Chemistry Reference
In-Depth Information
As the gut microbiota is established, the capacity of the GALT to produce immu-
noglobulin A (IgA)-secreting cells increases. Secretory IgA (sIgA) plays an important
(immune exclusion) role in the defense of the GIT. Maternal breast milk is full of
sIgA antibodies against her intestinal microflora (enteromammaric link). As a result,
a major percentage of the fecal microbes are coated with IgA, thereby preventing the
induction of immune reactions against commensal residents and attachment to and
subsequent translocation through mucosal membranes.
83,84
The level of sIgA antibody
is also associated with increased neutralization and clearance of viruses. Formula-fed
infants who lack the transfer of protective maternal sIgA from breast milk can benefit
from strategies to support maturation of (humoral) immunity and endogenous pro-
duction of sIgA. In an intervention study, infants fed on a formula supplemented with
a GOS/lcFOS mixture showed a trend toward higher fecal sIgA levels compared with
the standard formula-fed infants.
85
In contrast, infants fed on a probiotic (
B. lactis
BB12) formula showed a highly variable fecal sIgA concentration with no statistically
significant differences compared with the standard formula group. A recent double-
blind, randomized, placebo-controlled study also demonstrated higher concentra-
tions of fecal sIgA after consumption of GOS/lcFOS-supplemented infant formula,
suggesting a positive effect on mucosal immunity.
86
4.5.3.2 Allergy
In both eczema and food allergy, there is evidence of an inflammatory response
in the GIT.
87
In addition, the permeability of the intestinal mucosa is increased in
allergic disease, which can allow the systemic absorption of antigens, bypassing
antigen-presenting cells and thus producing systemic hyperresponsiveness.
88
Infants
with early onset allergic disease are also at risk of other allergic manifestations, a
phenomenon described as “the allergic march.” Atopic dermatitis (AD) is usually
the first manifestation of allergy during early infancy. AD is associated with delayed
maturation of Th1 immune responses during early infancy with raised total IgE and
IgE to dietary antigens in the serum.
A promising approach in high-risk infants seems to be prevention of allergic
diseases by dietary supplementation of pre- and/or probiotics. This has been shown
to enhance mucosal barrier function, participate in degradation of protein antigens,
promote early immune system maturation toward nonallergy, and alleviate symp-
toms of eczema.
87,89 -91
Breastfeeding has been reported to lower the incidence of
atopy-related disorders,
92-94
an effect that was also shown for a GOS/lcFOS mixture
(Figure 4.5).
95
In a murine type I allergy model, the allergic reaction following sen-
sitization with ovalbumin was attenuated in animals fed with dietary GOS/lcFOS.
96
The supplemented infant formulation reduced the cumulative incidence of AD in
high-risk infants by altering immune development. The supplementation was shown
to induce beneficial total serum antibody profiles (reduced IgE levels), specifically
modulating the immune response toward food allergens, while leaving vaccination
responses intact.
97-99
It was shown that total IgE, IgG
1
, IgG
2
, IgG
3
, but not IgG
4
,
levels decrease after 6 months of treatment. Dietary supplementation of a combina-
