The aim of this paper is to discuss issues that fall within the general concept of well-being, with special emphasis on approaches that have been used in studies of nutrition and behaviour. Following this, two specific studies are described in detail, the first examining high-fibre breakfast cereals and the second investigating effects of inulin. Studies of nutrition and well-being can be categorised in a number of ways. One method involves examining acute effects of nutrition on mood and cognitive functioning. Another method has been to examine cross-sectional associations between dietary habits and questionnaire measures of reported health. Examples are given showing that regular consumption of a high-fibre diet is associated with better-reported physical and mental health. The problem with such correlational studies is that it is impossible to infer causality. Intervention studies are necessary to achieve this and some examples of this approach are given. In the first study reported here, we examined whether consumption of high-fibre breakfast cereal led to an increase in energy. Such an effect was observed and plausible biological mechanisms underlying such results are described. A similar methodology has recently been used to examine the effects of inulin. In this case the results showed no negative side-effects of taking inulin but there were no beneficial effects of inulin on measures of well-being (both subjective reports and objective measures). Possible reasons for these effects are discussed.

Physiological stimuli in the gut induce regulatory reflexes to accomplish the digestive process, but are normally not perceived. However, under some circumstances, gut stimuli may activate perception pathways and induce conscious sensations. Experimental evidence gathered during the past decade suggests that patients with functional gut disorders and unexplained abdominal symptoms may have a sensory dysfunction of the gut, so that physiological stimuli would induce symptoms. Assessment of visceral sensitivity is still poorly developed, but in analogy to somatosensory testing, differential stimulation of visceral afferents may be achieved by a combination of stimulation techniques, which may help to characterize sensory dysfunctions. Visceral afferent input is modulated by a series of mechanisms at different levels of the brain–gut axis, and conceivably, a dysfunction of these regulatory mechanisms could cause hyperalgesia. The sensory dysfunction in functional patients seems to be associated with altered reflex activity, and both mechanisms may interact to produce the symptoms. Evidence of a gut sensory–reflex dysfunction as a common pathophysiological mechanism in different functional gastrointestinal disorders would suggest that they are different forms of the same process, and that the clinical manifestations depend on the specific pathways affected.

Inulin is a generic term to cover all β(2 → 1) linear fructans. Chicory inulin is a linear β(2 → 1) fructan (degree of polymerisation (DP) 2 to 60; DPav = 12), its partial enzymatic hydrolysis product is oligofructose (DP 2 to 8; DPav = 4), and by applying specific separation technologies a long-chain inulin knownas inulin HP (DP 10 to 60; DPav = 25) can be produced. Finally, a specific product known as oligofructose-enriched inulin is obtained by combining chicorylong-chain inulin and oligofructose. Because of the b-configuration of the anomeric C2 in their fructose monomers, inulin-type fructans resist hydrolysis byintestinal digestive enzymes, they classify as ‘non-digestible’ carbohydrates, and they are dietary fibres. By increasing faecal biomass and water content ofthe stools, they improve bowel habits, but they have characteristic features different from other fibres. They affect gastrointestinal functions not because oftheir physico-chemical properties but rather because of their biochemical and physiological attributes. In the colon, they are rapidly fermented to produceSCFA that are good candidates to explain some of the systemic effects of inulin-type fructans. Fermentation of inulin-type fructans in the large bowel is aselective process; bifidobacteria (and possibly a few other genera) are preferentially stimulated to grow, thus causing significant changes in the compositionof the gut microflora by increasing the number of potentially health-promoting bacteria and reducing the number of potentially harmful species. Both oligofructosead inulin are prebiotic. They also induce changes in colonic epithelium stimulating proliferation in the crypts, increasing the concentration ofpolyamines, changing the profile of mucins, and modulating endocrine as well as immune functions. From a nutrition labelling perspective, inulin-typefructans are not only prebiotic dietary fibres; they are also low-calorie carbohydrates [6·3 kJ/g (1·5 kcal/g)]. Supported by the results of a large numberof animal studies and human nutrition intervention trials, the claim ‘inulin-type fructans enhance calcium and magnesium absorption‘ is scientifically substantiated, but different inulin-type fructans have probably a different efficacy (in terms of effective daily dose), the most active product being the oligofructose-enriched inulin. A series of animal studies demonstrate that inulin-type fructans affect the metabolism of lipids primarily by decreasingtriglyceridaemia because of a reduction in the number of plasma VLDL particles. The human data largely confirm the animal experiments. They demonstratemainly a reduction in triglyceridaemia and only a relatively slight decrease in cholesterolaemia mostly in (slightly) hypertriglyceridaemic conditions. Inulinappears thus eligible for an enhanced function claim related to normalization of blood triacylglycerols. A large number of animal data convincingly showthat inulin-type fructans reduce the risk of colon carcinogenesis and nutrition intervention trials are now performed to test that hypothesis in human subjectsknown to be at risk for polyps and cancer development in the large bowel.

The behavioural and cognitive effects of oligofructose-enriched inulin at the doses of 5 and 10% in the diet, orally ingested daily during 2 weeks, wereinvestigated using a functional observational battery (FOB) and the light extinction test in male Wistar rats. Control rats received a standard diet and were tested in the same test situations. The behavioural effects were assessed 2 d before and 14 d after the beginning of the treatment period and the cognitive effects were investigated after the administration period by lever-pressing activity and learning discrimination using the light extinction test paradigm. In general, the study demonstrated that oligofructose-enriched inulin at 5% in the diet, and particularly at 10% in the diet, caused relaxing-like effects, stimulated and increased the general activity and interest of the rats to the test environment. In addition, both doses of oligofructose-enriched inulin showed significant effects on learning discrimination in male rats, in comparison with the control diet. These results suggest that oligofructose-enriched inulin, particularly at the dose of 10 %, improves cognitive performances in the light extinction test and the well-being of male rats using the FOB.

Acute gut disorder is a cause for significant medicinal and economic concern. Certain individual pathogens of the gut, often transmitted in food or water, have the ability to cause severe discomfort. There is a need to manage such conditions more effectively. The route of reducing the risk of intestinal infections through diet remains largely unexplored. Antibiotics are effective at inhibiting pathogens; however, these should not be prescribed in the absence of disease and therefore cannot be used prophylactically. Moreover, their indiscriminate use has reduced effectiveness. Evidence has accumulated to suggestthat some of the health-promoting bacteria in the gut (probiotics) can elicit a multiplicity of inhibitory effects against pathogens. Hence, an increase in their numbers should prove effective at repressing pathogen colonisation if/when infectious agents enter the gut. As such, fortification of indigenous bifidobacteria/lactobacilli by using prebiotics should improve protection. There are a number of potential mechanisms for lactic acid bacteria to reduce intestinal infections. Firstly, metabolic endproducts such as acids excreted by these micro-organisms may lower the gut pH to levels below those at which pathogens are able to effectively compete. Also, many lactobacilli and bifidobacteria species are able to excrete natural antibiotics, which can have a broad spectrum of activity. Other mechanisms include an improved immune stimulation, competition for nutrients and blocking of pathogen adhesion sites in the gut. Many intestinal pathogens like type 1 fimbriated Escherichia coli, salmonellae and campylobacters utilise oligosaccharide receptor sites in the gut. Once established, they can then cause gastroenteritis through invasive and/or toxin forming properties. One extrapolation of the prebiotic concept is to simulate such receptor sites in the gut lumen. Hence, the pathogen is ‘decoyed’ into not binding at the host mucosal interface. The combined effects of prebiotics upon the lactic acid flora and anti-adhesive strategies may lead towards new dietary interventions against food safety agents.

Non-digestible inulin-type fructans, such as oligofructose and high-molecular-weight inulin, have been shown to have the ability to alter the intestinal microbiota composition in such a way that members of the microbial community, generally considered as health-promoting, are stimulated. Bifidobacteria and lactobacilli are the most frequently targeted organisms. Less information exists on effects of inulin-type fructans on the composition, metabolism and healthrelated significance of bacteria at or near the mucosa surface or in the mucus layer forming mucosa-associated biofilms. Using rats inoculated with a human faecal flora as an experimental model we have found that inulin-type fructans in the diet modulated the gut microbiota by stimulation of mucosa-associated bifidobacteria as well as by partial reduction of pathogenic Salmonella enterica subsp. enterica serovar Typhimurium and thereby benefit health. In addition to changes in mucosal biofilms, inulin-type fructans also induced changes in the colonic mucosa stimulating proliferation in the crypts, increasing the release of mucins, and altering the profile of mucin components in the goblet cells and epithelial mucus layer. These results indicate that inulin-type fructans may stabilise the gut mucosal barrier. Dietary supplementation with these prebiotics could offer a new approach to supporting the barrier function of the mucosa.

The newborn infant leaves a germ-free intrauterine environment to enter a contaminated extrauterine world and must have adequate intestinal defences to prevent the expression of clinical gastrointestinal disease states. Although the intestinal mucosal immune system is fully developed after a full-term birth, the actual protective function of the gut requires the microbial stimulation of initial bacterial colonization. Breast milk contains prebiotic oligosaccharides, like inulin-type fructans, which are not digested in the small intestine but enter the colon as intact large carbohydrates that are then fermented by the resident bacteria to produce SCFA. The nature of this fermentation and the consequent pH of the intestinal contents dictate proliferation of specific resident bacteria. For example, breast milk-fed infants with prebiotics present in breast milk produce an increased proliferation of bifidobacteria and lactobacilli (probiotics), whereas formula-fed infants produce more enterococci and enterobacteria. Probiotics, stimulated by prebiotic fermentation, are important to the development and sustainment of intestinal defences. For example, probiotics can stimulate the synthesis and secretion of polymeric IgA, the antibody that coats and protects mucosal surfaces against harmful bacterial invasion. In addition, appropriate colonization with probiotics helps to produce a balanced T helper cell response (Th1 = Th2 = Th3/Tr1) and prevent an imbalance (Th1 > Th2 or Th2 > Th1) contributing in part to clinical disease (Th2 imbalance contributes to atopic disease and Th1 imbalance contributes to Crohn's disease and Helicobacter pylori-induced gastritis). Furthermore, a series of pattern recognition receptors, toll-like receptors on gut lymphoid and epithelial cells that interact with bacterial molecular patterns (e.g. endotoxin (lipopolysaccharide), flagellin, etc.), help modulate intestinal innate immunity and an appropriate adaptive immune response. Animal and clinical studies have shown that inulin-type fructans will stimulate an increase in probiotics (commensal bacteria) and these bacteria have been shown to modulate the development and persistence of appropriate mucosal immune responses. However, additional studies are needed to show that prebiotics can directly or indirectly stimulate intestinal host defences. If this can be demonstrated, then prebiotics can be used as a dietary supplement to stimulate a balanced and an appropriately effective mucosal immune system in newborns and infants.

Diet is known to modulate immune functions in multiple ways and to affect host resistance to infections. Besides the essential nutrients, non-essential food constituents such as non-digestible carbohydrates may also have an impact on the immune system, especially in the area of the gut-associated lymphoid tissue (GALT). Recent data now provide first evidence that prebiotics such as inulin/oligofructose (IN/OF) modulate functions of the immune system. In animal studies IN/OF primarily activated immune cells in Peyer's patches including IL-10 production and natural killer (NK) cell cytotoxicity. Other immune functions modulated by IN/OF included the concentration of secretory IgA in ileum and caecum, splenic NK cell cytotoxicity as well as splenocyte cytokine production. In different tumour models, a lower incidence of tumours was observed, which in the case of colonic tumours was associated with enhanced NK cell cytotoxicity in the GALT. Few human studies so far have investigated the effects of IN/OF alone or in combination with other dietary supplements on immunocompetence. Supplementation of IN/OF resulted in minor changes of systemic immune functions such as decrease in phagocytic activity. No data are available on the effects of IN/OF on the GALT in man. The mechanisms of the reported effects of IN/OF on the immune system are currently investigated and include: (i) direct effects of lactic acid-producing bacteria or bacterial constituents on immune cells; (ii) the production of SCFA and binding to SCFA receptors on leucocytes. In conclusion, the current data suggest that IN/OF primarily modulate immune parameters in the GALT, but splenocytes are also activated by IN/OF. Human studies are needed to find out whether IN/OF have the potential to modulate systemic immunity in wellnourished individuals and to lower the risk of diseases such as colon cancer.

The rationale for supplementing an infant formula with prebiotics is to obtain a bifidogenic effect and the implied advantages of a ‘breast-fed-like’ flora. So far, the bifidogenic effect of oligofructose and inulin has been demonstrated in animals and in adults, of oligofructose in infants and toddlers and of a longchain inulin (10 %) and galactooligosaccharide (90 %) mixture in term and preterm infants. The addition of prebiotics to infant formula softens stools but other putative effects remain to be demonstrated. Studies published post marketing show that infants fed a long-chain inulin/galactooligosaccharide mixture (0·8 g/dl) in formula grow normally and have no side-effects. The addition of the same mixture at a concentration of 0·8 g/dl to infant formula was therefore recognized as safe by the European Commission in 2001 but follow-up studies were recommended. It is thought that a bifidogenic effect is beneficial for the infant host. The rising incidence in allergy during the first year of life may justify the attempts to modulate the infant's flora. Comfort issues should not be confused with morbidity and are likely to be multifactorial. The functional effects of prebiotics on infant health need further study in controlled intervention trials.

A large and diverse variety of bacteria have evolved and adapted to live in the human intestinal habitat in a symbiotic arrangement that influences both physiology and pathology in the host. Symbiosis between host and flora can be optimised by prebiotics. Inulin-type fructans have been shown to improve the metabolic functions of the commensal flora. Clinical and experimental data suggest that they also improve the gut mucosal barrier. Furthermore, modulation of the trophic functions of the flora by these prebiotics could help in the prevention of inflammatory bowel diseases. The anti-inflammatory effects of inulin or oligofructose have been assessed in the rat model of distal colitis induced by dextran sodium sulphate, which histologically resembles human ulcerative colitis, and in the trinitrobenzene sulphonic acid model that resembles human Crohn's disease. Both inulin and oligofructose stimulate colonic production of SCFA and favour the growth of indigenous lactobacilli and/or bifidobacteria. These effects are associated with reduced mucosal inflammation and decreased mucosal lesion scores. Inulin has also been tested in a placebo-controlled clinical trial in patients with relapsing pouchitis. Treatment reduced endoscopic and histological parameters of inflammation of the pouch mucosa. Inulin and oligofructose may offer an opportunity to prevent chronic inflammatory intestinal disorders, and this potential should be tested in further clinical studies.

Ulcerative colitis (UC) is an acute and chronic inflammatory bowel disease of unknown aetiology, although bacterial species belonging to the normal colonic microbiota are known to be involved in its initiation and maintenance. Several organisms have been linked to the disease; however, mucosa-associated bacteria are more likely to be involved than their luminal counterparts, due to their close proximity to the host epithelium. Comparative bacteriological analyses were done on rectal biopsies to investigate differences in mucosal bacteria in patients with UC and healthy controls. Complex bacterial communities were found in both groups, with significant reductions in bifidobacterial numbers in UC, which suggested that they might have a protective role in the disease. Accordingly, a therapy for treating UC was designed, with the aim of modifying the mucosal microbiota to increase bifidobacterial colonisation and reduce inflammation. Ranges of mucosal and faecal bifidobacteria were tested for their substrate preferences and their abilities to survive under a variety of environmental conditions. A synbiotic comprising a probiotic (Bifidobacterium longum) isolated from healthy rectal mucosa combined with a prebiotic (oligofructose-enriched inulin – Synergy 1TM) was developed. The treatment was used in a randomised controlled trial involving eighteen patients with active UC, for a period of 1 month. Rectal biopsies were collected at the beginning and end of the study. Bacteriological analysis and transcription levels of epithelium-related immune markers were assessed. Results demonstrated that short-term synbiotic treatment resulted in increased bifidobacterial colonisation of the rectal mucosa and induced significant reductions in the expression of molecules that control inflammation in active UC.

Inulin-type fructans (β(2,1)fructans) extracted from chicory roots (Cichorium intybus) are prebiotic food ingredients, which in the gut lumen are fermented to lactic acid and SCFA. Research in experimental animal models revealed that inulin-type fructans have anticarcinogenic properties. A number of studies report the effects of inulin-type fructans on chemically induced pre-neoplastic lesions (ACF) or tumours in the colon of rats and mice. In twelve studies, there were twenty-nine individual treatment groups of which twenty-four measured aberrant crypt foci (ACF) and five measured tumours. There was a significant reduction of ACF in twenty-one of the twenty-four treatment groups and of tumour incidence in five of the five treatment groups. Higher beneficial effects were achieved by synbiotics (mixtures of probiotics and prebiotics), long-chain inulin-type fructans compared to short-chain derivatives, and feeding high-fat Western style diets. Inulin-type fructans reduced tumour incidence in APCMin mice in two of four studies and reduced growth and metastasising properties of implanted tumour cells in mice (four studies). The effects have been reported to be associated with gut flora-mediated fermentation and production of butyrate. In human cells, inulin-derived fermentation products inhibited cell growth, modulated differentiation and reduced metastasis activities. In conclusion, evidence has been accumulated that shows that inulin-type fructans and corresponding fermentation products reduced the risks for colon cancer. The involved mechanisms included the reduction of exposure to risk factors and suppression of tumour cell survival. Thus, this specific type of dietary fibre exerted both blocking agent and suppressing agent types of chemopreventive activities.

Experimental evidence on the anticancer properties of dietary prebiotics such as chicory inulin and oligofructose and dietary probiotics has accumulated in recent years. Various experimental models ranging from chemoprevention studies, tumour implantation models to genetically modified mice models, etc. have systematically shown the protective effects of these food ingredients. In some studies it appeared that synbiotics (combination of pre- and probiotics) exerted synergistic activity against processes of carcinogenesis. The logical next step in research was to find out if these observations also would be valid for human volunteers. This was the principal goal of the EU-sponsored SYNCAN project (QLK1-1999-346) which involved the integration of an in vitro study to select the most suitable synbiotic preparation, the application of this synbiotic in an in vivo rat model of chemically induced colon cancer, and, as the heart of the project, the investigation of the synbiotic effects in a human intervention study. The in vitro tests consisted of fermentation studies where the interaction of pre- and probiotics was studied. Cell-free supernatants were generated from various synbiotic combinations fermented by faecal slurry, which were then used to optimise a series of bioassays. In the rat study the anticarcinogenic effect of prebiotics and synbiotics but not of probiotics was demonstrated. Using tissue samples generated in this model, attempts were made to gain a better insight into the mechanisms underlying cancer development. The human intervention study consisted of two groups of volunteers. One group was composed of people at high risk (polypectomised subjects) for colon cancer and the other of volunteers (colon cancer subjects) who had previously undergone ‘curative resection‘ for colon cancer but were not currently receiving treatment. The present paper describes the experimental design of the SYNCAN study, and demonstrates a functional effect of the synbiotic preparation (probiotic survival during gastrointestinal transit and modification of the intestinal flora). Detailed experimental outcome of the human intervention study will be reported elsewhere.

Inulin-type fructans have been proposed to benefit mineral retention, thereby enhancing bone health. Many, but not all, experimental animal studies have shown increased mineral absorption by feeding non-digestible oligosaccharides. Possible reasons for inconsistencies are explored.A few studies have reported an enhanced bone mineral density or content. Bone health can be evaluated in chronic feeding studies with bone densitometry, bone breaking strength, bone mineral concentration and bone structure. Isotopic Ca tracers can be used to determine the point of metabolism affected by feeding a functional food ingredient. These methods and the effects of feeding inulin-type fructose are reviewed. Inulin-type fructans enhance Mg retention. Chicory long-chain inulin and oligofructose enhance femoral Ca content, bone mineral density and Ca retention through enhanced Ca absorption and suppressed bone turnover rates, but it is not bone-promoting under all conditions

During the last 50 years, a variety of methods have been developed to estimate Ca absorption in man. Mass balances were initially used, but these were unable to accurately measure fractional Ca absorption because they cannot distinguish unabsorbed dietary Ca from endogenous faecal Ca excretion (excretion of previously absorbed Ca back into the gut). A number of isotopic methods have been developed that can measure true fractional Ca absorption, employing radioisotopes, stable isotopes, or both. Different methods involve collection of urine, faecal or plasma samples. Of the currently available methods, the dual isotope tracer method with a timed urine collection is probably the most precise and reliable. It is also relatively straightforward to carry out and avoids the need for a faecal collection. The purpose of the present paper is to discuss the general advantages and disadvantages of the different methods of Ca absorption. In addition, the limitations the different methods have in examining the possible effects of non-digestible oligosaccharides on Ca absorption will be discussed.

If the primary role of diet is to provide sufficient nutrients to meet the metabolic requirements of an individual, there is an emerging rationale to support the hypothesis that, by modulating specific target functions in the body, it can help achieve optimal health. Regarding osteoporosis prevention, since Ca is most likely to be inadequate in terms of dietary intake, every strategy targeting an improvement in Ca absorption is very interesting. Actually, this process may be susceptible to manipulation by fermentable substrates. In this light, inulin-type fructans are very interesting, even if we need to gather more data targeting bone metabolism before health professionals can actively advocate their consumption to prevent senile osteoporosis. Besides targeting the prevention of postmenopausal osteoporosis, inulin-type fructans still remain a source for putative innovative dietary health intervention. Indeed, given in combination with isoflavones, they may have a potential for maintaining or improving the bone mass of human subjects, by modulating the bioavailability of phyto-oestrogens.

The inulin-type fructans are non-digestible oligosaccharides that are fermented in the gastrointestinal tract of farm animals and pets. This review focuses on the various effects of inulin-type fructans in pigs, poultry, calves and companion animals. Effects of the inulin-type fructans on gut microflora, digestion and availability of nutrients, gut morphology, fermentation characteristics and animal performance are discussed. Inulin-type fructans can support animal performance and health by affecting nutrient digestion, gut microflora and gut morphology, although results vary depending on composition of the basal diet, inclusion level, type of fructan, adaptation period and experimental hygienic conditions.

The scientific strategy of molecular gastronomy includes modelling ‘culinary definitions’ and experimental explorations of ‘culinary precisions’. A formalism that describes complex dispersed systems leads to a physical classification of classical sauces, as well as to the invention of an infinite number of new dishes

The glucoincretins, glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP), are intestinal peptides secreted in response to glucose or lipid intake. Data on isolated intestinal tissues, dietary treatments and knockout mice strongly suggest that GIP and GLP-1 secretion requires glucose and lipid metabolism by intestinal cells. However, incretin secretion can also be induced by non-digestible carbohydrates and involves the autonomic nervous system and endocrine factors such as GIP itself and cholecystokinin. The classical pharmacological approach and the recent use of knockout mice for the incretin receptors have shown that a remarkable feature of incretins is the ability to stimulate insulin secretion in the presence of hyperglycaemia only, hence avoiding any hypoglycaemic episode. This important role is the basis of ongoing clinical trials using GLP-1 analogues. Since most of the data concern GLP-1, we will focus on this incretin. In addition, GLP-1 is involved in glucose sensing by the autonomic nervous system of the hepato-portal vein controlling muscle glucose utilization and indirectly insulin secretion. GLP-1 has been shown to decrease glucagon secretion, food intake and gastric emptying, preventing excessive hyperglycaemia and overfeeding. Another remarkable feature of GLP-1 is its secretion by the brain. Recently, elegant data showed that cerebral GLP-1 is involved in cognition and memory. Experiments using knockout mice suggest that the lack of the GIP receptor prevents diet-induced obesity. Consequently, macronutrients controlling intestinal glucose and lipid metabolism would control incretin secretion and would consequently be beneficial for health. The control of incretin secretion represents a major goal for new therapeutic as well as nutrition strategies for treating and/or reducing the risk of hyperglycaemic syndromes, excessive body weight and thus improvement of well-being.

In the present paper, we summarise the data supporting the following hypothesis: dietary inulin-type fructans extracted from chicory root may modulate the production of peptides, such as incretins, by endocrine cells present in the intestinal mucosa, this phenomenon being involved in the regulation of food intake and/or systemic effects. To test this hypothesis, male Wistar rats received for 3 weeks either a standard diet or the same diet supplemented with 10% inulin-type fructans with different degrees of polymerisation. All the effects were most pronounced with the diet containing oligofructose, and consisted of (i) a decrease in mean daily energy intake and in epididymal fat mass; (ii) a higher caecal pool of the anorexigenic glucagon-like peptide-1 (7–36) amide (GLP-1), and peptide YY (PYY), due to caecal tissue proliferation; (iii) an increase in GLP-1 and of its precursor – proglucagon mRNA – concentrations in the proximal colon; (iv) an increase in portal serum level of GLP-1 and PYY; (v) a decrease in serum orexigenic peptide ghrelin. Moreover, oligofructose supplementation improved glucose homeostasis (i.e. decreased glycaemia, increased pancreatic and serum insulin content) in diabetic rats previously treated with streptozotocin, a phenomenon that is partly linked to the reduction in food intake and that correlates with the increase in colic and portal GLP-1 content. Based on these results it appears justified to test, in human subjects, the hypothesis that dietary inulin-type fructans could play a role in the management of obesity and diabetes through their capacity to promote secretion of endogenous gastrointestinal peptides involved in appetite regulation.