the past three decades alteration in gut microbiota grown to be an issue of interest
by literature due to their impact on human health, which have been established
to be altered by diet. Prebiotics are the main effectors on it. Some
oligosaccharides can demonstrate a prebiotic effect. Bifidobacteria is a
predominant part of human gut microbiota which decreased by age. Prebiotic
mixture of galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS)
found to mimics the molecular size distribution of human milk oligosaccharides.
Commercially existing prebiotics also encourage the growth of pathogenic, gram
negative anaerobes and E.coli.
which came with the necessity of developing an innovative selective prebiotics.
In human studies GOSs support the growth of bifidobacteria in well-being young,
older, and overweight, and in patients with metabolic syndrome, type 2 diabetes,
and irritable bowel syndrome. GOSs fermentation
and its bifidogenic effect lead to the production of short chain fatty acids (SCFAs),
which may sustain positive health effects. Bifidobacterium spp. produce
mainly the short chain fatty acid acetate and lactate. SCFAs found to promote
human health by enhancing immune system, delay metabolic diseases, support
well-being in mature population, and reduce the risk factors associated with
shifts in the colonic microbiota and fermentation resultant of ageing.
Chain Fatty Acids
words: Prebiotics, Galacto-oligosaccharides (GOSs),
Bifidobacteria, Intestine, Gut, Microbiotica
Effect of Galacto-Oligosaccharides
During the past three decades alteration
in gut microbiota grown to be an issue of interest by literature due to their
impact on human health, which have been found to be altered by diet. These microbiota
ferment undigested dietary sources of carbohydrates and proteins in the human
intestine (Walton et al., 2012). Prebiotics are the main
supplements used to alter the composition of the intestinal microbiota by thought-provoking
the growth of beneficial microorganisms and inhibition the growth of gram
negative and pathogenic bacteria (Musilova et al., 2014). Commercially
available prebiotics also promote the growth of pathogenic gut bacteria such as
gram negative anaerobes and E.coli.
which came with the necessity of developing an innovative selective prebiotics.
number of oligosaccharides established to demonstrate a prebiotic effect
including inulin, fructo-oligosaccharides (FOSs) and galacto-oligosaccharides
(GOSs). Prebiotic mixture of GOS and FOS can
mimics the molecular size distribution of human milk oligosaccharides (Musilova
et al., 2014). Over and over again GOSs found to target Bifidobacterium
spp. due to the size and structure of these oligosaccharides and inhibit the
growth of pathogenic gut bacteria such as gram negative anaerobes and E.coli. (Morel et al., 2015; Vulevic et la., 2008;
Vulevic et al., 2015; Walton et al., 2012). Bifidobacteria had defined as a
beneficial bacterial specieses that enhance human health (Musilova et al.,
defined as “a selectively fermented ingredient that allows specific
changes, both in the composition and/or activity in the gastrointestinal
microbiota that confers benefits upon host well-being and health” (Musilova
et al., 2014). The previous concept can be applicated on the GOSs as
innovative prebiotics. In human studies GOSs promote the growth of
bifidobacteria in healthy young, older, and overweight, and among patients with
irritable bowel syndrome, type 2 diabetes, and metabolic syndrome (Morel et al., 2015; Vulevic et la., 2008;
Vulevic et al., 2015; Walton et
Together degree of polymerization (DP) and the dose of non-digestible
oligosaccharides can alter their effect on the gut microbial composition and
activity, and the subsequent associated physiologic and health effects (Morel et
al., 2015; Vulevic et la., 2008). DP in manufactured GOSs products
depend on the reverse ?-Galactosidase that used in the synthesis (Vulevic et
Bifidobacteria found to be a predominant
part of neonates and infants gut microbiota which decreased with age which
promoted by human oligosaccharides. Though, bifidobacteria still characterized
as an important part of the adult gut microbiota. Bifidobacterium spp.
produce mainly the short chain fatty acids
acetate and lactate depending on the substrate and identified to enhance
butyrate production via cross-feeding with butyrogenic microorganisms (Musilova et al., 2014).
and Bifidobacterium spp. Interaction
et al. (2015), double blind, placebo (matodextrin)-controlled study, found
that 5.5 g GOSs daily supplementation for 10 weeks in elderly group led to a
significant increase in bifidobacteria and its related lactic acid in feces. Musilova
et al., 2014 also found that consumption of a mixture of 9 g GOSs and 1 g
maltodextrin daily for 5 days had significantly increased bifidobacteria count
in feces from 9.45 to 9.83 log colony-forming units (CFU)/g and decreased the E.
coli count from 7.23 to 6.28 log CFU/g. Another study by Walton et al.
(2012), 4 g supplement of GOSs twice
daily led to significantly more fecal bifidobacteria 9·16±1·09 log10 CFU/g as
compared to the placebo: 8·64±0·95 log10 CFU/g (P =0·024) in women above 50
years of age.
In a double-blind,
placebo-controlled, crossover study, 44 elderly subjects were randomly allocated
to receive 5.5 g/d B-GOS or placebo for 10 wk, then went through a 4-wk washout
period, and after that switched to the other treatment for the final 10 wk (Vulevic
et la., 2008).
The group supplemented with B-GOS showed a significantly increase in the
numbers of beneficial bacteria, mainly bifidobacteria and decreased the numbers
of pathogenic bacteria including E.coli and Desulfovibrio spp. compared
with the baseline and placebo (Vulevic et
Health impact of bifidogenic effect of
control of intestinal microbial composition by the use of prebiotics have the
health effect by prevention of constipation or diarrehea, modulation of the metabolism
of gut microorganisms, cancer prevention, enhanced mineral adsorption, enhanced
lipid metabolism, and immunomodulatory properties (Musilova et al.,
2014). These health effect associated with microbiota actions
that related to the improved expression of binding proteins, short-chain fatty
acids (SCFAs) production and the related decrease in colon PH (Musilova
et al., 2014). UP to 95% of
SCFAs produced of carbohydrate fermentation by microbiota may be absorbed and metabolized
by human body (Musilova et al., 2014). Another supposed mechanism that increased
in SCFAs promote gut peptide secretion
and as a consequence control appetite and food intake (Morel et al.,
2015). Morel et al. 2015, found that subjects
supplemented either with a mix of ?-GOSs of different degrees of polymerization or with a
formula rich in DP2, DP3, or DP4 for 15
day compared with control group showed a significant decrease in hunger, desire
to eat, and prospective consumption, while greater satiety and fullness were
is known to improve barrier function which may reduce inflammatory compounds
such as intestinal lipopolysaccharides (LPS). In Morel et al. (2015), LPS
levels was significantly lower after ?-GOS
intake for 15 days. This study found a significant (P < 0.001) negative correlation (r = –0.57) between GOSs dose and changes in plasma LPS. Also bifidobacteria can promote immune response by its effect on the regulation of T-cell. Adding to that the SCFA acetate produced by bifidobacteria has reported to activate natural killer (NK) cells and enhance the capability of gut epithelial cells (Vulevic et al., 2015). Also supplementation with GOSs in elderly have showed a significant increase in phagocytosis, NK cell activity, and the production of anti-inflammatory cytokine interleukin-10 (IL-10) and significant reduction in proinflammatory cytokines (IL-6, IL-1?, and tumor necrosis factor-?) production (Vulevic et la., 2008). Conclusion Consumption of GOSs from natural sources or as prebiotics can be used as a selective ingredient to beneficially alter gut microbiota by its bifidogenic effect which in turn can inhibit the growth of pathogenic and gram negative bacteria such as E. coli. The alteration in the gut microbiota mainly the increase of bifidobacteria and other beneficial microorganisms can promote human health, support well-being in mature population, and reduce the risk factors associated with shifts in the colonic microbiota and fermentation resultant of ageing.