Assessing the colonic microbiome, hydrogenogenic and hydrogenotrophic genes, transit and breath methane in constipation

• Published in: Neurogastroenterology and motility Vol. 29; no. 10; pp. 1 - 9
• Main Authors: Wolf, P. G., Parthasarathy, G., Chen, J., O'Connor, H. M., Chia, N., Bharucha, A. E., Gaskins, H. R.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.10.2017
• Subjects: Abundance; Adult; breath hydrogen; breath methane; Breath Tests; Coenzyme M; Colon; Constipation; Constipation - microbiology; Constipation - physiopathology; DNA, Bacterial - analysis; Fecal microflora; Feces; Female; Gases; Gastrointestinal Microbiome - physiology; Gastrointestinal Transit - physiology; Genes; Humans; hydrogen; Intestinal microflora; Lactulose; Methane; Methane - analysis; microbiome; microbiota; Middle Aged; Mucosa; rRNA 16S; Scintigraphy; Sulfite; Sulfite reductase; transit; breath methane; constipation; microbiota; breath hydrogen; genes; transit; methane; hydrogen; lactulose; microbiome
• ISSN: 1350-1925; 1365-2982; 1365-2982
• DOI: 10.1111/nmo.13056

Background Differences in the gut microbiota and breath methane production have been observed in chronic constipation, but the relationship between colonic microbiota, transit, and breath tests remains unclear. Methods In 25 healthy and 25 constipated females we evaluated the sigmoid colonic mucosal and fecal microbiota using 16S rRNA gene sequencing, abundance of hydrogenogenic FeFe (FeFe‐hydA) and hydrogenotrophic (methyl coenzyme M reductase A [mrcA] and dissimilatory sulfite reductase A [dsrA]) genes with real‐time qPCR assays, breath hydrogen and methane levels after oral lactulose, and colonic transit with scintigraphy. Key Results Breath hydrogen and methane were not correlated with constipation, slow colon transit, or with abundance of corresponding genes. After adjusting for colonic transit, the abundance of FeFehydA, dsrA, and mcrA were greater (P<.005) in colonic mucosa, but not stool, of constipated patients. The abundance of the selected functional gene targets also correlated with that of selected taxa. The colonic mucosal abundance of FeFe‐hydA, but not mcrA, correlated positively (P<.05) with breath methane production, slow colonic transit, and overall microbiome composition. In the colonic mucosa and feces, the abundance of hydrogenogenic and hydrogenotrophic genes were positively correlated (P<.05). Breath methane production was not associated with constipation or colonic transit. Conclusions & Inferences Corroborating our earlier findings with 16S rRNA genes, colonic mucosal but not fecal hydrogenogenic and hydrogenotrophic genes were more abundant in constipated vs. healthy subjects independent of colonic transit. Breath gases do not directly reflect the abundance of target genes contributing to their production. The relationship between colonic microbiota, transit, and breath hydrogen and methane production in chronic constipation is unclear. Corroborating our earlier findings with 16S rRNA genes, colonic mucosal but not fecal hydrogenogenic and hydrogenotrophic genes were more abundant in constipated than healthy subjects independent of colonic transit. Breath gas excretion after lactulose was not correlated with the abundance of target genes contributing to their production.