Potential Prebiotic Properties of Almond (Amygdalus communisL.) Seeds

Abstract

Almonds are known to have a number of nutritional benefits, including cholesterol-lowering effects and protection against diabetes. They are also a good source of minerals and vitamin E, associated with promoting health and reducing the risk for chronic disease. For this study we investigated the potential prebiotic effect of almond seeds in vitro by using mixed fecal bacterial cultures. Two almond products, finely ground almonds (FG) and defatted finely ground almonds (DG), were subjected to a combined model of the gastrointestinal tract which included in vitro gastric and duodenal digestion, and the resulting fractions were subsequently used as substrates for the colonic model to assess their influence on the composition and metabolic activity of gut bacteria populations. FG significantly increased the populations of bifidobacteria and Eubacterium rectale, resulting in a higher prebiotic index (4.43) than was found for the commercial prebiotic fructooligosaccharides (4.08) at 24 h of incubation. No significant differences in the proportions of gut bacteria groups were detected in response to DG. The increase in the numbers of Eubacterium rectale during fermentation of FG correlated with increased butyrate production. In conclusion, we have shown that the addition of FG altered the composition of gut bacteria by stimulating the growth of bifidobacteria and Eubacterium rectale.Functional foods are known as dietary components that may cause physiological effects on the consumer, leading to justifiable claims of health benefits (36). According to the European consensus document "Scientific concepts of functional foods," a food ingredient may be regarded as functional if it beneficially affects one or more target functions in the body, beyond its nutritional effects, in order to improve the state of health and/or reduce the risk of disease (9). A prebiotic is defined as "a nondigestible food ingredient which 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 improving host health" (15). Prebiotics of proven efficacy are able to modulate the gut microbiota by stimulating indigenous beneficial flora while inhibiting the growth of pathogenic bacteria, such as proteolytic bacteroides and clostridia (43). Bifidobacteria and lactobacilli are able to inhibit the growth of clostridia and pathogenic Enterobacteriaceae by the production of shortchain fatty acids and antimicrobial compounds, as well as by competition for growth substrate and adhesion sites (16,19,23). As such, these beneficial gut bacteria, together with mucins and antimicrobial peptides, represent part of the host's front line of defense against harmful microorganisms (24, 40). In order to be effective as a prebiotic, an ingredient must neither be hydrolyzed nor absorbed in the upper part of the gastrointestinal tract (GIT). Although any dietary material that enters the large intestine can be considered as potentially prebiotic, currently the best-known prebiotics a...

In vitro fermentation of nuts results in the formation of butyrate and c9,t11 conjugated linoleic acid as chemopreventive metabolites

“…These results indicate that the fermentation of nuts can contribute to chemoprevention against CRC by production of butyrate, which exhibits trophic effects on normal colonocytes and reduces the proliferation of colon cancer cells [33]. In addition, the fermentation of nuts might exert prebiotic effects by lowering the pH value, which could result in a selective growth promotion of bifidobacteria and lactobacilli [7,34]. Taken together, the observed effects might result in an enhanced toxicological defense of the colon mucosa against carcinogenic compounds.…”

A Study on the proximate composition and nutritive value of local tree almonds, Prunus amygdalus

“…The prebiotic activity of almonds has been studied. They are found to alter the composition of gut bacteria by stimulating the growth of bifid bacteria and Eubacterium rectale (Mandalari et al, 2008). Almonds also possess anticancer activity.…”

Novel Health Ingredients and Their Applications in Salad Dressings and Other Food Emulsions

“…Besides these traditional polysaccharides, a great number of research studies have explored new sources of non-digestible polysaccharides and oligosaccharides, including those of algal origin (Goni et al 2001, Panlasigui et al 2003, spent brewer's yeast such as β-glucan (Worrasinchai et al 2006), new fruits such as Chinese Jujuba (Huang et al 2008), seeds such as flaxseed and fenugreek (Hannan et al 2007, Stewart andMazza 2000), leaves such as the hsian tsao leaf (Lai and Lin 2004), and nuts such as almonds (Mandalari et al 2008). Studies on new plant and other sources of food hydrocolloids, and their potential health benefits at the concentrations at which they will be used in foods, need to be fully explored.…”