Chemistry Reference
In-Depth Information
Bacillus clausii
, a mix of four lactic acid bacteria (
L. delbrueckii
var.
bulgaricus
,
Streptococcus thermophilus
,
L. acidophilus
, and
Bifidobacterium bifidum),
), and
E. faecium
SF68. From the five preparations tested only LGG and the mix of four
strains were shown to be effective in reducing the duration of the diarrheal episodes,
whereas the other preparations were found ineffective in the target group tested. The
data for
Saccharomyces boulardii
were unexpected because in previous trials it was
shown to be beneficial in children and infants.
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Overall, it can be concluded that the individual effects on infants might be mod-
est, reducing the duration of diarrhea 17 to 30 hours. However, the larger effects
on the population may be significant. In a recent review, it was shown that effects
are strain specific, with LGG the most effective; dose-dependent (larger effect with
doses > 10
10
cfu/day); and most helpful for watery diarrhea (rotaviral) and viral gas-
troenteritis, but not for invasive bacterial diarrhea.
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15.4.3.2.2 Necrotizing Enterocolitis
NEC is the most commonly occurring gastrointestinal disease in preterm infants.
The disease results from an activation of the inflammatory cascade leading to high
expression of proinflammatory mediators caused by certain changes in microbiota.
The incidence is highest in infants with less than 1,500 g birth weight and mortality
rates approach 30 percent.
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The intestinal complications occur mostly in the first
weeks of life, suggesting that immaturity of the intestinal epithelial barrier function
and absorptive capacity play a role. In a recent study, probiotic bacteria were shown
to decrease intestinal permeability of preterm infants as measured by using the sugar
absorption test.
192
Bifidobacterium animalis
subsp
. lactis
BB-12 was shown to lower
the lactose/mannitol ratio (a marker for intestinal permeability) significantly com-
pared to the control group at day 30.
Results of recent clinical trials suggest that probiotic bacteria reduce the risk
of NEC in preterm neonates with less than 33-week gestation. Seven trials were
included in a meta-analysis using various probiotic strains (
B. breve
M-16V, LGG,
Saccharomyces boulardii
, BB-12, or a mix of strains). This showed an overall
reduced risk of developing NEC and a reduced risk of death due to all causes in
the probiotic group.
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If a larger well-designed trial, taking into account short-term
and long-term safety of probiotic bacteria in preterms, confirmed these results, this
would make a strong case for the routine use of probiotic bacteria in neonates. The
dose, duration, and type of probiotic agents (species, strain, single or combined, live
or killed) used for supplementation should be investigated in more detail.
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15.4.3.3 Influence on Postnatal Development of the Immune System
Probiotic bacteria have been shown to induce changes in gut barrier function
and immune responses in
in vitro
and
in vivo
animal studies. These are now also
being documented in human studies in adults, children, and infants. Effects include
responses of the innate nonspecific immune system like promotion of mucin pro-
duction, inhibition of pathogens, decrease in gut permeability, enhancement of
