Meta-Analysis of the Composition of Human Intestinal Gases.

BACKGROUND: Understanding intestinal gases volume and composition may contribute to diagnosing digestive diseases and the microbiome's status. This meta-analysis aimed to define the composition of human intestinal gases and changes associated with diet. METHODS: Studies were identified by systematic research of the MEDLINE(Ovid), Scopus, and Cochrane databases. Studies that measured the concentration of intestinal gases in healthy adult humans were retrieved. The JBI critical appraisal tool was used to evaluate the risk of bias. The primary outcomes analysed were the concentration of the most prevalent colonic gases. Participants were divided into groups according to dietary fibre content. RESULTS: Eleven studies were included. The following gases were identified in similar concentrations across all studies (mean ± standard deviation): nitrogen (65.1 ± 20.89%), oxygen (2.3 ± 0.98%), carbon dioxide (9.9 ± 1.6%), hydrogen (2.9 ± 0.7%), and methane (14.4 ± 3.7%). Differences according to the dietary fibre were observed, with a positive correlation between fibre and volume of gas produced, particularly in fermented gases (carbon dioxide, hydrogen, and methane). DISCUSSION: The meta-analysis has found defined concentrations of the five most common gases present in human colonic gas. Limitations included heterogenic methodologies, a low number of participants, and few recent studies. These findings may be helpful in diagnostic applications where colonic gas volume and composition are crucial factors, including functional disorders, microbiome analyses, and bowel perforation diagnostics.

Chyme recycling in the management of small bowel double enterostomy in pediatric and neonatal populations: A systematic review.

BACKGROUND & AIMS: Intestinal failure (IF) in neonatal and pediatric patients is associated with substantial morbidity. Management of IF includes the formation of a double enterostomy (DES) of the small bowel. Parenteral nutrition (PN) is frequently required, which is expensive. Recycling chyme from the proximal DES limb distally is an alternative therapy, but standardized data on this intervention is lacking. This review systematically evaluated the existing literature on chyme recycling (CR) in neonatal and pediatric populations. METHODS: Medical databases were systematically searched for articles reporting CR in neonatal and pediatric populations. Articles documenting CR indications, methods, clinical outcomes, benefits and adverse events (AEs) were reviewed. A narrative synthesis was performed on the extracted data. RESULTS: This review identified 20 full-text articles, in which 289 patients received CR, most commonly following necrotizing enterocolitis (n = 117 patients). The most common motivators for CR were proximally located DES (n = 7 articles) and to support nutrition and growth (n = 7 articles). Proximal DES output collection was predominantly manual (n = 11 articles), whereas distal CR was mostly automated (n = 12 articles), using customized peristaltic or syringe infusion pumps. Clinical benefits encompassed PN reduction (n = 19 patients) or cessation (n = 122 patients), weight gain, normalization of fluid balance, improvement in liver function tests and distal gut maturation. Technical problems commonly included tube dislodgement, leakage and effluent reflux (n = 9 articles). AEs included intestinal perforation (n = 3 patients) and haemorrhage (n = 1 patient). CONCLUSIONS: From the limited available data, CR is demonstrated as an effective therapeutic intervention for small bowel DES in pediatric and neonatal patients. However, standardized methods that improve the delivery of and minimise AEs associated with the intervention are needed.

Chyme Reinfusion for Small Bowel Double Enterostomies and Enteroatmospheric Fistulas in Adult Patients: A Systematic Review.

BACKGROUND: High-output double enterostomies (DESs) and enteroatmospheric fistulas (EAFs) of the small bowel account for substantial patient morbidity and mortality. Management may include parenteral nutrition (PN) and prolonged admissions, at high cost. Reinfusion of chyme into the distal bowel is a proposed therapeutic alternative when the distal DES limb is accessible; however, standardized information on this technique is required. This review aimed to critically assess the literature regarding chyme reinfusion (CR) to define its current status and future directions. METHODS: A systematic search of medical databases was conducted for articles investigating CR in adults. Articles reporting indications, methods, benefits, technical issues, and complications resulting from CR were reviewed. A narrative synthesis of the retrieved data was undertaken. RESULTS: In total, 24 articles reporting 481 cases of CR were identified, although articles were heterogeneous in their structure and reporting. CR was most frequently performed for remediation of high-output DES and intestinal failure and for proximally located DES. Effluent output collection was commonly manual, with distal reinfusion more commonly automated, and with few dedicated systems. Multiple benefits attributed to CR were reported, encompassing weight gain, cessation of PN, and improvements in liver function. Technical problems included distaste, labor-intensive methods, reflux of contents, and tube dislodgement. No serious AEs or mortality directly attributable to CR were reported. CONCLUSIONS: CR appears to be a promising, safe and well-validated intervention for small bowel DES and EAF. However, more efficient and acceptable methods are required to promote greater adoption of the practice of CR.