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function, providing substrates for microbial fermentation, modulating the structure
of gut microbe, and protecting the immune system (Minamida et al. 2014).
Certain gut bacteria can break down polysaccharides into short-chain fatty acids
(SCFAs). Among other functions, SCFAs furnish energy to the colon and modulate
immune responses. Besides, SCFAs protect against colitis/colorectal cancers keep
the epithelial barrier function, and improve epithelial proliferation (Hamer et al.
2008). For example, butyric acid improves colonic health by supplying energy to
the epithelial cells. Depending on its concentration, butyric acid can boost proliferation and differentiation of human cells and elicit apoptosis of tumor cells (Maslowski
and Mackay 2011).
One condition that is frequently reported to be associated with deranged microbiota is metabolic syndrome. Many polysaccharides have been reported to successfully ameliorate metabolic syndrome (Cani et al. 2008). A study by Liu et al. (2017)
documented that apple-derived pectin can reduce weight gain and excessive accumulation of fat in diet-induced obese mice. Soluble dietary fiber also suppressed
weight gain and accumulation of fat by increasing energy expenditure and modulating gut microbiota (Wang et al. 2018).
4.7.2 Antioxidant Activity
Polysaccharides play an important role as free radical scavengers and antioxidants
for the prevention of oxidative damage in living organisms. Oxidative stress also
evolves from the regulation of most cellular processes, including proliferation, differentiation, stress responses, and cell death. It is one of the direct factors which is
responsible for various diseases and aging (Wang et al. 2012). This makes the antioxidant effect of polysaccharides to be one of their main promising bioactivities.
Numerous polysaccharides with antioxidant properties have been discovered from
animals, plants, and microorganisms (Kofuji et al. 2012). Probiotic bacteria can
synthesize extracellular polysaccharides (EPSs). EPSs possess physiological and
therapeutic activities of commercial importance. These class of biomolecules also
play the role of removing reactive oxygen species (ROS) that are formed in the
intestine by various metabolic reactions (Wang et al. 2013).
The antioxidant properties of polysaccharides have a direct relationship with
their structures. The main physicochemical properties, which determine their antioxidant effects include:
• water solubility
• molecular weight higher than 90 ku
• backbone chain of β- (1 → 3)-D-glucose
• β- (1 → 6)-side chain
• degree of branching
• functional groups (polyhydroxyl, carboxymethyl, acetyl, formyl, etc),
• triple-helical structure (Kofuji et al. 2012; Yuan et al. 2015).
4 Bioactive Carbohydrates, Biological Activities, and Sources
function, providing substrates for microbial fermentation, modulating the structure
of gut microbe, and protecting the immune system (Minamida et al. 2014).
Certain gut bacteria can break down polysaccharides into short-chain fatty acids
(SCFAs). Among other functions, SCFAs furnish energy to the colon and modulate
immune responses. Besides, SCFAs protect against colitis/colorectal cancers keep
the epithelial barrier function, and improve epithelial proliferation (Hamer et al.
2008). For example, butyric acid improves colonic health by supplying energy to
the epithelial cells. Depending on its concentration, butyric acid can boost proliferation and differentiation of human cells and elicit apoptosis of tumor cells (Maslowski
and Mackay 2011).
One condition that is frequently reported to be associated with deranged microbiota is metabolic syndrome. Many polysaccharides have been reported to successfully ameliorate metabolic syndrome (Cani et al. 2008). A study by Liu et al. (2017)
documented that apple-derived pectin can reduce weight gain and excessive accumulation of fat in diet-induced obese mice. Soluble dietary fiber also suppressed
weight gain and accumulation of fat by increasing energy expenditure and modulating gut microbiota (Wang et al. 2018).
4.7.2 Antioxidant Activity
Polysaccharides play an important role as free radical scavengers and antioxidants
for the prevention of oxidative damage in living organisms. Oxidative stress also
evolves from the regulation of most cellular processes, including proliferation, differentiation, stress responses, and cell death. It is one of the direct factors which is
responsible for various diseases and aging (Wang et al. 2012). This makes the antioxidant effect of polysaccharides to be one of their main promising bioactivities.
Numerous polysaccharides with antioxidant properties have been discovered from
animals, plants, and microorganisms (Kofuji et al. 2012). Probiotic bacteria can
synthesize extracellular polysaccharides (EPSs). EPSs possess physiological and
therapeutic activities of commercial importance. These class of biomolecules also
play the role of removing reactive oxygen species (ROS) that are formed in the
intestine by various metabolic reactions (Wang et al. 2013).
The antioxidant properties of polysaccharides have a direct relationship with
their structures. The main physicochemical properties, which determine their antioxidant effects include:
• water solubility
• molecular weight higher than 90 ku
• backbone chain of β- (1 → 3)-D-glucose
• β- (1 → 6)-side chain
• degree of branching
• functional groups (polyhydroxyl, carboxymethyl, acetyl, formyl, etc),
• triple-helical structure (Kofuji et al. 2012; Yuan et al. 2015).
4 Bioactive Carbohydrates, Biological Activities, and Sources