Small intestinal length: a factor essential for gut adaptation

The Identification of a Glucuronyltransferase-Related Gene, GlcAT-S, with Putative Mucus Protection and Anti-Inflammatory Effects from Gut-Damaged Drosophila by Dextran Sulfate Sodium (DSS)

The intestinal epithelium, which is protected by mucosal surfaces composed of mucins and other glycoproteins, functions as a selective barrier that absorbs nutrients while preventing the translocation of harmful substances. To understand the mechanisms between mucosal disruption and tissue inflammation, we orally administrated a mucus-disrupting agent, dextran sodium sulfate, to Drosophila melanogaster and screened 63 differentially expressed genes (DEGs). Through a database search using bioinformatics tools (CHEA3 and WebGestalt), we identified ELK1 as a potential key transcription factor for the selected DEGs, and among the 63 DEGs, ELK1-related genes, B3GAT3, FIBP, and TENT2 (GlcAT-S, Fibp, and Wisp in Drosophila), were selected as the relevant genes that respond to mucus disruption. We confirmed that enterocyte (EC)-specific GlcAT-S knockdown by RNAi significantly reduced gut length and increased intestinal stem cell proliferation in Drosophila. Additionally, in EC-specific GlcAT-S-knockdown flies, it was observed that the mucus-production-related genes, Muc68D and Mur29B, were specifically reduced, whereas the inflammatory cytokines egr and upd3 were overexpressed. This study provides evidence that GlcAT-S is involved in the regulation of intestinal inflammation in Drosophila and plays a protective role against mucus disruption. Our findings suggest that GlcAT-S may be a potential therapeutic target for the treatment of intestinal inflammatory diseases such as IBD.

Mating and ecdysone signaling modify growth, metabolism, and digestive efficiency in the female Drosophila gut

Adaptive changes in organ size and physiology occur in most adult animals, but how these changes are regulated is not well understood. Previous research found that mating in Drosophila females drives not only increases in gut size and stem cell proliferation but also alters feeding behavior, intestinal gene expression, and whole-body lipid storage, suggesting altered gut metabolism. Here, we show that mating dramatically alters female gut metabolism and digestive function. In addition to promoting a preference for a high-protein diet, mating also altered levels of TCA cycle intermediates and fatty acids in the gut, increased total gut lipids and protein, reduced relative carbohydrate levels, and enhanced the efficiency of protein digestion relative to carbohydrate digestion. The expression of genes that mediate each of these metabolic processes was similarly altered. In addition, we noted the mating-dependent downregulation of oxidative stress response and autophagy genes. Mating-dependent increases in ecdysone signaling played an important role in re-programming many, but not all, of these changes in the female gut. This study contributes to our understanding of how steroid signaling alters gut physiology to adapt to the demands of reproduction.

Medicines management in children and young people: pharmacokinetics, drug calculations and off-label drug use

Medicines management in children and young people presents specific challenges because children differ from adults in their response to medicines. The way in which medicines work inside the human body, or pharmacokinetics, varies according to age and stage of development. Accurate drug calculations for a child rely on the careful consideration of a series of factors, such as weight and height, pharmacokinetics and drug characteristics. This article focuses on three fundamental aspects: pharmacokinetics, drug calculations, and unlicensed and off-label drug use.

Prognostic factor of patients with short bowel syndrome due to nonCrohn disease: A single institution observational study

Short bowel syndrome (SBS) is a severely disabling and potentially life-threatening condition. Survival data for patients with SBS are limited. This study aimed to investigate prognostic factors in patients with SBS undergoing surgery. We reviewed the medical records of 27 consecutive patients with SBS who were treated at our hospital between January 2018 and December 2022. SBS was defined as a remaining small bowel length <200 cm, excluding patients with Crohn disease. Of the 27 patients identified, 17 were males and 10 were females, with a median age of 77 (46-90) years and a total observation time of 137 (2-1628) days. All patients underwent surgery and received parenteral nutrition (PN) and follow-up in our hospital. Superior mesenteric artery stenosis (44.4%) and nonocclusive mesenteric ischemia (25.9%) most commonly caused SBS. The median residual small bowel length and postoperative hospital stay were 50 (5-150) cm and 48 (2-104) days, respectively. Jejunostomy was performed in 17 (62.9%) patients, and 4 (14.8%) patients were weaned off their PN. Death occurred in 14 (51.8%), and the median survival time was 209 days. The survival outcome was compared between the survival (n = 13) and the death groups (n = 14). Jejunostomy and PN rates were significantly higher in the death group (P < .01, P = .03, respectively). SBS is associated with significantly higher mortality rates. Jejunostomy and long PN duration are significantly associated with death in patients with SBS.

Intestinal barrier function in the naked mole-rat: an emergent model for gastrointestinal insights

The intestinal barrier plays a crucial role in homeostasis by both facilitating the absorption of nutrients and fluids and providing a tight shield to prevent the invasion by either pathogen or commensal microorganisms. Intestinal barrier malfunction is associated with systemic inflammation, oxidative stress, and decreased insulin sensitivity, which may lead to the dysregulation of other tissues. Therefore, a deeper understanding of physiological aspects related to an enhanced barrier function is of significant scientific and clinical relevance. The naked mole-rat has many unusual biological features, including attenuated colonic neuron sensitivity to acid and bradykinin and resistance to chemical-induced intestinal damage. However, insight into their intestinal barrier physiology is scarce. Here, we observed notable macroscopic and microscopic differences in intestinal tissue structure between naked mole-rats and mice. Moreover, naked mole-rats showed increased number of larger goblet cells and elevated mucus content. In measuring gut permeability, naked mole-rats showed reduced permeability compared with mice, measured as transepithelial electrical resistance, especially in ileum. Furthermore, intestinal ion secretion induced by serotonin, bradykinin, histamine, and capsaicin was significantly reduced in naked mole-rats compared with mice, despite the expression of receptors for all these agonists. In addition, naked mole-rats exhibited reduced prosecretory responses to the nonselective adenylate cyclase activator forskolin. Collectively, these findings indicate that naked mole-rats possess a robust and hard-to-penetrate gastrointestinal barrier that is resistant to environmental and endogenous irritants. Naked mole-rats may therefore provide valuable insights into the physiology of the intestinal barrier and set the stage for the development of innovative and effective therapies.NEW & NOTEWORTHY This is the first study to characterize the intestinal function of naked mole-rats. We found that these animals show a robust gut tissue structure, displaying thicker intestinal layers, longer villi, and larger crypts. Naked mole-rats showed more and larger goblet cells, with increased mucus content. Intestinal permeability, especially in the ileum, was substantially lower than that of mice. Finally, naked mole-rats showed reduced intestinal anion secretion in response to serotonin, bradykinin, histamine, capsaicin, and forskolin.

Short limb in biliary tract reconstruction: A retrospective study of living donor liver transplantation in children with biliary atresia

Roux-en-Y cholangiojejunostomy is a standard procedure for biliary reconstruction in pediatric living donor liver transplantation (LDLT). However, there is uncertainty on whether the adult standard of Roux branch limb is suitable for pediatric LDLT and its impact on postoperative biliary complications (BC). This study aimed to explore the effect of the short Roux limb and standard limb on pediatric LDLT biliary reconstruction. According to the length of the Roux limb, 168 LDLT children were divided into the routine limb group (n = 108) and the short limb group (n = 60). The incidences of postoperative biliary tract complications between the 2 groups were compared retrospectively. The mean Roux limb length in the short limb group was significantly shorter than that in the routine limb group group (P < .01). There were significant differences in age, height, and weight between the 2 groups (P < .01). However, there were no significant differences in graft-to-recipient weight ratio, intraoperative blood loss, cold ischemia time, and operation time between the 2 groups (P > .01). Moreover, postoperative BC, including refluxing cholangitis, were similar between the 2 groups (P = .876). Furthermore, the history of Kasai surgery, the history of postoperative RC of Kasai, and whether or not the Roux limb was reconstructed had no significant effect on the occurrence of postoperative RC. There was no significant difference in postoperative BC between the short limb and the routine limb in children with living donor liver transplantation.

ESPEN guideline on chronic intestinal failure in adults - Update 2023

BACKGROUND & AIMS

In 2016, ESPEN published the guideline for Chronic Intestinal Failure (CIF) in adults. An updated version of ESPEN guidelines on CIF due to benign disease in adults was devised in order to incorporate new evidence since the publication of the previous ESPEN guidelines.

METHODS

The grading system of the Scottish Intercollegiate Guidelines Network (SIGN) was used to grade the literature. Recommendations were graded according to the levels of evidence available as A (strong), B (conditional), 0 (weak) and Good practice points (GPP). The recommendations of the 2016 guideline (graded using the GRADE system) which were still valid, because no studies supporting an update were retrieved, were reworded and re-graded accordingly.

RESULTS

The recommendations of the 2016 guideline were reviewed, particularly focusing on definitions, and new chapters were included to devise recommendations on IF centers, chronic enterocutaneous fistulas, costs of IF, caring for CIF patients during pregnancy, transition of patients from pediatric to adult centers. The new guideline consist of 149 recommendations and 16 statements which were voted for consensus by ESPEN members, online in July 2022 and at conference during the annual Congress in September 2022. The Grade of recommendation is GPP for 96 (64.4%) of the recommendations, 0 for 29 (19.5%), B for 19 (12.7%), and A for only five (3.4%). The grade of consensus is "strong consensus" for 148 (99.3%) and "consensus" for one (0.7%) recommendation. The grade of consensus for the statements is "strong consensus" for 14 (87.5%) and "consensus" for two (12.5%).

CONCLUSIONS

It is confirmed that CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for the underlying gastrointestinal disease and to provide HPN support. Most of the recommendations were graded as GPP, but almost all received a strong consensus.

Definition, classification, and causes of short bowel syndrome

The term "short bowel syndrome (SBS)" defines "the clinical feature associated with a remaining small bowel in continuity of less than 200 cm from the ligament of Treitz" and is characterized by malabsorption, diarrhea, fatty stools, malnutrition, and dehydration. SBS is the primary pathophysiological mechanism of chronic intestinal failure (CIF), defined as the "reduction of gut function below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation (IVS) is required to maintain health and/or growth" in a metabolically stable patient. By contrast, the reduction of gut absorptive function that does not require IVS has been termed "intestinal insufficiency or deficiency" (II/ID). The classification of SBS can be categorized as follows: anatomical (anatomy and length of the residual bowel), evolutional (early, rehabilitative, and maintenance phases), pathophysiological (SBS with or without a colon in continuity), clinical (with II/ID or CIF), and severity of CIF (type and volume of the required IVS). Appropriate and homogeneous patient categorization is the mainstay of facilitating communication in clinical practice and in research.

Home Parenteral Nutrition for Children: What Are the Factors Indicating Dependence and Mortality?

Parenteral nutrition (PN) in children with short bowel syndrome is crucial and lifesaving. Taking care of such patients requires interprofessional practice and multiple team resource management. Home PN (HPN) usage allows patients and families to live regular lives outside hospitals. We share our experiences for the last two decades and identify the risk factors for complications and mortality. A retrospective study of HPN patients was conducted between January 2000 and February 2022. Medical records of age, body weight, diagnosis, length of residual intestines, HPN period, central line attempts, complications, weaning, and survival were collected and analyzed. The patients were classified as HPN free, HPN dependent, and mortality groups. A total of 25 patients received HPN at our outpatient clinic, and one was excluded for the adult age of disease onset. There were 13 patients (54.1%) who were successfully weaned from HPN until the record-enroled date. The overall mortality rate was 20.8% (five patients). All mortality cases had prolonged cholestasis, Child Class B or C, and a positive Pediatric End-Stage Liver Disease (PELD) score. For HPN dependence, extended resection and multiple central line placement were two significant independent factors. Cholestasis, Child Class B or C, and positive PELD score were the most important risk factors for mortality. The central line-related complication rate was not different in all patient groups. The overall central line infection rate was 1.58 per 1000 catheter days. Caution should be addressed to prevent cholestasis and intestinal failure-associated liver disease during the HPN period, to prevent mortality. By understanding the risks of HPN dependence and mortality, preventive procedures could be addressed earlier.

Bermúdez M, Campoy C. Impact of Total Parenteral Nutrition on Gut Microbiota in Pediatric Population Suffering Intestinal Disorders

Parenteral nutrition (PN) is a life-saving therapy providing nutritional support in patients with digestive tract complications, particularly in preterm neonates due to their gut immaturity during the first postnatal weeks. Despite this, PN can also result in several gastrointestinal complications that are the cause or consequence of gut mucosal atrophy and gut microbiota dysbiosis, which may further aggravate gastrointestinal disorders. Consequently, the use of PN presents many unique challenges, notably in terms of the potential role of the gut microbiota on the functional and clinical outcomes associated with the long-term use of PN. In this review, we synthesize the current evidence on the effects of PN on gut microbiome in infants and children suffering from diverse gastrointestinal diseases, including necrotizing enterocolitis (NEC), short bowel syndrome (SBS) and subsequent intestinal failure, liver disease and inflammatory bowel disease (IBD). Moreover, we discuss the potential use of pre-, pro- and/or synbiotics as promising therapeutic strategies to reduce the risk of severe gastrointestinal disorders and mortality. The findings discussed here highlight the need for more well-designed studies, and harmonize the methods and its interpretation, which are critical to better understand the role of the gut microbiota in PN-related diseases and the development of efficient and personalized approaches based on pro- and/or prebiotics.

Intestinal plasticity and metabolism as regulators of organismal energy homeostasis

The small intestine displays marked anatomical and functional plasticity that includes adaptive alterations in adult gut morphology, enteroendocrine cell profile and their hormone secretion, as well as nutrient utilization and storage. In this Perspective, we examine how shifts in dietary and environmental conditions bring about changes in gut size, and describe how the intestine adapts to changes in internal state, bowel resection and gastric bypass surgery. We highlight the critical importance of these intestinal remodelling processes in maintaining energy balance of the organism, and in protecting the metabolism of other organs. The intestinal resizing is supported by changes in the microbiota composition, and by activation of carbohydrate and fatty acid metabolism, which govern the intestinal stem cell proliferation, intestinal cell fate, as well as survivability of differentiated epithelial cells. The discovery that intestinal remodelling is part of the normal physiological adaptation to various triggers, and the potential for harnessing the reversible gut plasticity, in our view, holds extraordinary promise for developing therapeutic approaches against metabolic and inflammatory diseases.

Seasonality of Primary Small Bowel Volvulus and Its Variations Based on Sex and Place of Residence, North Western Ethiopia

Background

Primary small bowel volvulus is a common surgical emergency in some parts of the globe. Its seasonal nature has not been widely researched. The main objective of this study was to assess its underlying patterns among different gender and geographical location.

Materials and methods

A hospital-based retrospective cross-sectional study was conducted from November 2020 to February 2021 at two comprehensive specialized hospitals in North West Ethiopia. The monthly count of primary small bowel volvulus was analyzed for patterns using Minitab 18. Graphical techniques such as run sequence plots, multiple box plots, and correlogram were used. Additive decomposition was also done. The degree of seasonal variation was measured in terms of seasonal indices generated for each month. A chi-square goodness-of-fit test at p < 0.05 was applied to determine statistical significance.

Results

A total of 235 patients were found to have surgically confirmed diagnosis of primary small bowel volvulus over six years. Most were males (77.4%) and from rural residence (73.2%). The mean age in years was 40.5 (±16.7). Overall, 179 (76.2%) of the total cases, 148 (81.3%) of males, and 138 (80.2%) of rural cases were admitted during June through November.

Conclusion

Seasonal variation was found to be a feature of primary small bowel volvulus. Knowing its seasonal nature helps raise the threshold of suspicion among health care providers to pass timely clinical decisions particularly in resource-limited setups.

Impact of Pancreatic Enzymes on Enteral Fat and Nitrogen Absorption in Short Bowel Syndrome

OBJECTIVES

Patients with short bowel syndrome (SBS) can have a high morbidity rate. To minimize morbidity, enteral autonomy is the primary goal in clinical management of patients with SBS. This is often difficult to achieve because of significant malabsorption. To date, there are limited therapies that improve absorption in patients with SBS. The impact of pancreatic enzyme replacement treatment on enteral absorption has not been studied in this population and was the primary aim of this study.

SUBJECTS/METHODS

This was an interventional study in 11 subjects (6 pediatric subjects ages 4.0-17.9 years, 5 adult subjects 18-75 years) that compared enteral absorption in each subject before and after pancreatic enzyme medication (Creon). Coefficient of fat absorption (CFA) and coefficient of nitrogen absorption (CNA) were used as markers of enteral absorption of fat and protein, respectively.

RESULTS

There was no statistically significant mean change in CFA and CNA before and after pancreatic enzyme medication therapy. Six subjects demonstrated an increase in CFA and 8 subjects demonstrated an increase in CNA after the use of pancreatic enzyme medication therapy.

CONCLUSIONS

There was no statistically significant improvement in enteral fat and protein absorption in the cohort as a whole, though several subjects demonstrated an improvement. These results suggest that some patients with SBS may benefit from treatment with pancreatic enzymes. Further studies are needed to better evaluate the effect of pancreatic enzyme therapy on enteral absorption in subjects with SBS and to characterize factors that may predict a positive response.

Establishing normal ranges for fetal and neonatal small and large intestinal lengths: results from a prospective postmortem study

Objective

To establish reference intervals (RIs) for fetal and neonatal small and large intestinal lengths.

Methods

Linear measurements on small and large intestines were made upon postmortem examination of 131 preterm and term infants with gestational ages between 13 and 41 weeks. All cases were referred from the Eastern Ontario and Western Québec regions to a tertiary care hospital. Age and sex partitions were considered and RI limits were estimated.

Results

Data consisted of 72 male (54.96%) and 59 female (45.04%) fetuses and neonates with mean gestational age of 25.6 weeks. Results showed that small and large intestinal lengths increased linearly with gestational age. RIs for small intestinal length (cm) of fetuses and neonates aged 13–20 weeks were (21.1, 122.4); of those aged 21–28 weeks were (57.7, 203.8); of those aged 29–36 weeks were (83.6, 337.1); and of those aged 37–41 weeks were (132.8, 406.4). RIs for large intestinal length (cm) of fetuses and neonates from the same four age groups were (5.1, 21.4), (12.7, 39.7), (32.4, 62.4), and (29.1, 82.2).

Conclusions

Establishing accurate RIs for premature and term infants has clinical relevance for pathologists performing postmortem analysis and for surgeons planning postoperative management of patients. The results of this study reaffirm that fetal small and large intestinal lengths increase linearly with gestational age irrespective of sex. Future studies should aim to further investigate the role of possible confounders on growth of fetal intestinal length, including maternal factors such as age and substance use during pregnancy.

Comparative anatomy, pre- and postnatal changes during the development and maturation of the small intestine: Life-stage influences on exposure

The gastrointestinal (GI) system absorbs nutrients and xenobiotics, excretes waste, and performs immunologic and endocrine functions. The subdivisions of the mature gut and the complexity of their corrugated, absorptive luminal surfaces differ greatly among mammals. Regardless, the embryonic gut tube in all mammalian species arises when cephalocaudal folding incorporates the roof of the yolk sac into the embryo. The gut tube quickly lengthens and bulges into the umbilical cord. Upon reentry into the abdominal cavity, the gut tube begins to differentiate-a process that continues until well into the lactation period. Differentiation of the small intestine involves (1) increasing the absorptive surface area of the lumen; (2) establishing mechanisms to control the pH of luminal contents; (3) forming a hierarchical vascular system for distribution of absorbed nutrients; (4) developing a complex enteric nervous system to control motility; (5) providing a system for replenishment of cells; and (6) contributing to the immunity of the organism. Because the length of gestation varies among species typically used in safety tests and is much shorter than human gestation, the state of GI maturation at the time of parturition differs significantly. Differences in GI maturation can contribute to species differences in the rate and extent of absorption; these differences must be considered when designing and interpreting pharmacological/toxicological studies and extrapolating safety test results to humans.

Development of the Gastrointestinal Tract in Newborns as a Challenge for an Appropriate Nutrition: A Narrative Review

The second and third trimesters of pregnancy are crucial for the anatomical and functional development of the gastrointestinal (GI) tract. If premature birth occurs, the immaturity of the digestive and absorptive processes and of GI motility represent a critical challenge to meet adequate nutritional needs, leading to poor extrauterine growth and to other critical complications. Knowledge of the main developmental stages of the processes involved in the digestion and absorption of proteins, carbohydrates, and lipids, as well as of the maturational phases underlying the development of GI motility, may aid clinicians to optimize the nutritional management of preterm infants. The immaturity of these GI systems and functions may negatively influence the patterns of gut colonization, predisposing to an abnormal microbiome. This, in turn, further contributes to alter the functional, immune, and neural development of the GI tract and, especially in preterm infants, has been associated with an increased risk of severe GI complications, such as necrotizing enterocolitis. Deeper understanding of the physiological colonization patterns in term and preterm infants may support the promotion of these patterns and the avoidance of microbial perturbations associated with the development of several diseases throughout life. This review aims to provide a global overview on the maturational features of the main GI functions and on their implications following preterm birth. We will particularly focus on the developmental differences in intestinal digestion and absorption functionality, motility, gut–brain axis interaction, and microbiomes.

Presence of Natural Killer B Cells in Simian Immunodeficiency Virus-Infected Colon That Have Properties and Functions Similar to Those of Natural Killer Cells and B Cells but Are a Distinct Cell Population

There is low-level but significant mucosal inflammation in the gastrointestinal tract secondary to human immunodeficiency virus (HIV) infection that has long-term consequences for the infected host. This inflammation most likely originates from the immune response that appears as a consequence of HIV. Here, we show in an animal model of HIV that the chronically SIV-infected gut contains cytotoxic natural killer B cells that produce inflammatory cytokines and proliferate during infection.

Diagnostic Yields and Clinical Impacts of Capsule Endoscopy

Observing the entire small bowel is difficult due to the presence of complex loops and a long length. Capsule endoscopy (CE) provides a noninvasive and patient-friendly method for visualizing the small bowel and colon. Small bowel capsule endoscopy (SBCE) has a critical role in the diagnosis of small bowel disorders through the direct observation of the entire small bowel mucosa and is becoming the primary diagnostic tool for small bowel diseases. Recently, colon capsule endoscopy (CCE) was also considered safe and feasible for obtaining sufficient colonic images in patients with incomplete colonoscopy, in the absence of bowel obstruction. This review article assesses the current status of CE in terms of the diagnostic yield and the clinical impact of SBCE in patients with obscure gastrointestinal bleeding, who have known or suspected Crohn's disease, small bowel tumor and inherited polyposis syndrome, celiac disease, and those who have undergone CCE.

Characteristics of adult patients with chronic intestinal failure due to short bowel syndrome: An international multicenter survey

BACKGROUND AND AIMS

The case-mix of patients with intestinal failure due to short bowel syndrome (SBS-IF) can differ among centres and may also be affected by the timeframe of data collection. Therefore, the ESPEN international multicenter cross-sectional survey was analyzed to compare the characteristics of SBS-IF cohorts collected within the same timeframe in different countries.

METHODS

The study included 1880 adult SBS-IF patients collected in 2015 by 65 centres from 22 countries. The demographic, nutritional, SBS type (end jejunostomy, SBS-J; jejuno-colic anastomosis, SBS-JC; jejunoileal anastomosis with an intact colon and ileocecal valve, SBS-JIC), underlying disease and intravenous supplementation (IVS) characteristics were analyzed. IVS was classified as fluid and electrolyte alone (FE) or parenteral nutrition admixture (PN). The mean daily IVS volume, calculated on a weekly basis, was categorized as <1, 1-2, 2-3 and >3 L/day.

RESULTS

In the entire group: 60.7% were females and SBS-J comprised 60% of cases, while mesenteric ischaemia (MI) and Crohn' disease (CD) were the main underlying diseases. IVS dependency was longer than 3 years in around 50% of cases; IVS was infused ≥5 days/week in 75% and FE in 10% of cases. Within the SBS-IF cohort: CD was twice and thrice more frequent in SBS-J than SBS-JC and SBS-JIC, respectively, while MI was more frequent in SBS-JC and SBS-JIC. Within countries: SBS-J represented 75% or more of patients in UK and Denmark and 50-60% in the other countries, except Poland where SBS-JC prevailed. CD was the main underlying disease in UK, USA, Denmark and The Netherlands, while MI prevailed in France, Italy and Poland.

CONCLUSIONS

SBS-IF type is primarily determined by the underlying disease, with significant variation between countries. These novel data will be useful for planning and managing both clinical activity and research studies on SBS.

Digestion and Absorption of Milk Phospholipids in Newborns and Adults

Milk polar lipids provide choline, ethanolamine, and polyunsaturated fatty acids, which are needed for the growth and plasticity of the tissues in a suckling child. They may also inhibit cholesterol absorption by interacting with cholesterol during micelle formation. They may also have beneficial luminal, mucosal, and metabolic effects in both the neonate and the adult. The milk fat globule membrane contains large proportions of sphingomyelin (SM), phosphatidylcholine (PC), and phosphatidylethanolamine (PE), and some phosphatidylserine (PS), phosphatidylinositol (PI), and glycosphingolipids. Large-scale technical procedures are available for the enrichment of milk fat globule membrane (MFGM) in milk replacement formulations and food additives. Pancreatic phospholipase A2 (PLA2) and mucosal phospholipase B digest glycero-phospholipids in the adult. In the neonate, where these enzymes may be poorly expressed, pancreatic lipase-related protein 2 probably has a more important role. Mucosal alkaline SM-ase and ceramidase catalyze the digestion of SM in both the neonate and the adult. In the mucosa, the sphingosine is converted into sphingosine-1-phosphate, which is both an intermediate in the conversion to palmitic acid and a signaling molecule. This reaction sequence also generates ethanolamine. Here, we summarize the pathways by which digestion and absorption may be linked to the biological effects of milk polar lipids. In addition to the inhibition of cholesterol absorption and the generation of lipid signals in the gut, the utilization of absorbed choline and ethanolamine for mucosal and hepatic phospholipid synthesis and the acylation of absorbed lyso-PC with polyunsaturated fatty acids to chylomicron and mucosal phospholipids are important.

The Efficacy and Safety of Balloon Enteroscopy-Assisted Endoscopic Retrograde Cholangiography in Pediatric Patients with Surgically Altered Gastrointestinal Anatomy

Balloon enteroscopy-assisted endoscopic retrograde cholangiography (BEA-ERC) is useful and feasible in adults with pancreatobiliary diseases, but its efficacy and safety have not been established in pediatric patients. We compared the success rate and safety of BEA-ERC between adults and pediatric patients. This single-center retrospective study reviewed 348 patients (pediatric: 57, adult: 291) with surgically altered gastrointestinal anatomies who underwent BEA-ERC for biliary disorders from January 2007 to December 2019. The success rate of reaching the anastomosis or duodenal papilla was significantly lower in pediatric patients than in adult patients (66.7% vs. 88.0%, p < 0.01). The clinical success rate was also significantly lower in pediatric patients (64.9% vs. 80.4%, p = 0.014). The rate of adverse events was significantly higher in pediatric patients than in adults (14.2% vs. 7.7%, p = 0.037). However, if the anastomotic sites were reached in pediatric patients, the treatment was highly successful (97.3%). The time of reaching target site was significantly longer in pediatric patients than in adult patients. This study shows that BEA-ERC in pediatric patients is more difficult than that in adult patients. However, in patients where the balloon enteroscope was advanced to the anastomosis, clinical outcomes comparable to those in adults can be achieved.

In vitro models of gut digestion across childhood: current developments, challenges and future trends

The human digestion is a multi-step and multi-compartment process essential for human health, at the heart of many issues raised by academics, the medical world and industrials from the food, nutrition and pharma fields. In the first years of life, major dietary changes occur and are concomitant with an evolution of the whole child digestive tract anatomy and physiology, including colonization of gut microbiota. All these phenomena are influenced by child exposure to environmental compounds, such as drugs (especially antibiotics) and food pollutants, but also childhood infections. Due to obvious ethical, regulatory and technical limitations, in vivo approaches in animal and human are more and more restricted to favor complementary in vitro approaches. This review summarizes current knowledge on the evolution of child gut physiology from birth to 3 years old regarding physicochemical, mechanical and microbial parameters. Then, all the available in vitro models of the child digestive tract are described, ranging from the simplest static mono-compartmental systems to the most sophisticated dynamic and multi-compartmental models, and mimicking from the oral phase to the colon compartment. Lastly, we detail the main applications of child gut models in nutritional, pharmaceutical and microbiological studies and discuss the limitations and challenges facing this field of research.

Postprandial changes in gastrointestinal function and transit in cystic fibrosis assessed by Magnetic Resonance Imaging

BACKGROUND

Cystic fibrosis (CF) is a multi-system genetic disorder affecting >72,000 people worldwide. Most CF patients experience gastrointestinal symptoms and can develop complications. However, the mechanisms of CF gut disease are not well understood. We evaluated gut function and transit in CF using magnetic resonance imaging (MRI). We hypothesised oro-caecal transit time (OCTT) is longer in CF; with lower small bowel water content (SBWC).

METHODS

Twelve CF patients aged 12-40 years and 12 age and sex-matched controls underwent serial MRIs over 1 day with standardised meals. The primary endpoint was OCTT, assessed by the appearance of a food bolus in the caecum. Other measures included corrected SBWC and corrected colonic volume (both area under the curve, AUC), gastric half-emptying time and gastrointestinal symptoms.

RESULTS

OCTT was longer in CF (CF 330 mins [270, >360] vs. controls 210 mins [173, 315], p = 0.04), with no difference in gastric half-emptying times. Corrected SBWC was higher in CF (CF 62 L.min/m2 [36, 80] vs. controls 34 L.min/m2 [28, 41], p = 0.021); minimal postprandial decrease between T240 and T300 (CF 13 mL/m2 [-13, 57] vs. controls 102 mL/m2 [67, 108], p = 0.002) suggests impaired ileal emptying. Corrected colonic volumes were higher in CF (CF 186 L.min/m2 [167, 206] vs. controls 123 L.min/m2 [89, 146], p = 0.012). There were no differences in gastrointestinal symptoms.

CONCLUSIONS

MRI provides novel insights into CF pathophysiology. Sub-clinical ileal obstruction may be more prevalent than previously thought. Gastrointestinal MRI shows promise as an investigational tool in CF.

Recent advances in the ontogeny of drug disposition

Developmental changes that occur throughout childhood have long been known to impact drug disposition. However, pharmacokinetic studies in the paediatric population have historically been limited due to ethical concerns arising from incorporating children into clinical trials. As such, much of the early work in the field of developmental pharmacology was reliant on difficult-to-interpret in vitro and in vivo animal studies. Over the last 2 decades, our understanding of the mechanistic processes underlying age-related changes in drug disposition has advanced considerably. Progress has largely been driven by technological advances in mass spectrometry-based methods for quantifying proteins implicated in drug disposition, and in silico tools that leverage these data to predict age-related changes in pharmacokinetics. This review summarizes our current understanding of the impact of childhood development on drug disposition, particularly focusing on research of the past 20 years, but also highlighting select examples of earlier foundational research. Equally important to the studies reviewed herein are the areas that we cannot currently describe due to the lack of research evidence; these gaps provide a map of drug disposition pathways for which developmental trends still need to be characterized.

Rho GTPases as Key Molecular Players within Intestinal Mucosa and GI Diseases

Rho proteins operate as key regulators of the cytoskeleton, cell morphology and trafficking. Acting as molecular switches, the function of Rho GTPases is determined by guanosine triphosphate (GTP)/guanosine diphosphate (GDP) exchange and their lipidation via prenylation, allowing their binding to cellular membranes and the interaction with downstream effector proteins in close proximity to the membrane. A plethora of in vitro studies demonstrate the indispensable function of Rho proteins for cytoskeleton dynamics within different cell types. However, only in the last decades we have got access to genetically modified mouse models to decipher the intricate regulation between members of the Rho family within specific cell types in the complex in vivo situation. Translationally, alterations of the expression and/or function of Rho GTPases have been associated with several pathological conditions, such as inflammation and cancer. In the context of the GI tract, the continuous crosstalk between the host and the intestinal microbiota requires a tight regulation of the complex interaction between cellular components within the intestinal tissue. Recent studies demonstrate that Rho GTPases play important roles for the maintenance of tissue homeostasis in the gut. We will summarize the current knowledge on Rho protein function within individual cell types in the intestinal mucosa in vivo, with special focus on intestinal epithelial cells and T cells.

RYK-mediated filopodial pathfinding facilitates midgut elongation

Between embryonic days 10.5 and 14.5, active proliferation drives rapid elongation of the murine midgut epithelial tube. Within this pseudostratified epithelium, nuclei synthesize DNA near the basal surface and move apically to divide. After mitosis, the majority of daughter cells extend a long, basally oriented filopodial protrusion, building a de novo path along which their nuclei can return to the basal side. WNT5A, which is secreted by surrounding mesenchymal cells, acts as a guidance cue to orchestrate this epithelial pathfinding behavior, but how this signal is received by epithelial cells is unknown. Here, we have investigated two known WNT5A receptors: ROR2 and RYK. We found that epithelial ROR2 is dispensable for midgut elongation. However, loss of Ryk phenocopies the Wnt5a-/- phenotype, perturbing post-mitotic pathfinding and leading to apoptosis. These studies reveal that the ligand-receptor pair WNT5A-RYK acts as a navigation system to instruct filopodial pathfinding, a process that is crucial for continuous cell cycling to fuel rapid midgut elongation.

Variation in Small Bowel Length and Its Influence on the Outcomes of Sleeve Gastrectomy

PURPOSE

Small bowel length is drawing attention in the development of gastrointestinal bariatric/metabolic surgery, but the importance of the length of the small bowel in bariatric/metabolic is not clear. The present study was conducted to investigate variations in small bowel length and their clinical significance in patients undergoing laparoscopic sleeve gastrectomy (LSG).

MATERIALS AND METHODS

Small bowel length was measured in 620 patients diagnosed with obesity who underwent LSG between March 2014 and August 2018. Prospectively obtained demographic and clinical data were investigated, focusing on the association between small bowel length and weight loss.

RESULTS

Small bowel length varied widely among patients (mean 739.8 + 115.7 cm, range 380-1050 cm). Linear regression analysis revealed a significant association between small bowel length and body height, body weight, waist circumference, and serum levels of low-density lipoprotein cholesterol, hemoglobin, C-peptide, glycated hemoglobin (A1C), and gamma-glutamyl transferase (r-GT). Multivariate analysis confirmed that body height and serum A1C% levels independently predicted small bowel length in bariatric patients, strongly with body height (p < 0.001) but weakly with A1C%(p = 0.021). One-year follow-up rate was 75.3% (467/620), and small bowel length did not influence weight loss or the reduction of obesity related cardiovascular risk factors after LSG.

CONCLUSION

In this study, small bowel length varied widely among bariatric patients and was strongly associated with body height and weakly with serum A1C levels. Small bowel length has no significant role in weight loss or the resolution of cardiovascular risk factors after LSG.

Elevating EGFR-MAPK program by a nonconventional Cdc42 enhances intestinal epithelial survival and regeneration

The regulatory mechanisms enabling the intestinal epithelium to maintain a high degree of regenerative capacity during mucosal injury remain unclear. Ex vivo survival and clonogenicity of intestinal stem cells (ISCs) strictly required growth response mediated by cell division control 42 (Cdc42) and Cdc42-deficient enteroids to undergo rapid apoptosis. Mechanistically, Cdc42 engaging with EGFR was required for EGF-stimulated, receptor-mediated endocytosis and sufficient to promote MAPK signaling. Proteomics and kinase analysis revealed that a physiologically, but nonconventionally, spliced Cdc42 variant 2 (V2) exhibited stronger MAPK-activating capability. Human CDC42-V2 is transcriptionally elevated in some colon tumor tissues. Accordingly, mice engineered to overexpress Cdc42-V2 in intestinal epithelium showed elevated MAPK signaling, enhanced regeneration, and reduced mucosal damage in response to irradiation. Overproducing Cdc42-V2 specifically in mouse ISCs enhanced intestinal regeneration following injury. Thus, the intrinsic Cdc42-MAPK program is required for intestinal epithelial regeneration, and elevating this signaling cascade is capable of initiating protection from genotoxic injury.

Gut-Brain Axis in the Early Postnatal Years of Life: A Developmental Perspective

Emerging evidence suggests that alterations in the development of the gastrointestinal (GI) tract during the early postnatal period can influence brain development and vice-versa. It is increasingly recognized that communication between the GI tract and brain is mainly driven by neural, endocrine, immune, and metabolic mediators, collectively called the gut-brain axis (GBA). Changes in the GBA mediators occur in response to the developmental changes in the body during this period. This review provides an overview of major developmental events in the GI tract and brain in the early postnatal period and their parallel developmental trajectories under physiological conditions. Current knowledge of GBA mediators in context to brain function and behavioral outcomes and their synthesis and metabolism (site, timing, etc.) is discussed. This review also presents hypotheses on the role of the GBA mediators in response to the parallel development of the GI tract and brain in infants.

To Wean or Not to Wean: The Role of Autologous Reconstructive Surgery in the Natural History of Pediatric Short Bowel Syndrome on Behalf of Italian Society for Gastroenterology, Hepatology and Nutrition (SIGENP)

Pediatric Short Bowel Syndrome (SBS) can require prolonged parenteral nutrition (PN). Over the years, SBS management has been implemented by autologous gastrointestinal reconstructive surgery (AGIR). The primary objective of the present review was to assess the effect of AGIR on weaning off PN. We also evaluated how AGIR impacts survival, the need for transplantation (Tx) and the development of liver disease (LD). We conducted a systematic literature search to identify studies published from January 1999 to the present and 947 patients were identified. PN alone was weakly associated with higher probability of weaning from PN (OR = 1.1, p = 0.03) and of surviving (OR = 1.05, p = 0.01). Adjusting for age, the probability of weaning off PN but of not surviving remained significantly associated with PN alone (OR = 1.08, p = 0.03). Finally, adjusting for age and primary diagnosis (gastroschisis), any association was lost. The prevalence of TX and LD did not differ by groups. In conclusion, in view of the low benefit in terms of intestinal adaptation and of the not negligible rate of complications (20%), a careful selection of candidates for AGIR should be required. Bowel dilation associated with failure of advancing EN and poor growth, should be criteria to refer for AGIR.

De novo enteric neurogenesis in post-embryonic zebrafish from Schwann cell precursors rather than resident cell types

The enteric nervous system (ENS) is essential for normal gastrointestinal function. Although the embryonic origin of enteric neurons from the neural crest is well established, conflicting evidence exists regarding postnatal enteric neurogenesis. Here, we address this by examining the origin of de novo neurogenesis in the post-embryonic zebrafish ENS. Although new neurons are added during growth and after injury, the larval intestine appears to lack resident neurogenic precursors or classical glia marked by sox10, plp1a, gfap or s100 Rather, lineage tracing with lipophilic dye or inducible Sox10-Cre suggests that post-embryonic enteric neurons arise from trunk neural crest-derived Schwann cell precursors that migrate from the spinal cord into the intestine. Furthermore, the 5-HT4 receptor agonist prucalopride increases enteric neurogenesis in normal development and after injury. Taken together, the results suggest that despite the lack of resident progenitors in the gut, post-embryonic enteric neurogenesis occurs via gut-extrinsic Schwann cell precursors during development and injury, and is promoted by serotonin receptor agonists. The absence of classical glia in the ENS further suggests that neural crest-derived enteric glia might have evolved after the teleost lineage.This article has an associated 'The people behind the papers' interview.

Comparing the Intestinotrophic Effects of 2 Glucagon-Like Peptide-2 Analogues in the Treatment of Short-Bowel Syndrome in Neonatal Piglets

BACKGROUND

In treating short-bowel syndrome (SBS), autonomy from parenteral nutrition (PN) relies upon intestinal adaptation, which can be augmented by glucagon-like peptide-2 (GLP-2) analogues. In neonatal piglets with SBS, we compared intestinal adaptation following treatment with 2 GLP-2 analogues: teduglutide (TED) and apraglutide (APRA) METHODS: Following 75% distal small-intestinal resection, piglets were allocated to 4 treatment groups: saline (CON: n = 8), twice weekly APRA (5 mg/kg/dose; n = 8), and TED once daily (TED, 0.05 mg/kg/dose; n = 8) or twice daily (TEDBID, 0.05 mg/kg/dose; n = 7). Pharmacokinetic (PK) studies were undertaken, and on day 7, small-intestinal length and weight were measured and jejunal tissue collected for histology.

RESULTS

PK profiles were different between the 2 analogues. To achieve a comparable exposure to APRA, TED requires twice daily injection (TEDBID). Compared with CON, APRA and TEDBID increased small-bowel length (cm) (CON: 141, APRA: 166, TED: 153, TEDBID: 165; P = .004), whereas APRA increased small-bowel weight (g) (CON: 26, APRA: 33, TED: 28, TEDBID: 31; P = .007) and villus height (mm) (CON: 0.59, APRA: 0.90, TED: 0.58, TEDBID: 0.74; P < .001).

CONCLUSION

APRA injected only twice during the 7 consecutive days demonstrated a superior intestinotrophic effect compared with TED injected once daily. Even at more comparable drug exposure, when TED was injected twice a day, APRA showed superior trophic activity at the mucosal level. This is highly relevant for the treatment of pediatric SBS, given the markedly lower dose frequency by subcutaneous injection of APRA.

Fetal Physiologically Based Pharmacokinetic Models: Systems Information on the Growth and Composition of Fetal Organs

BACKGROUND

The growth of fetal organs is a dynamic process involving considerable changes in the anatomical and physiological parameters that can alter fetal exposure to xenobiotics in utero. Physiologically based pharmacokinetic models can be used to predict the fetal exposure as time-varying parameters can easily be incorporated.

OBJECTIVE

The objective of this study was to collate, analyse and integrate the available time-varying parameters needed for the physiologically based pharmacokinetic modelling of xenobiotic kinetics in a fetal population.

METHODS

We performed a comprehensive literature search on the physiological development of fetal organs. Data were carefully assessed, integrated and a meta-analysis was performed to establish growth trends with fetal age and weight. Algorithms and models were generated to describe the growth of these parameter values as functions of age and/or weight.

RESULTS

Fetal physiologically based pharmacokinetic parameters, including the size of the heart, liver, brain, kidneys, lungs, spleen, muscles, pancreas, skin, bones, adrenal and thyroid glands, thymus, gut and gonads were quantified as a function of fetal age and weight. Variability around the means of these parameters at different fetal ages was also reported. The growth of the investigated parameters was not consistent (with respect to direction and monotonicity).

CONCLUSION

Despite the limitations identified in the availability of some values, the data presented in this article provide a unique resource for age-dependent organ size and composition parameters needed for fetal physiologically based pharmacokinetic modelling. This will facilitate the application of physiologically based pharmacokinetic models during drug development and in the risk assessment of environmental chemicals and following maternally administered drugs or unintended exposure to environmental toxicants in this population.

Intestinal Organoids Generated from Human Pluripotent Stem Cells

The gastrointestinal system is one of the most complex organ systems in the human body, and consists of numerous cell types originating from three germ layers. To understand intestinal development and homeostasis and elucidate the pathogenesis of intestinal disorders, including unidentified diseases, several in vitro models have been developed. Human pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), have remarkable developmental plasticity and possess the potential for a wide variety of applications. Three-dimensional organs, termed organoids and produced in vitro by PSCs, contain not only epithelium but also mesenchymal tissue and partially recapitulate intestinal functions. Such intestinal organoids have begun to be applied in disease models and drug development and have contributed to a detailed analysis of molecular interactions and findings in the synergistic development of biomedicine for human digestive organs. In this review, we describe gastrointestinal organoid technology derived from PSCs and consider its potential applications.

Restoring gut physiology in short bowel patients: from bench to clinical application of autologous intestinal reconstructive procedures

Introduction: Short bowel syndrome represents the leading etiology that causes intestinal failure both in children and adults. Total parenteral nutrition support has dramatically improved the prognosis for these patients but, if related irreversible complications occur, the alternative is represented by surgery and/or transplantation. Areas covered: Autologous gastrointestinal reconstructive procedures are a feasible, alternative approach with good long-term outcome data inexperienced surgical centers. Expert opinion: Ongoing innovative efforts have driven the surgical options for successful autologous reconstructive surgery: bowel elongation/tapering techniques (LILT, STEP, and the new SILT) together with the 'reversed bowel segment' procedure are now recognized procedures and all must be tailored to the individual patient needs to obtain the optimal result in terms of enteral autonomy. Background laboratory experimentation with new procedures e.g. options for bowel dilation techniques and distraction-induced enterogenesis, may provide additional management and treatment modalities.

Short Bowel Syndrome as the Leading Cause of Intestinal Failure in Early Life: Some Insights into the Management

Intestinal failure (IF) is the critical reduction of the gut mass or its function below the minimum needed to absorb nutrients and fluids required for adequate growth in children. Severe IF requires parenteral nutrition (PN). Pediatric IF is most commonly due to congenital or neonatal intestinal diseases or malformations divided into 3 groups: 1) reduced intestinal length and consequently reduced absorptive surface, such as in short bowel syndrome (SBS) or extensive aganglionosis; 2) abnormal development of the intestinal mucosa such as congenital diseases of enterocyte development; 3) extensive motility dysfunction such as chronic intestinal pseudo-obstruction syndromes. The leading cause of IF in childhood is the SBS. In clinical practice the degree of IF may be indirectly measured by the level of PN required for normal or catch up growth. Other indicators such as serum citrulline have not proven to be highly reliable prognostic factors in children. The last decades have allowed the development of highly sophisticated nutrient solutions consisting of optimal combinations of macronutrients and micronutrients as well as guidelines, promoting PN as a safe and efficient feeding technique. However, IF that requires long-term PN may be associated with various complications including infections, growth failure, metabolic disorders, and bone disease. IF Associated Liver Disease may be a limiting factor. However, changes in the global management of IF pediatric patients, especially since the setup of intestinal rehabilitation centres did change the prognosis thus limiting "nutritional failure" which is considered as a major indication for intestinal transplantation (ITx) or combined liver-ITx.

Fifteen-minute consultation on the healthy child: Bowel habit in infants and children

A common presentation to the general paediatric clinic is a child or young person's difficult bowel habit, which is often a potent source of anxiety for parents and carers. A large proportion of these children will have a functional cause for their symptoms, with unnecessary investigation and non-evidence-based treatments adding to their difficulties. This article aims to explain what encompasses the normal bowel habit in children and young people, reassure where appropriate and identify those patterns that may be suggestive of a disorder or disease requiring treatment. We illustrate both extremes of the spectrum of normal bowel habit in children with two case studies.

Human Fetal TNF-α-Cytokine-Producing CD4+ Effector Memory T Cells Promote Intestinal Development and Mediate Inflammation Early in Life

Although the fetal immune system is considered tolerogenic, preterm infants can suffer from severe intestinal inflammation, including necrotizing enterocolitis (NEC). Here, we demonstrate that human fetal intestines predominantly contain tumor necrosis factor-α (TNF-α)⁺CD4⁺CD69⁺ T effector memory (Tem) cells. Single-cell RNA sequencing of fetal intestinal CD4⁺ T cells showed a T helper 1 phenotype and expression of genes mediating epithelial growth and cell cycling. Organoid co-cultures revealed a dose-dependent, TNF-α-mediated effect of fetal intestinal CD4⁺ T cells on intestinal stem cell (ISC) development, in which low T cell numbers supported epithelial development, whereas high numbers abrogated ISC proliferation. CD4⁺ Tem cell frequencies were higher in inflamed intestines from preterm infants with NEC than in healthy infant intestines and showed enhanced TNF signaling. These findings reveal a distinct population of TNF-α-producing CD4⁺ T cells that promote mucosal development in fetal intestines but can also mediate inflammation upon preterm birth.

Signals and forces shaping organogenesis of the small intestine

The adult gastrointestinal tract (GI) is a series of connected organs (esophagus, stomach, small intestine, colon) that develop via progressive regional specification of a continuous tubular embryonic organ anlage. This chapter focuses on organogenesis of the small intestine. The intestine arises by folding of a flat sheet of endodermal cells into a tube of highly proliferative pseudostratified cells. Dramatic elongation of this tube is driven by rapid epithelial proliferation. Then, epithelial-mesenchymal crosstalk and physical forces drive a stepwise cascade that results in convolution of the tubular surface into finger-like projections called villi. Concomitant with villus formation, a sharp epithelial transcriptional boundary is defined between stomach and intestine. Finally, flask-like depressions called crypts are established to house the intestinal stem cells needed throughout life for epithelial renewal. New insights into these events are being provided by in vitro organoid systems, which hold promise for future regenerative engineering of the small intestine.

CARE Dose 4D combined with sinogram-affirmed iterative reconstruction improved the image quality and reduced the radiation dose in low dose CT of the small intestine

OBJECTIVE

Multislice computed tomography (MSCT) has been used for diagnosis of small intestinal diseases. However, the radiation dose is a big problem. This study was to investigate whether CARE Dose 4D combined with sinogram-affirmed iterative reconstruction (SAFIRE) can provide better image quality at a lower dose for imaging small intestinal diseases compared to MSCT.

METHODS

The noise reduction ability of SAFIRE was assessed by scanning the plain water mold using SOMATOM Definition Flash double-source spiral CT. CT images at each stage of radiography for 239 patients were obtained. The patients were divided into groups A and B were based on different tube voltage and current or the image recombination methods. The images were restructured using with filtered back projection (FBP) and SAFIRE (S1-S5). The contrast noise ratio (CNR), CT Dose index (CTDI), subjective scoring, and objective scoring were compared to obtain the best image and reformation parameters at different stages of CT.

RESULTS

Twenty-six restructuring patterns of tube voltage and current were obtained by FBP and SAFIRE. The average radiation dose using CARE Dose 4D combined with SAFIRE (S4-S5) reduced approximately 74.85% compared to conditions where the tube voltage of 100 kV and tube current of 131 mAs for patients with MSCT small intestinal CT enterography at plain CT scan, arterial stage, small intestine, and portal venous phase. The objective and subjective scoring were all significantly different among groups A and B at each stage.

CONCLUSIONS

Combination of CARE Dose 4D and SAFIRE is shown to decrease the radiation dose while maintaining image quality.

Papio spp. Colon microbiome and its link to obesity in pregnancy

INTRODUCTION

Gut microbial communities are critical players in the pathogenesis of obesity. Pregnancy is associated with increased bacterial load and changes in gut bacterial diversity. Sparse data exist regarding composition of gut microbial communities in obesity combined with pregnancy.

MATERIAL AND METHODS

Banked tissues were collected under sterile conditions during necropsy, from three non-obese (nOb) and four obese (Ob) near-term pregnant baboons. Sequences were assigned taxonomy using the Ribosomal Database Project classifier. Microbiome abundance and its difference between distinct groups were assessed by a nonparametric test.

RESULTS

Three families predominated in both the nOb and Ob colonic microbiome: Prevotellaceae (25.98% and 32.71% respectively), Ruminococcaceae (12.96% and 7.48%), and Lachnospiraceae (8.78% and 11.74%). Seven families of the colon microbiome displayed differences between Ob and nOb groups.

CONCLUSION

Changes in gut microbiome in pregnant obese animals open the venue for dietary manipulation in pregnancy.

Gastrointestinal Development: Implications for Management of Preterm and Term Infants

The gastrointestinal (GI) system provides digestive, absorptive, neuroendocrine, and immunologic functions to support overall health. If normal development is interrupted, a variety of complications and disease can arise. This article explores normal development of the GI tract and specific clinical challenges pertinent to preterm and term infants. Specific topics include abnormal motility, gastroesophageal reflux, current feeding recommendations for preterm infants, effects of parenteral nutrition, and the relationship between the GI tract and the immune system.

Detection and interpretation of fecal host mRNA in rural Malawian infants aged 6-12 months at risk for environmental enteric dysfunction

Recent studies have suggested that environmental enteric dysfunction can be assessed in rural African children by measuring levels of fecal mRNA transcripts. The field collection of fecal samples is less invasive and cumbersome than administration of the lactulose:mannitol test, which is typically used to assess environmental enteric dysfunction. This study sought to determine if, as in children aged 12-60 months, an array of seven fecal host transcripts (CD53, CDX1, HLA-DRA, TNF, S100A8, MUC12, and REG1A) could predict environmental enteric dysfunction in rural African infants. Host fecal transcript abundance was correlated to the percentage of lactulose (%L) excreted in the urine for 340 samples from Malawian children aged 6-12 months. Permeability was categorized as not severe (%L < 0.45) and severe (%L ≥ 0.45). This study found the prevalence of severe environmental enteric dysfunction to be 114/834 (14%), lower than what was previously reported for 12-60 months old children, 595/1521 (39%, P = 0.001). In linear regression analysis with the seven host transcripts, two were associated with %L: β coefficients of -1.843 ( P = 0.035) and 0.215 ( P = 0.006) for CDX1 and REG1A, respectively. The seven fecal host transcripts in a random forest model did not predict severe environmental enteric dysfunction. Future models utilizing different transcripts identified from an untargeted, agnostic assessment of all potential host transcripts could provide accurate predictions of environmental enteric dysfunction in infants. Impact statement Environmental enteric dysfunction (EED) is associated with reduced linear growth. The dual sugar absorption test has been used as a non-invasive method to determine the gut health of individuals. Alternative methods using fecal host mRNAs as predictors of the gut health are promising. In older children, we have determined that seven transcripts can predict the gut health in a random forest model. Our current study determined that the host fecal mRNA is abundant in infants and toddlers alike. Severe EED in rural Malawian children is less prevalent in infants than in young children. REG1A and CDX1 are associated with gut health. Fecal host mRNA may well be a means to assess gut health in African infants, but the panel of transcripts used to do this will differ from that in older children.