Dietary modulation of the human colonic microbiota: updating the concept of prebiotics

Abstract

Prebiotics are non-digestible (by the host) food ingredients that have a beneficial effect through their selective metabolism in the intestinal tract. Key to this is the specificity of microbial changes. The present paper reviews the concept in terms of three criteria: (a) resistance to gastric acidity, hydrolysis by mammalian enzymes and gastrointestinal absorption; (b) fermentation by intestinal microflora; (c) selective stimulation of the growth and/or activity of intestinal bacteria associated with health and wellbeing. The conclusion is that prebiotics that currently fulfil these three criteria are fructo-oligosaccharides, galacto-oligosaccharides and lactulose, although promise does exist with several other dietary carbohydrates. Given the range of food vehicles that may be fortified by prebiotics, their ability to confer positive microflora changes and the health aspects that may accrue, it is important that robust technologies to assay functionality are used. This would include a molecular-based approach to determine flora changes. The future use of prebiotics may allow species-level changes in the microbiota, an extrapolation into genera other than the bifidobacteria and lactobacilli, and allow preferential use in disease-prone areas of the body.

Modulation of the gut microbiota by prebiotic fibres and bacteriocins

“…Prebiotics are a subgroup of dietary fibres with resistance to gastric acidity and the digestive enzymes of mammals, and which confer a variety of health benefits [37,38]. The main characteristic of prebiotics is their selective stimulation of the growth and/or activity of intestinal bacteria associated with health and well-being [38].…”

“…The main characteristic of prebiotics is their selective stimulation of the growth and/or activity of intestinal bacteria associated with health and well-being [38]. The most well-known prebiotics are inulin, fructooligosaccharides (FOS), lactulose and galactooligosaccharides (GOS) [39].…”

The effect of high and low dietary crude protein and inulin supplementation on nutrient digestibility, nitrogen excretion, intestinal microflora and manure ammonia emissions from finisher pigs

“…were chosen because of their health-promoting properties (Gibson and Roberfroid, 1995) while Enterobacteria spp. were chosen because of the harmful effects of some species in the gastro-intestinal tract (Gibson and Roberfroid, 1995). pH measurements Samples of digesta from the caecum and proximal colon were taken and placed in universal containers.…”

Mass spectrometric characterization of glycated β-lactoglobulin peptides derived from galacto-oligosaccharides surviving the in vitro gastrointestinal digestion

“…Tuohy et al [10] showed an increase of the more detrimental microorganisms against a diminution of the beneficial ones (bifidobacteria and lactobacilli) following fermentation of BSA glycated with glucose on fecal bacteria. However, to the best of our knowledge, no gut fermentation studies have so far been performed using proteins glycated with prebiotic carbohydrates (nondigestible compounds, mainly carbohydrates, which selectively stimulate the growth of certain intestinal bacteria beneficially affecting host health [11]). …”