Chemistry Reference
In-Depth Information
3.5 DIgEsTIvE TolErANCE oF FruCTANs
Fermentation of NDCHs in the colon by the microflora produces gases (H
2
,
CH
4
, and CO
2
), which may cause flatulence, abdominal pain, or osmotic diarrhea.
It appears that digestive tolerance thresholds for prebiotics are clearly influenced by
the chemical nature of the prebiotic, the administered dose, and individual factors
(Marteau and Seksik, 2004). The individual factors include visceral sensitivity and
differences in bacterial profile of the colonic flora (Cherbut, 2003); it has been seen
that populations of lactate-utilizing bacteria in subjects reporting the highest number
of symptoms of discomfort following consumption of FOS were different from sub-
jects reporting no disturbance (Cherbut, 2003). Digestive tolerance is also influenced
by the type of food (differing mainly between solid and liquid food) and the way of
consumption (isolated consumption outside meal times favors symptoms) (Absolonne
et al., 1995). Overall, it is important to note that digestive tolerance thresholds for
NDCHs are significantly higher than efficient doses, which supports the interest in
prebiotics as a safe and beneficial modulation of gut microflora.
Besides the evaluation of digestive tolerance of fructans, an increased interest
in their impact on the quality of life of subjects is to be noted. In a recent study,
it appeared that the regular consumption of sc-FOS at moderate doses (5 g/day
over 6 weeks) can improve digestive comfort and daily quality of life in a work-
ing and nonmedically treated population suffering from minor functional bowel
disorders (Paineau
et al., 2008). This was the first study to assess the effects
of prebiotics on quality of life with the use of relevant evaluation methods. A
quality-of-life questionnaire was completed at the start and end of the treatment
period to assess potential effects on well-being and social performance. At the
end of the consumption period, the intensity of digestive disorders decreased by
43.6 percent in the sc-FOS group versus a 13.8 percent increase in the placebo
group (
P
= 0.026). Expressed as change in quality of life (improvement, worsen-
ing, or unchanged), daily activities were significantly improved in the sc-FOS
group (
P
= 0.022).
3.6 CoNClusIoNs
Prebiotics are widely available food ingredients that may exert a number of ben-
eficial effects on human health. Most of these effects are mediated through their
bifidogenic properties. Promising effects include a benefit in different situations in
gastroenterology, such as infectious diarrhea, IBS, IBD, and colonic carcinogenesis.
Objectives of future studies must investigate mechanisms in humans to define the
optimal consumption of prebiotics. Well-controlled clinical trials in humans are
needed especially in IBS, IBD, and prevention of colonic polyps, which are all major
and increasing health problems in industrialized countries.
