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Background: Globally one out of four children under 5 years is affected by linear growth delay (stunting). This syndrome has severe long-term sequelae including increased risk of illness and mortality and delayed psychomotor development. Stunting is a syndrome that is linked to poor nutrition and repeated infections. To date, the treatment of stunted children is challenging as the underlying etiology and pathophysiological mechanisms remain elusive. We hypothesize that pediatric environmental enteropathy (PEE), a chronic inflammation of the small intestine, plays a major role in the pathophysiology of stunting, failure of nutritional interventions and diminished response to oral vaccines, potentially via changes in the composition of the pro- and eukaryotic intestinal communities. The main objective of AFRIBIOTA is to describe the intestinal dysbiosis observed in the context of stunting and to link it to PEE. Secondary objectives include the identification of the broader socio-economic environment and biological and environmental risk factors for stunting and PEE as well as the testing of a set of easy-to-use candidate biomarkers for PEE. We also assess host outcomes including mucosal and systemic immunity and psychomotor development. This article describes the rationale and study protocol of the AFRIBIOTA project., Methods: AFRIBIOTA is a case-control study for stunting recruiting children in Bangui, Central African Republic and in Antananarivo, Madagascar. In each country, 460 children aged 2-5 years with no overt signs of gastrointestinal disease are recruited (260 with no growth delay, 100 moderately stunted and 100 severely stunted). We compare the intestinal microbiota composition (gastric and small intestinal aspirates; feces), the mucosal and systemic immune status and the psychomotor development of children with stunting and/or PEE compared to non-stunted controls. We also perform anthropological and epidemiological investigations of the children's broader living conditions and assess risk factors using a standardized questionnaire., Discussion: To date, the pathophysiology and risk factors of stunting and PEE have been insufficiently investigated. AFRIBIOTA will add new insights into the pathophysiology underlying stunting and PEE and in doing so will enable implementation of new biomarkers and design of evidence-based treatment strategies for these two syndromes.

Much attention has been focused on the role of the bacterial microbiome in human health, but the virome is understudied. Although previously investigated in individuals with inflammatory bowel diseases or solid-organ transplants, virome dynamics in allogeneic hematopoietic stem cell transplantation (HSCT) and enteric graft-versus-host disease (GVHD) remain unexplored. Here we characterize the longitudinal gut virome in 44 recipients of HSCT using metagenomics. A viral 'bloom' was identified, and significant increases were demonstrated in the overall proportion of vertebrate viral sequences following transplantation (P = 0.02). Increases in both the rates of detection (P < 0.0001) and number of sequences (P = 0.047) of persistent DNA viruses (anelloviruses, herpesviruses, papillomaviruses and polyomaviruses) over time were observed in individuals with enteric GVHD relative to those without, a finding accompanied by a reduced phage richness (P = 0.01). Picobirnaviruses were detected in 18 individuals (40.9%), more frequently before or within a week after transplant than at later time points (P = 0.008). In a time-dependent Cox proportional-hazards model, picobirnaviruses were predictive of the occurrence of severe enteric GVHD (hazard ratio, 2.66; 95% confidence interval (CI) = 1.46-4.86; P = 0.001), and correlated with higher fecal levels of two GVHD severity markers, calprotectin and α1-antitrypsin. These results reveal a progressive expansion of vertebrate viral infections over time following HSCT, and they suggest an unexpected association of picobirnaviruses with early post-transplant GVHD.

Objective: Intestinal glucose absorption is orchestrated by specialized glucose transporters such as SGLT1 and GLUT2. However, the role of GLUT2 in the regulation of glucose absorption remains to be fully elucidated., Methods: We wanted to evaluate the role of GLUT2 on glucose absorption and glucose homeostasis after intestinal-specific deletion of GLUT2 in mice (GLUT2 ΔIEC mice)., Results: As anticipated, intestinal GLUT2 deletion provoked glucose malabsorption as visualized by the delay in the distribution of oral sugar in tissues. Consequences of intestinal GLUT2 deletion in GLUT2 ΔIEC mice were limiting body weight gain despite normal food intake, improving glucose tolerance, and increasing ketone body production. These features were reminiscent of calorie restriction. Other adaptations to intestinal GLUT2 deletion were reduced microvillus length and altered gut microbiota composition, which was associated with improved inflammatory status. Moreover, a reduced density of glucagon-like peptide-1 (GLP-1) positive cells was compensated by increased GLP-1 content per L-cell, suggesting a preserved enteroendocrine function in GLUT2 ΔIEC mice., Conclusions: Intestinal GLUT2 modulates glucose absorption and constitutes a control step for the distribution of dietary sugar to tissues. Consequently, metabolic and gut homeostasis are improved in the absence of functional GLUT2 in the intestine, thus mimicking calorie restriction.

The technically easier one-anastomosis (mini) gastric bypass (MGB) is associated with similar metabolic improvements and weight loss as the Roux-en-Y gastric bypass (RYGB). However, MGB is controversial and suspected to result in greater malabsorption than RYGB. In this study, we compared macronutrient absorption and intestinal adaptation after MGB or RYGB in rats. Body weight and food intake were monitored and glucose tolerance tests were performed in rats subjected to MGB, RYGB, or sham surgery. Carbohydrate, protein, and lipid absorption was determined by fecal analyses. Intestinal remodeling was evaluated by histology and immunohistochemistry. Peptide and amino acid transporter mRNA levels were measured in the remodeled intestinal mucosa and those of anorexigenic and orexigenic peptides in the hypothalamus. The MGB and RYGB surgeries both resulted in a reduction of body weight and an improvement of glucose tolerance relative to sham rats. Hypothalamic orexigenic neuropeptide gene expression was higher in MGB rats than in RYGB or sham rats. Fecal losses of calories and proteins were greater after MGB than RYGB or sham surgery. Intestinal hyperplasia occurred after MGB and RYGB with increased jejunum diameter, higher villi, and deeper crypts than in sham rats. Peptidase and peptide or amino acid transporter genes were overexpressed in jejunal mucosa from MGB rats but not RYGB rats. In rats, MGB led to greater protein malabsorption and energy loss than RYGB. This malabsorption was not compensated by intestinal overgrowth and increased expression of peptide transporters in the jejunum., (Copyright © 2016 the American Physiological Society.)

Faecal microbiota transplantation is effective for treating recurrent forms of Clostridium difficile infection and its use in this indication is recommended in the most recent European and North American guidelines. In this context, faecal microbiota transplantation is beginning to be performed in France in clinical practice, while the rules governing this procedure have been defined in France only for clinical trials. To unify, secure, and evaluate practice in this field in France, the French Group of Faecal microbiota Transplantation (FGFT) was created in October 2014 with the support of the French National Society of Gastroenterology, the French Infectious Disease Society, and the National Academy of Pharmacy. We present here the deliberations of this group regarding the use of faecal microbiota transplantation for recurrent Clostridium difficile infection. The issues addressed are the indications, therapeutic sequence, delivery procedures, donor selection, methods and conditions of specimen preparation, and traceability., (Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Background & Aim: Fructose diets have been shown to induce insulin resistance and to alter liver metabolism and gut barrier function, ultimately leading to non-alcoholic fatty liver disease. Citrulline, Glutamine and Arginine may improve insulin sensitivity and have beneficial effects on gut trophicity. Our aim was to evaluate their effects on liver and gut functions in a rat model of fructose-induced non-alcoholic fatty liver disease., Methods: Male Sprague-Dawley rats (n = 58) received a 4-week fructose (60%) diet or standard chow with or without Citrulline (0.15 g/d) or an isomolar amount of Arginine or Glutamine. All diets were made isonitrogenous by addition of non-essential amino acids. At week 4, nutritional and metabolic status (plasma glucose, insulin, cholesterol, triglycerides and amino acids, net intestinal absorption) was determined; steatosis (hepatic triglycerides content, histological examination) and hepatic function (plasma aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, bilirubin) were assessed; and gut barrier integrity (myeloperoxidase activity, portal endotoxemia, tight junction protein expression and localization) and intestinal and hepatic inflammation were evaluated. We also assessed diets effects on caecal microbiota., Results: In these experimental isonitrogenous fructose diet conditions, fructose led to steatosis with dyslipidemia but without altering glucose homeostasis, liver function or gut permeability. Fructose significantly decreased Bifidobacterium and Lactobacillus and tended to increase endotoxemia. Arginine and Glutamine supplements were ineffective but Citrulline supplementation prevented hypertriglyceridemia and attenuated liver fat accumulation., Conclusion: While nitrogen supply alone can attenuate fructose-induced non-alcoholic fatty liver disease, Citrulline appears to act directly on hepatic lipid metabolism by partially preventing hypertriglyceridemia and steatosis., (Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

The oligopeptide transporter peptide cotransporter-1 Slc15a1 (PEPT1) plays a major role in the regulation of nitrogen supply, since it is responsible for 70% of the dietary nitrogen absorption. Previous studies demonstrated that PEPT1 expression and function in jejunum are reduced in diabetes and obesity, suggesting a nitrogen malabsorption from the diet. Surprisingly, we reported here a decrease in gut nitrogen excretion in high-fat diet (HFD)-fed mice and further investigated the mechanisms that could explain this apparent contradiction. Upon HFD, mice exhibited an increased concentration of free amino acids (AAs) in the portal vein (60%) along with a selective increase in the expression of two AA transporters (Slc6a20a, Slc36a1), pointing to a specific and adaptive absorption of some AAs. A delayed transit time (+40%) and an increased intestinal permeability (+80%) also contribute to the increase in nitrogen absorption. Besides, HFD mice exhibited a 2.2-fold decrease in fecal DNA resulting from a reduction in nitrogen catabolism from cell desquamation and/or in the intestinal microbiota. Indeed, major quantitative (2.5-fold reduction) and qualitative alterations of intestinal microbiota were observed in feces of HFD mice. Collectively, our results strongly suggest that both increased AA transporters, intestinal permeability and transit time, and changes in gut microbiota are involved in the increased circulating AA levels. Modifications in nitrogen homeostasis provide a new insight in HFD-induced obesity and glucose intolerance; however, whether these modifications are beneficial or detrimental for the HFD-associated metabolic complications remains an open issue.

Background: Small bowel transplantation has now become a recognized treatment of irreversible, permanent, and subtotal intestinal failure., Objective: The aim of this study was to assess intestinal absorption at the time of weaning from parenteral nutrition in a series of children after intestinal transplantation., Design: Twenty-four children (age range: 14-115 mo) received intestinal transplantation, together with the liver in 6 children and the colon in 16 children. Parenteral nutrition was slowly tapered while increasing enteral tube feeding. The absorption rate was measured from a 3-d stool balance analysis performed a few days after the child had weaned from parenteral nutrition to exclusive enteral tube feeding. Results were analyzed according to the resting energy expenditure (REE; Schofield formula)., Results: All children were weaned from parenteral nutrition between 31 and 85 d posttransplantation. Median intakes were as follows: energy, 107 kcal · kg(-1) · d(-1) (range: 79-168 kcal · kg(-1) · d(-1)); lipids, 39 kcal · kg(-1) · d(-1) (range: 20-70 kcal · kg(-1) · d(-1)); and nitrogen, 17 kcal · kg(-1) · d(-1) (range: 11-27 kcal · kg(-1) · d(-1)). Median daily stool output was 998 mL/d (range: 220-2025 mL/d). Median absorption rates were 88% (range: 75-96%) for energy, 82% (range: 55-98%) for lipids, and 77% (range: 61-88%) for nitrogen. The ratios for ingested energy to REE and absorbed energy to REE were 2.2 (range: 1.6-3.6) and 1.8 (range: 1.3-3.3), respectively., Conclusion: These data indicate a suboptimal intestinal graft absorption capacity with fat malabsorption, which necessitates energy intakes of at least twice the REE.

Background: Segmental reversal of the small bowel (SRSB) is proposed in patients with short-bowel syndrome (SBS) as a rehabilitative therapy, but its effects on absorption have not been studied., Objective: We aimed to determine intestinal macronutrient absorption and home parenteral nutrition (HPN) dependence in SBS patients with intestinal failure., Design: We included in a retrospective study all consecutive patients who had an SRSB between 1985 and 2010 and underwent a study of macronutrient absorption. Patients were matched to SBS controls with the same digestive characteristics. Energy and macronutrient absorption were measured. The dependence on HPN was expressed by the number of infusions per week and by the calories infused daily divided by the basal energy expenditure multiplied by 1.5., Results: Seventeen patients who had an SRSB were matched to 17 control patients. Intestinal absorption was higher in the SRSB group for total calories (69.5% compared with 58.0%), fat (48.4% compared with 33.2%), and protein (62.7% compared with 53.4%) (P < 0.05). Median oral autonomy was 100% ± 38.4% in the SRSB group, whereas it was 79% ± 39.6% in the control group (P < 0.05). The number of calories infused was lower in the SRSB group (500 ± 283 compared with 684 ± 541; P < 0.05), as was HPN dependence (33% ± 20% compared with 48% ± 38%; P < 0.05) at the time of the study., Conclusion: SRSB allows a gain in macronutrient absorption, which is associated with a lower HPN dependence. To our view, SRSB should be integrated in intestinal rehabilitative adult programs.

Diagnosis of gastrointestinal GVHD (GI-GVHD) is based on clinical symptoms and histologic findings. No biomarkers predicting responses to treatment are routinely available even though 30% to 50% of patients will not respond to corticosteroids. In this study, we aimed to evaluate fecal calprotectin, α-1-antitrypsin (α(1)-AT), and elastase at the time of first symptoms as diagnostic and prognostic tools for GI-GVHD in 72 consecutive patients, of whom 51 developed GI-GVHD. The prognostic value of markers was evaluated by their association with complete response (CR) and steroid-resistant (SR) GVHD. Calprotectin and α(1)-AT concentrations increased with GI-GVHD initial stages but patients with initial stage 1 GI-GVHD had similar marker levels to patients without GI-GVHD, so sensitivity to diagnose GI-GVHD was weak. In contrast, calprotectin and α(1)-AT were predictors for SR-GVHD and CR. Multiple regression modeling identified calprotectin and α(1)-AT concentration as independently predicting SR-GVHD together with initial stage > 2 GI-GVHD. Our results showed that fecal calprotectin and α(1)-AT levels at the time of diagnosis are predictive for responses to treatment but are not diagnostic markers for initial stage 1 to 3 GI-GVHD.

In a multicenter study, potassium dichromate-preserved stools from patients infected with Cryptosporidium parvum (n = 20), C. hominis (n = 20), and other Cryptosporidium species (n = 10) and 60 controls were examined using four immunochromatographic assays. Assay sensitivity ranged between 50.1% and 86.7% for C. parvum and C. hominis but was <35% for other species.

This prospective study aimed to establish the effect of recombinant human growth hormone (rhGH) on intestinal function in children with short bowel syndrome (SBS). Eight children with neonatal SBS were included. All were dependent on parenteral nutrition (PN) for >3 years (range, 3.8-11.6 years), with PN providing >50% of recommended dietary allowance for age (range, 50%-65%). The subjects received rhGH (Humatrope) 0.13 mg/kg/d subcutaneously over a 12-week period. The follow-up was continued over a 12-month period after rhGH discontinuation. Clinical and biological assessments were performed at baseline, at the end of the treatment period, and 12 months after the end of treatment. No side effects related to rhGH were observed. PN requirements were decreased in all children during the course of rhGH treatment. Between baseline and the end of treatment, significant increases were observed in concentrations (mean ± standard deviation) of serum insulin-like growth factor 1 (103.1 ± 49.9 µg/L vs 153.5 ± 82.2 µg/L; P < .01), serum insulin-like growth factor-binding protein 3 (1.7 ± 0.6 mg/L vs 2.5 ± 0.9 mg/L; P < .001), and plasma citrulline (16.5 ± 14.8 µmol/L vs 25.2 ± 18.3 µmol/L; P < .05). A median 54% increase in enteral intake (range, 10%-244%) was observed (P < .001) and net energy balance improved significantly (P < .002). It was necessary for 6 children to be maintained on PN or restarted after discontinuation of rhGH treatment, and they remained on PN until the end of the follow-up period. A 12-week high-dose rhGH treatment allowed patients to decrease PN, but only 2 patients could be definitively weaned from PN. Indications and cost-effectiveness of rhGH treatment for SBS pediatric patients need further evaluation.

Defensins, endogenous antibiotic peptides, are part of the intestinal epithelial barrier. In this pilot study we analyzed the possibility of measuring fecal beta-defensin-2 (HBD2) in comparing inflammatory and noninflammatory conditions. In samples from healthy control individuals, low levels of HBD2 were detectable, which markedly rose under inflammatory conditions (P = 0.0002 vs normal control individuals), the highest levels being observed in patients with ulcerative colitis (median 356 ng/g, range 40-527). Despite frank inflammation, Crohn disease patients with colitis had significantly lower, albeit enhanced, HBD2 levels than did ulcerative colitis patients. These data confirm the possibility of quantifying HBD2 in feces and indicate that colitis in Crohn disease and colitis in ulcerative colitis differ from each other with respect to their ability to secrete HBD2.