Dietary Fiber in Bilberry Ameliorates Pre-Obesity Events in Rats by Regulating Lipid Depot, Cecal Short-Chain Fatty Acid Formation and Microbiota Composition

Distinct Gut Microbiota and Arachidonic Acid Metabolism in Obesity-Prone and Obesity-Resistant Mice with a High-Fat Diet

An imbalance of energy intake and expenditure is commonly considered as the fundamental cause of obesity. However, individual variations in susceptibility to obesity do indeed exist in both humans and animals, even among those with the same living environments and dietary intakes. To further explore the potential influencing factors of these individual variations, male C57BL/6J mice were used for the development of obesity-prone and obesity-resistant mice models and were fed high-fat diets for 16 weeks. Compared to the obesity-prone mice, the obesity-resistant group showed a lower body weight, liver weight, adipose accumulation and pro-inflammatory cytokine levels. 16S rRNA sequencing, which was conducted for fecal microbiota analysis, found that the fecal microbiome's structural composition and biodiversity had changed in the two groups. The genera Allobaculumbiota, SMB53, Desulfovibrio and Clostridium increased in the obesity-prone mice, and the genera Streptococcus, Odoribacter and Leuconostoc were enriched in the obesity-resistant mice. Using widely targeted metabolomics analysis, 166 differential metabolites were found, especially those products involved in arachidonic acid (AA) metabolism, which were significantly reduced in the obesity-resistant mice. Moreover, KEGG pathway analysis exhibited that AA metabolism was the most enriched pathway. Significantly altered bacteria and obesity-related parameters, as well as AA metabolites, exhibited strong correlations. Overall, the phenotypes of the obesity-prone and obesity-resistant mice were linked to gut microbiota and AA metabolism, providing new insight for developing an in-depth understanding of the driving force of obesity resistance and a scientific reference for the targeted prevention and treatment of obesity.

Effects of Konjac Glucomannan on Weight Management and Liver Health: Insights from Liver Lipidomics in Obese and Nonobese Mice

Konjac glucomannan (KGM) is a water-soluble dietary fiber and is used for weight management. However, there is a lack of research on KGM for weight management in nonobese groups and the effects of high-dose KGM supplementation on liver function. This study investigated the metabolic responses to KGM intervention in obese and nonobese mice and explored the underlying mechanisms based on lipidomics. The findings demonstrated that KGM supplementation decreased body weight and mitigated lipid metabolism disorders at the mRNA and protein levels in obese mice. In contrast, no significant impact on these parameters was observed in nonobese mice. Interestingly, KGM had a more significant impact on remodeling hepatic lipid composition in obese mice compared to nonobese mice, leading to reducing harmful lipids and increasing beneficial lipids. However, high-dose KGM increased the risk of hepatocyte bile acid toxicity in obese mice and did not promote liver antioxidant status in nonobese mice. In summary, this study identified distinct metabolic responses to KGM intervention between obese and nonobese mice, providing insights for weight management using KGM.

Blueberry Consumption and Changes in Obesity and Diabetes Mellitus Outcomes: A Systematic Review

Low-grade inflammation and oxidative stress are key mechanisms involved in obesity and related disorders. Polyphenols from blueberry (BB) and bilberries (BiB) might protect against oxidative damage and inflammation. To summarize the effects of BiB or BB consumption in parameters related to obesity and its comorbidities, a search of the literature was performed in PubMed, Embase, and Cochrane Library repositories to identify all studies that evaluated associations of whole BB or BiB with obesity and associated disorders. Thirty-one studies were eligible for inclusion in this review: eight clinical trials and 23 animal studies. In humans, BB consumption only consistently decreased oxidative stress and improved endothelial function. In rodents, BB or BiB consumption caused positive effects on glucose tolerance, nuclear factor-kappa B (Nf-κb) activity, oxidative stress, and triglyceride (TG) content in the liver and hepatic steatosis. The high content of anthocyanins present in BB and BiB seems to attenuate oxidative stress. The decrease in oxidative stress may have a positive impact on glucose tolerance and endothelial function. Moreover, in rodents, these berries seem to protect against hepatic steatosis, through the decreased accumulation of hepatic TGs. BB and BiB might also attenuate inflammation by decreasing Nf-κb activity and immune cell recruitment into the adipose tissue.

Diet-Related Changes of Short-Chain Fatty Acids in Blood and Feces in Obesity and Metabolic Syndrome

Obesity-related illnesses are one of the leading causes of death worldwide. Metabolic syndrome has been associated with numerous health issues. Short-chain fatty acids (SCFAs) have been shown to have multiple effects throughout the body, both directly as well as through specific G protein-coupled receptors. The main SCFAs produced by the gut microbiota are acetate, propionate, and butyrate, which are absorbed in varying degrees from the large intestine, with some acting mainly locally and others systemically. Diet has the potential to influence the gut microbial composition, as well as the type and amount of SCFAs produced. High fiber-containing foods and supplements increase the production of SCFAs and SCFA-producing bacteria in the gut and have been shown to have bodyweight-lowering effects. Dietary supplements, which increase SCFA production, could open the way for novel approaches to weight loss interventions. The aim of this review is to analyze the variations of fecal and blood SCFAs in obesity and metabolic syndrome through a systematic search and analysis of existing literature.

Mangrove fruit (Bruguiera gymnorhiza) increases circulating GLP-1 and PYY, modulates lipid profiles, and reduces systemic inflammation by improving SCFA levels in obese wistar rats

Bruguiera gymnorhiza (BG) has potential as a functional food because of its dietary fibre content and bioactive components such as flavonoids and phenolic compounds. However, it is not studied in the context of diet-related disease prevention. In the present study, we aimed to investigate the effects of Bruguiera gymnorhiza fruit flour (BGF) on satiety hormone, lipid profile, systemic inflammation, body weight, and caecum SCFA levels in diet-induced obese rats. A total of 28 obese male Wistar rats were divided into four groups. Group 1 (K1) was given a standard chow, group 2 (K2) standard chow + orlistat, group 3 (P1) standard chow + BGF 2 g/200 g BW/day, and group 4 (P2) standard chow + BGF 4 g/200 g BW/day for 28 days. The levels of GLP-1, PYY, total cholesterol (TC), triglyceride (TG), HDL, IL-6, TNF-α, and body weight were measured before and after the intervention; meanwhile, the caecum SCFA levels were assessed only after the intervention. In this study, BGF intervention increased the dose-dependent plasma GLP-1 and PYY levels (P < 0.000). In addition, BGF intervention also decreased lipid profiles (TC & TG) (P < 0.000, respectively) and systemic inflammation in a dose-dependent manner. Finally, acetate, propionate, and total SCFA concentrations were higher in the BGF intervention group (P2) compared to the other groups (p < 0.05). The SCFA levels were associated with satiety hormones, lipids, and systemic inflammation (P < 0.05). The BGF intervention improved satiety hormone, lipid profile, systemic inflammation, and SCFA levels.

Dried Bilberry (Vaccinium myrtillus L.) Alleviates the Inflammation and Adverse Metabolic Effects Caused by a High-Fat Diet in a Mouse Model of Obesity

Obesity is an increasing problem worldwide. It is often associated with co-morbidities such as type II diabetes, atherosclerotic diseases, and non-alcoholic fatty liver disease. The risk of these diseases can be lowered by relieving the systemic low-grade inflammation associated with obesity, even without noticeable weight loss. Bilberry is an anthocyanin-rich wild berry with known antioxidant and anti-inflammatory properties. In the present study, a high-fat-diet-induced mouse model of obesity was used to investigate the effects of air-dried bilberry powder on weight gain, systemic inflammation, lipid and glucose metabolism, and changes in the gene expression in adipose and hepatic tissues. The bilberry supplementation was unable to modify the weight gain, but it prevented the increase in the hepatic injury marker ALT and many inflammatory factors like SAA, MCP1, and CXCL14 induced by the high-fat diet. The bilberry supplementation also partially prevented the increase in serum cholesterol, glucose, and insulin levels. In conclusion, the bilberry supplementation alleviated the systemic and hepatic inflammation and retarded the development of unwanted changes in the lipid and glucose metabolism induced by the high-fat diet. Thus, the bilberry supplementation seemed to support to retain a healthier metabolic phenotype during developing obesity, and that effect might have been contributed to by bilberry anthocyanins.

The potential mechanisms of bergamot-derived dietary fiber alleviating high-fat diet-induced hyperlipidemia and obesity in rats

This study is aimed to investigate the health-associated benefits of bergamot-dietary fibers (DFs) with a special emphasis on weight loss and lipid-lowering effects, as well as the potential mechanisms involved. The feeding experiment of Sprague-Dawley (SD) rats for 6 weeks showed that DFs had dose-dependent regulatory effects against metabolic syndrome and they controlled obesity by slowing down the rate of weight growth, and reduced body mass index (BMI) and Lee's index without affecting appetite. Furthermore, DFs inhibited increment in TG, TC, LDL-C levels and AI index caused by a high-fat diet, and improved the pathological abnormality of the liver. Western blot results showed that DFs significantly up-regulated the protein expression levels of LXRα and CYP7A1, and down-regulated the levels of SREBP-1c, FAS, ACC and SREBP-2 in the liver. QRT-PCR results showed that DFs up-regulated PGC-1α, PRDM16, UCP-1, and PPARγ in brown adipose tissue. These results suggest that DFs played an effective role in reducing weight and lipids levels by promoting the decomposition and transport of lipids in liver, increasing the energy consumption of brown adipose tissue. DFs intervention reduced the difference in the intestinal microflora between rats fed with a normal diet and those fed with a high-fat diet. Soluble dietary fiber (SDF) and total dietary fiber (TDF) showed better weight loss and hypolipidemic potential compared to insoluble dietary fiber (IDF) at the same dose. In conclusion, bergamot-derived DFs demonstrated the potential to lower blood cholesterol and body weight and could be used to develop novel functional foods for the prevention or treatment of obesity and hyperlipidemia.

Exploring the Possible Link between the Gut Microbiome and Fat Deposition in Pigs

Excessive lipid accumulation and high oxidative stress have become a serious health and economic problem in the pig industry. Fatness characteristics are crucial in pig production since they are closely related to meat quality. The gut microbiome is well acknowledged as a key element in fat deposition. But the link between gut microbiota and fat accumulation in pigs remains elusive. To examine whether there is a link between pigs' gut microbiome, lipogenic properties, and oxidative stress, we selected 5 high-fat pigs and 5 low-fat pigs from 60 250-day-old Jinhua pigs in the present study and collected the colon content, serum sample, and liver and abdominal fat segments from each pig for metagenomic analysis, the oxidative stress assay, and RT-qPCR analysis, respectively. The backfat thickness and fat content of the longissimus dorsi muscle were considerably higher in the high-fat pigs than in the low-fat pigs (P < 0.05). An obvious difference in GSH-Px and MDA in the serum between the high- and low-fat pigs was observed. After RT-qPCR analysis, we found the gene expression of ACC1 and SREBP1 in the liver and FAS, PPARγ, and LPL in the abdominal fat were significantly higher in high-fat pigs than in low-fat pigs (P < 0.05). Additionally, metagenomic sequencing revealed that high-fat pigs had a higher abundance of Archaeal species with methanogenesis functions, leading to more-efficient fat deposition, while low-fat pigs had higher abundances of butyrate-producing bacteria species that improved the formation of SCFAs, especially butyrate, thus alleviating fat deposition in pigs. Furthermore, a total of 17 CAZyme families were identified to give significant enrichments in different fat phenotypes of pigs. This study would provide a detailed understanding of how the gut microbiome influences fat deposition in pigs, as well as a hint for improving growth performance and fatness traits by manipulating the gut microbiome.

Network pharmacology-based investigation to explore the effect and mechanism of Erchen decoction against the nonalcoholic fatty liver disease

This study aimed to uncover the potential mechanism of Erchen decoction (ECD) on the amelioration of nonalcoholic fatty liver disease (NAFLD). Network pharmacology and bioinformatics were used to determine the active components of ECD and its potential target in treating NAFLD. High fat diet (HFD)-induced NAFLD mice model was used. Liver tissues were stained with hematoxylin and eosin, and Oil Red O. Serum lipid profiles and hepatic inflammatory molecules in lipopolysaccharide (LPS)/Toll-like receptor-4 (TLR-4) pathway were confirmed by enzyme-linked immunosorbent assay. Intestinal barrier function, including intestinal epithelial tight junction (IETJ) proteins, fecal short-chain fatty acids (SCFAs) concentration and intestinal microbiota composition, was also assessed. Screening relevant databases revealed 123 active components and 158 potential target proteins in ECD, as well as 1,783 differential genes for NAFLD. Enrichment analyses predicted that the regulation of LPS, cholesterol metabolism and inflammatory pathways might be the underlying mechanisms of ECD in NAFLD treatment. ECD ameliorated the multi-profiles of NAFLD and reversed the high levels of inflammatory molecules such as, serum LPS, hepatic TLR-4, tumor necrosis factor-α, and interleukin-1β. Additionally, ECD upregulated the concentration levels of IETJ proteins and fecal SCFAs. 16s RNA sequencing indicated that ECD can improve the gut microbiota, such as Akkermansia, Clostridium XIVa, Coprococcus, and Ruminococcus. The current study demonstrated that ECD can reverse the HFD-induced intestinal barrier dysfunction, thereby reducing the LPS translocation and alleviating the hepatic inflammation, and eventually exhibiting a protective effect against NAFLD.

Intestinal dysbiosis in nonalcoholic fatty liver disease (NAFLD): focusing on the gut-liver axis

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders in humans, partly because it is closely related to metabolic disorders of the liver with increasing prevalence. NAFLD begins with hepatic lipid accumulation, which may cause inflammation and eventually lead to fibrosis in the liver. Numerous studies have demonstrated the close relationship between gut dysfunction (especially the gut microbiota and its metabolites) and the occurrence and progression of NAFLD. The bidirectional communication between the gut and liver, named the gut-liver axis, is mainly mediated by the metabolites derived from both the liver and gut through the biliary tract, portal vein, and systemic circulation. Herein, we review the effects of the gut-liver axis on the pathogenesis of NAFLD. We also comprehensively describe the potential molecular mechanisms from the perspective of the role of liver-derived metabolites and gut-related components in hepatic metabolism and inflammation and gut health, respectively. The study provides insights into the mechanisms underlying current summarizations that support the intricate interactions between a disordered gut and NAFLD and can provide novel strategies to lessen the prevalence and consequence of NAFLD.

Blueberry as an Attractive Functional Fruit to Prevent (Pre)Diabetes Progression

Prediabetes, a subclinical impairment between euglycemia and hyperglycemia, is a risk factor for the development of type 2 diabetes mellitus (T2DM) and associated micro- and macrovascular complications. Lifestyle therapy, the first-line treatment of prediabetes, includes physical exercise and dietary regimens enriched in phytochemicals with health-related properties. Blueberries (Vaccinium spp.), given their pleasant taste and great abundance in beneficial phytochemicals, have gained public interest all over the world. Along with a high antioxidant activity, this functional fruit is also well-recognized due to its hypoglycemic and insulin-sensitizing effects and has been recommended for overt T2DM management. Yet blueberries target several other pathophysiological traits, namely gut microbiota dysbiosis and hepatic dysmetabolism, that ensue when prediabetes begins and for which pharmacological interventions tend to be delayed. In this work, we revisited preclinical data from in vitro assays, animal models and human studies, aiming to disclose the potential mechanisms by which blueberries may be a fruitful source of phytochemicals able to prevent (pre)diabetes progression. Collectively, future efforts should focus on longer-term studies with standardized interventions and readouts, particularly in humans, that will hopefully bring more robust evidence and concrete guidance for blueberries' effective use in prediabetes.

Plant-Based Foods and Their Bioactive Compounds on Fatty Liver Disease: Effects, Mechanisms, and Clinical Application

Fatty liver disease (FLD), including nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), is a serious chronic metabolic disease that affects a wide range of people. Lipid accumulation accompanied by oxidative stress and inflammation in the liver is the most important pathogenesis of FLD. The plant-based, high-fiber, and low-fat diet has been recommended to manage FLD for a long time. This review discusses the current state of the art into the effects, mechanisms, and clinical application of plant-based foods in NAFLD and AFLD, with highlighting related molecular mechanisms. Epidemiological evidence revealed that the consumption of several plant-based foods was beneficial to alleviating FLD. Further experimental studies found out that fruits, spices, teas, coffee, and other plants, as well as their bioactive compounds, such as resveratrol, anthocyanin, curcumin, and tea polyphenols, could alleviate FLD by ameliorating hepatic steatosis, oxidative stress, inflammation, gut dysbiosis, and apoptosis, as well as regulating autophagy and ethanol metabolism. More importantly, clinical trials confirmed the beneficial effects of plant-based foods on patients with fatty liver. However, several issues need to be further studied especially the safety and effective doses of plant-based foods and their bioactive compounds. Overall, certain plant-based foods are promising natural sources of bioactive compounds to prevent and alleviate fatty liver disease.

The Effect of Chickpea Dietary Fiber on Lipid Metabolism and Gut Microbiota in High-Fat Diet-Induced Hyperlipidemia in Rats

Hyperlipidemia is a metabolic disorder characterized by high lipid levels, which may lead to cardiovascular diseases. Evidence suggests that improving the gut microbiota homeostasis is of great importance in lipid metabolism. Dietary fiber may positively regulate blood lipid and intestinal microbiota, therefore, we have investigated the effect of chickpea dietary fiber (CDF) on high-fat diet (HFD)-induced hyperlipidemia and gut bacterial dysbiosis. Fifty male Sprague Dawley rats purchased for this study were randomly divided into 5 groups of 10 rats each. The control group was fed with normal diet (ND), while the other four groups were all fed with HFD for inducing hyperlipidemia. Then one of the four HFD groups continued to be fed with only HFD, and the other three groups were fed with CDF in different doses: high CDF (30 g CDF/kg of HFD), medium CDF (15 g CDF/kg of HFD), and low CDF (5 g CDF/kg of HFD). After CDF treatment, the lipid level in serum was determined through biochemical methods, and microbial content of the fecal sample was determined by 16S rDNA sequencing. We found that CDF could decrease the levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol and increase the level of high-density lipoprotein cholesterol significantly. The diversity of gut microbiota in the ND group and CDF-treated groups were higher than HFD group. The β-diversity analysis showed that there were significant differences in gut microbiota among HFD-, ND-, and CDF-treated groups. Rats in CDF groups tended to be similar and interactive. CDF can effectively increase the abundance of Bacteroides and Lactobacillus in rats and increase the level of propionic acid. These results indicated that CDF might affect serum lipid and gut bacterial ecosystem positively.

Bilberry (Vaccinium myrtillus L.) Extracts Comparative Analysis Regarding Their Phytonutrient Profiles, Antioxidant Capacity along with the In Vivo Rescue Effects Tested on a Drosophila melanogaster High-Sugar Diet Model

Bilberries (Vaccinium myrtillus L.) have been reported to hold a plentitude of health-promoting properties beyond basic nutrition, mainly attributed to their anthocyanin content and antioxidant activity. In this article, we built the phytochemical profile of three wild bilberry fruit extract formulations (aqueous, methanolic, and hydro-methanolic) using UHPLC-ESI-MS/MS putative analysis, identifying 88 individual phytochemicals, mainly flavonoids (total content 8.41 ± 0.11 mg QE/g dw), free amino acids, polyphenols (total content 21.68 ± 0.19 mg GAE/g dw), carboxylic acids, and vitamins. Furthermore, the antioxidant activity of the extract was assessed, reaching 78.03 ± 0.16% DPPH free radical scavenging activity, comparable to literature values determined for bilberry extracts of other origin. Due to the increased prevalence of metabolic syndrome and based on the reviewed benefits of bilberries, we tested the most potent formulation of our bilberry extracts in this biological context. The in vivo rescue effect of a bilberry extract supplemented diet on Drosophila melanogaster was assessed by monitoring biochemical and genomic markers. Hemolymph trehalose levels were halved upon addition of 3% hydro-methanolic bilberry extract to a high-sugar (1.5 M sucrose) diet, as compared to the non-supplemented high-sugar diet. Noteworthy, the rescue seen for flies kept on the bilberry extract supplemented high-sugar diet appeared to parallel the trehalose levels observed in the case of the control diet (50 mM sucrose) flies. Moreover, next to the trehalose-lowering type of in vivo effects, other gene expression related rescues were also detected for genes such as InR, Akh, AstA, AstC, Irk, Npc2g, and CCHa2 upon supplementation of the high-sugar diet with our hydro-methanolic bilberry fruit extract. Our findings suggest that such a bilberry fruit extract could generate physiological and genomic type of compensatory mechanisms so that further translational approaches would advance the understanding of some human specific pathological conditions.