Escherichia coli translocation in experimental short bowel syndrome: probiotic supplementation and detection by polymerase chain reaction

Nutritional and pharmacological strategy in children with short bowel syndrome

Short bowel syndrome in neonates is a severe and life-threatening disease after a major loss of small bowel with or without large bowel. Intestinal adaptation, by which the organism tries to restore digestive and absorptive capacities, is entirely dependent on stimulation of the active enterocytes by enteral nutrition. This review summarizes recent knowledge about the pathophysiologic consequences after the loss of different intestinal parts and outlines the options for enteral nutrition and pharmacological therapies to support the adaptation process.

The effect of probiotics on ıntestinal motility in an experimental short bowel model

PURPOSE

To investigate the effect of probiotics on spontaneous contractions of smooth muscle isolated from jejunum and ileum of rat model.

METHODS

Four rat groups were created (n=8, in each) including control (Group 1), control+probiotic (Group 2), short bowel (Group 3), and short bowel+probiotic (Group 4). Groups 1 and 2 underwent sham operation, Groups 3 and 4 underwent massive bowel resection. Bifidobacterium Lactis was administered in Groups 2 and 4 daily (P.O.) for three weeks. On postoperative week 3, rats were sacrificed, and jejunum and ileum smooth muscle were isolated for organ bath. Muscle contraction changes were analyzed before and after addition of antagonists.

RESULTS

Short bowel group exhibited increased amplitude and frequency of spontaneous contractions. The addition of probiotics significantly decreased enhanced amplitude and frequency of bowel contraction in short bowel group and returned to control values. L-NNA increased amplitude and frequency of contractions in all groups. While indomethacin and nimesulide increased the amplitude in all groups, the frequency was only increased in jejunum. Hexamethonium and tetrodotoxin did not change the contraction characteristics in all groups.

CONCLUSION

We suggest that early use of probiotics may significantly regulate bowel motility, and accordingly improve absorption of nutrients in short bowel syndrome.

Soluble Mediators From Lactobacillus rhamnosus Gorbach-Goldin Support Intestinal Barrier Function in Rats After Massive Small-Bowel Resection

BACKGROUND

Intestinal barrier plays an essential role in maintaining gastrointestinal health. This study aimed to explore the effects of a soluble mediator preparation derived from Lactobacillus rhamnosus Gorbach-Goldin (LGG) on intestinal barrier function in a rat model of short bowel syndrome (SBS).

METHODS

Six-week-old male Sprague-Dawley rats underwent 80% small-bowel resection (SBR) and then were supplemented with water (SBS), 5 × 10⁸ colony-forming unit viable LGG (SBS+LGG), or the LGG soluble mediators (SBS+LSM) in an equivalent dose to LGG by intragastric gavage daily from day 2 throughout day 14 after operation. Rats that underwent bowel transection and reanastomosis were used as the sham group. Body weight, ileum histology, intestinal permeability and bacterial translocation, inflammatory cytokines, and tight junction protein expressions of ileum were evaluated.

RESULTS

Animals undergoing SBR showed higher intestinal permeability and decreased expression of tight junction proteins in the ileum than sham group. Both SBS+LGG and SBS+LSM groups had reduced bacterial translocation and intestinal permeability as compared with the SBS group, with lower levels of serum endotoxin and tumor necrotizing factor alpha in ileum tissues. Moreover, the SBS+LSM group showed better body weight gain, lower endotoxin and FD-40 levels, and higher expressions of claudin-1 and claudin-4 in ileum than the SBS+LGG group.

CONCLUSION

Enteral supplementation of LSMs or viable LGG can ameliorate intestinal barrier disruption in a rat model of SBS. The LSM preparation not only mimicked biological effects of viable LGG but also was revealed to be more effective in reducing inflammation and supporting intestinal barrier function.

Toll-like receptor 4 is critical for the development of resection-associated hepatic steatosis

BACKGROUND

A significant number of children with short bowel syndrome experience intestinal failure-associated liver disease. We recently demonstrated accelerated hepatic steatosis after 50% small bowel resection (SBR) in mice. Since SBR is associated with alterations in the gut microbiome, the purpose of this study was to determine whether TLR4 signaling is critical to the development of resection-associated hepatic steatosis.

METHODS

Male C57BL6 (control) and TLR4-knockout (KO) mice underwent 50% proximal SBR. Liver sections were analyzed to obtain the percent lipid content, and Ileal sections were assessed for morphological adaptation. Intestinal TLR4 mRNA expression was measured at 7days and 10weeks.

RESULTS

Compared to controls, TLR4 KO mice demonstrated similar weight gain and morphological adaptation after SBR. Hepatic steatosis was decreased 32-fold in the absence of TLR4. Intestinal TLR4 mRNA expression was significantly elevated 7days after SBR. We also found that TLR4 expression in the intestine was 20-fold higher in whole bowel sections compared with isolated enterocytes.

CONCLUSIONS

TLR4 signaling is critical for the development of resection-associated steatosis, but not involved in intestinal adaptation after massive SBR. Further studies are needed to delineate the mechanism for TLR4 signaling in the genesis of resection-associated liver injury.

LEVEL OF EVIDENCE

Animal study, not clinical.

Antioxidant Effects of Probiotics in Experimentally Induced Peritonitis

AIM

An experimental study was performed to evaluate the protective effects of probiotics on gut mucosa in peritonitis through antioxidant mechanisms.

METHODS

Thirty-two male Wistar albino rats were divided equally into four groups. The rats in Group 1 (control group) underwent laparotomy only. In group 2 (peritonitis group), peritonitis was induced in the rats by the cecal ligation and puncture (CLP) model. In group 3, the rats were treated with probiotics for five days after CLP-induced peritonitis. The last group of rats (group 4) were fed probiotics for five days before the CLP procedure and five days after the surgery. On the fifth day after surgery, all rats were killed, and tissue samples from the terminal ileum were obtained to evaluate the activities of myeloperoxidase (MPO), malondialdehyde (MDA), and glutathione (GSH). Histopathologic examinations were also performed to evaluate the grade of intestinal injury.

RESULTS

Myeloperoxidase and MDA activities were increased, GSH concentrations were decreased in group 2, compared with group 1. Intestinal MPO activities in group 4 were decreased compared with group 1 and group 2, indicating a reduction in oxidant activity. Malondialdehyde decreased in group 3 and decreased even more in group 4, compared with the peritonitis group (group 2). Glutathione concentrations were increased in group 4 compared with group 2 and group 3 (p < 0.05). The Chiu scores of the probiotics groups, groups 3 and 4, were lower than those in group 2, indicating reduced mucosal damage in the probiotically fed groups.

CONCLUSION

Probiotics have protective effects in peritonitis, which may be related to antioxidant mechanisms. This antioxidant effect of probiotics might occur when pre-conditioning with probiotics before peritonitis because there is sufficient time to prepare the tissues for oxidative damage.

In a Neonatal Piglet Model of Intestinal Failure, Administration of Antibiotics and Lack of Enteral Nutrition Have a Greater Impact on Intestinal Microflora Than Surgical Resection Alone

BACKGROUND

Data are limited on how short bowel syndrome (SBS) affects the healthy developing intestinal microbiome, with even less assessing different SBS anatomical surgical models. This study was conducted to describe the "ileal" and "colonic" microflora in 2 surgical models of SBS.

MATERIALS AND METHODS

Neonatal piglets (2-5 days old) underwent intestinal resection, leaving the ileum (JI anatomy, n = 6) or removing the ileum and ileocecal valve (JC anatomy, n = 5), or sham surgery (sham; n = 4). JI, JC, and sham piglets commenced parenteral nutrition on day 0 and received ampicillin and trimethoprim-sulfadoxine on days 0-4 for prevention of line sepsis. At day 7, ileal and colonic digesta were collected, and they were also collected from age-matched sow-fed piglets (n = 6). DNA extraction, sequencing, and annotation followed standard procedures.

RESULTS

Colonic and ileal bacterial genus diversity and relative bacterial abundance were greater ( P < .05) in sow-fed compared with JI, JC, and sham piglets; however, minor differences were observed in either location between sham, JI, and JC piglets and within the surgical model. In the colon, sow-fed piglets had higher ( P < .05) abundance of Lactobacillus (26%) and tended to have lower ( P = .06) abundance of Enterococcus (<.1%) than JI, JC, or sham piglets, in which Lactobacillus and Enterococcus abundance averaged <.1% and 9%, respectively.

CONCLUSIONS

Intestinal resection reduces bacterial diversity in the large bowel, and the difference is associated with the presence/absence of the ileum and ileocecal valve. The lack of enteral nutrition and antibiotic administration (ie, sow-fed vs surgery) had a greater influence on the observed shift in diversity and relative abundance than intestinal resection.

Disruptions of the intestinal microbiome in necrotizing enterocolitis, short bowel syndrome, and Hirschsprung's associated enterocolitis

Next generation sequencing techniques are currently revealing novel insight into the microbiome of the human gut. This new area of research seems especially relevant for neonatal diseases, because the development of the intestinal microbiome already starts in the perinatal period and preterm infants with a still immature gut associated immune system may be harmed by a dysproportional microbial colonization. For most gastrointestinal diseases requiring pediatric surgery there is very limited information about the role of the intestinal microbiome. This review aims to summarize the current knowledge and outline future perspectives for important pathologies like necrotizing enterocolitis (NEC) of the newborn, short bowel syndrome (SBS), and Hirschsprung’s disease associated enterocolitis (HAEC). Only studies applying next generation sequencing techniques to analyze the diversity of the intestinal microbiome were included. In NEC patients intestinal dysbiosis could already be detected prior to any clinical evidence of the disease resulting in a reduction of the bacterial diversity. In SBS patients the diversity seems to be reduced compared to controls. In children with Hirschsprung’s disease the intestinal microbiome differs between those with and without episodes of enterocolitis. One common finding for all three diseases seems to be an overabundance of Proteobacteria. However, most human studies are based on fecal samples and experimental data question whether fecal samples actually represent the microbiome at the site of the diseased bowel and whether the luminal (transient) microbiome compares to the mucosal (resident) microbiome. In conclusion current studies already allow a preliminary understanding of the potential role of the intestinal microbiome in pediatric surgical diseases. Future investigations could clarify the interface between the intestinal epithelium, its immunological competence and mucosal microbiome. Advances in this field may have an impact on the understanding and non-operative treatment of such diseases in infancy.

Non-alcoholic fatty liver disease, diet and gut microbiota

Non-alcoholic fatty liver disease (NAFLD) is a severe liver disease that is increasing in prevalence with the worldwide epidemic of obesity and its related insulin-resistance state. Evidence for the role of the gut microbiota in energy storage and the subsequent development of obesity and some of its related diseases is now well established. More recently, a new role of gut microbiota has emerged in NAFLD. The gut microbiota is involved in gut permeability, low-grade inflammation and immune balance, it modulates dietary choline metabolism, regulates bile acid metabolism and produces endogenous ethanol. All of these factors are molecular mechanisms by which the microbiota can induce NAFLD or its progression toward overt non-alcoholic steatohepatitis. Modification of the gut microbiota composition and/or its biochemical capacity by specific dietary or pharmacological interventions may advantageously affect host metabolism. Large-scale intervention trials, investigating the potential benefit of prebiotics and probiotics in improving cardiometabolic health in high-risk populations, are fervently awaited.

Role of probiotics in short bowel syndrome in infants and children--a systematic review

Short bowel syndrome (SBS) is a cause of significant morbidity and mortality in children. Probiotics, due to their beneficial effects on the gastrointestinal tract (e.g., improving gut barrier function, motility, facilitation of intestinal adaptation and decreasing pathogen load and inflammation) may have a therapeutic role in the management of SBS. To conduct a systematic review of the current evidence for the effects of probiotic supplementation in children with SBS, the standard Cochrane methodology for systematic reviews was used. The databases, Pubmed, Embase, ACTR, CENTRAL, and the international trial registry, and reference lists of articles were searched for randomised (RCT) or quasi-randomised controlled trials reporting on the use of probiotics in SBS. Our search revealed no RCTs on the use of probiotics in children with SBS. We found one small cross-over RCT (placebo controlled crossover clinical trial), one case control study and nine case reports on the use of probiotics in children with SBS. In the crossover RCT, there was no consistent effect on intestinal permeability (primary outcome) after supplementation with Lactobacillus rhamnosus (LGG) in nine children with SBS. The case control study (four cases: four controls) reported a trend for increase in height and weight velocity and improvement in non-clinical outcomes, such as gut flora, lymphocyte count and serum prealbumin. Five of the nine case reports showed that children (n = 12) with SBS were benefited (e.g., cessation of diarrhoea, improved faecal flora, weight gain and weaning from parenteral nutrition) by probiotic supplementation. The remaining four reported on the adverse effects, such as Lactobacillus sepsis (n = 3) and D-lactic acidosis (n = 2). There is insufficient evidence on the effects of probiotics in children with SBS. The safety and efficacy of probiotic supplementation in this high-risk cohort needs to be evaluated in large definitive trials.