Chemistry Reference
In-Depth Information
It is suspected that intestinal microbiota changes may produce a more proinflam-
matory signal to the mucosal immune cells and that such inflammatory activation could
contribute to systemic inflammation.
.
Mucosa-associated bacteria are suspected to have,
because of their location, more influence on the immunological and inflammatory
parameters of the host than bacteria in the intestinal lumen (fecal bacteria). However,
knowledge on the mucosa-associated bacteria is scarce in comparison to that of fecal
bacteria and in particular the changes mucosa-associated microbiota related to aging
have not been characterized adequately. Several findings indicate that aging may bring
significant compositional changes to the mucosa-associated microbiota. First, bifidobac-
terial strains isolated from the feces of elderly people are bound worse to the intestinal
mucus than those isolated from healthy adults, indicating a shift to a
Bifidobacterium
population with reduced adhesive abilities.
23
Second, the numbers of the mucin-degrad-
ing
A. muciniphila
-like bacteria have been found to decline in elderly individuals.
19
16.2 ProbIoTICs AND PrEbIoTICs For ElDErly INDIvIDuAls
16.2.1 Probiotics and Prebiotics
Probiotics are defined as viable microbes, which through oral administration
produce health benefits to the host. Probiotics act by functioning as members of
the healthy gut microbiota and by balancing the microbiota. Most studied probiotic
strains belong to the genus
Lactobacillus
or
Bifidobacterium
. The health benefits of
probiotics are reviewed in Chapters 12 through 16 of this topic.
Prebiotics act through promotion of specific groups of bacteria, which are consid-
ered to be essential in maintaining and enhancing gut health. Naturally, the prereq-
uisite for the prebiotic activity is that bacteria to be stimulated are already present in
the gut. Most prebiotic components have been shown to enhance the
Bifidobacterium
microbiota, but different prebiotic oligosaccharides have different microbiota-mod-
ifying properties. When assessing the efficacy of a prebiotic substrate it should be
considered that it might also enhance the levels of unknown microbes in human
gut and thus potentially facilitate undesirable effects. This emphasizes the impor-
tance of proper microbiota analysis at an adequate level of accuracy during clinical
interventions.
The objective of developing probiotic and prebiotic products for elderly people
is essentially the same as for other age groups with special emphasis to counteract
the microbiota changes related to aging, to improve bowel function (alleviate con-
stipation and diarrhea), and to enhance immunity and thereby to improve general
well-being and health. Selected recent clinical trials on probiotics and prebiotics for
elderly people are compiled in Table 16.2 and Table 16.3.
6,24-30
16.2.2 Efficacy of Probiotics
The particular challenges related to the probiotic research include the right selec-
tion criteria for probiotic strains for elderly individuals. Each probiotic strain has its
