Chemistry Reference
In-Depth Information
+ oligofructose mixture than in the placebo group, but no significant difference was
seen between the oligofructose group and the placebo group. The authors concluded
that modest intakes of an inulin + oligofructose mixture increases calcium absorp-
tion in girls at or near menarche.
154
Scholz-Ahrens et al.
5
reported that prebiotics are the most promising, but also
best investigated substances with respect to a bone health-promoting potential, com-
pared with probiotics and synbiotics.
18.4.2 obesity and Diabetes
Although the etiology of obesity and diabetes is complex, diet clearly plays an
important role both in development and management of these diseases.
11
This mainly
involves food products that help in management of hunger, increase satiety, and
stimulate energy expenditure. Recently, Yadav et al.
157
reported that the probiotic
dahi (yogurt)-supplemented diet significantly delayed the onset of glucose intoler-
ance, hyperglycemia, hyperinsulinemia, dyslipidemia, and oxidative stress in high
fructose-induced diabetic rats, indicating a lower risk of diabetes and its complica-
tions. Ludwig et al.
158
found that high dietary fiber (prebiotics) has a protective effect
against weight gain. Functional foods have also been reported to ameliorate diabetes
by improving insulin sensitivity and blood glucose levels.
18.5 ProbIoTICs As vACCINE CArrIErs
Delivery of vaccine antigens by live bacterial carriers has resulted in the elimi-
nation of humoral and cellular responses at the level of both systemic and mucosal
compartments. Commensal lactic acid bacteria is being exploited to deliver vaccines
and other biologically active material to the GIT.
159
Their use for vaccine delivery
is of special value because they provide protection at the site of pathogen entry,
and their immunomodulative effect makes them an attractive model antigen delivery
vehicle or
de novo
vaccines. The advantages of lactic acid bacteria delivery includes
ease of administration, survival in the gastric acid, inherent safety, particulate nature,
economic technology in that the bacteria manufacture the vaccine or therapeutic
agents.
Lactococcus lactis
and
L. plantarum
are being used as a means of antigen
delivery for mucosal immunization.
Novel high-efficacy
Lactobacillus
expression
vectors have been designed to allow antigen expression intracellularly, extracellu-
larly, or secreted and anchored to the surface.
160
These expression vectors have been
used successfully to construct different
Lactobacillus-
expressing antigens, such as
tetanus toxin fragment C (TTFC), several rotavirus proteins, or urease A and B sub-
units from
H. pylori
.
161
Several recent publications report potential of probiotic vaccine vectors, for
example,
Lactococcus lactis
prototype vaccine against
H. pylori,
161
Brucella abor-
tis,
162
Streptococcus
gordonii
prototype vaccines against HIV
163
and measles.
164
Lactobacillus
prototype vaccines against anthrax
165
and rotavirus
166
are under devel-
opment. Intrinsic immunogenicity as well as resistance to bile acid and persistence
