Hydrogen Sulfide and Methane on Breath Test Correlate with Human Small Intestinal Hydrogen Sulfide Producers and Methanogens
María Jesús Villanueva-Millán, Gabriela Leite, Ruchi Mathur, Ali Rezaie, Cristina Moreno Fajardo, Juliana de Freitas Germano, Walter Morales, Maritza Sanchez, Ignacio Rivera, Gonzalo Parodi, Stacy Weitsman, Mohamad Rashid, Ava Hosseini, Daniel Brimberry, Gillian M. Barlow, Mark Pimentel
Abstract
Evidence indicates that 3 gas breath testing (BT) correlates with stool microbial populations. Breath methane (CH 4 ) levels correlate with stool Methanobrevibacter smithii levels and constipation, while hydrogen sulfide (H 2 S) levels correlate with stool H 2 S producers and diarrhea. However, their relationships to small bowel microbes are unknown. To assess relationships between small bowel microbes and breath gases. REIMAGINE study subjects completed a fasting single-sample BT for CH 4 and H 2 S. During esophagogastroduodenoscopy without colon preparation, duodenal aspirates were obtained using double-lumen sterile aspiration catheters. Microbial DNAs underwent shotgun sequencing (NovaSeq6000). Duodenal bacterial profiles differed significantly in subjects with breath H 2 S ≥ 1.5 ppm vs. those with < 1.5 ppm, with 2.08-log 2 fold greater prevalence of phylum Thermodesulfobacteriota. Higher breath H 2 S levels correlated with greater duodenal prevalences of H 2 S producers, including Proteus mirabilis ( P = 0.002), Desulfosarcina widdelii ( P = 0.027), and Desulfobulbus oligotrophicus ( P = 0.041); co-occurrence of all 3 species correlated with ~ 50% higher breath H 2 S levels ( P = 0.0001). Duodenal archaeal profiles differed significantly in subjects with intestinal methanogen overgrowth (IMO, CH 4 ≥ 10 ppm), with 2.94-log 2 fold greater prevalence of family Methanobacteriaceae vs. non-IMO subjects. Higher breath CH 4 correlated with greater prevalences of methanogens including M. smithii ( P = 0.02), Halarchaeum sp. CBA1220 ( P = 0.003), Desulfurococcus mucosus ( P = 0.046), and Halobaculum rubrum ( P = 0.049). IMO was more common in subjects with co-occurrence of all 4 species ( P = 0.04). In IMO-positive subjects, CH 4 levels correlated with greater constipation severity ( P = 0.019); P. mirabilis ( P = 0.021) and D. oligotrophicus ( P = 0.003) correlated with looser stool in IMO-negative subjects. M. smithii prevalence correlated with known hydrogen-producing syntrophs, e.g., Christensenella minuta ( P < 0.001). This study demonstrates that duodenal prevalences of H 2 S-producing bacteria and methanogenic archaea contribute to H 2 S and CH 4 levels, respectively, on BT.