Oligofructose-enriched inulin improves some inflammatory markers and metabolic endotoxemia in women with type 2 diabetes mellitus: A randomized controlled clinical trial

Prebiotics in the management of components of the metabolic syndrome

Components of the metabolic syndrome (MetS), including abdominal obesity, low-grade chronic systemic inflammation, altered glucose metabolism, dyslipidemia and high blood pressure, are major threats to healthy aging in modern societies. The connection between MetS components and gut microflora is now acknowledged and multiple therapeutic strategies have been proposed to change the composition of the gut microbiota in order to promote optimal metabolic health. Prebiotics have the ability to favour growth of beneficial bacteria, especially short-chain fatty-acids (SCFA) producers. Increased SCFA in the gut is associated with improved satiety and weight loss, reduced systemic inflammation by increasing the gut barrier function, and improved glucose and lipid metabolism. The objective of this review is to examine the recent literature in order to determine the types and doses of prebiotics that could be recommended for the management of MetS. A review of the literature was executed using the MEDLINE database and clinical trials from 2013 to 2017 were selected for analysis. In conclusion, a daily supplementation of 10g of inulin, resistant starches or fructo-oligosaccharide-enriched inulin could have beneficial effects on MetS components in individuals with type 2 diabetes. In healthy subjects or in individuals with the MetS, the results are too heterogeneous and scarce to be able to set any specific recommendations. More clinical studies are needed to better understand the role of prebiotics in the management of MetS components.

A randomized controlled trial on the efficacy of resistant dextrin, as functional food, in women with type 2 diabetes: Targeting the hypothalamic-pituitary-adrenal axis and immune system

OBJECTIVE

The aim of this trial was to determine the efficacy of a resistant dextrin on immune-mediated inflammation and hypothalamic-pituitary-adrenal axis in women with type 2 diabetes mellitus (T2DM).

METHODS

Females (n = 55) with T2DM were randomly allocated into intervention group (n = 30) and control group (n = 25), in which they received 10 g/d of Nutriose^®06 (a resistant dextrin) or maltodextrin for 8 weeks, respectively. Fasting blood samples were taken to measure immune system related parameters like white blood cell count, CD4, CD8, interferon-γ (IFNγ), interleukins (IL12, IL4, IL10), cortisol, tryptophan (TRP), ACTH (Adrenocorticotropic hormone), Kynurenine (KYN) and plasma lipopolysaccharide (LPS) at the beginning and end of trial. Mental health was assessed using general health questionnaire (GHQ) and depression, anxiety and stress scale (DASS).

RESULTS

Resistant dextrin caused a significant decrease in levels of cortisol, KYN, KYN/TRP ratio, IFNγ, IL12, IFNγ/IL10 ratio, LPS, and a significant increase in the monocyte, GHQ, DASS, CD8, IL10, IL4 in the intervention group as compared with baseline. A significant decrease in the level of LPS (-6.20 EU/mL, -17.8%), IFNγ (-0.6 pg/ml, -26.8%), cortisol (-2.6 μg/dl, -20.9%), IFNγ/IL10 ratio (0.01, 10%), GHQ (-5.1, -12.5%), DASS (-10.4, -38.4%), KYN/TRP ratio (6.8, 29.1%), and a significant increase in levels of CD8 (6.4%, 6.1%) and IL10 (2.6 pg/ml, 21.6%) in the intervention group as compared with the control group (P < 0.05). No significant changes were observed in white blood cell count, CD4, CD4/CD8 ratio, ACTH, KYN, TRP, IL4 and IL12 in the intervention group as compared with the control group (P > 0.05).

CONCLUSION

Supplementation of Nutriose^®06 may have beneficial effects on mental health and the immune system response in women with T2DM.

Nutritional anti-inflammatories in the treatment and prevention of type 2 diabetes mellitus and the metabolic syndrome

AIMS

Obesity-fuelled metabolic syndrome and diabetes is now a global epidemic. There is increasing evidence that these and other chronic conditions have common inflammatory antecedents. There is an interest in nutritionally based anti-inflammatory treatments for type 2 diabetes and metabolic syndrome. The aim of this review is to examine the evidence from a 5-year period; 2011-2016, for nutritionally based anti-inflammatory treatments for the Metabolic Syndrome and Type 2 Diabetes Mellitus.

METHODS

A literature search produced a total number of 1377 records, of which 26 papers were evaluated.

RESULTS

Literature was analysed and tabulated according to date, outcome measures and results.

CONCLUSION

The evidence is strong for use of polyphenolic compounds, fish oils and vitamins in reducing inflammation biomarkers, however the impact on metabolic control is less evident.

Oligofructose decreases serum lipopolysaccharide and plasminogen activator inhibitor-1 in adults with overweight/obesity

OBJECTIVE

To determine the effect of prebiotic supplementation on metabolic endotoxemia and systemic inflammation in adults with overweight and obesity.

METHODS

Samples from a previously conducted randomized, double-blind, placebo-controlled trial were used for analysis. Participants were randomized to 21 g of oligofructose (n = 20; BMI 30.4 kg/m² ) or a maltodextrin placebo (n = 17; BMI 29.5 kg/m² ) for 12 weeks. A total of 37 participants had samples available for the current analysis. Resistin, adiponectin, plasminogen activator inhibitor-1 (PAI-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and macrophage chemoattractant protein-1 (MCP-1) were quantified using MILLIPLEX® assays. Lipopolysaccharide (LPS) was measured using PyroGene™ Recombinant Factor C Assay.

RESULTS

Plasma LPS concentrations were reduced by 40% in the oligofructose group over 12 weeks compared to a 48% increase in the placebo group (P = 0.04). PAI-1, a risk factor for thrombosis, was reduced to a greater extent in the oligofructose group (-17.3 ± 2.6 ng/ml) compared to the placebo group (-9.7 ± 1.8 ng/ml; P = 0.03). Oligofructose did not affect IL-6, TNF-α, MCP-1, adiponectin, or resistin.

CONCLUSIONS

Oligofructose reduces metabolic endotoxemia and PAI-1. Incorporating prebiotics into the diet through supplements or functional foods may help mitigate some markers of obesity-associated inflammation.

An Exploratory Investigation of Endotoxin Levels in Novice Long Distance Triathletes, and the Effects of a Multi-Strain Probiotic/Prebiotic, Antioxidant Intervention

Gastrointestinal (GI) ischemia during exercise is associated with luminal permeability and increased systemic lipopolysaccharides (LPS). This study aimed to assess the impact of a multistrain pro/prebiotic/antioxidant intervention on endotoxin unit levels and GI permeability in recreational athletes. Thirty healthy participants (25 males, 5 females) were randomly assigned either a multistrain pro/prebiotic/antioxidant (LAB⁴_ANTI; 30 billion CFU·day⁻¹ containing 10 billion CFU·day⁻¹Lactobacillus acidophilus CUL-60 (NCIMB 30157), 10 billion CFU·day⁻¹Lactobacillus acidophillus CUL-21 (NCIMB 30156), 9.5 billion CFU·day⁻¹Bifidobacterium bifidum CUL-20 (NCIMB 30172) and 0.5 billion CFU·day⁻¹Bifidobacterium animalis subspecies lactis CUL-34 (NCIMB 30153)/55.8 mg·day⁻¹ fructooligosaccharides/ 400 mg·day⁻¹ α-lipoic acid, 600 mg·day⁻¹N-acetyl-carnitine); matched pro/prebiotic (LAB⁴) or placebo (PL) for 12 weeks preceding a long-distance triathlon. Plasma endotoxin units (via Limulus amebocyte lysate chromogenic quantification) and GI permeability (via 5 h urinary lactulose (L): mannitol (M) recovery) were assessed at baseline, pre-race and six days post-race. Endotoxin unit levels were not significantly different between groups at baseline (LAB⁴_ANTI: 8.20 ± 1.60 pg·mL⁻¹; LAB⁴: 8.92 ± 1.20 pg·mL⁻¹; PL: 9.72 ± 2.42 pg·mL⁻¹). The use of a 12-week LAB⁴_ANTI intervention significantly reduced endotoxin units both pre-race (4.37 ± 0.51 pg·mL⁻¹) and six days post-race (5.18 ± 0.57 pg·mL⁻¹; p = 0.03, ηp² = 0.35), but only six days post-race with LAB⁴ (5.01 ± 0.28 pg·mL⁻¹; p = 0.01, ηp² = 0.43). In contrast, endotoxin units remained unchanged with PL. L:M significantly increased from 0.01 ± 0.01 at baseline to 0.06 ± 0.01 with PL only (p = 0.004, ηp² = 0.51). Mean race times (h:min:s) were not statistically different between groups despite faster times with both pro/prebiotoic groups (LAB⁴_ANTI: 13:17:07 ± 0:34:48; LAB⁴: 12:47:13 ± 0:25:06; PL: 14:12:51 ± 0:29:54; p > 0.05). Combined multistrain pro/prebiotic use may reduce endotoxin unit levels, with LAB⁴_ANTI potentially conferring an additive effect via combined GI modulation and antioxidant protection.

Effects of inulin-type fructans, galacto-oligosaccharides and related synbiotics on inflammatory markers in adult patients with overweight or obesity: A systematic review

BACKGROUND & AIMS

Studies in humans with overweight or obesity have reported that some prebiotics and synbiotics have beneficial effects on metabolic endotoxaemia and immune function. However, to date, no systematic review of controlled clinical trials assessed this topic. The aim of this study was to evaluate the effects of inulin-type fructans, galacto-oligosaccharides and related synbiotics on inflammatory markers in adults with overweight or obesity.

METHODS

A systematic review of the literature was performed until November 6, 2015 in four electronic databases and reference lists of all included articles and relevant reviews in the field, without using any filter.

RESULTS

Ten trials (six prebiotic and four synbiotic trials) representing 534 overweight/obese adults were included. All trials evaluated C-reactive protein or high-sensitivity C-reactive protein, four trials evaluated cytokines (two prebiotic and two synbiotic trials) and five trials evaluated endotoxin (four prebiotic and one synbiotic trials). Six trials (two with galacto-oligosaccharide, one with inulin and three with different synbiotics) showed a reduction on high-sensitivity C-reactive protein. Four trials (one with oligofructose-enriched inulin, one with inulin and two with different synbiotics) showed a reduction on interleukin-6 and/or tumor necrosis factor. Four trials (one with galacto-oligosaccharide, one with oligofructose-enriched inulin, one with inulin and one with synbiotic) showed a reduction on endotoxin.

CONCLUSIONS

Some prebiotics and synbiotics may have immunomodulatory action, however, more randomized controlled trials are needed to support the clinical use of inulin-type fructans, galacto-oligosaccharides or related synbiotics for the treatment of metabolic endotoxaemia or low-grade inflammation in overweight/obese people.

Effects of prebiotics on immune system and cytokine expression

Nowadays, use of prebiotics as feed and food additives has received increasing interest because of the beneficial effects of prebiotics on the health of animals and humans. One of the beneficial effects of prebiotics is stimulation of immune system, which can be direct or indirect through increasing population of beneficial microbes or probiotics, especially lactic acid bacteria and bifidobacteria, in the gut. An important mechanism of action of probiotics and prebiotics, by which they can affect the immune system, is changing the expression of cytokines. The present review tried to summarize the findings of studies that investigated the effects of prebiotics on immune system with focusing on their effects on cytokine expression. Generally, most of reviewed studies indicated beneficial effects for prebiotics in terms of improving immune system, by increasing the expression of anti-inflammatory cytokines, while reducing the expressions of proinflammatory cytokines. However, most of studies mainly considered the indirect effects of prebiotics on the immune system (through changing the composition and population of gut microbiota), and their direct effects still need to be further studied using prebiotics with different degree of polymerization in different hosts.

Resistant dextrin, as a prebiotic, improves insulin resistance and inflammation in women with type 2 diabetes: a randomised controlled clinical trial

Improvement of insulin resistance and inflammation is a basic strategy in the management of type 2 diabetes. There is limited evidence that prebiotics improve insulin resistance and inflammation. However, the ameliorating effect of resistant dextrin, as a prebiotic, on insulin resistance and inflammation in patients with type 2 diabetes has not been investigated so far. Therefore, the present study aimed to examine the effects of resistant dextrin on insulin resistance and inflammation in type 2 diabetic patients. In a randomised controlled clinical trial, fifty-five women with type 2 diabetes were assigned to two groups: the intervention group (n 30) and the control group (n 25). The intervention group received a daily supplement of 10 g resistant dextrin and the control group received a similar amount of maltodextrin as placebo for 8 weeks. Fasting plasma glucose (FPG), HbA1c, insulin, high-sensitivity C-reactive protein (hs-CRP), IL-6, TNF-α, malondialdehyde (MDA) and serum endotoxin concentrations were measured before and after the intervention. Data were analysed using SPSS (version 13). Paired and unpaired t tests and ANCOVA were used to compare quantitative variables after the intervention. Patients supplemented with resistant dextrin exhibited a significant decrease in fasting insulin (20.1 pmol/l, 22.8%), homeostasis model assessment of insulin resistance (1.3, 24.9%), quantitative insulin sensitivity check index (0.2, 7.2%), IL-6 (1.4 pg/ml, 28.4 %), TNF-α (5.4 pg/ml, 18.8 %), MDA (1.2 nmol/ml, 25.6 %) and endotoxin (6.2 endotoxin units/ml, 17.8%) concentrations than those supplemented with maltodextrin (P< 0.05). Decreases in FPG (0.05 mmol/l, 0.6%), HbA1c (0.5%, 9.6%) and hs-CRP (2.7 ng/ml, 35.1%) concentrations in the resistant dextrin group were not significant when compared with the maltodextrin group. In conclusion, resistant dextrin supplementation can modulate inflammation and improve insulin resistance in women with type 2 diabetes.

The effect of enriched chicory inulin on liver enzymes, calcium homeostasis and hematological parameters in patients with type 2 diabetes mellitus: A randomized placebo-controlled trial

BACKGROUNDS AND AIMS

Type 2 diabetic mellitus (T2DM) as one of the main causes of morbidity and mortality is associated with immune system disturbances and metabolic abnormalities. In the current study we aimed to evaluate the effects of enriched chicory inulin supplementation on liver enzymes, serum calcium and phosphorous concentrations and hematological parameters in patients with T2DM.

METHODS

Forty-six diabetic females patients were randomly allocated into intervention (n=27) and control (n=22) groups. Subjects in the intervention group received a daily dose of 10g of chicory and subjects in control group received a placebo for two months. Anthropometric variables, glucose homeostasis, hematological parameters and metabolic indices including serum alanine aminotransfersae (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), calcium and phosphorous as well as creatinine concentrations, glomerular filtration rate (GFR) and blood pressure were assessed at the beginning and end of the trial.

RESULTS

Significant reductions in fasting serum glucose (FSG), Hb A1C, AST and ALP concentrations were observed in chicory-treated group. Systolic and diastolic blood pressures were also reduced in chicory-treated group. Serum calcium significantly increased after chicory supplementation but no change in placebo treated group has been occurred (P=0.014). Supplementation with enriched chicory for two months significantly reduced hematocrit and mean corpuscular volume (MCV) values (P<0.05). Changes in serum insulin, creatinine and GFR were not significant.

CONCLUSION

The present study showed beneficial effects of oligofructose-enriched chicory on the improvement of the glucose and calcium homeostasis, liver function tests, blood pressure and reduction in hematologic risk factors of diabetes in female patients with T2DM. Further studies in both genders are needed to generalize these findings to total population.

GUT MICROBIOTA, PREBIOTICS, PROBIOTICS, AND SYNBIOTICS IN MANAGEMENT OF OBESITY AND PREDIABETES: REVIEW OF RANDOMIZED CONTROLLED TRIALS

OBJECTIVE

To review the data from randomized controlled trials (RCTs) for the roles of microbiota, pre-, pro- and synbiotics in metabolic conditions (obesity, prediabetes, and diabetes mellitus type 2 [DM2]).

METHODS

Primary literature was reviewed on the topics including RCTs of pre-, pro- and synbiotics use for metabolic disease.

RESULTS

Gut bacteria (microbiota) benefit digestion and have multiple other functions. Microbiota could increase harvesting of energy from the food and cause subclinical inflammation seen in metabolic disorders. Diet-related interventions including prebiotics, probiotics, and synbiotics (combining pre-and probiotics) may benefit metabolic conditions. Prebiotics are complex carbohydrates (i.e., dietary fiber). Results of RCTs of prebiotics suggested a neutral effect on body weight, decreased fasting and postprandial glucose, and improved insulin sensitivity and lipid profile. Some inflammation markers were reduced, sometimes substantially (20-30%). RCTs for probiotics demonstrated significant but small effects on body weight (<3%) and metabolic parameters. The effect was seen mostly with fermented milk or yogurt compared to capsule form, consumption for at least 8 weeks, and use of multiple rather than a single bacterial strain. Changes in microbiota were seen at times with both pre- and probiotics. Pickled and fermented foods, particularly vegetables and beans, could serve as a dietary source of pre-, pro-, and synbiotics. These foods showed possible benefits for morbidity and mortality in prospective cohort studies.

CONCLUSION

Pre-, pro-, and synbiotics could prove useful, but further research is needed to clarify their clinical relevance for the prevention and management of metabolic disease.

ABBREVIATIONS

A1c = glycohemoglobin A1c CI = confidence interval CVD = cardiovascular disease GMB = gut (large bowel) microbiota DM2 = diabetes mellitus type 2 HOMA-IR = homeostatic model assessment of insulin resistance LDL = low-density lipoprotein LPS = lipopolysaccharide NAFLD = nonalcoholic fatty liver disease RCT = randomized controlled trial SMD = standardized mean difference TG = triglycerides.

Metabolic endotoxemia with obesity: Is it real and is it relevant?

Obesity is associated with metabolic derangements in multiple tissues, which contribute to the progression of insulin resistance and the metabolic syndrome. The underlying stimulus for these metabolic derangements in obesity are not fully elucidated, however recent evidence in rodents and humans suggests that systemic, low level elevations of gut derived endotoxin (lipopolysaccharide, LPS) may play an important role in obesity related, whole-body and tissue specific metabolic perturbations. LPS initiates a well-characterized signaling cascade that elicits many pro- and anti-inflammatory pathways when bound to its receptor, Toll-Like Receptor 4 (TLR4). Low-grade elevation in plasma LPS has been termed "metabolic endotoxemia" and this state is associated with a heightened pro-inflammatory and oxidant environment often observed in obesity. Given the role of inflammatory and oxidative stress in the etiology of obesity related cardio-metabolic disease risk, it has been suggested that metabolic endotoxemia may serve a key mediator of metabolic derangements observed in obesity. This review provides supporting evidence of mechanistic associations with cell and animal models, and provides complimentary evidence of the clinical relevance of metabolic endotoxemia in obesity as it relates to inflammation and metabolic derangements in humans. Discrepancies with endotoxin detection are considered, and an alternate method of reporting metabolic endotoxemia is recommended until a standardized measurement protocol is set forth.

Gut Microbiota and Lifestyle Interventions in NAFLD

The human digestive system harbors a diverse and complex community of microorganisms that work in a symbiotic fashion with the host, contributing to metabolism, immune response and intestinal architecture. However, disruption of a stable and diverse community, termed "dysbiosis", has been shown to have a profound impact upon health and disease. Emerging data demonstrate dysbiosis of the gut microbiota to be linked with non-alcoholic fatty liver disease (NAFLD). Although the exact mechanism(s) remain unknown, inflammation, damage to the intestinal membrane, and translocation of bacteria have all been suggested. Lifestyle intervention is undoubtedly effective at improving NAFLD, however, not all patients respond to these in the same manner. Furthermore, studies investigating the effects of lifestyle interventions on the gut microbiota in NAFLD patients are lacking. A deeper understanding of how different aspects of lifestyle (diet/nutrition/exercise) affect the host-microbiome interaction may allow for a more tailored approach to lifestyle intervention. With gut microbiota representing a key element of personalized medicine and nutrition, we review the effects of lifestyle interventions (diet and physical activity/exercise) on gut microbiota and how this impacts upon NAFLD prognosis.

The Intestinal Immune System in Obesity and Insulin Resistance

Obesity and insulin resistance are associated with chronic inflammation in metabolic tissues such as adipose tissue and the liver. Recently, growing evidence has implicated the intestinal immune system as an important contributor to metabolic disease. Obesity predisposes to altered intestinal immunity and is associated with changes to the gut microbiota, intestinal barrier function, gut-residing innate and adaptive immune cells, and oral tolerance to luminal antigens. Accordingly, the gut immune system may represent a novel therapeutic target for systemic inflammation in insulin resistance. This review discusses the emerging field of intestinal immunity in obesity-related insulin resistance and how it affects metabolic disease.

Gut microbiota manipulation with prebiotics in patients with non-alcoholic fatty liver disease: a randomized controlled trial protocol

Background

Evidence for the role of the gut microbiome in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) is emerging. Strategies to manipulate the gut microbiota towards a healthier community structure are actively being investigated. Based on their ability to favorably modulate the gut microbiota, prebiotics may provide an inexpensive yet effective dietary treatment for NAFLD. Additionally, prebiotics have established benefits for glucose control and potentially weight control, both advantageous in managing fatty liver disease. Our objective is to evaluate the effects of prebiotic supplementation, adjunct to those achieved with diet-induced weight loss, on heptic injury and liver fat, the gut microbiota, inflammation, glucose tolerance, and satiety in patients with NAFLD.

Methods/design

In a double blind, placebo controlled, parallel group study, adults (BMI ≥25) with confirmed NAFLD will be randomized to either a 16 g/d prebiotic supplemented group or isocaloric placebo group for 24 weeks (n = 30/group). All participants will receive individualized dietary counseling sessions with a registered dietitian to achieve 10 % weight loss. Primary outcome measures include change in hepatic injury (fibrosis and inflammation) and liver fat. Secondary outcomes include change in body composition, appetite and dietary adherence, glycemic and insulinemic responses and inflammatory cytokines. Mechanisms related to prebiotic-induced changes in gut microbiota (shot-gun sequencing) and their metabolic by-products (volatile organic compounds) and de novo lipogenesis (using deuterium incorporation) will also be investigated.

Discussion

There are currently no medications or surgical procedures approved for the treatment of NAFLD and weight loss via lifestyle modification remains the cornerstone of current care recommendations. Given that prebiotics target multiple metabolic impairments associated with NAFLD, investigating their ability to modulate the gut microbiota and hepatic health in patients with NAFLD is warranted.

Trial registration

ClinicalTrials.gov (NCT02568605) Registered 30 September 2015

A Combination of Prebiotic Inulin and Oligofructose Improve Some of Cardiovascular Disease Risk Factors in Women with Type 2 Diabetes: A Randomized Controlled Clinical Trial

PURPOSE

This trial was conducted to evaluate the effects of oligofructose-enriched inulin on some of cardiovascular disease risk factors in women with type 2 diabetes.

METHODS

52 females (25<BMI<35 kg/m2) with type 2 diabetes were randomly assigned to two groups. Participants received 10g/d oligofructose-enriched inulin (n=27) or 10g/d placebo (n=25) for 8 weeks. Fasting blood samples were taken to measure metabolic profiles, malondialdehyd and antioxidant enzymes at baseline and after the 8 weeks intervention. Paired, unpaired sample t-test and analysis of covariance were used to comparison of quantitative variables.

RESULTS

After 8 weeks, in the oligofructose-enriched inulin group there was a significant increase in total antioxidant capacity (0.2 mmol/l, 20.0%) and a significant decrease in fasting plasma glucose (19.2 mg/dL, 9.4%) HbA1c (0.5%, 8.4%), total cholesterol (TC) (28.0 mg/dL, 14.1%), low-density lipoprotein cholesterol (LDL-c) (22.0 mg/dL, 21.7%), TC/HDL-c ratio (0.73, 20.7%), LDL-c/HDL-c ratio (0.55, 27.5%) and malondialdehyd (1.7 nmol/ml, 39.7%) compared to the placebo group. Changes in concentrations of triglycerides, high-density lipoprotein cholesterol (HDLc), superoxide dismutase, catalase and glutathione peroxidase were not significant in oligofructose-enriched inulin group compared to the placebo group.

CONCLUSION

Oligofructose-enriched inulin may improve glycemic indices, lipid profile, antioxidant status and malondialdehyd in women with type 2 diabetes.

An Investigation of the Acute Effects of Oligofructose-Enriched Inulin on Subjective Wellbeing, Mood and Cognitive Performance

Inulin is a natural food component found in many plants that are part of the human diet (e.g., leeks, onions, wheat, garlic, chicory and artichokes). It is added to many foods and is used to increase dietary fibre, replace fats or carbohydrates, and as a prebiotic (a stimulant of beneficial bacteria in the colon). Oligofructose, which is also present in these foods, produces similar effects and most research has used a combination of these products. A previous study (Smith, 2005) investigated the effects of regular consumption of oligofructose-enriched inulin on wellbeing, mood, and cognitive performance in humans. The results showed that oligofructose-enriched inulin had no negative effects but that it did not improve wellbeing, mood, or performance. The aim of the present study was to examine the acute effects of oligofructose-enriched inulin (5 g) over a 4 h period during which the participants remained in the laboratory. A double blind placebo (maltodextrin) controlled study (N = 47) was carried out with the order of conditions being counterbalanced and the two sessions a week apart. On each test day mood and cognitive performance were assessed at baseline (at 8:00) and then following inulin or placebo (at 11:00). Prior to the second test session (at 10:30) participants completed a questionnaire assessing their physical symptoms and mental health during the test morning. The inulin and placebo were provided in powder form in 5 g sachets. Volunteers consumed one sachet in decaffeinated tea or decaffeinated coffee with breakfast (9:00). Questionnaire results showed that on the day that the inulin was consumed, participants felt happier, had less indigestion and were less hungry than when they consumed the placebo. As for performance and mood tasks, the most consistent effects were on the episodic memory tasks where consumption of inulin was associated with greater accuracy on a recognition memory task, and improved recall performance (immediate and delayed). Further research is required to identify the mechanisms that underlie this effect with glucose metabolism being one candidate.

Gut microorganisms as promising targets for the management of type 2 diabetes

Each human intestine harbours not only hundreds of trillions of bacteria but also bacteriophage particles, viruses, fungi and archaea, which constitute a complex and dynamic ecosystem referred to as the gut microbiota. An increasing number of data obtained during the last 10 years have indicated changes in gut bacterial composition or function in type 2 diabetic patients. Analysis of this 'dysbiosis' enables the detection of alterations in specific bacteria, clusters of bacteria or bacterial functions associated with the occurrence or evolution of type 2 diabetes; these bacteria are predominantly involved in the control of inflammation and energy homeostasis. Our review focuses on two key questions: does gut dysbiosis truly play a role in the occurrence of type 2 diabetes, and will recent discoveries linking the gut microbiota to host health be helpful for the development of novel therapeutic approaches for type 2 diabetes? Here we review how pharmacological, surgical and nutritional interventions for type 2 diabetic patients may impact the gut microbiota. Experimental studies in animals are identifying which bacterial metabolites and components act on host immune homeostasis and glucose metabolism, primarily by targeting intestinal cells involved in endocrine and gut barrier functions. We discuss novel approaches (e.g. probiotics, prebiotics and faecal transfer) and the need for research and adequate intervention studies to evaluate the feasibility and relevance of these new therapies for the management of type 2 diabetes.

Is there any place for resistant starch, as alimentary prebiotic, for patients with type 2 diabetes?

OBJECTIVE

The aim of the present study was to determine effects of Resistant Starch (RS2) on metabolic parameters and inflammation in women with type 2 diabetes (T2DM).

METHODS

In this randomized controlled clinical trial, 60 females with T2DM were divided into intervention (n = 28) and placebo groups (n = 32). They received 10 g/d RS2 or placebo for 8 weeks, respectively. Fasting blood sugar (FBS), glycated hemoglobin (HbA1c), lipid profile, high-sensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured at baseline and at the end of the trial. Paired t test, unpaired t-test and ANCOVA were used to compare the quantitative variables. The data were analyzed using SPSS software version 13.0.

RESULTS

RS2 decreased HbA1c (-0.3%, -3.6%), TNF-α (-3.4 pg/mL, -18.9%), triglyceride (-33.4 mg/dL, -15.4%), and it increased HDL-c (+9.4 mg/dL, +24.6%) significantly compared with the placebo group (p < 0.05). Changes in FBS, total cholesterol, low-density lipoprotein, hs-CRP and IL-6 were not significant in the RS2 group compared with the control group. RS2 can improve glycemic status, inflammatory markers and lipid profile in women with T2DM.

CONCLUSIONS

Although findings of the present study indicated positive effects of RS2 on inflammation and metabolic parameters, more studies are needed to confirm efficacy of RS2 as an adjunct therapy in diabetes.

α-Galacto-oligosaccharides Dose-Dependently Reduce Appetite and Decrease Inflammation in Overweight Adults

BACKGROUND

Dietary fibers have been associated with a reduction in appetite and energy intake. Although a few studies suggest that nonviscous fibers can exert such effects, likely through colonic fermentation, limited data are available.

OBJECTIVE

The objective of this study was to determine whether α-galacto-oligosaccharides (α-GOSs), fermentable soluble fibers extracted from legumes, could reduce appetite, food intake, and inflammation in overweight subjects.

METHODS

In 2 single-center, double-blind, randomized, placebo-controlled trials, 88 overweight adults [50% men and 50% women; 18-60 y old; body mass index (in kg/m(2)): 25-28] were supplemented for 14 d with tea that contained α-GOSs with different α-GOS dosages (6, 12, or 18 g α-GOSs/d), formulas (12 g α-GOSs/d with >80% of molecules with a degree of polymerization of 2, 3, or 4), or a control substance (glucose syrup). Appetite scores (5 appetite dimensions were assessed on visual analog scales during a preload test meal), food intake (test meal and 24-h food recall), and inflammatory markers [plasma lipopolysaccharide (LPS) and C-reactive protein (CRP)] were evaluated at day 0 (baseline) and day 15.

RESULTS

Changes in appetite scores from day 0 to day 15 were significantly higher after α-GOS intake, with areas under the curve for the satiety score of +121 ± 108, +218 ± 218, and +306 ± 205 score · min for 6, 12, and 18 g α-GOSs/d, respectively, and -5 ± 64 score · min for the control group. We observed dose-dependent effects that did not vary by α-GOS composition. The administration of 6, 12, or 18 g α-GOSs/d significantly and dose-dependently increased the change in energy intake from day 0 to day 15 during a test meal (-13 ± 19, -26 ± 22, and -32 ± 22 kcal, respectively; +6 ± 21 kcal for the control group). Reductions in energy intake during lunch and dinner were also higher in the α-GOS groups in the dose-effect study. At day 15, LPS was dose-dependently reduced without an association with α-GOS composition (0.16 ± 0.02, 0.12 ± 0.08, and 0.08 ± 0.05 EU/mL for 6, 12, and 18 g α-GOSs/d, respectively, and 0.06 ± 0.04 EU/mL for the control group) and CRP was significantly lower in the α-GOS groups than in the control group in the formulation-effect study.

CONCLUSIONS

Consumption of α-GOSs for 14 d dose-dependently reduced appetite, food intake, and inflammation in overweight adults with no impact of α-GOS composition. Consequently, α-GOSs appear to promote long-term weight loss and mitigate metabolic disorders.

Maternal Supplementation with Oligofructose (10%) during Pregnancy and Lactation Leads to Increased Pro-Inflammatory Status of the 21-D-Old Offspring

Previously, we showed that oligofructose (10%) supplementation during pregnancy and lactation increased endotoxemia in 21-d-old pups. The present study evaluated the effect of 10% oligofructose diet supplementation during pregnancy and lactation in the presence or absence of hydrogenated vegetable fat on the pro-inflammatory status of 21-d-old offspring. On the first day of pregnancy, female Wistar rats were divided into the following groups: control diet (C), control diet supplemented with 10% oligofructose (CF), diet enriched with hydrogenated vegetable fat (T) or diet enriched with hydrogenated vegetable fat supplemented with 10% oligofructose (TF). Diets were maintained during pregnancy and lactation. Serum TNF-α (tumor necrosis factor alpha) was assessed using a specific kit. Protein expression was determined by Western Blotting, and the relative mRNA levels were analyzed by RT-PCR (real-time polymerase chain reaction). We observed that 10% oligofructose supplementation during pregnancy and lactation increased offspring’s IL-6R (interleukin-6 receptor) mRNA levels in the liver and RET (retroperitoneal white adipose tissue) and decreased ADIPOR2 (adiponectin receptor 2) and ADIPOR1 (adiponectin receptor 1) gene expression in liver and EDL (extensor digital longus)/ SOL (soleus) muscles of CF group. Additionally, TF group presented with increased serum TNF-α, protein expression of p-NFκBp65 (phosphorylated form of nuclear factor kappa B p65 subunit) in liver and IL-6R mRNA levels in RET. These findings were accompanied by decreased levels of ADIPOR1 mRNA in the EDL and SOL muscles of the TF group. In conclusion, supplementing the dam’s diet with 10% of oligofructose during pregnancy and lactation, independent of hydrogenated vegetable fat addition, contributes to the increased pro-inflammatory status of 21-d-old offspring, possibly through the activation of the TLR4 (toll like receptor 4) pathway.

Recent developments in prebiotics to selectively impact beneficial microbes and promote intestinal health

Prebiotics are non-digestible food ingredients that have a specific stimulatory effect upon selected populations of gut bacteria. The usual target microorganisms for prebiotic approaches are bifidobacteria. Numerous human feeding studies have shown the prebiotic influences that galactans and fructans can exert. Other candidate prebiotics are under investigation. The field is now moving towards identifying the health aspect associated with their use. Many avenues of gut related health are being researched, including reduction of diarrhoea, immune stimulation, and improved mineral bioavailability. Most current emphasis appears to be towards various parameters associated with metabolic syndrome. These include markers of insulin resistance, appetite, satiety, blood lipids and inflammatory status.

Jussara (Euterpe edulis Mart.) supplementation during pregnancy and lactation modulates the gene and protein expression of inflammation biomarkers induced by trans-fatty acids in the colon of offspring

Maternal intake of trans-fatty acids (TFAs) in the perinatal period triggers a proinflammatory state in offspring. Anthocyanins contained in fruit are promising modulators of inflammation. This study investigated the effect of Jussara supplementation in the maternal diet on the proinflammatory state of the colon in offspring exposed to perinatal TFAs. On the first day of pregnancy rats were divided into four groups: control diet (C), control diet with 0.5% Jussara supplementation (CJ), diet enriched with hydrogenated vegetable fat, rich in TFAs (T), or T diet supplemented with 0.5% Jussara (TJ) during pregnancy and lactation. We showed that Jussara supplementation in maternal diet (CJ and TJ groups) reduced carcass lipid/protein ratios, serum lipids, glucose, IL-6, TNF-α, gene expression of IL-6R, TNF-αR (P < 0.05), TLR-4 (P < 0.01), and increase Lactobacillus spp. (P < 0.05) in the colon of offspring compared to the T group. The IL-10 (P = 0.035) and IL-10/TNF-α ratio (P < 0.01) was higher in the CJ group than in the T group. The 0.5% Jussara supplementation reverses the adverse effects of perinatal TFAs, improving lipid profiles, glucose levels, body composition, and gut microbiota and reducing low-grade inflammation in the colon of 21-day-old offspring, and could contribute to reducing chronic disease development.

Daily Feeding of Fructooligosaccharide or Glucomannan Delays Onset of Senescence in SAMP8 Mice

We hypothesized that daily intake of nondigestible saccharides delays senescence onset through the improvement of intestinal microflora. Here, we raised senescence accelerated mice prone 8 (SAMP8) on the AIN93 diet (CONT), with sucrose being substituted for 5% of fructooligosaccharide (FOS) or 5% of glucomannan (GM), 15 mice per group. Ten SAMR1 were raised as reference of normal aging with control diet. Grading of senescence was conducted using the method developed by Hosokawa, and body weight, dietary intake, and drinking water intake were measured on alternate days. Following 38 weeks of these diets we evaluated learning and memory abilities using a passive avoidance apparatus and investigated effects on the intestinal microflora, measured oxidative stress markers, and inflammatory cytokines. Continuous intake of FOS and GM significantly enhanced learning and memory ability and decelerated senescence development when compared with the CONT group. Bifidobacterium levels were significantly increased in FOS and GM-fed mice. Urinary 8OHdG, 15-isoprostane, serum TNF-α, and IL-6 were also lower in FOS-fed mice, while IL-10 in FOS and GM groups was higher than in CONT group. These findings suggest that daily intake of nondigestible saccharides delays the onset of senescence via improvement of intestinal microflora.