Probiotics and prebiotics, targeting obesity with functional foods.

OBJECTIVES: This review aimed to discuss mechanisms through which gut microbiota could act as a key modifier of obesity and related metabolic abnormalities. Obesity is a growing health epidemic with an increasing incidence in European countries. It results from a combination of genetic, psychological, physiological and environmental factors. Probiotic and prebiotic ingredients provide an optimal target for the development of novel functional foods used in the prevention of obesity development as one of risk factors of chronic diseases. Knowledge about prebiotic and probiotic mechanisms of action, and novel functional foods supplemented with probiotics and prebiotics will facilitate their clinical application and development of personalized healthcare strategies (Fig. 1, Ref. 40) Keywords: gut microbiota, obesity, functional foods, nutrition.

Gut bacterial metabolites of indigestible polysaccharides in intestinal fermentation as mediators of public health.

OBJECTIVES: The gut microbiome is regarded as an essential dynamic organ that functions in nourishment, epithelial development and innate immunity. One important benefit of the dietary polysaccharides to human health is due to its fermentability in gut. It is been known quite well that dietary fiber is able of impacting colon microbiota. Fermented products from these polysaccharides, especially short-chain fatty acids (SCFAs) are bioactive molecules with health benefits. It is proposed that the dietary polysaccharide-deriving SCFAs could be converted into glucose and /or directly signal intestinal receptors and therefore contribute the benefits via gut-brain neural circuits. In addition, fermented polysaccharides can facilitate the beneficial bacteria to generate bioactive molecules important for the normal maturation of the host immune system. Manipulation of the microbiota and metabolites from intestinal microbiota might be a promising new approach for the prevention or treatment diseases (Fig. 2, Ref. 30).

Changes chemopreventive markers in colorectal cancer development after inulin supplementation.

BACKGROUND: Natural dietary compounds such as prebiotics modulate microbial composition and could prevent the colon cancer development as potential chemopreventive agent. OBJECTIVES: Effect of prebiotic-inulin on biochemical, microbial and chemopreventive markers were examined in Sprague-Dawley rats during experimental chemically dimethylhydrazine induced colon cancer development. METHODS: Rats were divided to 3 groups: control group (CG), group with dimethylhydrazine (DMH) and group with DMH and prebiotic (DMH+PRE). The efficacy of the prebiotic inulin (PRE) on the activities of ß-glucuronidase, short chain fatty acids (SCFAs), counts of coliforms and lactobacilli, immunoreactivity of cyclooxygenase-2 (COX-2), transcription nuclear factor kappa beta (NFκB) and inducible nitric oxide synthase (iNOS) in colon tissue were examined. RESULTS: Inulin significantly decreased coliforms counts (p<0.01), increased lactobacilli counts (p<0.001), and decreased activity of ß-glucuronidase (p<0.01) in fresh caecal digesta. Butyric and propionic acids concentrations were increased after inulin supplementation in comparison to DMH group. Application of inulin decreased immunoreactivity and numbers of COX-2, NFκB and iNOS positive cells in colon tissue in comparison to DMH group. CONCLUSION: Inulin suppressed expression observed markers, which play an important role in carcinogenesis and in the inflammatory process, which predisposes to the use of inulin in the prevention or treatment of inflammatory bowel disease (Tab. 1, Fig. 2, Ref. 17).

Effects of probiotics and prebiotics in ulcerative colitis.

OBJECTIVES: Inflammatory bowel diseases (IBD) are caused by the failure of immunoregulatory mechanisms due to external environmental factors in genetically predisposed individuals. Probiotics and prebiotics could be used in prevention and therapy of many disorders of gastrointestinal tract including ulcerative colitis. Probiotics are living microorganisms with good tolerability and minimal risk, which confer a health benefit for the host when administered in adequate amounts. Their effect is closely related to maintaining the natural function of the intestinal flora. In this respect, they are indispensable prebiotics to protect or reduce the incidence of inflammatory lesions in diseases of the digestive tract. CONCLUSION: Ingestion of probiotics and prebiotics may provide some clues in developing a new class of therapeutic agents for the treatment/ prevention of IBD and colitis-associated cancer (CAC) in the future (Tab. 2, Ref. 26).

Improved efficacy of prebiotic by flaxseed oil and horse chestnut in experimental colon cancer.

OBJECTIVES: This experimental work was designed to investigate the efficacy of prebiotic by itself and in combination with Hyppocastani extractum siccum, and Lini oleum virginale on selected parameters in rats with dimethylhydrazine induced colon cancer. METHODS: Rats were randomly divided into 5 experimental groups of 12 rats each. Rats were fed with high fat (HF) diet containing 10 % of fat, supplemented by prebiotic at a dose of 2 % of HF diet itself and in combination with Hyppocastani extractum siccum at a dose of 1 % of diet and Lini oleum virginale at a dose of 2 % of diet. Two weeks after the start of the diet dimethylhydrazine injections in dose 20 mg/kg b.w. were applied (DMH, Merck, DE), two times at week interval. The activity of beta-glucuronidase, concentration of lipid parameters, bile acids and short chain fatty acids were determined. RESULTS: Prebiotic and its combinations with selected substances significantly decreased the activity of bacterial enzyme beta-glucuronidase (p<0.001). Bile acids concentration was significantly decreased (p<0.01) excepting combination of prebiotic with Horse chestnut. Self applied prebiotic decreased (p<0.001) lipids parameters (total cholesterol and triacylglycerols), and enhanced short chain fatty acids production. CONCLUSION: Prebiotics have protective effect and may be the useful candidate agents for colon cancer prevention and treatment. The application of selected bioactive food components supported the effect of prebiotics (Tab. 2, Fig. 1, Ref. 16). Full Text in free PDF www.bmj.sk.

The effect of probiotic microorganisms and bioactive compounds on chemically induced carcinogenesis in rats.

Diet interventions and natural bioactive supplements have now been extensively studied to reduce risks of colon cancer, which is one of the major public health problem throughout the world. The objective of our investigation was to study the effects of probiotic, prebiotic, nutritional plant extract, and plant oil on selected biochemical and immunological parameters in rats with colon cancer induced by N,N dimethylhydrazine (DMH). Male and female Wistar albino rats were were fed by a high-fat (HF) diet (10% fat in the diet) and were divided into 9 groups: Control group; PRO group - HF diet supplemented with probiotic Lactobacillus plantarum to provide 3 x 109 c.f.u. of strain/1 ml of medium; PRE group - HF diet supplemented with inulin enriched with oligofructose (2% of HF diet); HES group - HF diet supplemented with plant extract of Aesculus hippocastanum L. (1% of HF diet); OIL group - HF diet comprised Linioleum virginale (2% of HF diet); and combination of probiotic microorganisms and bioactive compounds in the groups - PRO-PRE, PRO-HES, PRO-OIL, PRE-OIL. Carcinogenesis was initiated with subcutaneous injection of DMH (20 mg/kg) two times at week interval and dietary treatments were continued for the six weeks. Application of probiotic microorganisms and bioactive compounds in all treated groups significantly decreased the activities of bacterial enzymes (p<0.001), the fecal bile acids concentration (p<0.01; p<0.001) and significantly increased serum TNFalpha level (p<0.001) in comparison to the control rats. The number of coliforms was reduced in PRO, PRO-PRE, PRO-OIL and PRE-OIL groups and significantly higher count of lactobacilli (p<0.05) was observed in PRO-PRE, PRO-OIL and PRE-OIL groups in compare with the controls. In conclusion, the results of this study indicate that probiotic microorganisms and bioactive compounds could exert a preventive effect on colon carcinogenesis induced by DMH.

Prebiotic foodstuffs and their health benefits in experiment.

OBJECTIVES: The aim of the present experimental study was to evaluate the effect of prebiotic on chemically induced carcinogenensis in rats fed with high fat diet (HF). METHODS: Wistar albino rats were divided into control and experimental groups. In experimental group rats were treated with prebiotic at the dose of 2% of HF diet. N,N-dimethylhydrazine (DMH) injections were applicated in dose 20 mg/kg b.w., two times at week interval. In the end of eight weeks experimental period blood samples and feaces were taken from the rats and used for laboratory analysis. RESULTS: Treatment with prebiotic inulin significantly (p < 0.001) decreased enzymatic activity of bacterial enzymes in feaces. Similar tendency was noticed in concentration of bile acids and lipid parameters. Prebiotic undergo fermentation in the colon and enhanced short chain fatty acid production. CONCLUSION: Prebiotics may have potential health implications for protection against colon cancer (Tab. 2, Fig. 1, Ref. 14).

The risk of cancer in relationship to diet.

Globally, colorectal cancer is the leading cause of mortality due to malignant diseases. Probiotics are live microbial food supplements or functional foods containing specific nonpathogenic organisms that beneficially affect the host by improving the intestinal microbial balance. Therefore they can be used as an innovative tools to alleviate intestinal inflammation, normalize gut mucosal dysfunction, and down-regulate hypersensitivity reactions. In the past decade, there has been a dramatic increase of experiments and studies documenting prophylactic and therapeutic benefits of probiotics and prebiotics in order to reduce the risk of chronic civilization diseases. The current knowledges on probiotics qualify them as the pivotal components of self-care and complementary medicine (Ref. 27).

Short chain fatty acids and colonic health.

Recently, colonic health has been linked to the maintaining overall health status and reducing the risk of diseases by changes in lifestyle. Functional foods, such as "prebiotics" and "probiotics", dietary fibers, and other dietary components that target the colon and affect its environment enhancing short fatty acid (SCFA) production have been at the forefront. The topic of this review is the key end products of colonic fermentation, the SCFA butyric, acetic, and propionic acids. SCFA are readily absorbed. Butyrate is the major energy source for colonocytes. Propionate is largely taken up by the liver. Acetate enters the peripheral circulation to be metabolized by peripheral tissues. Specific SCFA may reduce the risk of developing gastrointestinal disorders, cancer, and cardiovascular disesase (Fig. 1, Ref. 30). Full Text (Free, PDF) www.bmj.sk.

Role of the peripheral serotoninergic system in the pathogenesis of vasovagal syncope.

OBJECTIVE: To evaluate the role of peripheral serotoninergic system in the pathogenesis of vasovagal syncope. BACKGROUND: Increased central serotoninergic activity was suggested to play a role in sudden inhibition of sympathetic activity responsible for the genesis of vasovagal syncope. There is good correlation between the central serotoninergic activity and the plasma levels of serotonine. METHODS: In twenty-two patients (mean age 48 +/- 19 years, 10 men, 12 women) with suspected vasovagal syncope head-up tilt test (HUT) was performed. Passive HUT (60 degrees, 20 minutes) was followed, if negative, by nitroglycerine stimulated HUT (400 microg sublingually, 15 minutes). Blood samples were obtained at baseline (in supine position), in 5 minute, 15 minute of HUT and finally at syncope or end of the test. Plasma levels of serotonine were measured by enzyme-immunoassay (EIA) method. RESULTS: HUT was positive in fifteen patients and negative in seven patients. In all HUT positive patients syncope developed after nitroglycerine stimulation. Mean duration of nitroglycerine phase was 4.8 +/- 1.2 min. In 5 min of HUT serotonine level was significantly lower in HUT positive patients HUT (102.40 +/- 43.11 vs 160.85 +/- 43.71 ng/ml, p = 0.01). At the time of syncope no significant differences were observed between HUT positive and HUT negative patients (184.26 +/- 118.72 vs 196.57 +/- 88.91 ng/ml, p = 0.40). CONCLUSION: In patients with vasovagal syncope lower level of plasma serotonine were observed during early HUT when compared to controls. No differences in serotonin activity were observed at the time of syncope (Tab. 1, Fig. 1, Ref. 24).

Bioavailability of chalcones.

Epidemiological evidence suggests that diets rich in fruits and vegetables decrease the risk of premature mortality from major clinical conditions, including cancer and heart disease. However, it is not yet clear which components or combination of components in fruit and vegatables are protective and what is their mechanism of action is. Phenolic compounds are important compounds because of their contribution to human health and their multiple biological activities. Although these compounds are not a panacea for good health, some of their beneficialt activities presented in this short review showed their importance and their possible usage in the prevention of various diseases (Tab. 1, Fig. 1, Ref: 42).

Matrix metalloproteinases: their biological functions and clinical implications.

Matrix metalloproteinases (MMPs), which are also known as matrixins, are proteinases that participate in extracellular matrix remodelling and degradation. Under normal physiological conditions, the activities of MMPs are precisely regulated at the level of transcription, at that of activation of the pro-MMP precursor zymogenes as well as at that of inhibition by endogenous inhibitors (tissue inhibitors of metalloproteinases, TIMPs). Alterations in the regulation of MMP activity are implicated in diseases such as cancer, fibrosis, arthritis and atherosclerosis. The pathological effects of MMPs and TIMPs in cardiovascular diseases involve vascular remodelling, atherosclerotic plaque instability and cardiac remodelling in congestive heart failure or after myocardial infarction. Since excessive tissue remodelling and increased matrix metalloproteinases activity have been demonstrated during atherosclerotic lesion progression (including plaque disruption), MMPs represent a potential target for therapeutic intervention aimed at the modification of vascular pathology by restoring the physiological balance between MMPs and TIMPs. Recent findings suggest that MMPs are also involved in cancer initiation, invasion and metastasis; MMP inhibitors could be considered for evaluation as cancer chemopreventive molecules. This review describes the members of MMP and TIMP families and discusses the structure, function and regulation of MMP activity. (Tab. 1, Ref: 45.)

Changes in ascorbic acid and malondialdehyde in rats after exposure to mercury.

BACKGROUND: Mercury is one of the ubiquitous pollutants participating in generation of reactive oxygen species leading to the formation of oxidative stress. METHODS: Changes in plasma concentrations of ascorbic acid and malondialdehyde were measured in rats after per os exposure to different doses of mercury (as mercuric chloride) for 30 d. RESULTS: The production of ascorbic acid and malondialdehyde was related to the dosage of mercuric chloride. Within the group of rats receiving mercuric chloride in the concentration of 10 micromol/L (corresponding to the LD50 of HgCl2), the concentrations of ascorbic acid and malondialdehyde were increased by 22.19 % and by 6.88 % respectively when compared with the control group. The doses of mercuric chloride lower than LD50 reduced the production of ascorbic acid and malondialdehyde statistically. CONCLUSIONS: Mercury is one of the inducers of oxidative stress in plasma of rats. The oxidation damage caused by mercuric chloride is proven by increased malondialdehyde formation and subsequently compensated by an overproduction of ascorbic acid (Tab. 3, Ref. 22).

Metallothioneins and zinc: their functions and interactions.

The impact of environmental and occupational contamination on living organisms has been an interesting topic for scientific and lay public for a long time. The synthesis of metallothioneins is one of the protection strategies, by which organisms protect themselves from metal-induced toxicity. There are four known isoforms of metallothioneins. This article summarizes the role of the widely expressed mammalian metallothionein-1 and metallothionein-2 isoforms in zinc homeostasis, apoptosis, and as novel potential marker of ageing. The metallothionein-3 and metallothionein-4 have been discovered to possess distinct functional properties. The properties of metallothioneins and their interplay are likely to be essential for the still elusive biological function of these proteins. (Ref. 49.).

Smokers--vitamin C--hypercholesterolaemia.

Cigarette smoking is one of the major public health problems of our times. Smokers are damaged by free radicals formed during smoking. The antioxidant capacity of smokers is reduced. Vitamin C (ascorbic acid) deficiency in heavy smokers with a total cholesterol more than 6.7 mmol/l ranges from 35-55%. It is mediated by smoking, by its low dietary intake by preferential high dietary intake of saturated and unsaturated fats. Vitamin C is an important water soluble antioxidant, therefore its intake can at least partially reduce the unfavourable effect of smoking caused by the attack of free radicals on the organism when smokers are unable to quit smoking.

[Immunoglobulin E and acute myocardial infarct]. / Imunoglobulín E a akútny infarkt myokardu.

The authors examined repeatedly the immunoglobulin E (IgE) and immunoglobulin G (IgG) level in patients hospitalized on account of acute myocardial infarction (AMI). In a group of 33 patients aged 40-59 years (25 men, and 8 women) the authors investigated the case-history for hay fever, allergic rhinitis, eczema, allergy to grass, sensitizing household dust or domestic animals. The authors assessed also the presence of asthma and eczema in parents or relatives. Furthermore the authors investigated the relationship of different components of the immunological profile in relation to IgE and AMI. They found that in AMI the IgE serum level rises or is high on the 5th day after acute myocardial ischaemia. On the 10th and 21st day of hospitalization the IgE level declined and by the end of the third week it was close to baseline values of 300 U/ml or less. The IgG level displayed an almost indirect relation, i.e. during the first days it was close to the borderline of normal values, while it increased significantly on the 21st day of hospitalization. The rise of the IgG level is a response of the immune system to recovery of the necrotic myocardial mass. Consistent with some authors abroad, the authors found that patients with AMI with a high initial IgE serum level have a better prognosis quo ad vitam.