Human gut microbiota

A number of reviews and studies have been published dealing with the potential health and nutritional benefits of EPSs from LAB in fermented dairy products for example, EPSs from LAB have been associated with various health benefits, such as the lowering of cholesterol (Liu et al., 2006 Maeda, Zhu, Omura, Suzuki, Kitamura, 2004 Nakajima, Suzuki, Hirota, 1992), anti-hypertensive effects (Maeda, Zhu, Suzuki, Suzuki, Kitamura, 2004), anticarcinogenic effects (Furukawa, Takahashi, Yamanaka, 1996 Kitazawa et al., 1991) and immunomodulatory activity (Chabot et al., 2001 Nishimura-Uemura et al., 2003 Vinderola, Matar, Palacios, Perdigon, 2007). Apart from these effects, there also appears be a complex web of interactions between LAB EPSs and human gut microbiota, some enteric pathogens and toxins, and gut epithelial cells and the immune system the discussion that follows presents evidence for health and nutritional benefits that are potentially derived from these relationships. 

The colon contains the most species-rich and densely populated human-associated microbial communities, and the most widely studied. The colonic microbiota comprises many hundreds of bacterial species, 1000s of strains and populations of about 10 cells/g contents. The physiology of the colon renders it a particularly suitable bacterial habitat, as the flow of intestinal digesta slows, allowing bacteria ready access to dietary growth substrates. The pH is moderately acidic in the proximal colon, mainly due to bacterial fermentation itself, and increases to a more neutral pH in the transverse and distal colon with secretions by the host and water absorption. Indeed, using in vitro models of the human gut microbiota, pH has been shown to be a critical modulator of both microbiota composition and metabolic activity under the physicochemical conditions of the human colon. ... 

Andersson AF, Lindberg M, Jakobsson H, Backhed F, Nyren P, Engstrand L. Comparative analysis of human gut microbiota by barcoded pyrosequencing. PLoS One. 2008 3(7) e2836. 

METAGENOMICS AND CULTIVATION-INDEPENDENT ASSESSMENT OF HUMAN GUT MICROBIOTA ... 

The stomach-associated bacterium Helicobacter pylori exemplifies co-evolution between microorganisms and humans. Patterns of H. sapiens migration from Africa across the globe can be traced from the strain diversity of this bacterial species. Comparing the human gut microbiota and microbiome worldwide is the only way, in principle, to reveal if there is a core set of gut microbial genes and organismal lineages that are shared by most, if not all, humans. 

Probiotic Microorganisms for Shaping the Human Gut Microbiota — Mechanisms and Efficacy into the Future... 

PROBIOTIC MICROORGANISMS FOR SHAPING THE HUMAN GUT MICROBIOTA - MECHANISMS AND EFFICACY INTO THE FUTURE... 

Lozupone CA, Stombaugh Jl, Gordon Jl, Jansson JK, Knight R. Diversity, stability and resilience of the human gut microbiota. Nature. 2012 489 220-230. 

Tuohy KM, Gougoulias C, Shen Q, Walton G, Fava F, Ramnani P. Studying the human gut microbiota in the trans-omics era—focus on metagenomics and metabonomics. Curr Pharm Des. 2009 15 1415-1427. 

Ramirez-Farias C, Slezak K, Fuller Z, Duncan A, Holtrop G, Louis P. Effect of inulin on the human gut microbiota stimulation of Bifidobacterium adolescentis and Faecalibacterium prausnitzii. Br ] Nutr. 2009 101 541-550. 

Costabile A, Klinder A, Eava F, et al. Whole-grain wheat breakfast cereal has a prebiotic effect on the human gut microbiota a double-blind, placebo-controlled, crossover study. Br J Nutr. 2008 99 110-120. 

Crittenden RG, Playne MJ. Production, properties and applications of food-grade oligosaccharides. Trends Food Sci Technol. 1996 7 353-361. Tuohy KM, Rouzaud GCM, Briick WM, Gibson GR. Modulation of the human gut microbiota towards improved health using prebiotics — assessment of efficacy. Curr Pharm Des. 2005 11 75-90. 

FIGURE 9.1 A schematic representation of diet microbe interactions and how they shape immune function within the gut. Key metabolic processes within the human gut microbiota, especially carbohydrate fermentation, the enterohepatic circulation of bile acids and biotransformation of plant bioactive polyphenols by the gut microbiota play important roles in regulating both inflammatory and metabolic processes within the intestine, but also in other body tissues, like the liver, adipose tissue and brain, which are intimately involved in regulating whole-body glucose, lipid and energy metabolism, and also the chronic low-grade inflammation characteristic of metabolic diseases like diabetes, CVD, Alzheimer s and metabolic syndrome. 

Zhang H, DiBaise JK, Zuccolo A, et al. Human gut microbiota in obesity and after gastric bypass. Proc Natl Acad Sci U S Am. 2009 106 (7) 2365 -2370. 

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