L’intestin un organe endocrine : de la physiologie aux implications thérapeutiques en nutrition

International audienc

Intestinal adaptation in short bowel syndrome. What is new?

Short bowel syndrome (SBS) is a well-known cause of intestinal failure (IF) (1). SBS occurs after extensive resection of the small bowel (RSB) resulting in a bowel length of less than 150/200 cm. The colon may have been partially or completely removed. SBS patients experience severe water and nutrient malabsorption, so that they are often managed with parenteral nutrition (PN) to supplement their oral intake (2-4). A complete understanding of the pathophysiology of SBS and postoperative adaptations may allow identifying the spontaneous processes that compensate for the reduction in absorptive surface. A better knowledge of these adaptive mechanisms may help to improve the management of patient nutrition, to reduce the need for PN and to prevent D-encephalopathy episodes. This review focuses on the overall adaptations described in adult SBS patients but does not review pediatric cases. PMID:El síndrome del intestino corto es la primera causa de fallo intestinal (que requiere suplementación intravenosa de fluidos, electrolitos y/o calorías). La adaptación fisiológica intestinal ocurre uno a dos años después de la resección quirúrgica. Esta adaptación incluye hiperfagia, cambios en la microbiota, cambios morfológicos intestinales (incluida la hiperplasia), adaptaciones hormonales y otros… El colon desempeña un papel importante y permite la recuperación hidroelectrolítica y energética. Es posible mejorar la adaptación fisiológica mediante la optimización de la intervención dietética, restaurando la continuidad y tratando con factores de crecimiento, como el análogo del GLP-2 (glucagon-like peptide-2)

Le syndrome de grêle court chez l’adulte: De l’insuffisance intestinale à l’adaptation intestinale

International audienceLe syndrome de grêle court, conséquence d’une résection étendue de l’intestin, est la principale cause d’insuffisance intestinale, définie comme la réduction de la fonction intestinale en dessous du minimum nécessaire à l’absorption des macronutriments, de l’eau et des électrolytes. La prise en charge nécessite alors la nutrition parentérale. L’évolution du syndrome de grêle court est schématiquement scindée en trois périodes successives : 1) la période post-opératoire, d’une durée de 3 à 6 semaines ; 2) la période adaptative, d’une durée de 2 ans environ ; et 3) la période de stabilisation, dite séquellaire. Le développement d’une hyperphagie, d’une adaptation intestinale permettant l’augmentation de la surface d’absorption et de la sécrétion d’entérohormones, ainsi qu’une modification du microbiote, se produisent spontanément, améliorant l’absorption intestinale et diminuant la dépendance à la nutrition parentérale. Cet article résume les principales conséquences physiopathologiques (bénéfiques ou délétères) d’une résection étendue de l’intestin grêle et la prise en charge nutritionnelle et médicamenteuse du syndrome de grêle court chez l’adulte

Orosensory perception of fat/sweet stimuli and appetite-regulating peptides before and after sleeve gastrectomy or gastric by-pass in adult women with obesity

International audienceThe aim of this study was to explore the impact of bariatric surgery on the fat and sweet taste perception and to determine the possible correlations with gut appetite-regulating pep-tides and subjective food sensations. Women with a severe obesity (BMI> 35 kg/m 2) were studied 2 weeks before and 6 months after a vertical sleeve gastrectomy (VSG, n=32) or a Roux-en-Y gastric bypass (RYGB, n=12). Linoleic acid (LA) and sucrose perception thresholds were determined using the three alternative-forced choice procedure, gut hormones were assayed before and after a test meal and subjective changes in oral food sensations were self-reported using a standardized questionnaire. Despite a global positive effect of both surgeries on the reported gustatory sensations, a change in the taste sensitivity was only found after RYGB for LA. However, the fat and sweet taste perceptions were not homogenous between patients undergone the same surgery procedure, suggesting the existence of 2 subgroups: patients with and without taste improvement. These gustatory changes were not correlated to the surgery-mediated modifications of the main gut appetite-regulating hormones. Collectively these data highlight the complexity of relationships between bariatric surgery and taste sensitivity and suggest that VSG and RYGB might impact differentially the fatty taste perception

A novel pathogenic variant in MRAP2 in an obese patient with successful outcome of bariatric surgery

International audienceAbstract Mutations in genes encoding proteins located in the leptin/melanocortin pathway have been identified in the rare cases of genetic obesities. Heterozygous variants of MRAP2, encoding a G coupled-protein receptor accessory protein implicated in energy control notably via the melanocortin-4 receptor, have been recently identified. A 24-year-old patient with early-onset severe obesity (body mass index [BMI]: 64 kg/m2) associated with hypertension, respiratory complications, nonalcoholic fatty liver disease, and type 2 diabetes was referred to our department. Sleeve gastrectomy was successful. A new heterozygous variant in MRAP2 (NM_138409.4: c.154G>C/p.G52R) variant was identified in the patient DNA. Functional assessment confirmed that this new variant was pathogenic. We report a new pathogenic loss-of-function mutation in MRAP2 in a patient suffering from a severe multicomplicated obesity. This confirms the metabolic phenotype in patients with this monogenic form of obesity. Longer follow-up will be necessary. Our finding will allow a personalized medicine

Long-Term Weight Outcome After Bariatric Surgery in Patients with Melanocortin-4 Receptor Gene Variants: a Case-Control Study of 105 Patients

Introduction: Pathogenic heterozygous MC4R variants are associated with hyperphagia and variable degrees of obesity. Several research groups have reported short-term weight loss outcomes after bariatric surgery in a few patients with MC4R variants, but lack of longer-term data prevents evidence-based clinical decision-making. Materials and Methods: Bariatric surgery patients with heterozygous (likely) pathogenic MC4R variants, from three collaborating centers in the Netherlands, France, and the UK, were compared to matched controls (matched 2:1 for age, sex, preoperative BMI, surgical procedure, and diabetes mellitus, but without MC4R mutations). Weight loss and regain outcomes up to 6 years of follow-up were compared. Results: At 60 months of follow-up after RYGB, cases with MC4R variants showed weight regain with a mean of 12.8% (± 10.4 SD) total weight loss (TWL) from nadir, compared to 7.9% (± 10.5 SD) in the controls (p = 0.062). Among patients receiving SG, the cases with MC4R variants experienced inferior weight loss (22.6% TWL) during the first year of follow-up compared to the controls (29.9% TWL) (p = 0.010). Conclusions: This multicenter study reveals inferior mid-term weight outcomes of cases with MC4R variants after SG, compared to RYGB. Since adequate weight loss outcomes were observed after RYGB, this procedure would appear to be an appropriate surgical approach for this group. However, the pattern of weight regain seen in cases with MC4R variants after both RYGB and SG highlights the need for pro-active lifelong management to prevent relapse, as well as careful expectation management. Graphical abstract: [Figure not available: see fulltext.]