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Implication of fructans in health: immunomodulatory and antioxidant mechanisms.

Franco-Robles E, López MG - ScientificWorldJournal (2015)

Bottom Line: Fructans are nonreducing carbohydrates composed of fructosyl units and terminated by a single glucose molecule.The indirect role of fructans in stimulating probiotic growth is one of the mechanisms through which fructans exert their prebiotic activity and improve health or ameliorate disease.In this review, we discuss recent advances in our understanding of fructans interaction with the intestinal immune system, the gut microbiota, and other components of the intestinal lumen to provide an overview of the mechanisms underlying the effects of fructans on health and disease.

View Article: PubMed Central - PubMed

Affiliation: Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato, Km 9.6 Libramiento Norte Carretera Irapuato-León, 36821 Irapuato, GTO, Mexico.

ABSTRACT
Previous studies have shown that fructans, a soluble dietary fiber, are beneficial to human health and offer a promising approach for the treatment of some diseases. Fructans are nonreducing carbohydrates composed of fructosyl units and terminated by a single glucose molecule. These carbohydrates may be straight or branched with varying degrees of polymerization. Additionally, fructans are resistant to hydrolysis by human digestive enzymes but can be fermented by the colonic microbiota to produce short chain fatty acids (SCFAs), metabolic by-products that possess immunomodulatory activity. The indirect role of fructans in stimulating probiotic growth is one of the mechanisms through which fructans exert their prebiotic activity and improve health or ameliorate disease. However, a more direct mechanism for fructan activity has recently been suggested; fructans may interact with immune cells in the intestinal lumen to modulate immune responses in the body. Fructans are currently being studied for their potential as "ROS scavengers" that benefit intestinal epithelial cells by improving their redox environment. In this review, we discuss recent advances in our understanding of fructans interaction with the intestinal immune system, the gut microbiota, and other components of the intestinal lumen to provide an overview of the mechanisms underlying the effects of fructans on health and disease.

No MeSH data available.


Mechanism for the indirect effect of fructans on the immune system.
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fig3: Mechanism for the indirect effect of fructans on the immune system.

Mentions: Other indirect pathways by which fructans exert immunomodulatory effects include the production of SCFAs, which are the fermentation products of fructans. Inulin fermentation increases the production of SCFAs (acetate, propionate, and butyrate), lactic acid, and hydrogen (H2), while decreasing the pH of the colonic environment [36]. Bifidobacterium species are able to use some monosaccharides in a unique manner to ultimately generate SCFAs [98] and acidify the colonic environment. The increase in SCFAs antagonizes the growth of some pathogenic bacterial strains [99] and favors mucin production in the colon [100]. SCFAs bind to SCFAs receptors on GALT immune cells [101–103], activating G protein-coupled receptors (GPR) [104], such as GPR41 and GPR43 [101, 102, 104]. This binding affects the recruitment of leukocytes to inflammatory sites [105, 106] and suppresses the production of proinflammatory cytokines and chemokines [106–108]. GPR43 is highly expressed in polymorphonuclear cells (PMNs, i.e., neutrophils) and is lowly expressed in peripheral blood mononuclear cells (PBMCs) and purified monocytes. Conversely, GPR41 is expressed in PBMCs but not in PMNs, monocytes, or DCs [102]. Importantly, butyrate decreases the glutamine requirement for epithelial cells and alters epithelial cell gene expression [71, 109]. The mechanism for the indirect effect of fructans on the immune system is shown in Figure 3.


Implication of fructans in health: immunomodulatory and antioxidant mechanisms.

Franco-Robles E, López MG - ScientificWorldJournal (2015)

Mechanism for the indirect effect of fructans on the immune system.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4417592&req=5

fig3: Mechanism for the indirect effect of fructans on the immune system.
Mentions: Other indirect pathways by which fructans exert immunomodulatory effects include the production of SCFAs, which are the fermentation products of fructans. Inulin fermentation increases the production of SCFAs (acetate, propionate, and butyrate), lactic acid, and hydrogen (H2), while decreasing the pH of the colonic environment [36]. Bifidobacterium species are able to use some monosaccharides in a unique manner to ultimately generate SCFAs [98] and acidify the colonic environment. The increase in SCFAs antagonizes the growth of some pathogenic bacterial strains [99] and favors mucin production in the colon [100]. SCFAs bind to SCFAs receptors on GALT immune cells [101–103], activating G protein-coupled receptors (GPR) [104], such as GPR41 and GPR43 [101, 102, 104]. This binding affects the recruitment of leukocytes to inflammatory sites [105, 106] and suppresses the production of proinflammatory cytokines and chemokines [106–108]. GPR43 is highly expressed in polymorphonuclear cells (PMNs, i.e., neutrophils) and is lowly expressed in peripheral blood mononuclear cells (PBMCs) and purified monocytes. Conversely, GPR41 is expressed in PBMCs but not in PMNs, monocytes, or DCs [102]. Importantly, butyrate decreases the glutamine requirement for epithelial cells and alters epithelial cell gene expression [71, 109]. The mechanism for the indirect effect of fructans on the immune system is shown in Figure 3.

Bottom Line: Fructans are nonreducing carbohydrates composed of fructosyl units and terminated by a single glucose molecule.The indirect role of fructans in stimulating probiotic growth is one of the mechanisms through which fructans exert their prebiotic activity and improve health or ameliorate disease.In this review, we discuss recent advances in our understanding of fructans interaction with the intestinal immune system, the gut microbiota, and other components of the intestinal lumen to provide an overview of the mechanisms underlying the effects of fructans on health and disease.

View Article: PubMed Central - PubMed

Affiliation: Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato, Km 9.6 Libramiento Norte Carretera Irapuato-León, 36821 Irapuato, GTO, Mexico.

ABSTRACT
Previous studies have shown that fructans, a soluble dietary fiber, are beneficial to human health and offer a promising approach for the treatment of some diseases. Fructans are nonreducing carbohydrates composed of fructosyl units and terminated by a single glucose molecule. These carbohydrates may be straight or branched with varying degrees of polymerization. Additionally, fructans are resistant to hydrolysis by human digestive enzymes but can be fermented by the colonic microbiota to produce short chain fatty acids (SCFAs), metabolic by-products that possess immunomodulatory activity. The indirect role of fructans in stimulating probiotic growth is one of the mechanisms through which fructans exert their prebiotic activity and improve health or ameliorate disease. However, a more direct mechanism for fructan activity has recently been suggested; fructans may interact with immune cells in the intestinal lumen to modulate immune responses in the body. Fructans are currently being studied for their potential as "ROS scavengers" that benefit intestinal epithelial cells by improving their redox environment. In this review, we discuss recent advances in our understanding of fructans interaction with the intestinal immune system, the gut microbiota, and other components of the intestinal lumen to provide an overview of the mechanisms underlying the effects of fructans on health and disease.

No MeSH data available.