Prebiotics as a Tool for the Prevention and Treatment of Obesity and Diabetes: Classification and Ability to Modulate the Gut Microbiota

Diabetes and obesity are metabolic diseases that have become alarming conditions in recent decades. Their rate of increase is becoming a growing concern worldwide. Recent studies have established that the composition and dysfunction of the gut microbiota are associated with the development of diabetes. For this reason, strategies such as the use of prebiotics to improve intestinal microbial structure and function have become popular. Consumption of prebiotics for modulating the gut microbiota results in the production of microbial metabolites such as short-chain fatty acids that play essential roles in reducing blood glucose levels, mitigating insulin resistance, reducing inflammation, and promoting the secretion of glucagon-like peptide 1 in the host, and this accounts for the observed remission of metabolic diseases. Prebiotics can be either naturally extracted from non-digestible carbohydrate materials or synthetically produced. In this review, we discussed current findings on how the gut microbiota and microbial metabolites may influence host metabolism to promote health. We provided evidence from various studies that show the ability of prebiotic consumption to alter gut microbial profile, improve gut microbial metabolism and functions, and improve host physiology to alleviate diabetes and obesity. We conclude among other things that the application of systems biology coupled with bioinformatics could be essential in ascertaining the exact mechanisms behind the prebiotic–gut microbe–host interactions required for diabetes and obesity improvement.

Refined sorghum flours precooked by extrusion enhance the integrity of the colonic mucosa barrier and promote a hepatic antioxidant environment in growing Wistar rats

The effects of precooked-refined sorghum flour consumption on antioxidant status, lipid profile, and colonic and bone health were evaluated. Twenty-four male Wistar rats were fed with control diet (C), or red or white precooked-refined sorghum based diets (SD) for 60 days. The intake of SD was lower than that of C, but the efficiency of all diets was similar. Rats fed with SD showed lower feces excretion, cecal pH and enzyme activities (β-glucosidase, β-glucuronidase and mucinase) than C. White SD improved intestinal architecture, cell proliferation and apoptosis, upregulated ZO1 and occludin tight junction proteins and stimulated goblet cell differentiation, enhancing the integrity of the mucosa barrier in both proximal and distal colonic mucosa in a better way than red SD. Consumption of SD significantly decreased serum triglyceride levels compared with the C diet. The mineral content of the right femur was not different among diets. The liver enzyme activities (superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase) did not show differences among diets. Liver reducing power and reduced glutathione/oxidize glutathione ratio were higher for animals consuming SD than C. It can be concluded that the consumption of precooked refined sorghum flours still has beneficial effects for health, mainly at the colonic level, despite the lower phenolics and fibre contents of refined flours with respect to whole grain flours.

Effects of extruded whole-grain sorghum (Sorghum bicolor (L.) Moench) based diets on calcium absorption and bone health of growing Wistar rats

Apparent calcium absorption, total bone mineral content and density, and mineral contents of the right femur were studied using a growing rat model. Twenty-four male Wistar rats were fed with diets based on extruded whole grain red (RSD) or white sorghum (WSD), and control diet (CD) up to 60 days. The animals fed with sorghum diets consumed less and gained less weight compared to those fed with CD, but the efficiency of all diets was similar. Calcium intake was lower in animals fed with sorghum diets, related to the lower total intake of these animals. Apparent calcium absorption in animals fed with RSD was lower than in those fed with CD (CD: 72.7%, RSD: 51.0%, WSD: 64.8%). No significant differences in bone mineral density of total body, spin, femur, distal femur, tibia and proximal tibia were observed among the groups. However, Ca and P contents in the right femur of the rats consuming RSD were lower, indicating a certain imbalance in the metabolism of these minerals.

Hypolipidemic and Hepatoprotective Effects of High-Polydextrose Snack Food on Swiss Albino Mice

In this study, the hepatoprotective and hypolipidemic effects of high-polydextrose snack food on Swiss albino mice were investigated. The mice were randomly divided into three groups: control diet, high-fat diet, and high-fat and fiber diet groups. Addition of high-polydextrose snack to the high-fat diet resulted in significant reduction in the liver weight, the accumulation of lipid droplets in liver, and the liver damage of hyperlipidemic mice in comparison with the high-fat diet. The high-polydextrose snack also decreased the content of total triglyceride, cholesterol, and low-density lipoprotein cholesterol as well as the alanine aminotransferase and aspartate aminotransferase activities in the mice serum. In addition, the high-polydextrose snack significantly increased the high-density lipoprotein cholesterol content of the hyperlipidemic mice. Consequently, use of high-polydextrose snack generated hepatoprotective and hypolipidemic effects on hyperlipidemic mice.

Plant- and Nutraceutical-based Approach for the Management of Diabetes and its Neurological Complications: A Narrative Review

Diabetes is an important metabolic disease affecting many organs and systems in the body. The nervous system is one of the body systems affected by diabetes and neuropathic complications are troublesome in diabetic patients with many consequences. As diabetes has deleterious influences almost on bodily systems, an integrative approach seems to be necessary accepting the body as a whole and integrating body systems with lifestyle and living environment. Like some traditional health systems such as Ayurveda, integrative approach includes additional modalities to overcome both diabetes and diabetic complications. In general, these modalities consist of nutraceuticals and plant products. Prebiotics and probiotics are two types of nutraceuticals having active ingredients, such as antioxidants, nutrient factors, microorganisms, etc. Many plants are indicated for the cure of diabetes. All of these may be employed in the prevention and in the non-pharmacological management of mildto- moderate diabetes. Severe diabetes should require appropriate drug selection. Being complementary, prebiotics, probiotics, plants and exercise may be additive for the drug therapy of diabetes. Similarly, there are complementary approaches to prevent and cure neurological and/or behavioral manifestations of diabetes, which may be included in therapy and prevention plans. A scheme is given for the prevention and therapy of comorbid depression, which is one of the most common behavioral complications of diabetes. Within this scheme, the main criterion for the selection of modalities is the severity of diseases, so that personalized management may be developed for diabetic patients using prebiotics and probiotics in their diets, plants and drugs avoiding possible interactions.

Colonic and systemic effects of extruded whole-grain sorghum consumption in growing Wistar rats

Colonic effects of extruded whole-grain sorghum diets were evaluated using a model of growing rats. In all, twenty-four male Wistar rats were fed control (C), extruded white sorghum (EWS) or red sorghum (ERS). Consumption of sorghum diets showed satiety properties, with reduction of caecal pH, and lower activity ofβ-glucosidase andβ-glucuronidase enzymes. Decreased copper zinc superoxide dismutase and manganese superoxide dismutase and increased catalase and glutathione peroxidase levels were observed in colonic mucosa. The induction of antioxidant enzymes occurred through the activation of the nuclear factor erythroid 2-related factor 2 protein and its subsequent translocation into the nucleus. ERS was able to decrease the proliferation of proximal mucosa of colon, demonstrating a possible effect against colorectal tumourigenesis. EWS increased proliferation and also apoptosis, ensuring the re-establishment of homoeostasis of the colonic mucosa. No antioxidant systemic effect (serum or hepatic level) was observed. It is likely that despite the extrusion the low bioavailability of the phenolic compounds of sorghum diets caused them to exert mainly acute effects at the colon level. Extruded whole-grain sorghum is a good functional ingredient that might be promising in dietary prevention of intestinal diseases.

A synbiotic composed of Lactobacillus fermentum CECT5716 and FOS prevents the development of fatty acid liver and glycemic alterations in rats fed a high fructose diet associated with changes in the microbiota

We investigated the effect of a high fructose diet (HFD) on Sprague Dawley rats and the impact of a synbiotic composed of Lactobacillus fermentum CECT5716 and fructooligosaccharides. Feeding the HFD for 5 weeks resulted in liver steatosis and insulin resistance but not obesity. These changes were associated with increased production of short-chain fatty acids and increased Bacteroidetes in feces, with an augmented Bacteroidetes/Firmicutes ratio, among other changes in the microbiota. In addition, barrier function was weakened, with increased LPS plasma levels. These data are consistent with increased fructose availability in the distal gut due to saturation of absorptive mechanisms, leading to dysbiosis, endotoxemia, hepatic steatosis, and insulin resistance. Treatment with the synbiotic prevented some of the pathological effects, so that treated rats did not develop steatosis or systemic inflammation, while dysbiosis and barrier function were greatly ameliorated. In addition, the synbiotic had hypolipidemic effects. The synbiotic composed by L. fermentum CECT5716 and fructooligosaccharides has beneficial effects in a model of metabolic syndrome induced by a HFD, suggesting it might be clinically useful in this type of condition, particularly considering that high fructose intake has been related to metabolic syndrome in humans.

Changes in glucose levels and fecal excretion of lipids due to consumption of yacon flour

Purpose

As studies investigating the effects of fructan sources, such as yacon, on glucose and lipid metabolism showed different results, additional research is required to establish a clear relationship between them. Thus, this paper aims to evaluate possible effects of the consumption of the yacon pulp flour (YPF) on biological and metabolic parameters such as food consumption, weight gain, serum glucose levels and fecal lipid excretion of rats, as well as determine the role of glycemic index (GI) of the diets added of this ingredient on those parameters.

Design/methodology/approach

For this purpose, 24 male albino Wistar rats were divided into four groups, which received the following treatments for 17 days: Group 1 (G1) (Control) – American Institute of Nutrition (AIN)-M; Group 2 (G2) – AIN-M added 5 per cent YPF; Group 3 (G3) – AIN-M added 10 per cent YPF and Group 4 (G4) – AIN-M added 15 per cent YPF. Analysis of fasting and postprandial glycemia was conducted for elaboration of the glycemic curve and calculation of the GI of the diets. Lipids loss was measured by quantification of crude fat in feces after consumption of the diet.

Findings

YPF, regarding the concentration in the diets, did not elevate the fasting glucose among the groups. The postprandial glucose of the animals declined in different postprandial glucose peaks of the groups ingesting YPF in relation to the control one, especially in group treated with 15 per cent YPF, between 30 and 60 min (p <0,05), confirming the influence of the dietary fiber on the absorption of the glucose. The ingestion of YPF increased dragging of lipids to the animal feces, proportional to the amounts of YPF added to the diets. According to the regression analysis, followed by regression testing to 5 per cent, there was a significant difference between the experimental groups, being that the elevation of the percentage of YPF added to the diet caused a proportional increase in the lipid levels in the animal feces.

Originality/value

YPF could be an alimentary source of interest, mainly when the focus is on disease risk prevention such as diabetes, obesity and dyslipidemias.

Polydextrose: Physiological Function, and Effects on Health

Polydextrose (PDX) is a non-digestible oligosaccharide used widely across most sectors of the food industry. It is a randomly linked glucose oligomer containing small amounts of sorbitol and citric acid. The random bonds in PDX prevent mammalian digestive enzymes from readily hydrolyzing the molecule and it has a reported energy value of 1 kcal/g. These properties have led to the acceptance in many countries that PDX provides similar physiological effects as other dietary fibers and has shown prebiotic potential. Dietary intervention with prebiotics has been shown to selectively stimulate the growth and/or activity of one or a limited number of intestinal bacteria associated with several physiological benefits on health. Therefore, the objective of this review was a survey of the literature on the effect of supplementation with PDX in health, and to list the benefits for maintaining health and/or reducing the development of diseases.

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.

Extruded whole grain diets based on brown, soaked and germinated rice. Effects on the lipid profile and antioxidant status of growing Wistar rats. Part II

The influence of whole grain (WG) rice based diets on the lipid profile and antioxidant status was evaluated.

Extruded whole grain diets based on brown, soaked and germinated rice. Effects on cecum health, calcium absorption and bone parameters of growing Wistar rats. Part I

The influence of diets with whole rice processed ingredients on cecum health, calcium absorption and bone parameters was studied using an animal model.