Diagnosis and pharmacological management of small intestinal bacterial overgrowth in children with intestinal failure

A Gastroenterologist's Guide to Care Transitions in Cystic Fibrosis from Pediatrics to Adult Care

Cystic Fibrosis is a chronic disease affecting multiple systems, including the GI tract. Clinical manifestation in patients can start as early as infancy and vary across different age groups. With the advent of new, highly effective modulators, the life expectancy of PwCF has improved significantly. Various GI aspects of CF care, such as nutrition, are linked to an overall improvement in morbidity, lung function and the quality of life of PwCF. The variable clinical presentations and management of GI diseases in pediatrics and adults with CF should be recognized. Therefore, it is necessary to ensure efficient transfer of information between pediatric and adult providers for proper continuity of management and coordination of care at the time of transition. The transition of care is a challenging process for both patients and providers and currently there are no specific tools for GI providers to help ensure a smooth transition. In this review, we aim to highlight the crucial features of GI care at the time of transition and provide a checklist that can assist in ensuring an effective transition and ease the challenges associated with it.

Factors Affecting the Gut Microbiome in Pediatric Intestinal Failure

BACKGROUND

There is little data on gut microbiome and various factors that lead to dysbiosis in pediatric intestinal failure (PIF). This study aimed to characterize gut microbiome in PIF and determine factors that may affect microbial composition in these patients.

METHODS

This is a single-center, prospective cohort study of children with PIF followed at our intestinal rehabilitation program. Stool samples were collected longitudinally at regular intervals over a 1-year period. Medical records were reviewed, and demographic and clinical data were collected. Medication history including the use of acid blockers, scheduled prophylactic antibiotics, and bile acid sequestrants was obtained. Gut microbial diversity among patients was assessed and compared according to various host characteristics of interest.

RESULTS

The final analysis included 74 specimens from 12 subjects. Scheduled prophylactic antibiotics, presence of central line associated bloodstream infection (CLABSI) at the time of specimen collection, use of acid blockers, and ≥50% calories delivered via parenteral nutrition (PN) was associated with reduced alpha diversity, whereas increasing age was associated with improved alpha diversity at various microbial levels ( P value <0.05). Beta diversity differed with age, presence of CLABSI, use of scheduled antibiotics, acid blockers, percent calories via PN, and presence of oral feeds at various microbial levels ( P value <0.05). Single taxon analysis identified several taxa at several microbial levels, which were significantly associated with various host characteristics.

CONCLUSION

Gut microbial diversity in PIF subjects is influenced by various factors involved in the rehabilitation process including medications, percent calories received parenterally, CLABSI events, the degree of oral feeding, and age. Additional investigation performed across multiple centers is needed to further understand the impact of these findings on important clinical outcomes in PIF.

Small Intestinal Bacterial Overgrowth-Pathophysiology and Its Implications for Definition and Management

The concept of small intestinal bacterial overgrowth (SIBO) arose in the context of maldigestion and malabsorption among patients with obvious risk factors that permitted the small bowel to be colonized by potentially injurious colonic microbiota. Such colonization resulted in clinical signs, symptoms, and laboratory abnormalities that were explicable within a coherent pathophysiological framework. Coincident with advances in medical science, diagnostic testing evolved from small bowel culture to breath tests and on to next-generation, culture-independent microbial analytics. The advent and ready availability of breath tests generated a dramatic expansion in both the rate of diagnosis of SIBO and the range of associated gastrointestinal and nongastrointestinal clinical scenarios. However, issues with the specificity of these same breath tests have clouded their interpretation and aroused some skepticism regarding the role of SIBO in this expanded clinical repertoire. Furthermore, the pathophysiological plausibility that underpins SIBO as a cause of maldigestion/malabsorption is lacking in regard to its purported role in irritable bowel syndrome, for example. One hopes that the application of an ever-expanding armamentarium of modern molecular microbiology to the human small intestinal microbiome in both health and disease will ultimately resolve this impasse and provide an objective basis for the diagnosis of SIBO.

An ESPGHAN Position Paper on the Use of Breath Testing in Paediatric Gastroenterology

OBJECTIVES

Given a lack of a systematic approach to the use of breath testing in paediatric patients, the aim of this position paper is to provide expert guidance regarding the indications for its use and practical considerations to optimise its utility and safety.

METHODS

Nine clinical questions regarding methodology, interpretation, and specific indications of breath testing and treatment of carbohydrate malabsorption were addressed by members of the Gastroenterology Committee (GIC) of the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN).A systematic literature search was performed from 1983 to 2020 using PubMed, the MEDLINE and Cochrane Database of Systematic Reviews. Grading of Recommendations, Assessment, Development, and Evaluation was applied to evaluate the outcomes.During a consensus meeting, all recommendations were discussed and finalised. In the absence of evidence from randomised controlled trials, recommendations reflect the expert opinion of the authors.

RESULTS

A total of 22 recommendations were voted on using the nominal voting technique. At first, recommendations on prerequisites and preparation for as well as on interpretation of breath tests are given. Then, recommendations on the usefulness of H2-lactose breath testing, H2-fructose breath testing as well as of breath tests for other types of carbohydrate malabsorption are provided. Furthermore, breath testing is recommended to diagnose small intestinal bacterial overgrowth (SIBO), to control for success of Helicobacter pylori eradication therapy and to diagnose and monitor therapy of exocrine pancreatic insufficiency, but not to estimate oro-caecal transit time (OCTT) or to diagnose and follow-up on celiac disease.

CONCLUSIONS

Breath tests are frequently used in paediatric gastroenterology mainly assessing carbohydrate malabsorption, but also in the diagnosis of small intestinal overgrowth, fat malabsorption, H. pylori infection as well as for measuring gastrointestinal transit times. Interpretation of the results can be challenging and in addition, pertinent symptoms should be considered to evaluate clinical tolerance.

Results of an International Survey on Feeding Management in Infants With Short Bowel Syndrome-Associated Intestinal Failure

OBJECTIVES

Short bowel syndrome (SBS) is a complex and rare condition (incidence 1200/100,000 live births) that requires a multidisciplinary team approach to management. In January 2019, the first European Reference Network on Rare and Inherited Congenital Anomalies (ERNICA) Intestinal Failure (IF) workshop was held. Several questions about the strategies used in managing IF associated with SBS were devised. The aim of our study was to collect data on the enteral feeding strategies adopted by the ERNICA centres.

METHODS

A questionnaire (36 questions) about strategies used to introduce enteral nutrition post-operatively and start complementary food/solids in infants with SBS associated IF was developed and sent to 24 centres in 15 countries that participated in the ERNICA-IF workshop. The answers were collated and compared with the literature.

RESULTS

There was a 100% response rate. In infants, enteral nutrition was introduced as soon as possible, ideally within 24-48 hours post-small intestinal surgical resection. In 10 of 24 centres, bolus feeding was used, in nine continuous, and in five a combination of both. Twenty-three centres used mothers' own milk as the first choice of feed with extensively hydrolysed feed, amino acid-based feed, donor human milk or standard preterm/term formula as the second choice. Although 22 centres introduced complementary/solid food by 6 months of age, food choice varied greatly between centres and appeared to be culturally based.

CONCLUSIONS

There is diversity in post-surgical enteral feeding strategies among centres in Europe. Further multi-centre studies could help to increase evidence-based medicine and management on this topic.

Small Bowel Resection Increases Paracellular Gut Barrier Permeability via Alterations of Tight Junction Complexes Mediated by Intestinal TLR4

BACKGROUND

Short bowel syndrome resulting from small bowel resection (SBR) is associated with significant morbidity and mortality. Many adverse sequelae including steatohepatitis and bacterial overgrowth are thought to be related to increased bacterial translocation, suggesting alterations in gut permeability. We hypothesized that after intestinal resection, the intestinal barrier is altered via toll-like receptor 4 (TLR4) signaling at the intestinal level.

METHODS

B6 and intestinal-specific TLR4 knockout (iTLR4 KO) mice underwent 50% SBR or sham operation. Transcellular permeability was evaluated by measuring goblet cell associated antigen passages via two-photon microscopy. Fluorimetry and electron microscopy evaluation of tight junctions (TJ) were used to assess paracellular permeability. In parallel experiments, single-cell RNA sequencing measured expression of intestinal integral TJ proteins. Western blot and immunohistochemistry confirmed the results of the single-cell RNA sequencing.

RESULTS

There were similar number of goblet cell associated antigen passages after both SBR and sham operation (4.5 versus 5.0, P > 0.05). Fluorescein isothiocyanate-dextran uptake into the serum after massive SBR was significantly increased compared with sham mice (2.13 ± 0.39 ng/μL versus 1.62 ± 0.23 ng/μL, P < 0.001). SBR mice demonstrated obscured TJ complexes on electron microscopy. Single-cell RNA sequencing revealed a decrease in TJ protein occludin (21%) after SBR (P < 0.05), confirmed with immunostaining and western blot analysis. The KO of iTLR4 mitigated the alterations in permeability after SBR.

CONCLUSIONS

Permeability after SBR is increased via changes at the paracellular level. However, these alterations were prevented in iTLR4 mice. These findings suggest potential protein targets for restoring the intestinal barrier and obviating the adverse sequelae of short bowel syndrome.

Antibiotic Utilization and Infection Among Infants with Abdominal Wall Defects

BACKGROUND

Neonates with abdominal wall defects are at an increased infection risk because of the defect itself and prolonged neonatal intensive care unit (NICU) stays. Antibiotic prophylaxis until closure of the defect is common. However, infection risk and antibiotic use have not been well quantified in these infants.

METHODS

A retrospective cohort study of infants with abdominal wall defects (gastroschisis and omphalocele) admitted to a single-center NICU from 2007 to 2018. Demographic and clinical information, including microbiologic studies, antibiotic dosing and surgical care, were collected. Antibiotic use was quantified using days of therapy (DOT) per 1000 patient-days. Sepsis was defined as culture of a pathogen from a normally sterile site.

RESULTS

Seventy-four infants were included; 64 (86%) with gastroschisis and 10 (14%) with omphalocele. Median day of closure was 8 days [interquartile range (IQR) 6-10, range 0-31]. All infants received ≥1 course of antibiotics; median antibiotic DOT/infant was 24.5 (IQR 18-36) for an average of 416.5 DOT per 1000 patient-days. Most antibiotic use was preclosure prophylaxis (44%) and treatment of small intestinal bowel overgrowth (24%). Suspected and proven infection accounted for 26% of all antibiotic use. Skin and soft tissue infection (13/74, 18%) and late-onset sepsis (11/74, 15%) were the most common infections; 2 infants had sepsis while on antibiotic prophylaxis. All infants survived to discharge.

CONCLUSIONS

Most antibiotic use among infants with abdominal wall defects was prophylactic. Infection on prophylaxis was rare, but 35% of infants had infection after prophylaxis. Improved stewardship strategies are needed for these high-risk infants.

Metabolic bone diseases in intestinal failure

Metabolic bone diseases are a group of conditions that are common complications in patients with intestinal failure. These may occur as a result of the underlying condition, leading to intestinal failure, particularly inflammatory conditions such as Crohn's disease and their associated treatments including corticosteroids. Malabsorption, as a result of a loss of enterocyte mass or gut function, of many nutrients, including vitamin D, may further compound metabolic bone problems, and there has been historical contamination of parenteral nutrition with aluminium that has prevented normal bone metabolism contributing to osteoporosis. This review looks at the diagnosis and current management of bone health in patients with intestinal failure.

Etiology and Medical Management of Pediatric Intestinal Failure

Pediatric intestinal failure occurs when gut function is insufficient to meet the growing child's hydration and nutrition needs. After massive bowel resection, the remnant bowel adapts to lost absorptive and digestive capacity through incompletely defined mechanisms newly targeted for pharmacologic augmentation. Management seeks to achieve enteral autonomy and mitigate the development of comorbid disease. Care has improved, most notably related to reductions in blood stream infection and liver disease. The future likely holds expansion of pharmacologic adaptation augmentation, refinement of intestinal tissue engineering techniques, and the development of a learning health network for efficient multicenter study and care improvement.

Pediatric Intestinal Failure: A Review of the Scope of Disease and a Regional Model of a Multidisciplinary Care Team

The term "intestinal failure" signifies the inability of the body to meet the digestive, absorptive and nutritive needs of the body. In children, intestinal failure is most often due to short bowel syndrome, often a result of necrotizing enterocolitis, a severe GI ischemic pathology that is generally associated with prematurity. With advances in neonatal care, more preterm infants are surviving, and subsequently we care for more children with SBS than ever before. These children require parenteral nutrition (PN) for survival. Neurodevelopmental outcomes are tied to nutrition in early years; thus these children are the most vulnerable to the sequelae of intestinal failure. As such, the development of multi-disciplinary intestinal rehabilitation programs have emerged as the state of the art in the care of children with intestinal failure.

Serum Unconjugated Bile Acids and Small Bowel Bacterial Overgrowth in Pediatric Intestinal Failure: A Pilot Study

BACKGROUND

We determined qualitative and quantitative serum unconjugated bile acid (SUBA) levels among children with history of intestinal failure (IF) and suspected small bowel bacterial overgrowth (SBBO).

METHODS

This was a single-center, case-control pilot study conducted at Cincinnati Children's Hospital Medical Center. Children with history of IF and suspected SBBO were enrolled as subjects. Age-matched children without IF or suspected SBBO served as controls. All participants underwent small bowel fluid sampling for microbial culture analysis. Additionally, serum fractionated and total bile acids were measured by liquid chromatography-mass spectrometry at enrollment and following treatment for SBBO.

RESULTS

SUBA concentrations were elevated in IF subjects (median 1.16 μM, range 0.43-10.65 μM) compared with controls (median 0.10 μM, range 0.05-0.18 μM, P = 0.001). Among SUBA, chenodeoxycholic acid (CDCA) was significantly elevated in subjects (median 0.8 μM, range 0-7.08 μM) compared with controls (median 0 μM, range 0-0.03 μM, P = 0.012). When controls were excluded from analysis, IF subjects with positive aspirates for SBBO demonstrated higher concentration of CDCA (median 7.36 μM, range 1.1-8.28 μM) compared with IF subjects with negative aspirates (median 0.18 μM, range 0-1.06 μM, P = 0.017). Treatment for SBBO did not alter SUBA concentration.

CONCLUSIONS

SUBA concentrations are elevated in children with history of IF and presumed SBBO compared with non-IF controls. CDCA was more prevalent in IF subjects with positive aspirates for SBBO compared with IF subjects with negative aspirates. The determination of SUBA concentration may be a useful surrogate to small bowel fluid aspiration in the diagnosis of SBBO in children with history of IF.

Pediatric Intestinal Failure Review

The term, ‘intestinal failure’, signifies the inability of the body to meet the digestive, absorptive and nutritive needs of the body. As such, these individuals require parenteral nutrition (PN) for survival. The subsequent nutritional, medical and surgical facets to the care are complex. Improved care has resulted in decreased need for intestinal transplantation. This review will examine the unique etiologies and management strategies in pediatric patients with intestinal failure.

Bacterial overgrowth, dysbiosis, inflammation, and dysmotility in the Cystic Fibrosis intestine

Gastrointestinal disease in Cystic Fibrosis (CF) is caused by defective chloride and bicarbonate transport in intestinal cells leading to reduced intraluminal fluidity, increased mucous viscosity and consequently development of intestinal inflammation, dysbiosis and often times dysmotility. This triad is also referred to as the "CF gut". A diagnosis is mainly based on clinical observation and treatment is often times decided empirically. This review of the literature should provide CF caregivers with some tools to identify intestinal inflammation, dysbiosis and dysmotility as possible cause for their patient's gastrointestinal complaints and provide an overview of our current approach to its management.

Outcome of breath tests in adult patients with suspected small intestinal bacterial overgrowth

AIM

The aim was to investigate breath test outcomes in patients with suspected SIBO and indicative symptoms of SIBO, diagnosed by breath testing.

BACKGROUND

Breath testing is used to detect small intestinal bacterial overgrowth (SIBO) by measuring hydrogen and methane produced by intestinal bacteria.

METHODS

This retrospective cross sectional study included 311 patients with gastrointestinal symptoms who underwent the breath test for evaluation of SIBO at Celiac Disease Center at Columbia University, New York, in 2014-2015. The patients were divided into two groups based on the physician's choice: lactulose breath test group (72%) and glucose breath test group (28%). Among them, 38% had a history of celiac disease or non-celiac gluten sensitivity.

RESULTS

In total, 46% had a positive breath test: 18% were positive for methane, 24 % positive for hydrogen and 4% positive for both gases (p=0.014). Also, 50% had a positive lactulose breath result and 37% had a positive glucose breath result (p=0.036). The most common symptom for performing the breath test was bloating and the only clinical symptom that significantly showed a positive glucose breath test was increased gas (p=0.028).

CONCLUSION

Lactulose breath test was more often positive than glucose breath test. Positivity for hydrogen was more common than methane. Bloating was the most frequently perceived symptom of the patients undergoing the breath test but the only statistically significant clinical symptom for a positive glucose breath test was increased gas. Furthermore, the results showed that there was no significant association between positive breath test result and gender, age, non-celiac gluten sensitivity or celiac disease.

Gastrointestinal, Pancreatic, and Hepatobiliary Manifestations of Cystic Fibrosis

Pulmonary disease is the primary cause of morbidity and mortality in people with cystic fibrosis (CF), but significant involvement within gastrointestinal, pancreatic, and hepatobiliary systems occurs as well. As in the airways, defects in CFTR alter epithelial surface fluid, mucus viscosity, and pH, increasing risk of stasis through the various hollow epithelial-lined structures of the gastrointestinal tract. This exerts secondary influences that are responsible for most gastrointestinal, pancreatic, and hepatobiliary manifestations of CF. Understanding these gastrointestinal morbidities of CF is essential in understanding and treating CF as a multisystem disease process and improving overall patient care.

Intestinal failure following necrotizing enterocolitis: A clinical approach

Intestinal failure is a recognized complication of surgically-managed necrotizing enterocolitis (NEC). Functional adaptation of remaining bowel means that many children are eventually able to achieve enteral autonomy. Integrated multidisciplinary care in the early post-operative phase is key to long-term success. The objective of this review is to outline a clinical approach to management of intestinal and nutritional complications experienced by children following intestinal resection for NEC.

Cystic fibrosis from the gastroenterologist's perspective

Cystic fibrosis is a life-limiting, recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Increased survival outcomes and the multisystem nature of the disease, including the involvement of hepatobiliary and gastrointestinal tracts, now require the need for more extensive knowledge and expertise in cystic fibrosis among gastroenterologists. Manifestations are either a direct consequence of the primary defect in cystic fibrosis or a secondary complication of the disease or therapy. Adult patients with cystic fibrosis also have an increased risk of malignancy in the gastrointestinal and pancreatico-biliary tracts compared with the general population. Novel treatments that target the basic defects in the CFTR protein have emerged, but to date not much is known about their effects on the gastrointestinal and hepatobiliary systems. The introduction of such therapies has provided new opportunities for the application of intestinal endpoints in clinical trials and the understanding of underlying disease mechanisms that affect the gut in cystic fibrosis.

Small Bowel Bacterial Overgrowth in Children

OBJECTIVES

The aim of study was to perform a comprehensive review of the pathogenesis, available diagnostic procedures, prevalence, clinical manifestations, and consequences of small bowel bacterial overgrowth (SBBO) as well as treatment options in the pediatric population.

METHODS

A literature search including MEDLINE, PubMed, and Web of Science databases was performed.

RESULTS

SBBO is found in a variety of childhood conditions in which the normal homeostatic mechanisms restricting bacterial colonization in the small bowel are disturbed by congenital or acquired anatomical abnormalities, diminished gastric acid secretion, congenital alteration of intestinal motility or acquired small bowel diseases, or other chronic disorders including primary or acquired immunodeficiency. Data show that SBBO may be an underrecognized cause of pediatric morbidity. Although several diagnostic tests for SBBO determination are available, each has its drawbacks and limitations. Indeed, there is still no "criterion standard" for SBBO diagnosis in the pediatric population. Owing to lack of established guidelines and few published interventional studies that assess the effectiveness of SBBO therapy, treatment of children with SBBO remains empiric and comprises antibiotic or probiotic therapy.

CONCLUSIONS

Further research is needed to determine the clinical impact of SBBO and to establish diagnostic and therapeutic guidelines applicable to children.

Antimicrobial usage among hospitalized children in Latvia: a neonatal and pediatric antimicrobial point prevalence survey

BACKGROUND AND OBJECTIVE

The point prevalence survey was conducted as part of the Antibiotic Resistance and Prescribing in European Children (ARPEC) Project. The study aimed at analyzing pediatric and neonatal antimicrobial prescribing patterns in Latvian hospitals, to identify targets for quality improvement.

MATERIALS AND METHODS

A one day cross-sectional point prevalence survey on antibiotic use in hospitalized children was conducted in November 2012 in 10 Latvian hospitals, using a previously validated and standardized method. The survey included all inpatient pediatric and neonatal beds and identified all children receiving an antimicrobial treatment on the day of survey.

RESULTS

Overall 549 patients were included in the study; 167 (39%) patients admitted to pediatric wards and 25 (21%) patients admitted to neonatal wards received at least one antimicrobial. Pediatric top three antibiotic groups were third-generation cephalosporins (55 prescriptions, 28%), extended spectrum penicillins (n=32, 16%) and first-generation cephalosporins (n=26, 13%). Eleven pediatric patients (85%) received surgical prophylaxis more than 1 day; 143 pediatric patients (86%) received antibiotics intravenously. Lower respiratory tract infections were the most common indications for antibiotic use both in pediatric (n=60, 35.9%) and neonatal patients (n=9, 36%). The most used antibiotics for neonatal patients were benzylpenicillin (n=12, 32%), and gentamicin (n=9, 24%).

CONCLUSIONS

We identified a few problematic areas, which need improvement: the high use of third-generation cephalosporins for pediatric patients, prolonged surgical prophylaxis, predominant use of parenteral antibiotics and an urgent need for local antibiotic guidelines.

Gastrointestinal bacterial overgrowth: pathogenesis and clinical significance

Small intestinal bacterial overgrowth (SIBO) is defined as the presence of an abnormally high number of coliform bacteria in the small bowel. It is associated with a broad range of predisposing small intestinal motility disorders and with surgical procedures that result in bowel stasis. The most common symptoms associated with SIBO include diarrhea, flatulence, abdominal pain and bloating. Quantitative culture of small bowel contents and a variety of indirect tests have been used over the years in an attempt to facilitate the diagnosis of SIBO. The indirect tests include breath tests and biochemical tests based on bacterial metabolism of a variety of substrates. Unfortunately, there is no single valid test for SIBO, and the accuracy of all current tests remains limited due to the failure of culture to be a gold standard and the lack of standardization of the normal bowel flora in the small intestine. Currently, the ideal approach to treat SIBO is to treat the underlying disease, eradicate overgrowth, and address nutritional deficiencies that may be associated with the development of SIBO.

Effectiveness of trimethoprim-sulfamethoxazole and metronidazole in the treatment of small intestinal bacterial overgrowth in children living in a slum

Trimethoprim-sulfamethoxazole and metronidazole were used for 14 days to treat 20 children with small intestine bacterial overgrowth (SIBO). SIBO was diagnosed using the lactulose hydrogen breath test. The breath test was repeated 1 month after treatment, and 19 (95.0%) of 20 children showed no evidence of SIBO (P < 0.001). The area under the individual curves showed that children with SIBO exhibited greater hydrogen production before treatment in both the first hour and between 60 and 180 minutes after the breath test. The treatment did not decrease methane production. In conclusion, trimethoprim-sulfamethoxazole and metronidazole was effective in treating children with SIBO.