BioFiles Volume 6, Number 2 — Nutrition Research
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Table of Contents
The human digestive system has the dual challenges of nutrient absorption (vitamins, lipids, minerals, carbohydrates etc.) while providing host protection (pathogens and carcinogens). To serve these dual roles, the human digestive system is dependent on the commensal microbes within the intestinal tract. It is estimated that the human gut is home to 100 trillion microbes consisting of a diverse collection of over 400 different bacterial species.
Advances in metagenomics have enabled microbiologists to analyze the colonic microbiota, the comprehensive microbial community within the colon, as opposed to the traditional approach of investigating a single microbial species isolated from the colon. The National Institute of Health sponsored Human Microbiome Project (HMP) is laying the foundation for future studies of human intestinal microbiota. The goals of this project are to characterize the human microbiome via the sequencing of 600 bacterial genomes and to facilitate research focused on the relationship between microbiota and human health or disease. The publicly available data sets published by the HMP (www.hmpdacc.org) are an important tool for evaluating the impact of probiotic treatments and prebiotic food components.
It is proposed that the intestinal microbiome contains more than 100 times the number of nonredundant genes in the human genome. This supplementary microbiome provides the human body with functionality that we have not had to evolve ourselves. The influence of probiotics to alter the intestinal microbiota by acidification of the intestinal environment via fermentation of complex carbohydrates to short-chain fatty acids (SCFA), that would otherwise be indigestible, exemplifies the ancillary functionality provided by the microbiome.
Probiotics are taking on a key role in the functional food industry. The name “probiotics” is derived from Latin (pro) and Greek (biotic) roots meaning “for life”. The Food and Agriculture Organization (FAO) defines probiotics as live microorganisms, which when administered in adequate amounts confer a health benefit on the host. Lactic acid bacteria (LAB), most frequently Lactobacillus and Bifidobacterium species are the most commonly used probiotics, however certain yeasts and bacilli are also known to have positive effects. In most cases, probiotics are produced directly by fermentation in foods such as yogurt, or are supplied through dietary supplements.
Increasingly, prebiotics are being evaluated as functional food components. Prebiotics alter the intestinal microbiota by functioning as a ferementation substrate, yielding increased SCFA production. Per the FAO, a prebiotic is a food component that confers a health benefit on the host that is associated with microbiota modulation. More specifically, a prebiotic food component is nondigestible by the host and beneficially affects the host by selectively stimulating the growth and/or activity of bacteria already in the colon. Data suggests prebiotics positively impact immune and digestive function by influencing mucosal barrier development, immune system activation, bile acid metabolism, and vitamin synthesis.
This issue of BioFiles explores the functionality and health benefits of probiotics and prebiotics and highlights biochemicals and kits for the detection and evaluation of these promising nutritional ingredients.
From micronutrients to medicinal plants, nutritionists, pharmacologists, and medical researchers are studying the physiological, therapeutic, and chemopreventive properties of food components and their constituents. Sigma Life Science offers an extensive selection of researcher trusted products and complementary online resources for nutrition research. This issue of BioFiles includes products from several nutritional product groups. For a comprehensive list of our nutrition research products, please visit sigma.com/nutrition.