Intestinal adaptation following massive ileocecal resection in 20-day-old weanling rats

Systematic review: the effect of right hemicolectomy for cancer on postoperative bowel function

BACKGROUND

Right-sided cancer accounts for approximately 30% of bowel cancer in women and 22% in men. Colonic resection can cause changes in bowel function which affect daily activity. The aims are to assess the impact of right hemicolectomy for cancer on bowel function and to identify useful treatment modalities for managing bowel dysfunction after right hemicolectomy.

METHOD

The review was conducted in line with PRISMA. Eligible studies evaluated the impact of right hemicolectomy on bowel function in those treated for colorectal neoplasia or assessed the effect of surgical technique or other intervention on bowel function after right hemicolectomy. Right hemicolectomy for inflammatory bowel disease or benign cases only were excluded. Articles were limited to studies on human subjects written in English published between January 2008 and December 2018.

RESULTS

The searches identified 7531 articles. Nine articles met the inclusion criteria, of which eight were cohort studies and one was a randomised trial. Loose stool, increased bowel frequency and/or nocturnal defaecation following right-sided colectomy occurs in approximately one in five patients. Some of these symptoms may improve spontaneously with time. Bile acid malabsorption and/or small bowel bacterial overgrowth may be the cause for chronic dysfunction. Some studies report that no or little difference in outcome between right-sided and rectal resections likely suggests poor function after right-sided resection.

CONCLUSION

Right hemicolectomy can result in changes to bowel function. Patients should be counselled preoperatively, and follow-up should be designed to identify and effectively treat significantly altered bowel function.

Enhancement of Colonic Absorptive Function after the Massive Resection of the Small Intestine Based on the Creation of an Artificial Colonic Valve

The colon can have an absorptive function similar to that of the small intestine after the massive resection of the small bowel. To improve colonic absorptive function, we created a valve in the colon (artificial colonic valve, ACV). ACVs were created in 20 rats that had 80 percent of their small intestine resected, with an observation time of 30 weeks. The ACV rats were compared with those in the non-operated control group, the short bowel syndrome (SBS) group and the colon interposition (CI) group. The ACV rats were much heavier than those in the control group, SBS group and CI group. In terms of histology and the levels of α-amylase and the Na⁺-dependent bile salt transporter, the absorptive function of the colons before the valves resembled that of the small intestine. The colonic absorptive function was more obvious in ACV rats than in CI rats. An ACV can enhance colonic absorptive function after the massive resection of the small intestine. The colonic absorptive function of ACV rats was better than that of the rats in the CI group.

Digestive enzyme expression in the large intestine of children with short bowel syndrome in a late stage of adaptation

BACKGROUND AND AIMS

Intestinal adaptation in short bowel syndrome (SBS) includes morphologic processes and functional mechanisms. This study investigated whether digestive enzyme expression in the duodenum and colon is upregulated in SBS patients.

METHOD

Sucrase-isomaltase (SI), lactase-phlorizin hydrolase (LPH), and neutral Aminopeptidase N (ApN) were analyzed in duodenal and colonic biopsies from nine SBS patients in a late stage of adaptation as well as healthy and disease controls by immunoelectron microscopy (IEM), Western blots, and enzyme activities. Furthermore, proliferation rates and intestinal microbiota were analyzed in the mucosal specimen.

RESULTS

We found significantly increased amounts of SI, LPH, and ApN in colonocytes in most SBS patients with large variation and strongest effect for SI and ApN. Digestive enzyme expression was only partially elevated in duodenal enterocytes due to a low proliferation level measured by Ki-67 staining. Microbiome analysis revealed high amounts of Lactobacillus resp. low amounts of Proteobacteria in SBS patients with preservation of colon and ileocecal valve. Colonic expression was associated with a better clinical course in single cases.

CONCLUSION

In SBS patients disaccharidases and peptidases can be upregulated in the colon. Stimulation of this colonic intestinalization process by drugs, nutrients, and pre- or probiotics might offer better therapeutic approaches.

Is maintenance of the ileocecal valve important to the intestinal adaptation mechanisms in a weaning rat model of short bowel?

PURPOSE

To evaluate the role of maintenance of the ileocecal valve (ICV) in intestinal adaptation mechanisms, in a weaning rat experimental model of short bowel.

METHODS

Forty animals were operated on to produce short bowel syndrome. They were divided into five groups: maintenance (MV) or resection of ICV (RV), kill after 4 days (MV4 and RV4) or 21 days (MV21 and RV21), and a control group (21-day-old rats). Body weights, small bowel and colon lengths and diameters, villus heights, crypt depths, lamina propria and muscle layer thickness, as well as the apoptosis index of villi and crypts and expression of pro- and anti-apoptotic genes, were studied.

RESULTS

Preservation of the ICV promoted increased weight gain (p = 0.0001) and intestinal villus height after 21 days; crypt depth was higher in comparison to controls. It was verified a higher expression of Ki-67 in bowel villi and crypts (p = 0.018 and p = 0.015, respectively) in RV4 group and a higher expression in bowel villi of MV4 group animals (p = 0.03). The maintenance of ICV promoted late increased expression of the anti-apoptotic gene Bcl-XL in the colon (p = 0.043, p = 0.002, p = 0.01).

CONCLUSION

The maintenance of the ICV led to positive changes in this model.

Are there differences in the growth adaptation processes of growing and mature organism models of short bowel syndrome?

OBJECTIVES

The purpose of this study was to present an experimental model of short bowel syndrome (SBS) in weaning rats and to compare the adaptative mechanisms of the remaining bowel in weaning rats and adult animals by means of morphometric, histologic and molecular methods.

METHODS

Twenty-four weaning rats were divided into 3 groups of 8 animals, one control group and two short bowel groups (euthanasia after 4 and 21 days), and were compared with similar adult groups. Morphometric evaluations of the animals and histopathological and molecular studies of the remaining bowel were performed.

RESULTS

The weight of young rats increased after enterectomy, whereas that of adult rats decreased after enterectomy (p<0.0001). The ratio of intestinal length/body weight was significantly higher in weaning rats than in adults (p<0.002), showing that intestinal growth was more intense in weaning rats. Intestinal resection promoted increased thickness of the small bowel lamina propria (p=0.001) and reduced thickness of the colon lamina propria (p=0.04) in weaning rats relative to those in adults. In addition, intestinal resection promoted increased expression of the Bcl-xl gene (antiapoptotic) in adult animals compared with that in weaning rats (p=0.001).

CONCLUSION

Morphometric, histological and molecular differences were shown in the adaptation processes of growing and mature organisms.

Starch Tolerance and the Short Bowel

Short bowel syndrome with intestinal failure is a rare disease with a massive impairment in quality of life, requiring a multidisciplinary team approach to medical, surgical, and nutritional therapy. Current pharmacological and surgical therapeutic options are limited; an important cornerstone is enteral and parenteral nutrition. The changed physiology of carbohydrate digestion plays a major role in the adaptation process and can be a target for specific enteral nutrition interventions. An important prognostic factor is the preservation of at least portions of the colon in continuity with small bowel. This strategy has to include an evaluation of the anatomical situation and small bowel absorptive capacity, adaptation processes, and luminal microbiota including its fermentative properties. Starch is probably the most important complex carbohydrate in short bowel syndrome nutrition, because it is absorbed or fermented almost completely. Benefits of supplementation with complex carbohydrates include improved adaptive processes, positive trophic effects on the mucosa and its hormonal response, longer transit time, and possibly a faster time to wean from parenteral nutrition, but supplementation advice needs to weigh carefully the risks and benefits, especially considering bacterial overgrowth, osmotic load, and D-lactate acidosis.

Pancreatic-like enzymes of microbial origin restore growth and normalize lipid absorption in a pig model with exocrine pancreatic insufficiency

INTRODUCTION

The standard therapy for exocrine pancreatic insufficiency (EPI) is porcine-derived pancreatic enzyme replacement therapy (PERT). In the present study we tested a new approach with a mixture of pancreatic-like enzymes of microbial origin (PLEM) in a 1-week efficacy study in EPI pigs. In addition to the conventionally used coefficient of fat and nitrogen absorption (CFA and CNA), parameters that more accurately reflect the nutritional and health status, such as changes in the lipemic index (LI), plasma triglyceride (TG) and non-esterified fatty acid (NEFA) levels, and somatic growth, were determined.

MATERIAL AND METHODS

A PLEM dose containing 120 000 active lipase units, 80 000 active protease units and 12 000 active amylase units (all from Sigma, St. Louis, MO) was given as a powder, twice daily with a meal (40 g fat/meal) to 8 EPI pigs for 7 days. Ten healthy pigs were used as a comparator.

RESULTS

The PLEM enhanced fat and protein digestion, and reversed growth impairment in EPI pigs. With treatment, CFA and CNA increased by 59% and 43% (p < 0.05), respectively. Although fat and protein absorption were lower than in the comparator, the postprandial blood lipid profile was normal as in healthy pigs. The mucosal thickness significantly increased by 27%, 50% and 26%, in the proximal, middle, and distal jejunum (p < 0.05) with treatment and resembled that of healthy animals.

CONCLUSIONS

Pancreatic-like enzymes of microbial origin supported somatic growth and normalized the postprandial lipid profile. As a measure of efficacy, postprandial LI, TG and NEFA are viable endpoints to be explored in human trials.

Ileocaecal valve syndrome after surgery in adult patients: myth or reality?

AIM

The onset of symptoms after removal of the ileocaecal valve (ICV) may be perceived as an unwanted effect of surgery and induce patients to bring unnecessary litigation against surgeons. The aim of our study is to assess the real impact on the quality of life of patients whose ICV has been surgically removed, using three validated questionnaires.

METHOD

In patients who had their ICV removed surgically, the Gastrointestinal Quality of life (GIQLI) questionnaire and those used by the European Organization for research and Treatment of Cancer (EORTC) were administered before and after surgery. The empirical rule effect size method was used to evaluate the clinical significance of the statistical data.

RESULTS

We interviewed 225 patients. Data collected through the three questionnaires highlighted a trend towards postoperative improvement of the selected gastrointestinal symptoms compared with the baseline. The GIQLI questionnaire showed a statistically significant improvement in 'pain', 'nausea' and 'constipation' during the follow-up. Constipation appeared more frequently in patients older than 70 years compared with younger ones. The EORTC-QLQ-C30 questionnaire showed a significant correlation between diarrhoea and extended right colectomy at 3 months after surgery, which was not confirmed at 6 months. The EORTC QLQ-CR29 questionnaire showed a slight deterioration of 'leakage of stools from the anal opening' at 6 months after surgery, but this symptom was not deemed clinically significant.

CONCLUSION

We found that bowel functions in most patients after surgical removal of the ICV were satisfactory. Providing patients with a comprehensive and exhaustive informed consent during preoperative consultations could promote patient trust and avoid misunderstandings.

Effects of exogenous glucagon-like peptide-2 and distal bowel resection on intestinal and systemic adaptive responses in rats

OBJECTIVE

To determine the effects of exogenous glucagon-like peptide-2 (GLP-2), with or without massive distal bowel resection, on adaptation of jejunal mucosa, enteric neurons, gut hormones and tissue reserves in rats.

BACKGROUND

GLP-2 is a gut hormone known to be trophic for small bowel mucosa, and to mimic intestinal adaptation in short bowel syndrome (SBS). However, the effects of exogenous GLP-2 and SBS on enteric neurons are unclear.

METHODS

Sprague Dawley rats were randomized to four treatments: Transected Bowel (TB) (n = 8), TB + GLP-2 (2.5 nmol/kg/h, n = 8), SBS (n = 5), or SBS + GLP-2 (2.5 nmol/kg/h, n = 9). SBS groups underwent a 60% jejunoileal resection with cecectomy and jejunocolic anastomosis. All rats were maintained on parenteral nutrition for 7 d. Parameters measured included gut morphometry, qPCR for hexose transporter (SGLT-1, GLUT-2, GLUT-5) and GLP-2 receptor mRNA, whole mount immunohistochemistry for neurons (HuC/D, VIP, nNOS), plasma glucose, gut hormones, and body composition.

RESULTS

Resection increased the proportion of nNOS immunopositive myenteric neurons, intestinal muscularis propria thickness and crypt cell proliferation, which were not recapitulated by GLP-2 therapy. Exogenous GLP-2 increased jejunal mucosal surface area without affecting enteric VIP or nNOS neuronal immunopositivity, attenuated resection-induced reductions in jejunal hexose transporter abundance (SGLT-1, GLUT-2), increased plasma amylin and decreased peptide YY concentrations. Exogenous GLP-2 attenuated resection-induced increases in blood glucose and body fat loss.

CONCLUSIONS

Exogenous GLP-2 stimulates jejunal adaptation independent of enteric neuronal VIP or nNOS changes, and has divergent effects on plasma amylin and peptide YY concentrations. The novel ability of exogenous GLP-2 to modulate resection-induced changes in peripheral glucose and lipid reserves may be important in understanding the whole-body response following intestinal resection, and is worthy of further study.

Apo AIV and Citrulline Plasma Concentrations in Short Bowel Syndrome Patients: The Influence of Short Bowel Anatomy

INTRODUCTION

Parenteral nutrition (PN) dependence in short bowel syndrome (SBS) patients is linked to the functionality of the remnant small bowel (RSB). Patients may wean off PN following a period of intestinal adaptation that restores this functionality. Currently, plasma citrulline is the standard biomarker for monitoring intestinal functionality and adaptation. However, available studies reveal that the relationship the biomarker with the length and function of the RSB is arguable. Thus, having additional biomarkers would improve pointing out PN weaning.

AIM

By measuring concomitant changes in citrulline and the novel biomarker apolipoprotein AIV (Apo AIV), as well as taking into account the anatomy of the RSB, this exploratory study aims to a better understanding of the intestinal adaptation process and characterization of the SBS patients under PN.

METHODS

Thirty four adult SBS patients were selected and assigned to adapted (aSBS) and non-adapted (nSBS) groups after reconstructive surgeries. Remaining jejunum and ileum lengths were recorded. The aSBS patients were either on an oral diet (ORAL group), those with intestinal insufficiency, or on oral and home parenteral nutrition (HPN group), those with chronic intestinal failure. Apo AIV and citrulline were analyzed in plasma samples after overnight fasting. An exploratory ROC analysis using citrulline as gold standard was performed.

RESULTS

Biomarkers, Apo AIV and citrulline showed a significant correlation with RSBL in aSBS patients. In jejuno-ileocolic patients, only Apo AIV correlated with RSBL (rb = 0.54) and with ileum length (rb = 0.84). In patients without ileum neither biomarker showed any correlation with RSBL. ROC analysis indicated the Apo AIV cut-off value to be 4.6 mg /100 mL for differentiating between the aSBS HPN and ORAL groups.

CONCLUSIONS

Therefore, in addition to citrulline, Apo AIV can be set as a biomarker to monitor intestinal adaptation in SBS patients. As short bowel anatomy is shown to influence citrulline and Apo AIV plasma values, both biomarkers complement each other furnishing a new insight to manage PN dependence.

Animal models of gastrointestinal and liver diseases. Animal models of infant short bowel syndrome: translational relevance and challenges

Intestinal failure (IF), due to short bowel syndrome (SBS), results from surgical resection of a major portion of the intestine, leading to reduced nutrient absorption and need for parenteral nutrition (PN). The incidence is highest in infants and relates to preterm birth, necrotizing enterocolitis, atresia, gastroschisis, volvulus, and aganglionosis. Patient outcomes have improved, but there is a need to develop new therapies for SBS and to understand intestinal adaptation after different diseases, resection types, and nutritional and pharmacological interventions. Animal studies are needed to carefully evaluate the cellular mechanisms, safety, and translational relevance of new procedures. Distal intestinal resection, without a functioning colon, results in the most severe complications and adaptation may depend on the age at resection (preterm, term, young, adult). Clinically relevant therapies have recently been suggested from studies in preterm and term PN-dependent SBS piglets, with or without a functional colon. Studies in rats and mice have specifically addressed the fundamental physiological processes underlying adaptation at the cellular level, such as regulation of mucosal proliferation, apoptosis, transport, and digestive enzyme expression, and easily allow exogenous or genetic manipulation of growth factors and their receptors (e.g., glucagon-like peptide 2, growth hormone, insulin-like growth factor 1, epidermal growth factor, keratinocyte growth factor). The greater size of rats, and especially young pigs, is an advantage for testing surgical procedures and nutritional interventions (e.g., PN, milk diets, long-/short-chain lipids, pre- and probiotics). Conversely, newborn pigs (preterm or term) and weanling rats provide better insights into the developmental aspects of treatment for SBS in infants owing to their immature intestines. The review shows that a balance among practical, economical, experimental, and ethical constraints will determine the choice of SBS model for each clinical or basic research question.

Early enteral fat supplementation improves protein absorption in premature infants with an enterostomy

BACKGROUND

Early enteral fat supplementation and fish oil (FO) stimulates post-resection intestinal adaptation in rats and increases fat absorption in premature infants with bowel resection and an enterostomy.

OBJECTIVE

To test the hypothesis that early fat supplement and FO increases post-resection protein absorption, intestinal RNA, protein without decreasing intestinal arachidonic acid (AA) in premature infants with an enterostomy.

METHODS

36 premature infants (<2 months old) with an enterostomy after surgical treatment for necrotizing enterocolitis or spontaneous intestinal perforation who tolerated enteral feeding at 20 ml/kg/day were randomized to usual care (control, n = 18) or early supplementing enteral Microlipid (ML) and FO (treatment, n = 18). Intralipid was decreased as the dose of enteral fat was increased. Daily weight, ostomy output and nutritional intake were recorded. Weekly 24-hour ostomy effluent was collected to measure fecal protein. Protein absorption was calculated by subtracting fecal protein from dietary protein. Tissue samples from the functional stoma and the nonfunctional distal diverted end were collected during bowel reanastomosis to measure RNA, protein, and fatty acid (FA) profile.

RESULTS

Compared to controls, the treatment group had higher protein absorption (g/kg/day) and intestinal RNA and protein (μg/mg tissue) proximal to the ostomy. The two groups had similar FA profiles except that the treatment group had higher n-3 eicosapentaenoic acid (EPA, μg/mg tissue) proximal to the ostomy.

CONCLUSION

Early supplementation of enteral ML and FO to premature infants with an enterostomy increased dietary protein absorption, intestinal RNA, protein and n-3 EPA content without altering other FA content.

Early enteral fat supplement and fish oil increases fat absorption in the premature infant with an enterostomy

OBJECTIVE

To test the hypothesis that in the premature infant with an enterostomy, early enteral supplementation with Microlipid (fat supplement) and fish oil increases enteral fat absorption and decreases the requirement for Intralipid (intravenous fat emulsion).

STUDY DESIGN

Premature infants (<2 months old) with an enterostomy after surgical treatment for necrotizing enterocolitis or spontaneous intestinal perforation and tolerating enteral feeding at 20 mL/kg/day were randomized to usual care (control 18 infants) or early supplementing enteral fat and fish oil (treatment 18 infants). Intravenous fat emulsion was decreased as enteral fat intake was increased. Daily weight, ostomy output, and nutrition data were recorded. Weekly 24-hour ostomy effluent was collected until bowel reanastomosis, and fecal fat, fecal liquid, and dry feces were measured. Fat absorption (g/kg/d) was calculated by subtracting fecal fat from dietary fat. The fecal liquid and dry feces were reported as mg/g wet stool. Date were analyzed by using ANOVA and mixed-effects model.

RESULTS

The interval from initial postoperative feeding to bowel reanastomosis varied from 2 to 10 weeks. The treatment group received more dietary fat and less intravenous fat emulsion and had higher enteral fat absorption, less fecal liquid, and drier feces than the control group. These effects were greater among infants with a high ostomy compared with those with a low ostomy. Enteral fat intake was significantly correlated with fat absorption.

CONCLUSION

Early enteral fat supplement and fish oil increases fat absorption and decreases the requirement for intravenous fat emulsion. This approach could be used to promote bowel adaptation and reduce the use of intravenous fat emulsion in the premature infant with an enterostomy.

Dietary fish oil increases fat absorption and fecal bile acid content without altering bile acid synthesis in 20-d-old weanling rats following massive ileocecal resection

INTRODUCTION

Dietary fish oil (FO) was reported to lower fecal fat excretion in a weanling rat model of short bowel syndrome (SBS) after ileocecal resection (ICR), and to induce changes in secretion and synthesis of bile acid (BA) in adults. We hypothesized that dietary FO, as compared with corn oil (CO), increases intestinal fat absorption in weanling SBS rats in part due to increased hepatic BA synthesis and luminal BA concentrations.

METHODS

After undergoing ICR, 20-d-old rats were fed ad lib for 7 d with a CO or FO diet containing 5% sucrose polybehenate (SPB), a marker for dietary fat absorption. Fecal fatty acid, fecal and intestine luminal BA, liver mRNA expressions of cholesterol 7α-hydroxylase (Cyp7α1) and sterol-12α-hydroxylase (Cyp8β1), and serum 7α-hydroxy-4-cholesten-3-1 (7αC4) levels were determined.

RESULTS

As compared with CO-ICR rats, FO-ICR rats had higher intestinal absorption of total fat and most individual fatty acids. Although the BA content per gram of dry stool was increased in FO-ICR rats, there were no differences between groups for the BA content in remnant jejunum, liver mRNA expression of BA biosynthetic enzymes, Cyp7α1 and Cyp8β1, or serum 7αC4, a marker for BA synthesis.

CONCLUSION

Dietary FO increases dietary fat absorption without increasing hepatic BA synthesis in weanling SBS rats.

The effect of hepatocyte growth factor on gene transcription during intestinal adaptation

PURPOSE

Previously, we investigated the physiologic effects of hepatocyte growth factor (HGF) on intestinal adaptation using a massive small bowel resection (MSBR) rat model. To correlate these altered physiologic changes with gene alterations, we used microarray technology at 7, 14, and 21 days after MSBR.

METHODS

Forty-five adult female rats were divided into 3 groups and underwent 70% MSBR, MSBR + HGF (intravenous 150 μg/kg per day), or sham operation (control). Five animals per group were killed at each time point. Ileal mucosa was harvested and RNA extracted. Rat Gene Chips and Expression Console software (Affymetrix, Santa Clara, CA) were used. Statistical analysis was done by analysis of variance using Partek Genomics Suite (Partek, Inc, St Louis, MO). Results were significant if fold change was more than 2 or less than -2, with P < .05.

RESULTS

Compared with the control group, MSBR group had significant increases in up-regulated and down-regulated genes. The MSBR-HGF group had further increases in up-regulated and down-regulated genes compared with the MSBR group. At 7 days, 6 cellular hypertrophy families had 30 genes up-regulated, and HGF up-regulated an additional 14 genes. At 21 days, 5 hyperplasia gene families had 32 up-regulated genes. Hepatocyte growth factor up-regulated an additional 16 genes.

CONCLUSIONS

Microarray analysis of intestinal adaptation identified an early emphasis on hypertrophy and later emphasis on hyperplasia. This is the first demonstration that the effect of HGF on intestinal adaptation is recruitment of more genes rather than an increase in the fold change of already up-regulated genes.

Sustained glucagon-like peptide-2 infusion is required for intestinal adaptation, and cessation reverses increased cellularity in rats with intestinal failure

Glucagon-like peptide-2 (GLP-2) is a nutrient-dependent, proglucagon-derived hormone that is a proposed treatment for human short bowel syndrome (SBS). The objective was to determine how the timing, duration, and cessation of GLP-2 administration affect intestinal adaptation and enterocyte kinetics in a rat model of human SBS that results in intestinal failure requiring total parenteral nutrition (TPN). Rats underwent 60% jejunoileal resection plus cecectomy and jugular vein cannulation and were maintained exclusively with TPN for 18 days in these treatments: TPN control (no GLP-2); sustained GLP-2 (1-18 days); early GLP-2 (1-7 days, killed at 7 or 18 days); and delayed GLP-2 (12-18 days). Body weight gain was similar across groups, and plasma bioactive GLP-2 was significantly increased with coinfusion of GLP-2 (100 μg·kg⁻¹·day⁻¹) with TPN. GLP-2-treated rats showed significant increases in duodenum and jejunum mucosal dry mass, protein, DNA, and sucrase activity compared with TPN control. The increased jejunum cellularity reflected significantly decreased apoptosis and increased crypt mitosis and crypt fission due to GLP-2. When GLP-2 infusion stopped at 7 days, these effects were reversed at 18 days. Sustained GLP-2 infusion significantly increased duodenum length and decreased 18-day mortality to 0% from 37.5% deaths in TPN control (P = 0.08). Colon proglucagon expression quantified by real-time RT-qPCR was increased in TPN controls and attenuated by GLP-2 infusion; jejunal expression of the GLP-2 receptor did not differ among groups. In summary, early, sustained GLP-2 infusion reduces mortality, induces crypt fission, and is required for intestinal adaptation, whereas cessation of GLP-2 reverses gains in mucosal cellularity in a rat model of intestinal failure.

Effects of dietary fish oil on intestinal adaptation in 20-day-old weanling rats after massive ileocecal resection

Long chain polyunsaturated fatty acids (LCPUFA)seem to be the most trophic macronutrients in inducing intestinal adaptation in adult short bowel syndrome (SBS), although their effects on intestinal adaptation in infants with SBS remain unknown.It is hypothesized that a high fat diet enriched with n-3 LCPUFA derived from fish oil (FO) will increase intestinal adaptation compared with a diet dominated by n-6 PUFA from corn oil (CO) in weanling SBS rats after massive ileocecal resection (ICR). Twenty-day-old rats were sorted into four groups, CO-sham, FO-sham,CO-ICR, and FO-ICR groups, and fed ad lib with the CO or FO diet, respectively, for 7 d after sham or ICR surgery. Compared with CO-ICR rats, FO-ICR rats consumed less diet per gram of weight gain, had less diarrhea and fecal fat excretion, and demonstrated a tendency toward better weight gain. The mucosal mass, DNA and RNA levels of the colon and RNA levels of the distal jejunum, and the colonic mucosal area (%) were significantly higher in FO-ICR rats than in CO-ICR rats. These results suggest that the beneficial effect of dietary FO is associated with better adaptation in the colon in weanling rats after ICR.