Summary: Background: A low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet can ameliorate symptoms in adult irritable bowel syndrome (IBS) within 48 h.Aim: To determine the efficacy of a low FODMAP diet in childhood IBS and whether gut microbial composition and/or metabolic capacity are associated with its efficacy.Methods: In a double‐blind, crossover trial, children with Rome III IBS completed a 1‐week baseline period. They then were randomised to a low FODMAP diet or typical American childhood diet (TACD), followed by a 5‐day washout period before crossing over to the other diet. GI symptoms were assessed with abdominal pain frequency being the primary outcome. Baseline gut microbial composition (16S rRNA sequencing) and metabolic capacity (PICRUSt) were determined. Metagenomic biomarker discovery (LEfSe) compared Responders (≥50% decrease in abdominal pain frequency on low FODMAP diet only) vs. Nonresponders (no improvement during either intervention).Results: Thirty‐three children completed the study. Less abdominal pain occurred during the low FODMAP diet vs. TACD [1.1 ± 0.2 (SEM) episodes/day vs. 1.7 ± 0.4, P < 0.05]. Compared to baseline (1.4 ± 0.2), children had fewer daily abdominal pain episodes during the low FODMAP diet (P < 0.01) but more episodes during the TACD (P < 0.01). Responders were enriched at baseline in taxa with known greater saccharolytic metabolic capacity (e.g. Bacteroides, Ruminococcaceae, Faecalibacterium prausnitzii) and three Kyoto Encyclopedia of Genes and Genomes orthologues, of which two relate to carbohydrate metabolism.Conclusions: In childhood IBS, a low FODMAP diet decreases abdominal pain frequency. Gut microbiome biomarkers may be associated with low FODMAP diet efficacy.ClinicalTrials.gov identifier: NCT01339117.

Summary: Background: Peppermint oil has been used for centuries as a treatment for gastrointestinal ailments. It has been shown to have several effects on gastrointestinal physiology relevant to clinical care and management.Aim: To review the literature on peppermint oil regarding its metabolism, effects on gastrointestinal physiology, clinical use and efficacy, and safety.Methods: We performed a PubMed literature search using the following terms individually or in combination: peppermint, peppermint oil, pharmacokinetics, menthol, oesophagus, stomach, small intestine, gallbladder, colon, transit, dyspepsia, nausea, abdominal pain, and irritable bowel syndrome. Full manuscripts evaluating peppermint oil that were published through 15 July 2017 were reviewed. When evaluating therapeutic indications, only randomised clinical trials were included. References from selected manuscripts were used if relevant.Results: It appears that peppermint oil may have several mechanisms of action including: smooth muscle relaxation (via calcium channel blockade or direct enteric nervous system effects); visceral sensitivity modulation (via transient receptor potential cation channels); anti‐microbial effects; anti‐inflammatory activity; modulation of psychosocial distress. Peppermint oil has been found to affect oesophageal, gastric, small bowel, gall‐bladder, and colonic physiology. It has been used to facilitate completion of colonoscopy and endoscopic retrograde cholangiopancreatography. Placebo controlled studies support its use in irritable bowel syndrome, functional dyspepsia, childhood functional abdominal pain, and post‐operative nausea. Few adverse effects have been reported in peppermint oil trials.Conclusion: Peppermint oil is a natural product which affects physiology throughout the gastrointestinal tract, has been used successfully for several clinical disorders, and appears to have a good safety profile.

We sought to determine whether a low fermentable substrate diet (LFSD) decreases abdominal pain frequency in children with irritable bowel syndrome (IBS) and to identify potential microbial factors related to diet efficacy. Pain symptoms, stooling characteristics, breath hydrogen and methane, whole intestinal transit time, stool microbiome, and metabolite composition were collected and/or documented in eight children with IBS at baseline and during one week of an LFSD intervention. Pain frequency (P 50% decrease in abdominal pain frequency while on the LFSD). There were no differences between responders and non-responders with respect to hydrogen production, methane production, stooling characteristics, or gut transit time. Responders were characterized by increased pre-LFSD abundance of bacterial taxa belonging to the genera Sporobacter (P<0.05) and Subdoligranulum (P<0.02) and decreased abundance of taxa belonging to Bacteroides (P<0.05) relative to non-responders. In parallel, stool metabolites differed between responders and non-responders and were associated with differences in microbiome composition. These pilot study results suggest that an LFSD may be effective in decreasing GI symptoms in children with IBS. Microbial factors such as gut microbiome composition and stool metabolites while on the diet may relate to LFSD efficacy.

Objective: Most studies of ketamine administered to children for procedural sedation are limited to emergency department use. The objective of this study was to describe the practice of ketamine procedural sedation outside of the operating room and identify risk factors for adverse events.Design: Observational cohort review of data prospectively collected from 2007 to 2015 from the multicenter Pediatric Sedation Research Consortium.Setting: Sedation services from academic, community, free-standing children’s hospitals and pediatric wards within general hospitals.Patients: Children from birth to 21 years old or younger.Interventions: None.Measurements and Main Results: Describe patient characteristics, procedure type, and location of administration of ketamine procedural sedation. Analyze sedation-related adverse events and severe adverse events. Identify risk factors for adverse events using multivariable logistic regression. A total of 22,645 sedations performed using ketamine were analyzed. Median age was 60 months (range, < 1 mo to < 22 yr); 72.0% were American Society of Anesthesiologists-Physical Status less than III. The majority of sedations were performed in dedicated sedation or radiology units (64.6%). Anticholinergics, benzodiazepines, or propofol were coadministered in 19.8%, 57.9%, and 35.4%, respectively. The overall adverse event occurrence rate was 7.26% (95% CI, 6.92–7.60%), and the frequency of severe adverse events was 1.77% (95% CI, 1.60–1.94%). Procedures were not completed in 39 of 19,747 patients (0.2%). Three patients experienced cardiac arrest without death, all associated with laryngospasm.Conclusions: This is a description of a large prospectively collected dataset of pediatric ketamine administration predominantly outside of the operating room. The overall incidence of severe adverse events was low. Risk factors associated with increased odds of adverse events were as follows: cardiac and gastrointestinal disease, lower respiratory tract infection, and the coadministration of propofol and anticholinergics.

Accurate diagnosis and stratification of children with irritable bowel syndrome (IBS) remain challenging. Given the central role of recurrent abdominal pain in IBS, we evaluated the relationships of pediatric IBS and abdominal pain with intestinal microbes and fecal metabolites using a comprehensive clinical characterization and multiomics strategy. Using rigorous clinical phenotyping, we identified preadolescent children (aged 7 to 12 years) with Rome III IBS (n = 23) and healthy controls (n = 22) and characterized their fecal microbial communities using whole-genome shotgun metagenomics and global unbiased fecal metabolomic profiling. Correlation-based approaches and machine learning algorithms identified associations between microbes, metabolites, and abdominal pain. IBS cases differed from controls with respect to key bacterial taxa (eg, Flavonifractor plautii and Lachnospiraceae bacterium 7_1_58FAA), metagenomic functions (eg, carbohydrate metabolism and amino acid metabolism), and higher-order metabolites (eg, secondary bile acids, sterols, and steroid-like compounds). Significant associations between abdominal pain frequency and severity and intestinal microbial features were identified. A random forest classifier built on metagenomic and metabolic markers successfully distinguished IBS cases from controls (area under the curve, 0.93). Leveraging multiple lines of evidence, intestinal microbes, genes/pathways, and metabolites were associated with IBS, and these features were capable of distinguishing children with IBS from healthy children. These multi-omics features, and their links to childhood IBS coupled with nutritional interventions, may lead to new microbiome-guided diagnostic and therapeutic strategies.