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"In view of the
carcinogenic potential of these enzymes, the induced changes that occurred in this
study by lactulose,oligofructose-enriched inulin, L. casei Shirota and
B. breve on the bacterial beta-glucuronidase activity could be considered as beneficial
for the host and may have important implications for health," wrote lead
author Vicky De Preter from University Hospital Gasthuisberg, Leuven.
Writing in the European Journal
of Clinical Nutrition, the researchers report the findings of their investigation
into the potential benefits of the
prebiotics lactulose
(Duphalac Solvay Pharma) and oligofructose-enriched inulin (Raftilose Synergy 1,
Orafti), and the probiotics Lactobacillus casei Shirota
(Yakult), Bifidobacterium breve (Yakult) and Saccharomyces boulardii
(Perenterol, Biodiphar) on the activity and levels of the enzymes beta-glucuronidase
and beta-glucosidase on 53 healthy volunteers (age range 19-26).
Probiotics are bacteria found in
the gut that are understood to have health benefits. Prebiotics are ingredients
that stimulate growth of probiotics in the gut, and synbiotics are a combination
of the two.
The subjects were randomly assigned
to one of the five intervention groups and crossed over after four weeks of intervention.
A two-week washout period separated the interventions. Faecal samples were collected
over a period of 72 hours at the start and end of the intervention period.
De Preter reports that both prebiotics
significantly decreased beta-glucuronidase activity, as did the probiotics L. casei
Shirota and B. breve. S. boulardii was found to have no affect on
the enzymes, they said.
On the other hand, the probiotic
was found to increase the levels of beta-glucosidase.
"Supplementation
with the synbiotic did not appear to be more beneficial than either compound alone,"
stated the researchers.
"Administration
of lactulose, oligofructose-enriched inulin, L. casei Shirota or B. breve
resulted in a decrease of the beta-glucuronidase activity, which is considered beneficial
for the host," they concluded.
Talking exclusively to NutraIngredients.com,
lead researcher Professor Kristin Verbeke said that it was currently difficult to
indicate the relevance of the observations.
"First of all, we
have performed our measurements in young, "healthy" individuals and it is very difficult
to render healthy people more healthy. Secondly, we have shown that administration
of pre- and probiotics can decrease the activity of potential harmful bacterial
enzymes (and other parameters of colonic metabolism) but we have not (yet) shown
that people will live longer or healthier because of these changes," said Prof.
Verbeke.
"We should need
large, long-term diet intervention studies to prove the link between changes in
colonic metabolism and health and this will be very difficult."
Professor Verbeke also revealed
that the research in ongoing with work focusing on the evaluation of new potential
pre- and probiotic substrates.
"We will [also]
apply the methodology to patients in which an abnormal colon metabolism is expected
(such as inflammatory bowel disease and irritable bowel disease). In this way, we
want to investigate whether similar changes on colonic metabolism are observed as
in healthy individuals and whether changes in colonic metabolism correlate with
changes in disease activity," said Prof. Verbeke.
"This would already
be a first step in indicating the relevance of colonic metabolism to health."
Source: European Journal of Clinical
Nutrition
Advance online publication, doi:
10.1038/sj.ejcn.1602706
"Effect of dietary intervention
with different pre- and probiotics on intestinal bacterial enzyme activities"
Authors: V. De Preter, H. Raemen,
L. Cloetens, E. Houben, P. Rutgeerts and K. Verbeke
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