra extract may significantly raise AMPK-α levels while significantly lowering PEPCK and hormone-sensitive lipase (HSL) levels, in addition to improving glucose and lipid profiles. By stimulating KB1, these substances increased AMPK-α activation. Additionally, AMPK-α activation improved insulin resistance and Glucose transporter type 4 (GLUT4) gene expression levels. Since AMPK-α maintains energy balance and its activity has not been reported to be inhibited so far, it could be a potent therapeutic target. PRACTICAL APPLICATIONS: The development of effective AMPK-α agonists and antagonists holds promise for the treatment of metabolic disorders like diabetes. Dietary polyphenols are a valuable source for developing new drugs. However, due to the lack of understanding of the underlying mechanisms of their effect on cells, their use in the treatment of diabetes is controversial. In addition to chemicals that have medicinal benefits, chemists are searching for less harmful substances. Using plants containing bioactive chemicals for this purpose can be a good alternative to chemical drugs.

Positive association of unhealthy plant-based diets with the incidence of abdominal obesity in Korea: a comparison of baseline, most recent, and cumulative average diets

OBJECTIVES

Different approaches for analyzing repeated dietary measurements may yield differences in the magnitude and interpretation of findings. We aimed to compare 3 dietary measurements (baseline, most recent, and cumulative average) in terms of the association between plant-based diet indices (PDIs) and incident abdominal obesity in Korean adults aged 40-69 years.

METHODS

This study included 6,054 participants (54% women) free of abdominal obesity (defined as waist circumference ≥90 cm for men and ≥85 cm for women) at baseline. As exposures, baseline, most recent, and cumulative average measurements for PDI, healthy-PDI (hPDI), and unhealthy-PDI (uPDI) were created. A Cox proportional-hazard model was used to estimate the hazard ratios (HRs) for abdominal obesity.

RESULTS

During 45,818 person-years of follow-up (median, 9 years), we identified 1,778 incident cases of abdominal obesity. In the multivariable-adjusted analysis, a higher uPDI was associated with a higher risk of abdominal obesity in both total and stratified analyses. The findings were consistent across all approaches (Q5 vs. Q1: HRbaseline=1.70; 95% confidence interval [CI], 1.46 to 1.98; HRmost recent=1.52; 95% CI, 1.30 to 1.78; HRcumulative average=1.76; 95% CI, 1.51 to 2.06 in the total set). PDI showed no meaningful association with abdominal obesity risk in any analyses. hPDIaverage had a suggestive inverse association with abdominal obesity risk in men, and hPDIbaseline had a positive association with abdominal obesity risk in women.

CONCLUSIONS

Greater adherence to unhealthy plant-based diets may increase the risk of developing abdominal obesity in Korean adults. The findings were generally consistent across all approaches.

Flaxseed Polysaccharide Alters Colonic Gene Expression of Lipid Metabolism and Energy Metabolism in Obese Rats

Obesity is one of the most serious public health challenges. Recently, we found that flaxseed polysaccharides (FPs) had an anti-obesity effect through promoting lipid metabolism, but the obesity-inhibiting pathway of FP is still unclear. In this study, after FP intervention in an obese rat model, a transcriptome study was performed to further investigate how FP intervention alters the gene expression of colonic epithelial tissues (CETs). The results showed that there were 3785 genes differentially expressed due to the FP intervention, namely 374 downregulated and 3411 upregulated genes. After analyzing all the differentially expressed genes, two classical KEGG pathways were found to be related to obesity, namely the PPAR-signaling pathway and energy metabolism, involving genes Fabp1–5, Lpl, Gyk, Qqp7, Pparg, Rxrg, Acsl1, Acsl4, Acsl6, Cpt1c, Car1–4, Ca5b, Car8, Car12–14, Cps1, Ndufa4l2, Cox6b2, Atp6v1g2, Ndufa4l2 and Cox4i2. QRT-PCR results showed a consistent expression trend. Our results indicate that FP promotes lipid metabolism by changing the expression of some key genes of CETs, thus inhibiting obesity.

Spexin modulates molecular thermogenic profile of adipose tissue and thermoregulatory behaviors in female C57BL/6 mice

Thermoregulation is the physiological process by which an animal regulates body temperature in response to its environment. It is known that galanin, a neuropeptide widely distributed throughout the central nervous system and secreted by the gut, plays a role in thermoregulatory behaviors and metabolism. We tested the ability of the novel neuropeptide spexin, which shares sequence homology to galanin, to regulate these functions in female mice. Supraphysiological levels of spexin in C57BL/6 mice did not lead to weight loss after 50 days of treatment. Behavioral analysis of long-term spexin treatment showed it decreased anxiety and increased thermoregulatory nest building, which was not observed when mice were housed at thermoneutral temperatures. Treatment also disrupted the thermogenic profile of brown and white adipose tissue, decreasing mRNA expression of Ucp1 in BAT and immunodetection of β3-adrenergic receptors in gWAT. Our results reveal novel functions for spexin as a modulator of thermoregulatory behaviors and adipose tissue metabolism.

Functional Fiber Reduces Mice Obesity by Regulating Intestinal Microbiota

Obesity may cause metabolic syndrome and has become a global public health problem, and dietary fibers (DF) could alleviate obesity and metabolic syndrome by regulating intestinal microbiota. We developed a functional fiber (FF) with a synthetic mixture of polysaccharides, high viscosity, water-binding capacity, swelling capacity, and fermentability. This study aimed to investigate the effect of FF on obesity and to determine its prevention of obesity by modulating the gut microbiota. Physiological, histological, and biochemical parameters, and gut microbiota composition were investigated in the following six groups: control group (Con), high-fat diet group (HFD), low-fat diet group (LFD, conversion of HFD to LFD), high-fat +8% FF group (8% FF), high-fat +12% FF group (12% FF), and high-fat +12% FF + antibiotic group (12% FF + AB). The results demonstrated that 12% FF could promote a reduction in body weight and epididymal adipocyte area, augment insulin sensitivity, and stimulate heat production from brown adipose tissue (BAT) (p < 0.05). Compared with the HFD, 12% FF could also significantly improve the intestinal morphological integrity, attenuate systemic inflammation, promote intestinal microbiota homeostasis, and stabilize the production of short-chain fatty acids (SCFAs) (p < 0.05). Consistent with the results of 12% FF, the LFD could significantly reduce the body weight and epididymal adipocyte area relative to the HFD (p < 0.05), but the LFD and HFD showed no significant difference (p > 0.05) in the level of inflammation and SCFAs. Meanwhile, 12% FF supplementation showed an increase (p < 0.05) in the abundance of the Bifidobacterium, Lactococcus, and Coprococcus genus in the intestine, which had a negative correlation with obesity and insulin resistance. Additionally, the treatment with antibiotics (12% FF + AB) could inhibit the effect of FF in the HFD. The Kyoto Encyclopedia of Genes and Genomes (KEGG) function prediction revealed that 12% FF could significantly inhibit the cyanogenic amino acid metabolic pathway and decrease the serum succinate concentration relative to the HFD group. The overall results indicate that 12% FF has the potential to reduce obesity through the beneficial regulation of the gut microbiota and metabolites.

The different effects of intramuscularly-injected lactate on white and brown adipose tissue in vivo

BACKGROUND

Lactate is an important product of glycolysis metabolism during exercise and has long been recognized as an important metabolic signaling molecule involved in inhibiting lipolysis and promoting lipogenesis, which consequently leads to regulated adipose tissue metabolism. However, recent studies have shown that lactate promotes the browning of white adipose tissue (WAT), which induces heat production and energy expenditure and ultimately causes weight loss. These studies assessing the effects of lactate on lipid metabolism in adipose tissue have revealed conflicting data, making it an important area worthy of further research.

METHODS

In this study, using intramuscular injection of lactate to the gastrocnemius, we identified the role of lactate treatment on lipid metabolism and mitochondrial biogenesis of white adipose tissue and brown adipose tissue (BAT).

RESULTS

Our results showed that lactate treatment activated the cAMP/PKA signaling pathway and promoted the expression of lipolysis-related proteins (AMPK, HSL, ATGL) and mitochondrial biomarkers (PGC-1α, COXIV) of WAT, while BAT showed an opposite trend after lactate treatment. Further studies showed that lactate treatment significantly increased serum epinephrine and promoted β3-AR protein expression in WAT and significantly decreased in BAT.

CONCLUSION

Our study shows that lactate seems to regulate β3-adrenergic receptors differently in WAT and BAT, thereby eliciting disparate responses in adipose tissue.

Melatonin inhibits testosterone synthesis in Roosters Leydig cells by regulating lipolysis of lipid droplets

Leydig cells are important component of testis cells, which can synthesize testosterone with free cholesterol derived from lipid droplets (LDs). It is well known that melatonin could regulate synthesis of testosterone. However, it is still unclear whether melatonin participates in the synthesis of testosterone by regulating the lipolysis of LDs in Leydig cells. The purpose of this study was to elucidate the effect of melatonin on synthesis of testosterone in roosters Leydig cells by regulating lipolysis of LDs. The results showed that melatonin decreased synthesis of testosterone and intracellular free cholesterol in roosters Leydig cells. Exogenous addition of 22-OH-Cholesterol counteracted the inhibitory effect of melatonin on synthesis of testosterone. Furthermore, melatonin increased the LDs content and expression of perilipin 1 (PLIN1), and decreased expression of hormone-sensitive lipase (HSL) and triacylglycerol hydrolase (ATGL) in roosters Leydig cells. In addition, silencing PLIN1 reversed the inhibitory effect of melatonin on synthesis of testosterone in roosters Leydig cells by increasing free cholesterol content and expression of HSL and ATGL, and decreasing the lipid droplet content. Activation of cAMP/PKA pathway by using the pathway activators Forskolin and 8-Bromo-cAMP attenuated the inhibitory effect of melatonin on synthesis of testosterone accompanied by increasing level of free cholesterol content and expression of HSL and ATGL, and decreasing level of lipid droplet content and expression of PLIN1 in roosters Leydig cells. These results suggested that melatonin could inhibit the synthesis of testosterone in roosters Leydig cells by reducing the content of intracellular free cholesterol in which expression of PLIN1 and cAMP/PKA pathway were inhibited to reduce the lipolysis of LDs.

Russelioside B: a Pregnane Glycoside with Pharmacological Potential

Pregnanes and pregnane glycosides or their esters are well-studied secondary metabolites, many of them exhibit immunomodulator, anticancer, antidiabetic, antarthritic, antiulcer, anti-nociceptive, hypolipidemic, anti-inflammatory, and antibacterial properties. Pregnane glycosides are widely distributed in the families Apocyanaceae and Asclepiadaceae. Plant members of the genus Caralluma R.Br., Apocynaceae, are among the most studied species because of uses in traditional medicine or as food. They are a rich source of pregnane glycosides, as russelioside B. However, the bioactivity profile of this pregnane glycoside has not been reviewed until now. The present review aims to summarize the most important pharmacological and therapeutic applications of russelioside B with specific emphasis on the mechanism of actions associated with its administration in preclinical models. Russelioside B has many pharmacological effects including antidiabetic, anti-obesity, anti-nociceptive, antiulcer, anti-inflammatory, anti-arthritis effects, and antibiofilm, and wound healing activities. Despite its outstanding pharmacotherapeutic potential, russelioside B has never been tested in clinical trials. This review indicates that russelioside B is a potentially promising bioactive candidate, but further deeper mechanistic studies and clinical trials are needed in the future to elucidate its interaction with receptors of specific genes.

Dopamine receptor D1 signaling stimulates lipolysis and browning of white adipocytes

Adipocytes express several kinds of catecholamine receptors, including adrenergic receptors, and dopamine receptors. Signaling pathways mediated by catecholamine receptors, such as β3-adrenergic receptor pathway, can induce body energy expenditure via activating thermogenesis of adipose tissue. However, the roles of adipose dopamine receptors on adipocytes are still unclear. Here, we investigate the role of dopamine receptor D1 (DRD1) on adipocytes. To this end, we use DRD1 agonist Fenoldopam and antagonist SCH23390 to stimulate and inhibit DRD1 signaling, respectively. We found that, compared with control group mice, Fenoldopam-treated and SCH23390-treated high-fat-diet (HFD)-fed mice showed smaller and bigger white adipose tissue/adipocyte sizes, respectively. Meanwhile, activating of DRD1 signaling enhanced intracellular levels of cAMP, phosphorylation levels of protein kinase A substrates, and hormone-sensitive lipase, a key enzyme for lipolysis in mature 3T3-L1 adipocytes and white adipose tissue of HFD-fed mice. As a result, the levels of free fatty acid or glycerol were increased, indicating stimulation of lipolysis by DRD1 activation. Moreover, activating DRD1 can induce the browning of adipocytes, as indicated by enhanced phosphorylation of P38 MAP kinase, increased expression of beige cell markers (PGC-1α, UCP-1, and CD81), mitochondrion content, and expression of β-oxidation related genes. All of these effects were reduced after treating with SCH23390 both in vitro and in HFD-fed mice. Collectively, our study indicated that DRD1 signaling stimulates lipolysis and browning of white adipocytes in vitro and in vivo. Understanding the functions of DRD1 on human adipocytes and adipose tissues will help us to design novel strategies to treat obesity.

Arsenic and weight loss: At a crossroad between lipogenesis and lipolysis

Arsenic is found in soil, food, water and earth crust. Arsenic exposure is associated with chronic diseases such as cancer, cardiovascular disease as well as diabetes. One of complex effects of arsenic is on weight gain or loss. Involvement of arsenic in both weight loss and gain signaling pathways has previously been reported; however, too little attention has been paid to its weight reducing effect. Animal studies exhibited a role of arsenic in weight loss. In this regard, arsenic interference with endocrine system, leptin and adiponectin hormones as well as thermogenesis is more evidence. Apparently, arsenic-induced weight lossis generally meditated by its interaction with thermogenesis. In this review we have discussed the irregularities in metabolic pathways induced by arsenic that can lead to weight loss.

Oat fiber supplementation alleviates intestinal inflammation and ameliorates intestinal mucosal barrier via acting on gut microbiota-derived metabolites in LDLR-/- mice

OBJECTIVE

Gut microbiota-derived metabolites are involved in intestinal inflammation, which can affect the development of atherosclerotic plaques. Previous studies have shown that oat fiber can delay the progression of atherosclerosis via improving lipid metabolism. The aim of this study was to evaluate how oat fiber acted on gut microbiota-derived metabolites, inhibited intestinal inflammation, and protected the intestinal mucosal barrier.

METHODS

Male low-density lipoprotein receptor knock-out (LDLR^-/-) mice were fed a high-fat/cholesterol diet with or without oat fiber for 14 wk. Histopathology of the aorta was detected by Oil Red O staining, and the small intestine mucosal pathology was measured through hematoxylin and eosin staining. Non-targeted metabolomics of feces was performed using liquid chromatography-mass spectrometry. Western blot method was used to assess the relative levels of the proteins involved in the toll-like receptor (TLR)4 signal pathway and intestinal mucosal barrier in interest tissues.

RESULTS

Pathologically, oat fiber reversed the increment of the atherosclerotic lesion and ameliorated intestinal mucosal barrier in LDLR^-/- mice. Oat fiber regulated the levels of gut microbiota-derived metabolites along with a decrease in isobutyrylcarnitine, valerylcarnitine, 1-methylguanosine, and 2-methylguanosine, and an increase in l-tyrosine and niacinamide. Notably, oat fiber blocked the TLR4 signal pathway and decreased the expression of nuclear factor-κB p65 in both the aorta and gut tissues. Also, oat fiber raised the expression of tight junction proteins including ZO-1 and occludin.

CONCLUSION

Taken together, the present study revealed that oat fiber feeding effectively attenuated the development of atherosclerosis, at least partly via affecting gut microbiota-derived metabolites, inhibiting the intestinal inflammatory response, and maintaining the integrity of the intestinal mucosal barrier.

Cyperus rotundus L. reverses the olanzapine-induced weight gain and metabolic changes-outcomes from network and experimental pharmacology

Cyperus rotundus L. is used to treat multiple clinical conditions like inflammation, diarrhea, pyrosis, and metabolic disorders including diabetes and obesity. The present study aimed to predict the interaction of reported bioactives from Cyperus rotundus against obesity via network pharmacology and to evaluate the efficacy of hydroalcoholic extract of Cyperus rotundus against the olanzapine-induced weight gain and metabolic disturbances in experimental animals. Reported phytochemicals of Cyperus rotundus were retrieved from the open-source database(s) and published literature and their targets were predicted using SwissTargetPrediction, enriched in STRING, and bioactives-proteins-pathways network was constructed using Cytoscape. Further, the hydroalcoholic extract of Cyperus rotundus (100, 200, and 400 mg/kg/day, p.o.) was co-administered with olanzapine (2 mg/kg, i.p.) for 21 days in Sprague Dawley rats. During treatment, body weight and food intake were recorded; after the successful completion of 21 days of treatment, animals were fasted to perform oral glucose and insulin tolerance tests. Further, the animals were euthanized; blood and abdominal fat were collected for lipid profiling and histopathological examination respectively. Herein, network pharmacology predicted neuroactive ligand-receptor interaction as a primarily modulated pathway and protein tyrosine phosphatase 1b as a majorly triggered protein via the combined action of bioactives. Further, Cyperus rotundus significantly reversed weight gain, cumulative food intake, ameliorated the lipid and glucose metabolism, and promoted energy expenditure.

Chitosan modifies glycemic levels in people with metabolic syndrome and related disorders: meta-analysis with trial sequential analysis

BACKGROUND

Chitosan supplementation has been shown to modulate glycemic levels; however, studies have reported conflicting results. The present meta-analysis with trial sequential analysis was conducted to verify the overall influence of chitosan on glycemic levels in patients with metabolic syndrome.

METHODS

The PubMed, Cochrane library, and EMBASE databases were systematically searched for randomized controlled studies of chitosan intake and glycemic levels.

RESULTS

A total of ten clinical trials including 1473 subjects were included in this meta-analysis. Pooled effect sizes were determined by random-effects meta-analysis. Subgroup analysis was performed to analyze the sources of heterogeneity and their influence on the overall results. The results revealed a significant reduction in fasting glucose levels (SMD: - 0.39 mmol/L, 95% CI: - 0.62 to - 0.16) and hemoglobin A1c (HbA1c) levels (SMD: -1.10; 95% CI: - 2.15 to - 0.06) following chitosan supplementation but no effect on insulin levels (SMD: - 0.20 pmol/L, 95% CI: - 0.64 to 0.24). Subgroup analyses further demonstrated significant reductions in fasting glucose levels in subjects administered 1.6-3 g of chitosan per day and in studies longer than 13 weeks. Trial sequential analysis of the pooled results of the hypoglycemic effect demonstrated that the cumulative Z-curve crossed both the conventional boundary and trial sequential monitoring boundary for glucose and HbA1c.

CONCLUSIONS

The glucose level of patients who are diabetic and obese/overweight can be improved by supplementation with chitosan for at least 13 weeks at 1.6-3 g per day. Additional clinical research data are needed to confirm the role of chitosan, particularly in regulating glycosylated hemoglobin and insulin.

Effects of prebiotic dietary fibers and probiotics on human health: With special focus on recent advancement in their encapsulated formulations

Background

Dietary fibers (DFs) are known as potential formulations in human health due to their beneficial effects in control of life-threatening chronic diseases including cardiovascular disease (CVD), diabetes mellitus, obesity and cancer. In recent decades scientists around the globe have shown tremendous interest to evaluate the interplay between DFs and gastrointestinal (GIT) microbiota. Evidences from various epidemiological and clinical trials have revealed that DFs modulate formation and metabolic activities of the microbial communities residing in the human GIT which in turn play significant roles in maintaining health and well-being. Furthermore, interestingly, a rapidly growing literature indicates success of DFs being prebiotics in immunomodulation, namely the stimulation of innate, cellular and humoral immune response, which could also be linked with their significant roles in modulation of the probiotics (live beneficial microorganisms).

Scope and approach

The main focus of the current review is to expressively highlight the importance of DFs being prebiotics in human health in association with their influence on gut microbiota. Now in order to significantly achieve the promising health benefits from these prebiotics, it is aimed to develop novel formulations to enhance and scale up their efficacy. Therefore, finally, herein unlike previously published articles, we highlighted different kinds of prebiotic and probiotic formulations which are being regarded as hot research topics among the scientific community now a days.

Conclusion

The information in this article will specifically provide a platform for the development of novel functional foods the demands for which has risen drastically in recent years.

Ecklonia stolonifera Extract Suppresses Lipid Accumulation by Promoting Lipolysis and Adipose Browning in High-Fat Diet-Induced Obese Male Mice

Obesity develops due to an energy imbalance and manifests as the storage of excess triglyceride (TG) in white adipose tissue (WAT). Recent studies have determined that edible natural materials can reduce lipid accumulation and promote browning in WAT. We aimed to determine whether Ecklonia stolonifera extract (ESE) would increase the energy expenditure in high-fat diet (HFD)-induced obese mice and 3T3-L1 cells by upregulating lipolysis and browning. ESE is an edible brown marine alga that belongs to the family Laminariaceae and contains dieckol, a phlorotannin. We report that ESE inhibits body mass gain by regulating the expression of proteins involved in adipogenesis and lipogenesis. In addition, ESE activates protein kinase A (PKA) and increases the expression of lipolytic enzymes including adipose triglyceride lipase (ATGL), phosphorylated hormone-sensitive lipase (p-HSL), and monoacylglycerol lipase (MGL) and also thermogenic genes, such as carnitine palmitoyltransferase 1 (CPT1), PR domain-containing 16 (PRDM16), and uncoupling protein 1 (UCP1). These findings indicate that ESE may represent a promising natural means of preventing obesity and obesity-related metabolic diseases.

The Effects of New Selective PPARα Agonist CP775146 on Systematic Lipid Metabolism in Obese Mice and Its Potential Mechanism

PURPOSE

Peroxisome proliferator-activated receptor α (PPARα) plays a crucial role in the control of lipid homeostasis. Here, we investigated the effects of CP775146, a new selective PPARα agonist, on lipid metabolism in diet-induced obese mice and its possible mechanism.

METHODS

C57BL/6 mice were fed a high-fat diet (HFD) for 12 weeks to induce obesity and then received CP775146 via intraperitoneal injection for 3 days. The content/morphology of the liver, serum lipid, and liver function was measured. The expression of genes related to lipolysis and synthesis in liver was detected by quantitative real-time PCR (qRT-PCR).

RESULTS

The safe dose of CP775146 was <0.3 mg/kg. CP775146 reduced the serum levels of liver enzymes, such as alanine aminotransferase (ALT) and glutamic-oxaloacetic transaminase (AST) and lipid metabolism-related biomarkers, including triglycerides (TGs) and low-density lipoprotein cholesterol (LDL-c), non-high-density lipoprotein cholesterol (non-HDL-c), and hepatic TG content, at a dosage of 0.1 mg/kg. HFD-induced pathological liver changes improved after CP775146 treatment. The expression of genes involved in liver fatty acid oxidation (acyl-coenzyme A dehydrogenase, long chain (Acadl), acyl-CoA oxidase 1 (Acox-1), carnitine palmitoyltransferase-1 (CPT-1), and enoyl-CoA, hydratase/3-hydroxyacyl CoA dehydrogenase (Ehhadh)) was upregulated in CP775146-treated mice. Furthermore, CP775146 induced the expression of thermogenesis genes (cell death-inducing DFFA-like effector a (Cidea), uncoupling protein 1 (Ucp1)) and lipolysis genes (hormone-sensitive lipase (Hsl), adipose tissue triglyceride lipase (Atgl)) in epididymal white adipose tissue (eWAT), activating browning and thermogenesis.

CONCLUSION

CP775146 efficiently alleviates obesity-induced liver damage, prevents lipid accumulation by activating the liver fatty acid β-oxidation pathway, and regulates the expression of genes that control brown fat-like pathway in eWAT.

6-Gingerol, a Functional Polyphenol of Ginger, Promotes Browning through an AMPK-Dependent Pathway in 3T3-L1 Adipocytes

The main purpose of the present study was to investigate the browning effect of 6-gingerol (6G), one of the main functional compounds in the ethyl acetate extract of ginger (ginger ethyl acetate fraction, GEF), and its underlying mechanisms. In this study, we first discovered that GEF stimulated brown adipocyte differentiation by upregulating the expression levels of browning-specific transcription makers (UCP1, PRDM16, and PGC-1α), thereby reducing lipogenesis transcriptional regulator (C/EBPα) expression in 3T3-L1-differentiated adipocytes. Then, 6G (47.81 ± 0.62 mg/g) was identified as one of the main functional compounds in GEF using high-performance liquid chromatography. 6G promoted adipocyte browning, as evidenced by an increase in some brown/beige fat-specific genes (PGC-1α, Cidea, Prdm16, Cited1, SIRT1, Tmem26, and Ucp1) and proteins (UCP1, CEBP/β, PGC-1α, and PRDM16) expression levels. Moreover, 6G greatly improved mitochondrial respiration and energy metabolism by upregulating the expression levels of some mitochondrial biogenesis markers (Tfam, Nrf1, SIRT1, and p-AMPK/AMPK) and increasing the uncoupled oxygen consumption rate of protons leaked in 3T3-L1 cells. Comparison of the experimental results obtained with an inhibitor (dorsomorphin) and an activator (5-aminoimidazole-4-carboxamide ribonucleotide) suggested that the 6G-associated regulation of the energy metabolism effect was mediated partly through the AMPK signaling pathway. This study provides new insight into the promotion of fat browning and regulation of lipid metabolism by 6G and suggests that 6G likely has potential therapeutic effects on obesity.

Microbial fermentation of flaxseed fibers modulates the transcriptome of GPR41-expressing enteroendocrine cells and protects mice against diet-induced obesity

Dietary fibers, an integral part of the human diet, require the enzymatic activity of the gut microbiota for complete metabolism into short-chain fatty acids (SCFAs). SCFAs are important modulators of host metabolism and physiology and act in part as signaling molecules by activating G protein-coupled receptors (GPCRs), such as GPR41. Flaxseed fibers improve metabolism in rodents and mice, but their fermentation profiles, effects on enteroendocrine cells, and associated metabolic benefits are unknown. We fed GPR41-red fluorescent protein mice, an enteroendocrine reporter mouse strain, chow, high-fat diet (HFD), or HFD supplemented either with 10% nonfermentable fiber cellulose or fermentable flaxseed fibers for 12 wk to assess changes in cecal gut microbiota, enteroendocrine cell transcriptome in the ileum and colon, and physiological parameters. We observed that flaxseed fibers restructured the gut microbiota and promoted proliferation of the genera Bifidobacterium and Akkermansia compared with HFD. The shifts in cecal bacterial composition restored levels of the SCFAs butyrate similar to the chow diet, resulting in colonic but not ileal enteroendocrine cell transcriptional changes in genes related to cell cycle, mRNA, and protein transport compared with HFD. Consistent with the effects on enteroendocrine functions, flaxseed fibers also protected mice from diet-induced obesity, potentially by preventing a reduction in energy expenditure induced by an HFD. Our study shows that flaxseed fibers alter cecal microbial ecology, are fermented to SCFAs in the cecum, and modulate enteroendocrine cell transcriptome in the colon, which may contribute to their metabolically favorable phenotype.

Effect of a high sucrose and high fat diet in BDNF (+/-) mice on oxidative stress markers in adipose tissues

The purpose of this study was to investigate the effects of a high fat and a high sucrosediet in wild type and BDNF (+/-) mice on oxidative stress in epididymal and subcutaneousadipose tissues by measuring different markers of oxidative stress and antioxidant enzymes. Wild type (WT) and BDNF (+/-) male mice were divided into six groups receiving fed control diet (CD), high sucrose diet (HSD), or high fat diet (HFD) for four months. Levels of 3-nitrotyrosine (3-NT) increased in the HFD-fed BDNF (+/-) mice, while 4-hydroxynonenal (4-HNE) levels increased in the CD and HFD-fed BDNF (+/-) groups. Malondialdehyde (MDA) levels decreased in subcutaneous tissue compared to epididymal adipose tissue, independently of diet type. Superoxide dismutase (SOD) activity was reduced by HFD (p < 0.05), butglutathione peroxidase (GSH-Px) activity was increased by HSD in epididymal adipose tissuein BDNF (+/-) mice (p < 0.05). GSH-Px activities was increased by CD and HFD in subcutaneous adipose tissue of BDNF (+/-) (p < 0.05). SOD2 and GSH-Px3 expressions were only decreased by HSD in epididymal and subcutaneous adipose tissues of BDNF (+/-) mice (p < 0.05). In conclusion, reduced BDNF may increase OS in epididymal adipose tissue, but not in subcutaneous adipose tissue following HSD and HFD.

Brown and Brite: The Fat Soldiers in the Anti-obesity Fight

Brown adipose tissue (BAT) is proposed to maintain thermal homeostasis through dissipation of chemical energy as heat by the uncoupling proteins (UCPs) present in their mitochondria. The recent demonstration of the presence of BAT in humans has invigorated research in this area. The research has provided many new insights into the biology and functioning of this tissue and the biological implications of its altered activities. Another finding of interest is browning of white adipose tissue (WAT) resulting in what is known as beige/brite cells, which have increased mitochondrial proteins and UCPs. In general, it has been observed that the activation of BAT is associated with various physiological improvements such as a reduction in blood glucose levels increased resting energy expenditure and reduced weight. Given the similar physiological functions of BAT and beige/ brite cells and the higher mass of WAT compared to BAT, it is likely that increasing the brite/beige cells in WATs may also lead to greater metabolic benefits. However, development of treatments targeting brown fat or WAT browning would require not only a substantial understanding of the biology of these tissues but also the effect of altering their activity levels on whole body metabolism and physiology. In this review, we present evidence from recent literature on the substrates utilized by BAT, regulation of BAT activity and browning by circulating molecules. We also present dietary and pharmacological activators of brown and beige/brite adipose tissue and the effect of physical exercise on BAT activity and browning.

Pharmacological Action of a Pregnane Glycoside, Russelioside B, in Dietary Obese Rats: Impact on Weight Gain and Energy Expenditure

Background and purpose: Russelioside B (RB) is a pregnane glycoside obtained from Caralluma quadrangula; a herb with antidiabetic, anti-inflammatory, and antihyperlipidemic activities. The present experiment tested the possible role of RB in controlling weight gain in rats fed on high fat (HF) diet. Methods: RB was separated from the n-butanol fraction of the crude methanolic extract by chromatographic separation on a Si gel column according to the procedures described previously. The experiment of the biological assessment of RB used 32 male Wistar rats (4 groups, n = 8). Group 1 rats were fed with a palatable normal diet. Group 2, 3, and 4 were fed on HF diet for 16 weeks. Group 2 served as the HF diet control group while Group 3 and 4 received daily oral doses of RB (25 and 50 mg/kg) during the last four weeks. Animals' parameters like weight gain, fasting level of blood sugar, serum lipids, and serum liver enzyme activities were measured. Liver or adipose tissue weight was divided by the rat's body weight and multiplied by 100 to obtain the liver or adipose tissue index, respectively. Adipose tissues were processed for histopathological examination, measurement of mRNA expression of visfatin, leptin, adiponectin, uncoupling protein-1 (UCP-1), and carnitine palmitoyl transferase-1 (CPT-1). Furthermore, serum levels of insulin, interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), leptin, resistin, and adiponectin were assessed using ELISA kits. Results: Rats fed with the HF diet exhibited significant body weight gain, abnormal liver function, disturbed lipid profile, and greater serum level of pro-inflammatory cytokines in addition to greater insulin resistance, adipose tissue and liver indices. Further, rats fed with the HF diet displayed upregulations in the expression of visfatin and leptin with downregulations in the expression of adiponectin, UCP-1, and CPT-1 compared to normal rats. Interestingly, RB (25 or 50 mg/kg) favorably modulated the measured parameters. Conclusion: Data from this study documented the beneficial role of RB in diminishing weight gain, improving the inflammatory perturbations and energy expenditure in HF diet fed rats. Therefore, RB might be a promising candidate for obesity.

Cereal Fiber Ameliorates High-Fat/Cholesterol-Diet-Induced Atherosclerosis by Modulating the NLRP3 Inflammasome Pathway in ApoE-/- Mice

Cereal fiber is associated with decreasing the risk of cardiovascular diseases. However, whether cereal fiber modulates inflammatory response and improves atherosclerosis remains unclear. This study evaluated the anti-atherosclerotic effect of cereal fibers from oat or wheat bran and explored the potential anti-inflammatory mechanisms. Male ApoE^-/- mice were given a high-fat/cholesterol (HFC) diet or a HFC diet supplemented with 0.8% oat fiber or wheat bran fiber. After 18 weeks of the feeding period, serum lipids and inflammatory cytokines were measured. The relative protein levels of the nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome pathway and nuclear factor κB (NF-κB) were determined by the western blot method in aorta tissues. Pathologically, oat fiber and wheat fiber significantly reduced atherosclerotic plaques by 43.3 and 27.1%, respectively. Biochemically, cereal fiber markedly decreased the protein levels of myeloid differentiation factor 88 (MyD88) and toll-like receptor 4 (TLR4) in aortic tissues. The expression of NF-κB was similarly inhibited by both cereal fibers. In comparison to wheat bran fiber, oat fiber had greater effects in reducing the plague size and inhibiting TLR4/MyD88/NF-κB pathways. Such differences might come from modulation of the NLRP3 inflammasome pathway because the expressions of the cleavage of caspase-1 and interleukin (IL)-1β were inhibited only by oat fiber. The present study demonstrates that cereal fibers can attenuate inflammatory response and atherosclerosis in ApoE^-/- mice. Such effects are pronounced with oat fiber and likely mediated by specific inhibition of oat fiber on the NLRP3 inflammasome pathway.

Increasing low-energy-dense foods and decreasing high-energy-dense foods differently influence weight loss trial outcomes

BACKGROUND/OBJECTIVE

Although reducing energy density (ED) enhances weight loss, it is unclear whether all dietary strategies that reduce ED are comparable, hindering effective ED guidelines for obesity treatment. This study examined how changes in number of low-energy-dense (LED) (<4.186 kJ/1.0 kcal g-1) and high-energy-dense (HED) (>12.56 kJ/3.0 kcal g-1) foods consumed affected dietary ED and weight loss within an 18-month weight loss trial.

METHODS

This secondary analysis examined data from participants randomized to an energy-restricted lifestyle intervention or lifestyle intervention plus limited non-nutrient dense, energy-dense food variety (n=183). Number of daily LED and HED foods consumed was calculated from three, 24-h dietary recalls and anthropometrics were measured at 0, 6 and 18 months. Multivariable-adjusted generalized linear models and repeated-measures mixed linear models examined associations between 6-month changes in number of LED and HED foods and changes in ED, body mass index (BMI), and percent weight loss at 6 and 18 months.

RESULTS

Among mostly female (58%), White (92%) participants aged 51.9 years following an energy-restricted diet, increasing number of LED foods or decreasing number of HED foods consumed was associated with 6- and 18-month reductions in ED (β=-0.25 to -0.38 kJ g-1 (-0.06 to -0.09 kcal g-1), P<0.001). Only increasing number of LED foods consumed was associated with 6- and 18-month reductions in BMI (β=-0.16 to -0.2 kg m-2, P<0.05) and 6-month reductions in percent weight loss (β=-0.5%, P<0.05). Participants consuming ⩽2 HED foods per day and ⩾6.6 LED foods per day experienced better weight loss outcomes at 6- and 18-month than participants only consuming ⩽2 HED foods per day.

CONCLUSION

Despite similar reductions in ED from reducing number of HED foods or increasing number of LED foods consumed, only increasing number of LED foods related to weight loss. This provides preliminary evidence that methods used to reduce dietary ED may differentially influence weight loss trajectories. Randomized controlled trials are needed to inform ED recommendations for weight loss.

Microbial Mechanistic Insight into the Role of Inulin in Improving Maternal Health in a Pregnant Sow Model

General consumption of “western diet” characterized by high refined carbohydrates, fat and energy intake has resulted in a global obesity epidemics and related metabolic disturbance even for pregnant women. Pregnancy process is accompanied by substantial hormonal, metabolic and immunological changes during which gut microbiota is also remarkably remodeled. Dietary fiber has been demonstrated to have a striking role in shifting the microbial composition so as to improve host metabolism and health in non-pregnant individuals. The present study was conducted to investigate effects of adding a soluble dietary fiber inulin (0 or 1.5%) to low- or high- fat (0 or 5% fat addition) gestational diet on maternal and neonatal health and fecal microbial composition in a sow model. Results showed that inulin addition decreased the gestational body weight gain and fat accumulation induced by fat addition. Circulating concentrations of pro-inflammatory cytokine IL-6, adipokine leptin and chemerin were decreased by inulin supplementation. Inulin addition remarkably reduced the average BMI of newborn piglets and the within litter BMI distributions (%) ranging between 17 and 20 kg/m², and increased the BMI distribution ranging between 14 and 17 kg/m². 16S rRNA gene sequencing of the V3-V4 region showed that fecal microbial changes at different taxonomic levels triggered by inulin addition predisposed the pregnant sow to be thinner and lower inflammatory. Meanwhile, fecal microbial composition was also profoundly altered by gestation stage with distinct changes occurring at perinatal period. Most representative volatile fatty acid (VFA) producing-related genera changed dramatically when reaching the perinatal period and varied degrees of increases were detected with inulin addition. Fecal VFA concentrations failed to show any significant effect with dietary intervention, however, were markedly increased at perinatal period. Our findings indicate that positive microbial changes resulted by 1.5% soluble fiber inulin addition would possibly be the potential mechanisms under which maternal body weight, metabolic and inflammatory status and neonatal BMI were improved. Besides, distinct changes of microbial community at perinatal period indicated the mother sow is undergoing a catabolic state with increased energy loss and inflammation response at that period compared with other stages of gestation.

Dietary steamed wheat bran increases postprandial fat oxidation in association with a reduced blood glucose-dependent insulinotropic polypeptide response in mice

Obesity is a global epidemic associated with a higher risk of cardiovascular disease and metabolic disorders, such as type 2 diabetes. Previous studies demonstrated that chronic feeding of steamed wheat bran (WB) decreases obesity. To clarify the underlying mechanism and the responsible component for the anti-obesity effects of steamed WB, we investigated the effects of dietary steamed WB and arabinoxylan on postprandial energy metabolism and blood variables. Overnight-fasted male C57BL/6J mice were fed an isocaloric diet with or without steamed WB (30%). Energy metabolism was evaluated using an indirect calorimeter, and plasma glucose, insulin, and glucose-dependent insulinotropic polypeptide (GIP) levels were measured for 120 min after feeding. We similarly investigated the effect of arabinoxylan, a major component of steamed WB. Mice fed the WB diet had higher postprandial fat oxidation and a lower blood GIP response compared with mice fed the control diet. Mice fed the arabinoxylan diet exhibited a dose-dependent postprandial blood GIP response; increasing the arabinoxylan content in the diet led to a lower postprandial blood GIP response. The arabinoxylan-fed mice also had higher fat oxidation and energy expenditure compared with the control mice. In conclusion, the findings of the present study revealed that dietary steamed WB increases fat oxidation in mice. Increased fat oxidation may have a significant role in the anti-obesity effects of steamed WB. The postprandial effects of steamed WB are due to arabinoxylan, a major component of WB. The reduction of the postprandial blood GIP response may be responsible for the increase in postprandial fat utilization after feeding on a diet containing steamed WB and arabinoxylan.