PhysioPathologie des Adaptations Nutritionnelles

The number of surviving children born prematurely has increased substantially during the last 2 decades. The major goal of enteral nutrient supply to these infants is to achieve growth similar to foetal growth coupled with satisfactory functional development. The accumulation of knowledge since the previous guideline on nutrition of preterm infants from the Committee on Nutrition of the European Society of Paediatric Gastroenterology and Nutrition in 1987 has made a new guideline necessary. Thus, an ad hoc expert panel was convened by the Committee on Nutrition of the European Society of Paediatric Gastroenterology, Hepatology, and Nutrition in 2007 to make appropriate recommendations. The present guideline, of which the major recommendations are summarised here (for the full report, see http://links.lww.com/A1480), is consistent with, but not identical to, recent guidelines from the Life Sciences Research Office of the American Society for Nutritional Sciences published in 2002 and recommendations from the handbook Nutrition of the Preterm Infant. Scientific Basis and Practical Guidelines, 2nd ed, edited by Tsang et al, and published in 2005. The preferred food for premature infants is fortified human milk from the infant's own mother, or, alternatively, formula designed for premature infants. This guideline aims to provide proposed advisable ranges for nutrient intakes for stable-growing preterm infants up to a weight of approximately 1800 g, because most data are available for these infants. These recommendations are based on a considered review of available scientific reports on the subject, and on expert consensus for which the available scientific data are considered inadequate.

BACKGROUND: There are gaps in our knowledge of the prevalence of adult atopic dermatitis (AD). OBJECTIVE: To estimate the prevalence of AD in adults and by disease severity. METHODS: This international, cross-sectional, web-based survey was performed in the United States, Canada, France, Germany, Italy, Spain, United Kingdom, and Japan. Adult members of online respondent panels were sent a questionnaire for AD identification and severity assessment; demographic quotas ensured population representativeness for each country. A diagnosis of AD required subjects to be positive on the modified UK Working Party/ISAAC criteria and self-report of ever having an AD diagnosis by a physician. The proportion of subjects with AD who reported being treated for their condition was determined and also used to estimate prevalence. Severity scales were Patient-Oriented SCORAD, Patient-Orientated Eczema Measure, and Patient Global Assessment. RESULTS: Among participants by region, the point prevalence of adult AD in the overall/treated populations was 4.9%/3.9% in the US, 3.5%/2.6% in Canada, 4.4%/3.5% in the EU, and 2.1%/1.5% in Japan. The prevalence was generally lower for males vs females, and decreased with age. Regional variability was observed within countries. Severity varied by scale and region; however, regardless of the scale or region, proportion of subjects reporting severe disease was lower than mild or moderate disease. CONCLUSIONS: Prevalence of adult AD ranged from 2.1% to 4.9% across countries. Severe AD represented a small proportion of the overall AD population regardless of measure or region.

Research into the analysis, physical properties and health effects of dietary fibre has continued steadily over the last 40-50 years. From the knowledge gained, countries have developed guidelines for their populations on the optimal amount of fibre to be consumed each day. Food composition tables from many countries now contain values for the dietary fibre content of foods, and, from these, combined with dietary surveys, population intakes have been determined. The present review assessed the uniformity of the analytical methods used, health claims permitted, recommendations and intakes, particularly from national surveys across Europe and around the world. It also assessed current knowledge on health effects of dietary fibre and related the impact of different fibre types on health. The overall intent was to be able to provide more detailed guidance on the types of fibre which should be consumed for good health, rather than simply a total intake figure, the current situation. Analysis of data indicated a fair degree of uniformity in the definition of dietary fibre, the method used for analysis, the recommended amount to be consumed and a growing literature on effects on digestive health and disease risk. However, national dietary survey data showed that intakes do not reach recommendations and very few countries provide guidance on the types of fibre that are preferable to achieve recommended intakes. Research gaps were identified and ideas suggested to provide information for more detailed advice to the public about specific food sources that should be consumed to achieve health benefits.

OBJECTIVE: To describe the evolving epidemiology, management, and risk factors for death of invasive Candida infections in intensive care units (ICUs). DESIGN: Prospective, observational, national, multicenter study. SETTING: One hundred eighty ICUs in France. PATIENTS: Between October 2005 and May 2006, 300 adult patients with proven invasive Candida infection who received systemic antifungal therapy were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred seven patients (39.5%) with isolated candidemia, 87 (32.1%) with invasive candidiasis without documented candidemia, and 77 (28.4%) with invasive candidiasis and candidemia were eligible. In 37% of the cases, candidemia occurred within the first 5 days after ICU admission. C. albicans accounted for 57.0% of the isolates, followed by C. glabrata (16.7%), C. parapsilosis (7.5%), C. krusei (5.2%), and C. tropicalis (4.9%). In 17.1% of the isolates, the causative Candida was less susceptible or resistant to fluconazole. Fluconazole was the empirical treatment most commonly introduced (65.7%), followed by caspofungin (18.1%), voriconazole (5.5%), and amphotericin B (3.7%). After identification of the causative species and susceptibility testing results, treatment was modified in 86 patients (31.7%). The case fatality ratio in ICU was 45.9% and did not differ significantly according to the type of episode. Multivariate analysis showed that factors independently associated with death in ICU were type 1 diabetes mellitus (odds ratio [OR] 4.51; 95% confidence interval [CI] 1.72-11.79; p = 0.002), immunosuppression (OR 2.63; 95% CI 1.35-5.11; p = 0.0045), mechanical ventilation (OR 2.54; 95% CI 1.33-4.82; p = 0.0045), and body temperature >38.2 degrees C (reference, 36.5-38.2 degrees C; OR 0.36; 95% CI 0.17-0.77; p = 0.008). CONCLUSIONS: More than two thirds of patients with invasive candidiasis in ICU present with candidemia. Non-albicans Candida species reach almost half of the Candida isolates. Reduced susceptibility to fluconazole is observed in 17.1% of Candida isolates. Mortality of invasive candidiasis in ICU remains high.

BACKGROUND: Growing evidence suggests that patients with irritable bowel syndrome (IBS) have increased intestinal permeability. In addition, mucosal soluble mediators are involved in the pathophysiology of pain in IBS. We aimed to investigate (1) paracellular permeability in colonic biopsies of patients with IBS; and (2) the ability of soluble factors from colonic biopsies to reproduce these alterations in vitro. METHODS: Paracellular permeability in colonic biopsies of healthy subjects and patients with IBS was measured by mounting the biopsies in Ussing chambers. Cleared supernatant (SUP) of the culture from colonic biopsies was collected and applied to Caco-2 cells for 48 h. Paracellular permeability and transepithelial resistance (TER) were evaluated. mRNA expression of the tight junction proteins, zonula occludens (ZO)-1 and occludin, was assessed in colonic biopsies. Abdominal pain was assessed using a validated questionnaire. RESULTS: Permeability of colonic biopsies was significantly higher in patients with IBS compared to healthy subjects. These changes were associated with significantly lower expression of ZO-1 mRNA in biopsies of IBS as compared to healthy subjects. Compared to healthy subjects, SUP of IBS markedly reduced TER and significantly increased permeability in Caco-2 cells. SUP of IBS patients induced a significant decrease of ZO-1 mRNA in Caco-2 as compared to healthy subjects. SUP-induced increased paracellular permeability correlated with the severity of abdominal pain. CONCLUSIONS: Our study shows that colonic soluble mediators are able to reproduce functional (permeability) and molecular (ZO-1 mRNA expression) alterations observed in IBS patients. These findings might pave the way both to identify novel biomarkers as well as new therapeutic targets in IBS.

Recent research has demonstrated that all body fluids assessed contain substantial amounts of vesicles that range in size from 30 to 1000 nm and that are surrounded by phospholipid membranes containing different membrane microdomains such as lipid rafts and caveolae. The most prominent representatives of these so-called extracellular vesicles (EVs) are nanosized exosomes (70-150 nm), which are derivatives of the endosomal system, and microvesicles (100-1000 nm), which are produced by outward budding of the plasma membrane. Nanosized EVs are released by almost all cell types and mediate targeted intercellular communication under physiological and pathophysiological conditions. Containing cell-type-specific signatures, EVs have been proposed as biomarkers in a variety of diseases. Furthermore, according to their physical functions, EVs of selected cell types have been used as therapeutic agents in immune therapy, vaccination trials, regenerative medicine, and drug delivery. Undoubtedly, the rapidly emerging field of basic and applied EV research will significantly influence the biomedicinal landscape in the future. In this Perspective, we, a network of European scientists from clinical, academic, and industry settings collaborating through the H2020 European Cooperation in Science and Technology (COST) program European Network on Microvesicles and Exosomes in Health and Disease (ME-HAD), demonstrate the high potential of nanosized EVs for both diagnostic and therapeutic (i.e., theranostic) areas of nanomedicine.

Atopic dermatitis (AD) is a highly pruritic, chronic inflammatory skin disease. The diagnosis is made using evaluated clinical criteria. Disease activity and burden are best measured with a composite score, assessing both objective and subjective symptoms, such as SCORing Atopic Dermatitis (SCORAD). AD management must take into account clinical and pathogenic variabilities, the patient's age and also target flare prevention. Basic therapy includes hydrating and barrier-stabilizing topical treatment universally applied, as well as avoiding specific and unspecific provocation factors. Visible skin lesions are treated with anti-inflammatory topical agents such as corticosteroids and calcineurin inhibitors (tacrolimus and pimecrolimus), which are preferred in sensitive locations. Topical tacrolimus and some mid-potency corticosteroids are proven agents for proactive therapy, which is defined as the long-term intermittent anti-inflammatory therapy of frequently relapsing skin areas. Systemic anti-inflammatory or immunosuppressive treatment is a rapidly changing field requiring monitoring. Oral corticosteroids have a largely unfavourable benefit-risk ratio. The IL-4R-blocker dupilumab is a safe, effective and licensed, but expensive, treatment option with potential ocular side-effects. Other biologicals targeting key pathways in the atopic immune response, as well as different Janus kinase inhibitors, are among emerging treatment options. Dysbalanced microbial colonization and infection may induce disease exacerbation and can justify additional antimicrobial treatment. Systemic antihistamines (H1R-blockers) only have limited effects on AD-related itch and eczema lesions. Adjuvant therapy includes UV irradiation, preferably narrowband UVB or UVA1. Coal tar may be useful for atopic hand and foot eczema. Dietary recommendations should be patient-specific, and elimination diets should only be advised in case of proven food allergy. Allergen-specific immunotherapy to aeroallergens may be useful in selected cases. Psychosomatic counselling is recommended to address stress-induced exacerbations. Efficacy-proven 'Eczema school' educational programmes and therapeutic patient education are recommended for both children and adults.

Kallmann syndrome combines anosmia, related to defective olfactory bulb morphogenesis, and hypogonadism due to gonadotropin-releasing hormone deficiency. Loss-of-function mutations in KAL1 and FGFR1 underlie the X chromosome-linked form and an autosomal dominant form of the disease, respectively. Mutations in these genes, however, only account for approximately 20% of all Kallmann syndrome cases. In a cohort of 192 patients we took a candidate gene strategy and identified ten and four different point mutations in the genes encoding the G protein-coupled prokineticin receptor-2 (PROKR2) and one of its ligands, prokineticin-2 (PROK2), respectively. The mutations in PROK2 were detected in the heterozygous state, whereas PROKR2 mutations were found in the heterozygous, homozygous, or compound heterozygous state. In addition, one of the patients heterozygous for a PROKR2 mutation was also carrying a missense mutation in KAL1, thus indicating a possible digenic inheritance of the disease in this individual. These findings reveal that insufficient prokineticin-signaling through PROKR2 leads to abnormal development of the olfactory system and reproductive axis in man. They also shed new light on the complex genetic transmission of Kallmann syndrome.

BACKGROUND: Little is known on the current global prevalence of atopic dermatitis (AD) in the pediatric population. OBJECTIVE: To estimate the real-world global prevalence of AD in the pediatric population and by disease severity. METHODS: This international, cross-sectional, web-based survey of children and adolescents (6 months to <18 years old) was conducted in the following 18 countries: North America (Canada, United States), Latin America (Argentina, Brazil, Columbia, Mexico), Europe (France, Germany, Italy, Spain, United Kingdom), Middle East and Eurasia (Israel, Saudi Arabia, Turkey, United Arab Emirates, Russia), and East Asia (Japan, Taiwan). Prevalence was determined using the following 2 definitions: (1) diagnosed as having AD according to the International Study of Asthma and Allergies in Childhood (ISAAC) criteria and self- or parent-report of ever being told by a physician that they or their child child had AD (eczema); and (2) reported AD based on the ISAAC criteria only. Severity was assessed using the Patient Global Assessment (PtGA) and Patient-Oriented Eczema Measure (POEM). RESULTS: Among 65,661 responders, the 12-month diagnosed AD prevalence (ISAAC plus self-reported diagnosis) ranged from 2.7% to 20.1% across countries; reported AD (ISAAC only) was 13.5% to 41.9%. Severe AD evaluated with both PtGA and POEM was generally less than 15%; more subjects rated AD as mild on PtGA than suggested by POEM. No trends in prevalence were observed based on age or sex; prevalence was generally lower in rural residential settings than urban or suburban. CONCLUSION: This global survey in 18 countries revealed that AD affects a substantial proportion of the pediatric population. Although prevalence and severity varied across age groups and countries, less than 15% had severe AD.

BACKGROUND: Primary Sjögren syndrome (pSS) is an autoimmune disorder characterized by ocular and oral dryness or systemic manifestations. OBJECTIVE: To evaluate efficacy and harms of rituximab in adults with recent-onset or systemic pSS. DESIGN: Randomized, placebo-controlled, parallel-group trial conducted between March 2008 and January 2011. Study personnel (except pharmacists), investigators, and patients were blinded to treatment group. (ClinicalTrials.gov: NCT00740948). SETTING: 14 university hospitals in France. PATIENTS: 120 patients with scores of 50 mm or greater on at least 2 of 4 visual analogue scales (VASs) (global disease, pain, fatigue, and dryness) and recent-onset (< 10 years) biologically active or systemic pSS. INTERVENTION: Randomization (1:1 ratio) to rituximab (1 g at weeks 0 and 2) or placebo. MEASUREMENTS: Primary end point was improvement of at least 30 mm in 2 of 4 VASs by week 24. RESULTS: No significant difference between groups in the primary end point was found (difference, 1.0% [95% CI, -16.7% to 18.7%]). The proportion of patients with at least 30-mm decreases in at least two of the four VAS scores was higher in the rituximab group at week 6 (22.4% vs. 9.1%; P = 0.036). An improvement of at least 30 mm in VAS fatigue score was more common with rituximab at weeks 6 (P < 0.001) and 16 (P = 0.012), and improvement in fatigue from baseline to week 24 was greater with rituximab. Adverse events were similar between groups except for a higher rate of infusion reactions with rituximab. LIMITATION: Low disease activity at baseline and a primary outcome that may have been insensitive to detect clinically important changes. CONCLUSION: Rituximab did not alleviate symptoms or disease activity in patients with pSS at week 24, although it alleviated some symptoms at earlier time points.

The evidence- and consensus-based guideline on atopic eczema was developed in accordance with the EuroGuiDerm Guideline and Consensus Statement Development Manual. Four consensus conferences were held between December 2020 and July 2021. Twenty-nine experts (including clinicians and patient representatives) from 12 European countries participated. This first part of the guideline includes general information on its scope and purpose, the health questions covered, target users and a methods section. It also provides guidance on which patients should be treated with systemic therapies, as well as recommendations and detailed information on each systemic drug. The systemic treatment options discussed in the guideline comprise conventional immunosuppressive drugs (azathioprine, ciclosporin, glucocorticosteroids, methotrexate and mycophenolate mofetil), biologics (dupilumab, lebrikizumab, nemolizumab, omalizumab and tralokinumab) and janus kinase inhibitors (abrocitinib, baricitinib and upadacitinib). Part two of the guideline will address avoidance of provocation factors, dietary interventions, immunotherapy, complementary medicine, educational interventions, occupational and psychodermatological aspects, patient perspective and considerations for paediatric, adolescent, pregnant and breastfeeding patients.

The mucus layer covering the gastrointestinal mucosa is considered the first line of defense against aggressions arising from the luminal content. It is mainly composed of high molecular weight glycoproteins called mucins. Butyrate, a short-chain fatty acid produced during carbohydrate fermentation, has been shown to increase mucin secretion. The aim of this study was to test 1) whether butyrate regulates the expression of various MUC genes, which are coding for protein backbones of mucins, and 2) whether this effect depends on butyrate status as the major energy source of colonocytes. Butyrate was provided at the apical side of human polarized colonic goblet cell line HT29-Cl.16E in glucose-rich or glucose-deprived medium. In glucose-rich medium, butyrate significantly increased MUC3 and MUC5B expression (1.6-fold basal level for both genes), tended to decrease MUC5AC expression, and had no effect on MUC2 expression. In glucose-deprived medium, i.e., when butyrate was the only energy source available, MUC3 and MUC5B increase persisted, whereas MUC5AC expression was significantly enhanced (3.7-fold basal level) and MUC2 expression was strikingly increased (23-fold basal level). Together, our findings show that butyrate is able to upregulate colonic mucins at the transcriptional level and even better when it is the major energy source of the cells. Thus the metabolism of butyrate in colonocytes is closely linked to some of its gene-regulating effects. The distinct effects of butyrate according to the different MUC genes could influence the composition and properties of the mucus gel and thus its protective function.

BACKGROUND: Prophylactic administration of tranexamic acid has been associated with reduced postpartum blood loss after cesarean delivery in several small trials, but evidence of its benefit in this clinical context remains inconclusive. METHODS: In a multicenter, double-blind, randomized, controlled trial, we assigned women undergoing cesarean delivery before or during labor at 34 or more gestational weeks to receive an intravenously administered prophylactic uterotonic agent and either tranexamic acid (1 g) or placebo. The primary outcome was postpartum hemorrhage, defined as a calculated estimated blood loss greater than 1000 ml or receipt of a red-cell transfusion within 2 days after delivery. Secondary outcomes included gravimetrically estimated blood loss, provider-assessed clinically significant postpartum hemorrhage, use of additional uterotonic agents, and postpartum blood transfusion. RESULTS: Of the 4551 women who underwent randomization, 4431 underwent cesarean delivery, 4153 (93.7%) of whom had primary outcome data available. The primary outcome occurred in 556 of 2086 women (26.7%) in the tranexamic acid group and in 653 of 2067 (31.6%) in the placebo group (adjusted risk ratio, 0.84; 95% confidence interval [CI], 0.75 to 0.94; P = 0.003). There were no significant between-group differences in mean gravimetrically estimated blood loss or in the percentage of women with provider-assessed clinically significant postpartum hemorrhage, use of additional uterotonic agents, or postpartum blood transfusion. Thromboembolic events in the 3 months after delivery occurred in 0.4% of women (8 of 2049) who received tranexamic acid and in 0.1% of women (2 of 2056) who received placebo (adjusted risk ratio, 4.01; 95% CI, 0.85 to 18.92; P = 0.08). CONCLUSIONS: Among women who underwent cesarean delivery and received prophylactic uterotonic agents, tranexamic acid treatment resulted in a significantly lower incidence of calculated estimated blood loss greater than 1000 ml or red-cell transfusion by day 2 than placebo, but it did not result in a lower incidence of hemorrhage-related secondary clinical outcomes. (Funded by the French Ministry of Health; TRAAP2 ClinicalTrials.gov number, NCT03431805.).

Evidence indicates that human milk (HM) is the best form of nutrition uniquely suited not only to term but also to preterm infants conferring health benefits in both the short and long-term. However, HM does not provide sufficient nutrition for the very low birth weight (VLBW) infant when fed at the usual feeding volumes leading to slow growth with the risk of neurocognitive impairment and other poor health outcomes such as retinopathy and bronchopulmonary dysplasia. HM should be supplemented (fortified) with the nutrients in short supply, particularly with protein, calcium, and phosphate to meet the high requirements of this group of babies. In this paper the European Milk Bank Association (EMBA) Working Group on HM Fortification discusses the existing evidence in this field, gives an overview of different fortification approaches and definitions, outlines the gaps in knowledge and gives recommendations for practice and suggestions for future research. EMBA recognizes that "Standard Fortification," which is currently the most utilized regimen in neonatal intensive care units, still falls short in supplying sufficient protein for some VLBW infants. EMBA encourages the use of "Individualized Fortification" to optimize nutrient intake. "Adjustable Fortification" and "Targeted Fortification" are 2 methods of individualized fortification. The quality and source of human milk fortifiers constitute another important topic. There is work looking at human milk derived fortifiers, but it is still too early to draw precise conclusions about their use. The pros and cons are discussed in this Commentary in addition to the evidence around use of fortifiers post discharge.

OBJECTIVES: To study the effects of physical stimulation based on walking exercises, equilibrium and endurance on cognitive function and walking efficiency in patients with dementia. METHODS: Randomized controlled trial including 31 subjects suffering from dementia (age: 81.8 +/- 5.3 years). The intervention group (n = 16) benefited from a 15-week physical activity programme involving three 1-hour sessions per week. The control group (n = 15) did not practice any physical activities. Before and after rehabilitation, all subjects were evaluated with the Rapid Evaluation of Cognitive Functions test (ERFC French version) and walking analysis. RESULTS: After the 15 weeks of rehabilitation, the subjects from the intervention group improved their overall ERFC score (p < 0.01), while those in the control group decreased their overall ERFC score. Interactions were also observed between walking parameters and groups (p < 0.01); the intervention group improved walking capacities through heightened walking speed, stride length and a reduction in double limb support time. Lastly, the subjects from the control group presented a reduction in both walking speed and stride length. CONCLUSION: This study shows that a physical activity programme can slow cognitive decline and improve quality of walking in elderly persons suffering from dementia.

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The evidence- and consensus-based guideline on atopic eczema was developed in accordance with the EuroGuiDerm Guideline and Consensus Statement Development Manual. Four consensus conferences were held between December 2020 and July 2021. Twenty-nine experts (including clinicians and patient representatives) from 12 European countries participated. This second part of the guideline includes recommendations and detailed information on basic therapy with emollients and moisturizers, topical anti-inflammatory treatment, antimicrobial and antipruritic treatment and UV phototherapy. Furthermore, this part of the guideline covers techniques for avoiding provocation factors, as well as dietary interventions, immunotherapy, complementary medicine and educational interventions for patients with atopic eczema and deals with occupational and psychodermatological aspects of the disease. It also contains guidance on treatment for paediatric and adolescent patients and pregnant or breastfeeding women, as well as considerations for patients who want to have a child. A chapter on the patient perspective is also provided. The first part of the guideline, published separately, contains recommendations and guidance on systemic treatment with conventional immunosuppressive drugs, biologics and janus kinase (JAK) inhibitors, as well as information on the scope and purpose of the guideline, and a section on guideline methodology.

Short-chain fatty acids (SCFA), particularly butyrate, were shown to regulate cell proliferation in vitro and in vivo. Indeed, butyrate is the major fuel for colonic epithelial cells, and it can influence cell proliferation through the release of growth factors or gastrointestinal peptides such as gastrin, or through modulation of mucosal blood flow. Lastly, SCFA can act directly on genes regulating cell proliferation, and butyrate is the main SCFA to display such an effect. Butyrate inhibits histone deacetylase, which will allow histone hyperacetylation. Such hyperacetylation leads to transcription of several genes, including p21/Cip1. Moreover, it will allow cyclin D3 hyper-expression by inhibiting its degradation. The induction of the cyclin-dependent kinase inhibitory protein p21/Cip1 accounts for cell arrest in the G1 phase of the cell cycle. However, in the absence of p21 other mechanisms are initiated, leading to inhibition of cell proliferation.

Five European laboratories tested a simple in vitro batch system for dietary fibre fermentation studies. The inoculum was composed of fresh human faeces mixed with a carbonate-phosphate buffer complex supplemented with trace elements and urea. Five dietary fibre sources (cellulose, sugarbeet fibre, soyabean fibre, maize bran and pectin) were used by each laboratory on three occasions to determine pH, residual non-starch polysaccharides (NSP) and short-chain fatty acid production during fermentation. Cellulose and maize bran degradabilities were very low (7.2(SE 10.8) and 6.2 (SE 9.1)% respectively after 24 h), whereas pectin and soyabean fibre were highly degraded (97.4 (SE 4.4) and 91.1 (SE 3.4)% respectively after 24 h). Sugarbeet fibre exhibited an intermediate level of degradability (59.5 (SE 14.9)%). Short-chain fatty acid production was closely related to NSP degradation (r 0.99). Although each variable was ranked similarly by all laboratories, some differences occurred with respect to absolute values. However, the adaptation of donors to the experimental substrates was not an influential factor. Interlaboratory differences could be reduced either by adding less substrate during incubations or using less-diluted inocula. In vitro fermentations with inocula made from human faeces and from rat caecal contents gave similar results. There was a close correspondence between the data obtained in the present experiment and those previously published in in vivo studies in the rat using the same fibres. The in vitro batch system tested during the present study provides a rapid means of obtaining quantitative estimates of the fermentation and the estimation of the energy content of new sources of dietary fibre.

The short-chain fatty acid butyrate, which is mainly produced in the lumen of the large intestine by the fermentation of dietary fibers, plays a major role in the physiology of the colonic mucosa. It is also the major energy source for the colonocyte. Numerous studies have reported that butyrate metabolism is impaired in intestinal inflamed mucosa of patients with inflammatory bowel disease (IBD). The data of butyrate oxidation in normal and inflamed colonic tissues depend on several factors, such as the methodology or the models used or the intensity of inflammation. The putative mechanisms involved in butyrate oxidation impairment may include a defect in beta oxidation, luminal compounds interfering with butyrate metabolism, changes in luminal butyrate concentrations or pH, and a defect in butyrate transport. Recent data show that butyrate deficiency results from the reduction of butyrate uptake by the inflamed mucosa through downregulation of the monocarboxylate transporter MCT1. The concomitant induction of the glucose transporter GLUT1 suggests that inflammation could induce a metabolic switch from butyrate to glucose oxidation. Butyrate transport deficiency is expected to have clinical consequences. Particularly, the reduction of the intracellular availability of butyrate in colonocytes may decrease its protective effects toward cancer in IBD patients.