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Type 1 diabetes mellitus is a metabolic disease characterized by dysbiosis. Modulation of the gut microbiota by oligosaccharides and aerobic training are proposed mechanisms that ameliorate the disease through affecting host-microbiota interactions.

Type 1 diabetes mellitus is characterized with decreased microbial diversity. Gut microbiota is essential for the normal physiological functioning of many organs, especially the brain. Prebiotics are selectively fermentable oligosaccharides [xylooligosaccharides (XOS), galactooligosaccharides, etc.] that promote the growth and activity of gut microbes and influence the gut–brain axis. Aerobic exercise is a non-pharmacological approach for the control of diabetes and could improve cognitive functions. The potential beneficial effect of XOS and/or aerobic training on cognition, the lipid profile and oxidative stress markers of experimental rats were evaluated in this study. Male Wistar rats were randomly divided into three streptozotocin-induced diabetic groups and a control group. Some of the rats, either on a XOS treatment or a standard diet, underwent aerobic training. The results showed that the aerobic training independently lowered the total cholesterol levels compared to the sedentary diabetic rats (p = 0.032), while XOS lowers the malondialdehyde levels in the trained diabetic rats (p = 0.034). What is more the exercise, independently or in combination with XOS beneficially affected all parameters of the behavioral tests. We conclude that aerobic exercises alone or in a combination with the prebiotic XOS could ameliorate the dyslipidemia, oxidative stress, and cognitive abilities in experimental type 1 diabetic animals.

This study examined the effect of lactulose, galactooligosaccharide, fructooligosaccharide, inulin, and β-glucan on the probiotic strain Lactobacillus delbrueckii subsp. bulgaricus L14, cultivated in an in vitro gastrointestinal system model. We analyzed the degree of hydrolysis of the studied prebiotic oligosaccharides in condition of simulated gastric fluid. The results showed that lactulose had the highest resistance, galactooligosaccharide underwent hydrolysis, and fructooligosaccharide was the most sensitive. Among the polysaccharides, fructose was released from inulin and glucose from β-glucan. Short-chain oligosaccharides and metabolites derived from studied prebiotic oligosaccharides and polysaccharides, supported the growth of probiotic strain L14, which showed the highest growth with fructooligosaccharides and β-glucan as carbohydrate sources. The profile of the activated enzymes secreted by the probiotic strain L14, indicated their inducible character. Beta-galactosidase was activated in the presence of lactulose and GalOS, inulinase was activated in the presence of inulin and fructooligosaccharides, and β-glucosidase was activated in the presence of β-glucan fragments. Analysis of the produced organic and short-chain fatty acids showed that the typical representative of the homofermentative lactobacilli Lb. delbrueckii subsp. bulgaricus L14 changes its metabolism from a homofermentative to a heterofermentative type, best expressed in the presence of lactulose, galactooligosaccharide, and β-glucan. [ABSTRACT FROM AUTHOR]

Amylases are a part of the group of glycosyl hydrolases enzymes, that catalyze the breakdown of complex carbohydrates. The three main classes are α-, β- and ɣ-amylases. The main function of all amylases is to degrade starch, glycogen and other sugars. All α-amylases are metalloenzymes requiring Ca2+ activity. In animals and humans, α-amylases occur in the pancreas, saliva, liver, serum, urine, etc. Salivary and pancreatic amylases are the main ones. They have 97% protein chain homology with each other. The secreted salivary α-amylase initiates the carbohydrates digestion in the mouth. The concept of prebiotics was introduced in 1995 by Gibson and Roberfroid, as a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves the host’s health. Later it became clear, that prebiotics have beneficial effects beyond the gastrointestinal tract. The purpose of the present experiment is to investigate the effect of oligosaccharides on the enzymatic activity of salivary α-amylase, since enzyme inhibitors are used as second line drugs in the therapy of type 2 diabetes. For this purpose, the α-amylase activity was determined by the Bernfeled method (1955) with some modifications. The reaction time was 10 minutes. Ten measurements for each group have been made. Groups were separareted as it follows: control, 1% lactulose, 2% lactulose, 1% fructooligosaccharide (FOS), 2% FOS, 1% inulin and 2% inulin. Statistical analyses were performed using GraphPad Prism version 7.00 for Windows (GraphPad Software, La Jolla California USA), descriptive statistical tests including mean, standard deviation were performed. The groups were compared using Student’s t test. Differences with p <0.05 were considered statistically significant. Statistically significant decrease in the α-amylase activity was found when the control group (at 0 minute) was compared with FOS 1%, FOS 2%, 1% inulin and 2% inulin groups (p<0.05). Statistically decreased activity was registered in the presence of all oligosaccharides (p<0.05) on the 10th minute. At the results reported on the 10th minute, statistically decreased activity was found only between FOS 1% and FOS 2% (p=0.001). Between other groups were found no statistically significant differences (p˃0.05). Lowering of the postprandial glucose level was observed in an inhibition of pancreatic α-amylase. Increased levels of salivary α-amylase are found in patients with diabetes. Our results indicate that the salivary α-amylase activity decreases significantly in the presence of oligosaccharides after 10 minutes, which could be a prerequisite for a potential inhibitory effect and lowering of glucose concentration. From the present experiment we can’t conclude the mechanism of inhibition, but it is known that lowering the pH levels in the oral cavity leads to a decrease in the activity of salivary α-amylase. Prebiotics can optimize the oral microflora and, hence, lower the local pH in the oral cavity, reducing the activity of α-amylase. This could give us a possible explanation for the effect of oligosaccharides on salivary α-amylase. [ABSTRACT FROM AUTHOR]

Type I diabetes mellitus is an autoimmune disease, in which the immune system attacks the β-cells of the islets of Langerhans in the pancreas, which produce insulin. Some of the main complications of this disease are the micro- and the macrovascular damages with main consequence: cardiovascular diseases, which appear to be the leading cause of mortality in this widespread, socially significant disease. The development of type I diabetes is affected by non-genetic factors such as the development of the optimal microbiome in early life, which programs the immune system. Patients have different intestinal microflora in comparison to healthy individuals as well as alterations in the intestinal permeability, inflammation and insulin resistance. Prebiotics represent a selective fermentative ingredient of food, which allows specific changes in both the composition and in the activity of the intestinal microflora of the person and thus improves his health and well-being. Human milk oligosaccharides, present in breast milk, are modulators of the microbiota and are known for directly regulating the immune response. They are vital for the protection of children at risk of developing type I diabetes by assisting the development of the immune and intestinal microbiota in early life. Soybean oligosaccharides are potential prebiotics, which improve the immune function. After 22 days of administration of 4 g/kg weight soybean oligosaccharides, they significantly affect the proliferation of bifidobacteria and lactic acid bacteria compared to the control group. Probiotic microorganisms show favorable interrelations with their host by influencing the intestinal cell proliferation and differentiation and the immune system, and they counteract pathogenic microorganisms. The supposed direct effects of oligosaccharides on pathogenic flora infections include mimicry of receptors and influence on their virulence. The regulation of virulent genes through the presence of oligosaccharides and polysaccharides in the nutrient medium has been described for a number of pathogenic bacteria. The indirect effects of prebiotics on the immune system can result from the stimulation of the growth of probiotic bacteria and the stimulation of the production of short chain fatty acids. The increase of the number of probiotic bacteria stimulates the immune system and leads to protection against pathogenic invasion. Oxidative stress, which is an important component of a number of diseases, is characterized by an imbalance in the level of oxidants and antioxidants in favor of the oxidants. It can lead to irreversible impairment of lipids, nucleic acids and proteins. It has been proved that the administration of synbiotics has a positive effect on the parameters of the oxidative stress. The elevated level of serum cholesterol is recognized as a risk factor for the development of atherosclerosis, cardiovascular diseases and hypertension. It has been proved that there are significant changes in the lipid profile of patients, treated with galactooligosaccharides. Prebiotics are a cheap and a low risk supplement, which can be used to favorably influence type I diabetes mellitus. They can also improve the glycemic control through changes in the intestinal microflora, the permeability of the intestines and inflammation. The purpose of this review is for the influence of new prebiotics (galactooligosaccharides and xylooligosaccharides) on the lipid and antioxidant profile of patients with type I diabetes mellitus to be studied. [ABSTRACT FROM AUTHOR]