6 replies to this topic

[FunkOdyssey]

© 2006 American Society for Nutrition J. Nutr. 136:70-74, January 2006

Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions
Dietary Fructooligosaccharides Affect Intestinal Barrier Function in Healthy Men
Sandra J. M. Ten Bruggencate*, Ingeborg M. J. Bovee-Oudenhoven*,1, Mischa L. G. Lettink-Wissink*, Martijn B. Katan{dagger} and Roelof van der Meer*

* Nutrition and Health Program, Wageningen Center for Food Sciences/NIZO Food Research, 6710 BA Ede, The Netherlands and {dagger} Nutrition and Health Program, Wageningen Center for Food Sciences, Wageningen, The Netherlands

1 To whom correspondence should be addressed: E-mail: ingeborg.bovee@nizo.nl.

ABSTRACT

In contrast to most expectations, we showed previously that dietary fructooligosaccharides (FOS) stimulate intestinal colonization and translocation of invasive Salmonella enteritidis in rats. Even before infection, FOS increased the cytotoxicity of fecal water, mucin excretion, and intestinal permeability. In the present study, we tested whether FOS has these effects in humans. A double-blind, placebo-controlled, crossover study of 2 x 2 wk, with a washout period of 2 wk, was performed with 34 healthy men. Each day, subjects consumed lemonade containing either 20 g FOS or placebo and the intestinal permeability marker chromium EDTA (CrEDTA). On the last 2 d of each supplement period, subjects scored their gastrointestinal complaints on a visual analog scale and collected feces and urine for 24 h. Fecal lactic acid was measured using a colorimetric enzymatic kit. The cytotoxicity of fecal water was determined with an in vitro bioassay, fecal mucins were quantified fluorimetrically, and intestinal permeability was determined by measuring urinary CrEDTA excretion. In agreement with our animal studies, FOS fermentation increased fecal wet weight, bifidobacteria, lactobacilli, and lactic acid. Consumption of FOS increased flatulence and intestinal bloating. In addition, FOS consumption doubled fecal mucin excretion, indicating mucosal irritation. However, FOS did not affect the cytotoxicity of fecal water and intestinal permeability. The FOS-induced increase in mucin excretion in our human study suggests mucosal irritation in humans, but the overall effects are more moderate than those in rats.

[xanadu]

Is FOS ordinary fructose? Someone had to ask.

[Shepard]

Nope.

[syr_]

phew

[xanadu]

What are they then and where are they found? Info like this means nothing to most people unless they can relate it to their diet or something. I haven't seen any Fructooligosaccharides listed on the labels I've looked at.

[FunkOdyssey]

FOS and Inulin are being added to all kinds of supplements, sweetener products, yogurts, etc, so its important to be familiar with them.

Fructooligosaccharides are short chains of fructose molecules that are largely indigestable by humans. They are found in small amounts in many vegetables -- onions, artichokes, garlic, and bananas are some common sources. They pass through the intestinal tract mostly intact and then act as prebiotics (food) for the gut flora (ideally only the friendly bacteria, but there is some evidence that they boost the population of other genera besides bifido and lactobacillus).

Many people are unaware of the distinction between FOS and Inulin. FOS has a degree of polymerization (DP) of <10, whereas Inulin has a DP ranging from 2 to 60. The chain length affects the manner and degree to which it is fermented in the gut -- inulin with its longer chain lengths seems to have more desirable effects in the human colon. I'll post some research I've collected on inulin tomorrow.

[Shepard]

Now sells both a FOS and Inulin powder, which I like. Um, they require a beginner period where you might want to avoid people.