Research on Prebiotics and Heart Health

 Effects of lifelong intervention with an oligofructose-enriched inulin in rats on general health and lifespan

• The aim of the study was to investigate the effects of lifelong supplementation with an oligofructose-enriched inulin on morphological and biological markers and lifespan in male and female rats.
• Male and female rats, age 3 months, were randomised into two groups to receive either a diet with 10 % of an oligofructose-enriched inulin or a standard diet (control) for 27 months. The rats were weighed every 2 weeks and their food intake was evaluated on four successive days every 4–6 weeks. Samples were taken at 12, 18 and 24 months of age.
• During the whole intervention period, male rats receiving oligofructose-enriched inulin displayed lower body weight, cholesterol and plasma triacylglycerolaemia compared with the controls (Cont-M).
• The survival rate at 24 months of age of SYN1-M rats was 35·3 % greater than that of Cont-M rats.
• In female rats, the Synergy1 supplementation (SYN1-F) group also reduced body weight, cholesterol and triacylglycerolaemia levels
• The survival rate at 24 months of age in SYN1-F rats was 33·3 % greater compared with that of the control (Cont-F) group.
• To conclude, lifelong intervention with oligofructose-enriched inulin improved biological markers during ageing and survival rate (lifespan) of rats. 

• Results from animal and human studies suggest a moderate cholesterol-lowering action of dairy products fermented with appropriate strain(s) of lactic acid bacteria and bifidobacteria.
• Mechanistically, probiotic bacteria ferment food-derived indigestible carbohydrates to produce short-chain fatty acids in the gut, which can then cause a decrease in the systemic levels of blood lipids by inhibiting hepatic cholesterol synthesis and/or redistributing cholesterol from plasma to the liver.
• Furthermore, some bacteria may interfere with cholesterol absorption from the gut by deconjugating bile salts and therefore affecting the metabolism of cholesterol, or by directly assimilating cholesterol.
• For prebiotic substances, the majority of studies have been done with the fructooligosaccharides inulin and oligofructose, and convincing lipid-lowering effects have been observed in animals.
• Reports in humans are few in number. In studies conducted in normal-lipidemic subjects, two reported no effect of inulin or oligofructose on serum lipids, whereas two others reported a significant reduction in serum triglycerides (19 and 27%, respectively) with more modest changes in serum total and LDL cholesterol.
• At present, data suggest that effects on serum triglycerides are the dominant feature. 

• The proliferation of certain bacteria by fermentation of non-digestible carbohydrates has been shown to be able to inhibit the colonization of the intestine by pathogens, thus giving a protective effect vis-à-vis acute or chronic intestinal disorders.
• The fermentation of prebiotics may promote some specific physiological functions through the release of metabolites from the bacteria, especially short chain fatty acids (acetate, propionate, butyrate, lactate, etc.) into the lumen of the intestine.
• Short chain fatty acids may act directly or indirectly (by modifying the pH) on intestinal cells and may be involved in the control of various processes such as the proliferation of mucosa, inflammation, colorectal carcinogenesis, mineral absorption and the elimination of nitrogenated compounds.
• Prebiotics may have systemic physiological effects that are related to beneficial effects on lipid metabolism and various cardiovascular risk factors. 

• Nutraceuticals are medicinal foods that play a role in maintaining well being, enhancing health, modulating immunity and thereby preventing as well as treating specific diseases.
• Thus the field of nutraceuticals can be envisioned as one of the missing blocks in the health benefit of an individual.
• More than any other disease, the etiology of cardiovascular disease reveals many risk factors that are amenable to nutraceutical intervention.
• The ability of nutraceuticals to positively influence cardiovascular risk factors should be recognized as an enormous opportunity in the treatment of a highly prevalent disease.
• Nutraceuticals hold promise in clinical therapy as they have the potential to significantly reduce the risk of side effects associated with chemotherapy along with reducing the global health care cost.
• In this review, an attempt has been made to summarize some of the recent research findings on garlic, omega-3-fatty acids, soy products, dietary fibres, vitamins, antioxidants, plant sterols, flavonoids, prebiotics and probiotics that have beneficial effects on the heart, in order to update the practising clinician on the benefit of using nutraceuticals for the management of cardiovascular diseases.