Effects of fructans-type prebiotics on lipid metabolism

Impact of using whole chestnut flour as a substitute for cake flour on digestion, functional and storage properties of chiffon cake: A potential application study

Developing fresh cake product with rich nutrition and high quality has become a hot spot in food industry. In this study, whole chestnut flour as a high-quality dietary source was successfully substituted for cake flour in the production of chestnut chiffon cake with 40-55% substitution rate, and its application prospects were further evaluated through studying nutritional and storage properties. The results showed that chestnut chiffon cake with 45% and 50% substitution rate could significantly increase the resistant component, scavenging activity and ferric reducing antioxidant power, surprisingly decrease predicted glycemic index to 54.05-57.28, and reduce the acetate/propionate ratio and Firmicutes/Bacteroidetes value for human gut microbiota as well. Comparatively, chestnut chiffon cake with 45% substitution rate had more application potential due to its higher free water retention at day 7 and higher resilience throughout the storage time. Overall, this study could provide valuable information for the development of modern nutritional cake industry.

In vitro prebiotic activity of rhLf and galactooligosaccharides on infant intestinal microbiota

Introduction

Objective: human lactoferrin (Lf) and human milk oligosaccharides possess a wide range of functions. So, the present study focusses on the role of Lf and/or galactooligosaccharides (GOS) in the modulation of gut microbiota composition. Methods: recombinant human lactoferrin (rhLf) was added to the first infant formula (0.10, 0.15, 0.20 %) alone or in combination with GOS (1 %) in vessels of a small-scale batch culture fermentation model. Short-chain fatty acids (SCFAs), microbial population groups, and pH were monitored through fermentation for 24 hours. Results: insignificant changes were observed in pH values and acetic acid accumulated during fermentation. Propionic acid content has been insignificantly increased while butyric acid has been insignificantly decreased. Moreover, increments in all bacterial groups except for Bacteroides were observed through the fermentation process. Lactobacillus and Bifidobacterium showed an increase in relation to initial time over the fermentation process, demonstrating the prebiotic effect of lactoferrin and GOS. After 24 hours of fermentation, all tested ingredients showed significant similarities in Enterococcus for controls except for 0.20 % rhLf + 1 % GOS, which provoked a diminution of Enterococci growth. Conclusion: despite the importance of the batch culture fermentation technique in uncovering the prebiotic activity of food ingredients, it is not useful for detecting the prebiotic nature of Lf due to its nature as a protein. Thus, Lf maybe shows its prebiotic activity on the gut microbiota through other mechanisms.

Obesity and Its Multiple Clinical Implications between Inflammatory States and Gut Microbiotic Alterations

Obesity is a chronic multifactorial disease that has become a serious health problem and is currently widespread over the world. It is, in fact, strongly associated with many other conditions, including insulin resistance, type 2 diabetes, cardiovascular and neurodegenerative diseases, the onset of different types of malignant tumors and alterations in reproductive function. According to the literature, obesity is characterized by a state of low-grade chronic inflammation, with a substantial increase in immune cells, specifically macrophage infiltrates in the adipose tissue which, in turn, secrete a succession of pro-inflammatory mediators. Furthermore, recent studies on microbiota have postulated new possible mechanisms of interaction between obesity and unbalanced nutrition with inflammation. This intestinal "superorganism" complex seems to influence not only the metabolic balance of the host but also the immune response, favoring a state of systemic inflammation and insulin resistance. This review summarizes the major evidence on the interactions between the gut microbiota, energetic metabolism and host immune system, all leading to a convergence of the fields of immunology, nutrients physiology and microbiota in the context of obesity and its possible clinical complications. Finally, possible therapeutic approaches aiming to rebalance the intestinal microbial ecosystem are evaluated to improve the alteration of inflammatory and metabolic states in obesity and related diseases.

Intestinal microbiota in the treatment of metabolically associated fatty liver disease

Metabolically associated fatty liver disease (MAFLD) is a common cause of chronic liver disease, the hepatic manifestation of metabolic syndrome. Despite the increasing incidence of MAFLD, no effective treatment is available. Recent research indicates a link between the intestinal microbiota and liver diseases such as MAFLD. The composition and characteristics of the intestinal microbiota and therapeutic perspectives of MAFLD are reviewed in the current study. An imbalance in the intestinal microbiota increases intestinal permeability and exposure of the liver to adipokines. Furthermore, we focused on reviewing the latest "gut-liver axis" targeted therapy.

Production of Xylooligosaccharide from Cassava Pulp’s Waste by Endo-β-1,4-D-Xylanase and Characterization of Its Prebiotic Effect by Fermentation of Lactobacillus acidophilus

This study explores the production of prebiotic xylooligosaccharide (XOS) from cassava pulp waste and its effectiveness for the growth of Lactobacillus acidophilus (L. acidophilus). We successfully produced and characterized XOS from cassava pulp xylan using a Bacillus sp. endo-β-1,4-D-xylanase. The XOS was added to modify the MRS medium (MRSm) in various concentrations (0, 1, 3 and 5%) in which the L. acidophilus was inoculated. The growth of L. acidophilus was observed every 12 h for 2 days, and the fermentation products were analyzed for pH, sugar content, and short-chain fatty acids (SCFA) in terms of types and amount. The study showed that L. acidophilus grew well in MRSm. The optimum XOS concentration in MRSm was 5%, indicated by the highest growth of L. acidophilus (8.61 log CFU mL−1). The profile of SCFA products is 14.42 mM acetic acid, 0.25 mM propionic acid, 0.13 mM isobutyric acid, 0.41 mM n-butyric acid, 0.02 mM n-valeric acid, 0.25 mM isovaleric acid, and 25.08 mM lactic acid.

The gut microbiota - a vehicle for the prevention and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) arises principally against a background of cirrhosis and these two diseases are responsible globally for over 2 million deaths a year. There are few treatment options for liver cirrhosis and HCC, so it is vital to arrest these pathologies early in their development. To do so, we propose dietary and therapeutic solutions that involve the gut microbiota and its consequences. Integrated dietary, environmental and intrinsic signals result in a bidirectional connection between the liver and the gut with its microbiota, known as the gut-liver axis. Numerous lifestyle factors can result in dysbiosis with a change in the functional composition and metabolic activity of the microbiota. A panoply of metabolites can be produced by the microbiota, including ethanol, secondary bile acids, trimethylamine, indole, quinolone, phenazine and their derivatives and the quorum sensor acyl homoserine lactones that may contribute to HCC but have yet to be fully investigated. Gram-negative bacteria can activate the pattern recognition receptor toll-like receptor 4 (TLR4) in the liver leading to nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, which can contribute to HCC initiation and progression. The goal in preventing HCC should be to ensure a healthy gut microbiota using probiotic supplements containing beneficial bacteria and prebiotic plant fibers such as oligosaccharides that stimulate their growth. The clinical development of TLR4 antagonists is urgently needed to counteract the pathological effects of dysbiosis on the liver and other organs. Further nutrigenomic studies are required to understand better how the diet influences the gut microbiota and its adverse effects on the liver.

Effects of Combinations of Goat Milk and Oligosaccharides on Altering the Microbiota, Immune Responses, and Short Chain Fatty Acid Levels in the Small Intestines of Mice

Goat milk and oligosaccharides play important roles in gastrointestinal health. A combination of goat milk with three oligosaccharides, stachyose (STS), fructo-oligosaccharide (FOS), and a prebiotics mixture (FGS), was fed to mice. Changes and functions of the microbiota, short chain fatty acid (SCFA) concentrations, and immune gene expression in the small intestines were determined. The FOS treatment increased the beneficial bacteria Lactobacillus and Bifidobacterium, the FGS treatment helped stabilize the microbial community, and the STS treatment significantly enhanced microbial diversity and the growth of Bacteroidetes. The oligosaccharide treatments regulated the gene expression levels of the immune factors tumor necrosis factor alpha (Tnfα), granzyme B (Gzmb), perforin (Prf), and aryl hydrocarbon receptor (Ahr). Stachyose significantly increased the concentrations of acetate and propionate compared with other treatments. These findings demonstrate that STS is the preferred carbon source for microbiota, slightly modulates SCFA production, and results in low immunogenicity in the small intestines of mice.

Assessing the effects of inulin-type fructan intake on body weight, blood glucose, and lipid profile: A systematic review and meta-analysis of randomized controlled trials

Inulin-type fructan (ITF) intake has been suggested to alleviate several features of metabolic syndrome including obesity, diabetes, and hyperlipidemia; yet, results from the human trials remained inconsistent. We aimed to systematically evaluate the effects of ITF intake on body weight, glucose homeostasis, and lipid profile on human subjects with different health status, including healthy, overweight and obese, prediabetes and diabetes, and hyperlipidemia. Weighted mean differences (WMDs) between ITF and control groups were calculated by a random-effects model. A total of 33 randomized controlled human trials were included. Significant effect of ITF intake was only observed in the diabetics, but not in the other subject groups. Specifically, ITF intervention significantly decreased the WMD of blood glucose (-0.42 mmol/L; 95% CI: -0.71, -0.14; p = .004), total cholesterol (-0.46 mmol/L; 95% CI: -0.75, -0.17; p = .002), and triglycerides (TAG) (-0.21 mmol/L; 95% CI: -0.37, -0.05; p = .01) compared with the control. The stability of these favorable effects of ITF on diabetics was confirmed by sensitivity analysis. Also, ITF tends to lower LDL cholesterol (p = .084). But body weight and blood insulin were not affected by ITF intake. It should be noted that blood glucose, total cholesterol, and LDL cholesterol exhibited high unexplained heterogeneity. In conclusion, ITF intake lowers blood glucose, total cholesterol, and TAG in the people with diabetes, and they may benefit from addition of inulin into their diets, but the underlying mechanisms responsible for these effects are inconclusive.

The first insights on trans-galactooligosaccharide effects on fatty acids profile and microstructure of muscle in common carp

The aim of the study was to determine the effects of prebiotic GOS on muscle histomorphometry and the total lipid, total cholesterol content and fatty acids profile in the meat of common carp. The 60-day-long experiment was performed on one-year-old fish. Three diets were used in the experiment: control diet 1 (C) with no microbiota affecting feed additives, diet 2 (B1) with 1 % of GOS, and diet 3 (B2) with 2 % of GOS. At the end of the trial, 16 individuals from each treatment group were used for the analyses. Fish meat from the B1 group had significantly higher lipid content compared to B2, but neither B1 nor B2 groups were different from the control group. The percentages of SFA, MUFA, PUFA, indexes n-3/n-6, PUFA/SFA, AI and TI, and total cholesterol content were not affected, in contrast to C14:0, C16:1 n-7, C18:0, C18:2 n-6, C20:4 n-6, and total n-6 FA. GOS significantly increased the percentage of normal fibres, while the lower number of fibre atrophy and splitting were observed. The results confirm that diet supplemented with 2 % GOS may be recommended as feed additive in carp nutrition due to positive effects on some fatty acids profiles and muscle microstructure.

The interaction between the gut microbiota and dietary carbohydrates in nonalcoholic fatty liver disease

Imbalance between fat production and consumption causes various metabolic disorders. Nonalcoholic fatty liver disease (NAFLD), one such pathology, is characterized by abnormally increased fat synthesis and subsequent fat accumulation in hepatocytes1,2. While often comorbid with obesity and insulin resistance, this disease can also be found in lean individuals, suggesting specific metabolic dysfunction2. NAFLD has become one of the most prevalent liver diseases in adults worldwide, but its incidence in both children and adolescents has also markedly increased in developed nations3,4. Progression of this disease into nonalcoholic steatohepatitis (NASH), cirrhosis, liver failure, and hepatocellular carcinoma in combination with its widespread incidence thus makes NAFLD and its related pathologies a significant public health concern. Here, we review our understanding of the roles of dietary carbohydrates (glucose, fructose, and fibers) and the gut microbiota, which provides essential carbon sources for hepatic fat synthesis during the development of NAFLD.

Chronic oral exposure to pesticides and their consequences on metabolic regulation: role of the microbiota

Pesticides have long been used in agriculture and household treatments. Pesticide residues can be found in biological samples for both the agriculture workers through direct exposure but also to the general population by indirect exposure. There is also evidence of pesticide contamination in utero and trans-generational impacts. Whilst acute exposure to pesticides has long been associated with endocrine perturbations, chronic exposure with low doses also increases the prevalence of metabolic disorders such as obesity or type 2 diabetes. Dysmetabolism is a low-grade inflammation disorder and as such the microbiota plays a role in its etiology. It is therefore important to fully understand the role of microbiota on the genesis of subsequent health effects. The digestive tract and mostly microbiota are the first organs of contact after oral exposure. The objective of this review is thus to better understand mechanisms that link pesticide exposure, dysmetabolism and microbiota. One of the key outcomes on the microbiota is the reduced Bacteroidetes and increased Firmicutes phyla, reflecting both pesticide exposure and risk factors of dysmetabolism. Other bacterial genders and metabolic activities are also involved. As for most pathologies impacting microbiota (including inflammatory disorders), the role of prebiotics can be suggested as a prevention strategy and some preliminary evidence reinforces this axis.

Plant Prebiotics and Their Role in the Amelioration of Diseases

Prebiotics are either natural or synthetic non-digestible (non-)carbohydrate substances that boost the proliferation of gut microbes. Undigested fructooligosaccharides in the large intestine are utilised by the beneficial microorganisms for the synthesis of short-chain fatty acids for their own growth. Although various food products are now recognized as having prebiotic properties, several others, such as almonds, artichoke, barley, chia seeds, chicory, dandelion greens, flaxseeds, garlic, and oats, are being explored and used as functional foods. Considering the benefits of these prebiotics in mineral absorption, metabolite production, gut microbiota modulation, and in various diseases such as diabetes, allergy, metabolic disorders, and necrotising enterocolitis, increasing attention has been focused on their applications in both food and pharmaceutical industries, although some of these food products are actually used as food supplements. This review aims to highlight the potential and need of these prebiotics in the diet and also discusses data related to the distinct types, sources, modes of action, and health benefits.

Active phase prebiotic feeding alters gut microbiota, induces weight-independent alleviation of hepatic steatosis and serum cholesterol in high-fat diet-fed mice

Growing evidence suggests that prebiotics may induce weight loss and alleviate non-alcoholic fatty liver disease (NAFLD) via modulation of the gut microbiota. However, key members of the gut microbiota that may mediate the beneficial effects of prebiotics remain elusive. Here, we find that restricted prebiotic feeding during active phase (HF-ARP) induced weight-independent alleviation of liver steatosis and reduced serum cholesterol in high-fat diet (HF) fed mice more significantly than unrestricted feeding (HF-UP). HF-ARP mice also showed concomitantly altered gut microbiota structure that was different from HF-UP group along with significantly increased production of total short-chain fatty-acids (SCFAs). Amplicon sequence variants (ASVs) were clustered into co-abundant groups (CAGs) as potential functional groups that may respond distinctively to prebiotic consumption and prebiotic feeding regime. Prebiotic feeding induces significant alterations in CAG abundances by day 7. Eight of 32 CAGs were promoted by prebiotics, including CAG17 with the most abundant ASV from Parabacteroides, CAG22 with Bacteroides thetaiotamicron and CAG32 with Fecalibaculum and Akkermansia. Among the prebiotic-promoted CAGs, CAG20 with ASVs from Lachnospiraceae and CAG21 with ASVs from Bifidobacterium and Lachnospiraceae were significantly enhanced in HF-ARP compared to HF-UP. Moreover, most of the prebiotic-promoted CAGs were also significantly associated with improvements in hepatic steatosis, reduction in serum cholesterol and increased cecal propionate production. Together, these results suggest that the impact of prebiotics on weight-independent alleviation of liver steatosis and cholesterol-lowering effect can be optimized by restricting prebiotic intake to active phase and is associated with a distinct change of gut microbiota with increased SCFA production.

Gut Microbiota Metabolites in NAFLD Pathogenesis and Therapeutic Implications

Gut microbiota dysregulation plays a key role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) through its metabolites. Therefore, the restoration of the gut microbiota and supplementation with commensal bacterial metabolites can be of therapeutic benefit against the disease. In this review, we summarize the roles of various bacterial metabolites in the pathogenesis of NAFLD and their therapeutic implications. The gut microbiota dysregulation is a feature of NAFLD, and the signatures of gut microbiota are associated with the severity of the disease through altered bacterial metabolites. Disturbance of bile acid metabolism leads to underactivation of bile acid receptors FXR and TGR5, causal for decreased energy expenditure, increased lipogenesis, increased bile acid synthesis and increased macrophage activity. Decreased production of butyrate results in increased intestinal inflammation, increased gut permeability, endotoxemia and systemic inflammation. Dysregulation of amino acids and choline also contributes to lipid accumulation and to a chronic inflammatory status. In some NAFLD patients, overproduction of ethanol produced by bacteria is responsible for hepatic inflammation. Many approaches including probiotics, prebiotics, synbiotics, faecal microbiome transplantation and a fasting-mimicking diet have been applied to restore the gut microbiota for the improvement of NAFLD.

Dietary pectic oligosaccharide supplementation improves rat reproductive performance via regulating intestinal volatile fatty acids during middle gestation

As a kind of green additive, pectic oligosaccharide (POS) may regulate some physiological functions of animals, such as gut health, antioxidant capacity, immunity and lipid metabolism. This study aimed to identify whether POS administration can improve maternal reproduction, and to determine the possible metabolism. A total of 48 pregnant Wistar rats randomly allotted into 2 groups, and each group was fed a diet supplemented with 0 or 800 mg/kg of POS. Pectic oligosaccharide administration increased rat born number (P < 0.05), did not affect rat embryo number on d 7 of gestation, but increased rat fetus number on d 14 of gestation (P < 0.05). On d 14 of gestation, POS treatment improved Lactobacillus and Bifidobacterium populations and volatile fatty acid concentrations of cecal digesta (P < 0.05), hormone (progesterone and nitric oxide) and cytokine (interleukin 2) concentrations of serum (P < 0.05), and antioxidant capacity of serum (increased total antioxidant capacity and decreased malondialdehyde) and placenta (increased total superoxide dismutase, decreased malondialdehyde) (P < 0.05) in pregnant rats. These results suggest that POS administration improved rat reproduction via decreasing fetus loss in middle gestation. This was due to the increased volatile fatty acid concentrations in rat gut improving hormone and inflammatory-cytokine productions, and antioxidant capacity.

Intestinal microbiome and NAFLD: molecular insights and therapeutic perspectives

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of dysregulated lipid and glucose metabolism, which is often associated with obesity, dyslipidemia and insulin resistance. In view of the high morbidity and health risks of NAFLD, the lack of effective cure has drawn great attention. In recent years, a line of evidence has suggested a close linkage between the intestine and liver diseases such as NAFLD. We summarized the composition and characteristics of intestinal microbes and reviewed molecular insights into the intestinal microbiome in development and progression of NAFLD. Intestinal microbes mainly include bacteria, archaea, viruses and fungi, and the crosstalk between non-bacterial intestinal microbes and human liver diseases should be paid more attention. Intestinal microbiota imbalance may not only increase the intestinal permeability to gut microbes but also lead to liver exposure to harmful substances that promote hepatic lipogenesis and fibrosis. Furthermore, we focused on reviewing the latest "gut-liver axis"-targeting treatment, including the application of antibiotics, probiotics, prebiotics, synbiotics, farnesoid X receptor agonists, bile acid sequestrants, gut-derived hormones, adsorbents and fecal microbiota transplantation for NAFLD. In this review, we also discussed the potential mechanisms of "gut-liver axis" manipulation and efficacy of these therapeutic strategies for NAFLD treatment.

Probiotic and synbiotic supplementation could improve metabolic syndrome in prediabetic adults: A randomized controlled trial

AIMS

Modulation of the gastrointestinal microbiome is suggested to contribute to the progression of metabolic syndrome associated diseases. This study was designed to assess the effects of probiotics and synbiotics on metabolic syndrome in individuals with prediabetes.

METHODS

120 adults with prediabetes were enrolled in a double-blind, placebo-controlled randomized parallel-group clinical trial. Participants were randomized to a multi-species probiotic or inulin-based synbiotic or placebo. Blood samples and anthropometric measures were collected at baseline, 12 and 24 weeks after treatment. The primary outcome measures were the changes between groups in metabolic syndrome and its components' prevalence.

RESULTS

A significant trend for a reduction in the prevalence of hyperglycemia in probiotic and synbiotic groups (p = 0.01 and 0.005 respectively), and hypertension in probiotic group (p = 0.04) was found. The decreases in metabolic syndrome prevalence were significant after taking probiotic and synbiotic supplementation as compared with placebo (p = 0.02). Also, the prevalence of low HDL-cholesterol level was decreased during the study in the probiotic group compared with placebo (p = 0.02).

CONCLUSIONS

The potential benefits of using probiotic and synbiotic for metabolic syndrome management in prediabetes have been supported by the results in the current study which might provide an important strategy to combat metabolic syndrome-associated diseases.

The links between the gut microbiome and non-alcoholic fatty liver disease (NAFLD)

NAFLD is currently the main cause of chronic liver disease in developed countries, and the number of NAFLD patients is growing worldwide. NAFLD often has similar symptoms to other metabolic disorders, including type 2 diabetes and obesity. Recently, the role of the gut microbiota in the pathophysiology of many diseases has been revealed. Regarding NAFLD, experiments using gut microbiota transplants to germ-free animal models showed that fatty liver disease development is determined by gut bacteria. Moreover, the perturbation of the composition of the gut microbiota has been observed in patients suffering from NAFLD. Numerous mechanisms relating the gut microbiome to NAFLD have been proposed, including the dysbiosis-induced dysregulation of gut endothelial barrier function that allows for the translocation of bacterial components and leads to hepatic inflammation. In addition, the various metabolites produced by the gut microbiota may impact the liver and thus modulate NAFLD susceptibility. Therefore, the manipulation of the gut microbiome by probiotics, prebiotics or synbiotics was shown to improve liver phenotype in NAFLD patients as well as in rodent models. Hence, further knowledge about the interactions among dysbiosis, environmental factors, and diet and their impacts on the gut-liver axis can improve the treatment of this life-threatening liver disease and its related disorders.

Gut microbiota: novel therapeutic target for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common and increasing liver diseases worldwide with a prevalence of 20-33%. NAFLD may progress to fibrosis, compensated cirrhosis, advanced cirrhosis, or hepatocellular carcinoma. Despite the increasing prevalence of NAFLD, definitive medical treatment has not been established, with the exception of lifestyle modification with exercise. Because of the direct connection via portal vein between the intestines and the liver (gut-gut microbiota-liver axis), gut microbiota and associated dysbiosis have been known as regulators in the pathophysiology of NAFLD. Area covered: New therapeutic approaches for modulation of gut microbiota have been proposed and the effectiveness of new therapies including probiotics, prebiotics, synbiotics, bile acid regulation, absorbent, and fecal microbiota transplantation have been demonstrated in recent several studies. This review focuses on the available evidences for new therapies modulating gut microbiota in the management and the prevention of NAFLD. Expert commentary: Gut-gut microbiota-liver axis may play an important role in the etiology of many liver diseases, including NAFLD. It is logical to seek the manipulation of this axis, and further studies are required to understand the underlying precise mechanisms of microbiota-modulation on NAFLD.

Microbiota-accessible pectic poly- and oligosaccharides in gut health

Diverse human intestinal microbiota are regarded as a prerequisite for a healthy intestine. Commercial prebiotic products have a limited ability to provide microbial diversity in the human gut, because they mostly comprise oligomers of the same monosaccharide residues and a small fraction of them can reach the distal colon. Therefore, the demand for diverse prebiotic ingredients and dietary fibers with improved functional properties is increasing tremendously. The main sources of carbohydrates in our diet are plant-derived polysaccharides, which are consumed by the bacteria present in the intestine. Among these, pectin-derived poly- and oligosaccharides serve as the best alternative, as they are resistant to human gastric juice and are fermented slowly in the large intestine to impart a prebiotic effect. The main components of pectin are polygalacturonic acids in association with neutral polysaccharides such as arabinan, arabinogalactan, and galactan. The present review deals with the health-related functional properties of pectic poly- and oligosaccharides and their applications in the food industry. Different mechanisms involved in the hydrolysis of these carbohydrates by the intestinal bacteria and in maintaining the microbial diversity of the intestine are also discussed. It also emphasizes the current methods for the production and purification of different pectins and their oligosaccharides.

Smallanthus sonchifolius (Yacon) Flour Improves Visceral Adiposity and Metabolic Parameters in High-Fat-Diet-Fed Rats

Smallanthus sonchifolius (yacon), a native plant of South America, was observed to improve lipid profile in rodents and humans. This study aimed to investigate the antiobesity properties of yacon roots in a high-fat-diet (HFD) model and the underlying mechanisms. A total of 30 Wistar male rats were divided into five groups (n=6): the standard chow diet (SD) group was fed a SD; the HFD group was fed a HFD; and the HFD Y340 and HFD Y680 groups were fed a HFD plus yacon flour (340 and 680 mg FOS/kg b. w./day, respectively). HFD Y340 and HFD Y680 rats exhibited marked attenuation of weight gain, a decrease in visceral fat pad weight, a restoration of the serum lipid profile and atherogenic index in a dose-dependent manner, being the higher dose more effective (p < 0.05). In addition, we found that HFD Y680 rats showed lower glucose and insulin levels, improved glucose tolerance, and insulin sensitivity (p < 0.5). A downregulation of several adipocyte specific-transcription factors, including peroxisome proliferator-activated receptor gamma2 (PPAR-γ2), CCAAT/enhancer binding protein a (C/EBP-a) and activating protein (aP2) mRNA levels, was determined in the visceral adipose tissue of HFD Y680 rats (p < 0.05). An improvement of adipokine profile in HFD Y680 rats and decreased serum proinflammatory cytokine levels (p < 0.05) were determined by ELISA. Decreased macrophage infiltration and F4/80 and MCP-1 expression in the visceral adipose tissue of HFD Y680 rats (p < 0.5), together with a higher pAkt/Akt expression (p < 0.05) were also observed by immunofluorescence and immunoblotting. A significant increase in glucagon (Gcg) and PYY mRNA levels in distal ileum of HFD Y680 rats (p < 0.05) were also detected. In the second approach, we determined that yacon supplementation potentiates the effects of the HFD reversion to a standard diet. In conclusion, yacon showed antiobesity properties by inhibiting adipogenesis and improving the visceral adipose tissue function.

Modulation of gut microbiome in nonalcoholic fatty liver disease: pro-, pre-, syn-, and antibiotics

Nonalcoholic fatty liver disease (NAFLD) is one of the most common types of liver diseases worldwide and its incidence continues to increase. NAFLD occurs when the body can no longer effectively store excess energy in the adipose tissue. Despite the increasing prevalence of NAFLD, making lifestyle changes, including increased exercise, is often an elusive goal for patients with NAFLD. The liver directly connects to the gut-gastrointestinal milieu via the portal vein, which are all part of the gut-liver axis. Therefore, the gut-microbiome and microbial products have been actively studied as likely key factors in NAFLD pathophysiology. Hence, dysbiosis of the gut microbiome and therapeutic manipulation of the gut-liver axis are being investigated. Novel therapeutic approaches for modulating gut microbiota through the administration of probiotics, prebiotics, synbiotics, and antibiotics have been proposed with numerous promising initial reports on the effectiveness and clinical applications of these approaches. This review delves into the current evidence on novel therapies that modulate gut microbiota and discusses ongoing clinical trials targeting the gut-liver axis for the management and prevention of NAFLD.

Outside the liver box: The gut microbiota as pivotal modulator of liver diseases

The gut microbiota affects host physiology and has evolved as an important contributor to health and disease. Gut and liver are closely connected and communicate via the portal vein and the biliary system so the liver is constantly exposed to gut-derived bacterial products and metabolites. The intestinal barrier is important for maintaining physical and functional separation between microbes in the gut and the interior of the host and disruption of the barrier function can lead to bacterial translocation and increased leakage of bacterial metabolites. Liver diseases have been associated with dysbiotic changes in the gut microbiota and impaired gut barrier integrity, thus a future strategy to treat liver disease may be to target the gut microbiota and thereby restore the gut barrier function. This review will summarize and discuss studies that have shown a link between the gut microbiota and liver disease with the main focus on non-alcoholic fatty liver disease and alcoholic liver disease.

Effects of the intake of white wheat bread added with garlic and resistant starch: action on calcium bioavailability and metabolic parameters of growing Wistar rats

Functional bread with resistant starch and garlic improved the metabolism of calcium and lipids and the growth of beneficial gut microbiota.

Characterization of fructans and dietary fibre profiles in raw and steamed vegetables

Dietary fibre (DF) has many positive effects on human health associated with its functionality in the gastrointestinal tract. These benefits vary according to the type of DF. Vegetables can be a natural source of DF in the diet. However, to provide adequate nutritional advice, the content and profile of their various DF types must be characterised. This study aimed to determine the DF profile of 29 vegetables cultivated in Wallonia (Belgium) and the impact of steaming on these profiles. Using a combination of enzymatic, gravimetric and chromatographic methods, fructans, total dietary fibre (TDF), low- and high-molecular-weight soluble dietary fibre (SDF), and insoluble dietary fibre (IDF) were analysed. Results show that the DF content varies considerably among the 29 investigated vegetable varieties and species, but the influence of steaming is limited to a shift from IDF to high-molecular-weight SDF for 18 of the 29 tested vegetables, while fructans are preserved with not actual reduction in the DP.

Gut microbiota as a potential target of metabolic syndrome: the role of probiotics and prebiotics

Metabolic syndrome (MS) comprises central obesity, increased plasma glucose levels, hyperlipidemia and hypertension, and its incidence is increasing due to changes in lifestyle and dietary structure in recent years. MS has been proven to be associated with an increased incidence of cardiovascular diseases and type 2 diabetes mellitus, leading to morbidity and mortality. In this manuscript, we review recent studies concerning the role of the gut microbiota in MS modulation. Manipulation of the gut microbiota through the administration of prebiotics or probiotics may assist in weight loss and reduce plasma glucose and serum lipid levels, decreasing the incidence of cardiovascular diseases and type 2 diabetes mellitus. To the best of our knowledge, short-chain fatty acids (SCFAs), bile salt hydrolase (BSH), metabolic endotoxemia and the endocannabinoid (eCB) system are essential in regulating the initiation and progression of MS through the normalization of adipogenesis and the regulation of insulin secretion, fat accumulation, energy homeostasis, and plasma cholesterol levels. Therefore, the gut microbiota may serve as a potential therapeutic target for MS. However, further studies are needed to enhance our understanding of manipulating the gut microbiota and the role of the gut microbiota in MS prevention and treatment.

Exopolysaccharides Produced by Lactic Acid Bacteria and Bifidobacteria as Fermentable Substrates by the Intestinal Microbiota

The functional food market, including products formulated to maintain a "healthy" gut microbiota, i.e. probiotics and prebiotics, has increased enormously since the end of the last century. In order to favor the competitiveness of this sector, as well as to increase our knowledge of the mechanisms of action upon human health, new probiotic strains and prebiotic substrates are being studied. This review discusses the use of exopolysaccharides (EPS), both homopolysaccharides (HoPS) and heteropolysaccharides (HePS), synthesized by lactic acid bacteria and bifidobacteria as potential prebiotics. These extracellular carbohydrate polymers synthesized by some gut inhabitants seem to be resistant to gastrointestinal digestion; these are susceptible as well to biodegradability by the intestinal microbiota depending on both the physicochemical characteristics of EPS and the pool of glycolytic enzymes harbored by microbiota. Therefore, although the chemical composition of these HoPS and HePS is different, both can be fermentable substrates by intestinal inhabitants and good candidates as prebiotic substrates. However, there are limitations for their use as additives in the food industry due to, on the one hand, their low production yield and, on the other hand, a lack of clinical studies demonstrating the functionality of these biopolymers.

Gut microbiome and liver diseases

The gut microbiota has recently evolved as a new important player in the pathophysiology of many intestinal and extraintestinal diseases. The liver is the organ which is in closest contact with the intestinal tract, and is exposed to a substantial amount of bacterial components and metabolites. Various liver disorders such as alcoholic liver disease, non-alcoholic liver disease and primary sclerosing cholangitis have been associated with an altered microbiome. This dysbiosis may influence the degree of hepatic steatosis, inflammation and fibrosis through multiple interactions with the host's immune system and other cell types. Whereas few results from clinical metagenomic studies in liver disease are available, evidence is accumulating that in liver cirrhosis an oral microbiome is overrepresented in the lower intestinal tract, potentially contributing to disease process and severity. A major role for the gut microbiota in liver disorders is also supported by the accumulating evidence that several complications of severe liver disease such as hepatic encephalopathy are efficiently treated by various prebiotics, probiotics and antibiotics. A better understanding of the gut microbiota and its components in liver diseases might provide a more complete picture of these complex disorders and also form the basis for novel therapies.

Produto a base de yacon e modulação da microbiota, perfil de ácidos graxo e lipídico em ratas ovariectomizadas

RESUMO Objetivo: Este trabalho avaliou a modulação da microbiota gastrointestinal, do perfil de ácidos orgânicos e de lipídeos em ratas Wistar ovariectomizadas, sendo que algumas receberam dieta suplementada com 6% de fruto-oligossacarídeos e inulina, a partir do produto a base de yacon, e outras não. Métodos: Analisou-se o peso do ceco, pH e ácidos orgânicos, microbiota do conteúdo cecal, colesterol total e frações. Resultados: No grupo que recebeu a dieta suplementada durante todo o experimento ocorreu modulação benéfica da microbiota intestinal em função da fermentação dos fruto-oligossacarídeos/inulina, bem como aumento do perfil de lactato (p<0,05) e do nível de lipoproteina alta densidade (p<0,05). Conclusão: Isso sugere que o hábito de consumo contínuo do yacon tem potencial para modular a microbiota intestinal, o perfil de ácidos orgânicos e para diminuir as dislipidemias.

How to Manipulate the Microbiota: Prebiotics

During the last century, human nutrition has evolved from the definition of our nutritional needs and the identification of ways to meet them, to the identification of food components that can optimise our physiological and psychological functions. This development, which aims to ensure the welfare, health and reduced susceptibility to disease during life, gave birth to the concept of "functional foods". In this context, there is an increasing interest in the physiological effects induced by the dense and diverse microbiota which inhabits the human colon and whose development depends on the fermentation of undigested food residues. Thus, much research aims at identifying ways to guide these impacts in order to benefit the health of the host. It is in this context that the concept of "prebiotics" was developed in the 1990s. Since then, prebiotics have stimulated extensive work in order to clarify their definition, their nature and their physiological properties in accordance with the evolution of knowledge on the intestinal microbiota. However many questions remain open about their specificities, their mechanism(s) of action and therefore the relevance of their current categorisation.

Agavins Increase Neurotrophic Factors and Decrease Oxidative Stress in the Brains of High-Fat Diet-Induced Obese Mice

BACKGROUND

Fructans obtained from agave, called agavins, have recently shown significant benefits for human health including obesity. Therefore, we evaluated the potential of agavins as neuroprotectors and antioxidants by determining their effect on brain-derived neurotrophic factor (BDNF) and glial-derived neurotrophic factor (GDNF) as well as oxidative brain damage in of obese mice.

METHODS

Male C57BL/6J mice were fed a high-fat diet (HFD) and treated daily with 5% (HFD/A5) or 10% (HFD/A10) of agavins or a standard diet (SD) for 10 weeks. The levels of BDNF and GDNF were evaluated by ELISA. The oxidative stress was evaluated by lipid peroxidation (TBARS) and carbonyls. SCFAs were also measured with GC-FID. Differences between groups were assessed using ANOVA and by Tukey's test considering p < 0.05.

RESULTS

The body weight gain and food intake of mice HFD/A10 group were significantly lower than those in the HFD group. Agavins restored BDNF levels in HFD/A5 group and GDNF levels of HFD/A5 and HFD/A10 groups in cerebellum. Interestingly, agavins decreased TBARS levels in HFD/A5 and HFD/A10 groups in the hippocampus, frontal cortex and cerebellum. Carbonyl levels were also lower in HFD/A5 and HFD/A10 for only the hippocampus and cerebellum. It was also found that agavins enhanced SCFAs production in feces.

CONCLUSION

Agavins may act as bioactive ingredients with antioxidant and protective roles in the brain.

The Role of Gut Microflora and the Cholinergic Anti-inflammatory Neuroendocrine System in Diabetes Mellitus

The obesity epidemic has drastically impacted the state of health care in the United States. Paralleling this epidemic is the incidence of diabetes mellitus, with a notable shift toward a much younger age of onset. While central to the pathogenesis of diabetes associated with obesity is the role of inflammation attributed to "adiposopathy." Emerging data suggest that changes in sympathetic/parasympathetic balance regulated by the brain precede changes in the inflammatory cascade. It has now been established that the gut microflora contributes significantly to the activation and inhibition of autonomic control and impact the set of the neuroinflammatory inhibitory reflex mediated by the cholinergic nervous system. There has been a paradigm shift toward further investigating commensal bacteria in the pathogenesis of obesity and diabetes mellitus and its complications, as dysbiosis is thought to play a pivotal role in diabetic-associated disorders. This paper is intended to evaluate the role of intestinal dysbiosis in the pathogenesis of diabetes mellitus and examine the potential for restoration of balance via use of probiotics.

Impact of the gut microbiota on inflammation, obesity, and metabolic disease

The human gut harbors more than 100 trillion microbial cells, which have an essential role in human metabolic regulation via their symbiotic interactions with the host. Altered gut microbial ecosystems have been associated with increased metabolic and immune disorders in animals and humans. Molecular interactions linking the gut microbiota with host energy metabolism, lipid accumulation, and immunity have also been identified. However, the exact mechanisms that link specific variations in the composition of the gut microbiota with the development of obesity and metabolic diseases in humans remain obscure owing to the complex etiology of these pathologies. In this review, we discuss current knowledge about the mechanistic interactions between the gut microbiota, host energy metabolism, and the host immune system in the context of obesity and metabolic disease, with a focus on the importance of the axis that links gut microbes and host metabolic inflammation. Finally, we discuss therapeutic approaches aimed at reshaping the gut microbial ecosystem to regulate obesity and related pathologies, as well as the challenges that remain in this area.

Probiotics and Prebiotics: Present Status and Future Perspectives on Metabolic Disorders

Metabolic disorders, including type 2 diabetes (T2DM) and cardiovascular disease (CVD), present an increasing public health concern and can significantly undermine an individual's quality of life. The relative risk of CVD, the primary cause of death in T2DM patients, is two to four times higher in people with T2DM compared with those who are non-diabetic. The prevalence of metabolic disorders has been associated with dynamic changes in dietary macronutrient intake and lifestyle changes over recent decades. Recently, the scientific community has considered alteration in gut microbiota composition to constitute one of the most probable factors in the development of metabolic disorders. The altered gut microbiota composition is strongly conducive to increased adiposity, β-cell dysfunction, metabolic endotoxemia, systemic inflammation, and oxidative stress. Probiotics and prebiotics can ameliorate T2DM and CVD through improvement of gut microbiota, which in turn leads to insulin-signaling stimulation and cholesterol-lowering effects. We analyze the currently available data to ascertain further potential benefits and limitations of probiotics and prebiotics in the treatment of metabolic disorders, including T2DM, CVD, and other disease (obesity). The current paper explores the relevant contemporary scientific literature to assist in the derivation of a general perspective of this broad area.

Intestinal microbiota in liver disease

The intestinal microbiota have emerged as a topic of intense interest in gastroenterology and hepatology. The liver is on the front line as the first filter of nutrients, toxins and bacterial metabolites from the intestines and we are becoming increasingly aware of interactions among the gut, liver and immune system as important mediators of liver health and disease. Manipulating the microbiota with therapeutic intent is a rapidly expanding field. In this review, we will describe what is known about the contribution of intestinal microbiota to liver homeostasis; the role of dysbiosis in the pathogenesis of liver disease including alcoholic and non-alcoholic fatty liver disease, cirrhosis and hepatocellular carcinoma; and the therapeutic manifestations of altering intestinal microbiota via antibiotics, prebiotics, probiotics and fecal microbiota transplantation.

Assessment of the prebiotic effect of quinoa and amaranth in the human intestinal ecosystem

Quinoa and amaranth belong to the group of the so called “superfoods” and have a nutritional composition that confers multiple benefits.

α-Galactosides present in lupin flour affect several metabolic parameters in Wistar rats

The aim of this study is to evaluate the influence of α-galactosides present in a lupin diet on metabolic parameters in growing Wistar rats.

Alleviation of high fat diet-induced obesity by oligofructose in gnotobiotic mice is independent of presence of Bifidobacterium longum

Scope

Diet‐induced obesity is associated with changes in the gut microbiota and low‐grade inflammation. Oligofructose was reported to ameliorate high fat diet‐induced metabolic disorders in mice by restoring the number of intestinal bifidobacteria. However, this has not been experimentally demonstrated.

Methods and results

We fed conventional mice, germfree mice, mice associated with a simplified human gut microbiota composed of eight bacterial species including Bifidobacterium longum (SIHUMI), and mice associated with SIHUMI without B. longum a low fat diet (LFD), a high fat diet (HFD), or a HFD containing 10% oligofructose (HFD + OFS) for five weeks. We assessed body composition, bacterial cell numbers and metabolites, markers of inflammation, and gut permeability. Conventional mice fed HFD or HFD + OFS did not differ in body weight gain and glucose tolerance. The gnotobiotic mouse groups fed LFD or HFD + OFS gained less body weight and body fat, and displayed an improved glucose tolerance compared with mice fed HFD. These differences were not affected by the presence of B. longum. Mice fed HFD showed no signs of inflammation or increased intestinal permeability.

Conclusion

The ability of oligofructose to reduce obesity and to improve glucose tolerance in gnotobiotic mice fed HFD was independent of the presence of B. longum.

Choline and Fructooligosaccharide: Non-alcoholic Fatty Liver Disease, Cardiac Fat Deposition, and Oxidative Stress Markers

This study investigates the treatment of non-alcoholic fatty liver disease (NAFLD) in rats with choline and fructooligosaccharide (FOS). The healthy control group received standard diet. The other three groups consisted of animals with NAFLD. Group E_str received standard diet; group E_cho received standard diet plus choline (3 g/100 g diet); and group E_fos received standard diet plus FOS (10 g/100 g diet). Food intake, weight, urinary nitrogen, urinary ammonia, total cholesterol, serum triacylglyceride, liver and heart weights, tissue nitrogen, tissue fat, vitamin E, TBARS, and reduced glutathione (GSH) were measured in hepatic and heart tissue. Choline and FOS treatments resulted in total mean fat reduction in liver and heart tissue of 0.2 and 1.7 g, respectively. Both treatments were equally effective in reducing hepatic and cardiac steatosis. There were no differences in the TBARS level among experimental and control groups, indicating that the proposed treatments had no added protection against free radicals. While all experimental groups had increased vitamin E and GSH levels, choline treatment led to a significant increase compared to control.

In vitro assessment of the prebiotic potential of Aloe vera mucilage and its impact on the human microbiota

Aloe veramucilage is reported to be rich in acemannan that is a polysaccharide with a backbone of β-(1→4)-d-mannose residues acetylated at the C-2 and C-3 positions and contains some side chains of galactose and arabinose attached to the C-6 carbon.