Birg Aleksandr, Ritz Nathaniel, Barton Larry L, Lin Henry C
Division of Gastroenterology and Hepatology, University of New Mexico, Albuquerque, NM, 87106, USA.
Biomedical Research Institute of New Mexico, Albuquerque, NM, 87108, USA.
Dig Dis Sci. 2023 Apr;68(4):1253-1259. doi: 10.1007/s10620-022-07743-x. Epub 2022 Nov 2.
Hydrogen gas (H) is produced by H-producing microbes in the gut during polysaccharide fermentation. Gut microbiome also includes H-consuming microbes utilizing H for metabolism: methanogens producing methane, CH, and sulfate-reducing bacteria producing hydrogen sulfide, HS. HS is not measured in the evaluation of gaseous byproducts of microbial fermentation. We hypothesize that the availability of measured H depends on both hydrogen producers and hydrogen consumers by measuring H in vitro and in vivo. In the in vitro study, groups were Bacteroides thetaiotaomicron (B. theta, H producers), Desulfovibrio vulgaris (D. vulgaris, H consumers), and D. vulgaris + B. theta combined. Gas samples were collected at 2 h and 24 h after incubation and assayed for H, CH, and HS. In the in vivo study Sprague-Dawley rats were gavaged with suspended bacteria in four groups: B. theta, D. vulgaris, combined, and control. Gas was analyzed for H at 60 min. In the in vitro experiment, H concentration was higher in the combined group (188 ± 93.3 ppm) compared with D. vulgaris (27.17 ± 9.6 ppm) and B. theta groups (34.2 ± 29.8 ppm; P < 0.05); HS concentration was statistically higher in the combined group (10.32 ± 1.5 ppm) compared with B. theta (0.19 ± 0.03 ppm) and D. vulgaris group (3.46 ± 0.28 ppm; P < 0.05). In the in vivo study, H concentrations were significantly higher in the B. theta group (44.3 ± 6.0 ppm) compared with control (31.8 ± 4.3) and the combined group (34.2 ± 8.7, P < 0.05). This study shows that sulfate-reducing bacteria could convert available H to HS, leading to measured hydrogen levels that are dependent on the actions of both H producers and H consumers.
在多糖发酵过程中，肠道内产氢微生物会产生氢气（H₂）。肠道微生物群还包括利用氢气进行代谢的耗氢微生物：产生甲烷（CH₄）的产甲烷菌和产生硫化氢（H₂S）的硫酸盐还原菌。在评估微生物发酵的气态副产物时，并未对H₂S进行测量。我们假设，通过体外和体内测量氢气，所测得的氢气量取决于产氢菌和耗氢菌。在体外研究中，分组为多形拟杆菌（B. theta，产氢菌）、普通脱硫弧菌（D. vulgaris，耗氢菌）以及D. vulgaris + B. theta组合。孵育2小时和24小时后收集气体样本，并检测其中的H₂、CH₄和H₂S。在体内研究中，将斯普拉格-道利大鼠分为四组灌胃悬浮细菌：B. theta组、D. vulgaris组、组合组和对照组。在60分钟时分析气体中的H₂。在体外实验中，组合组的H₂浓度（188±93.3 ppm）高于D. vulgaris组（27.17±9.6 ppm）和B. theta组（34.2±29.8 ppm；P<0.05）；组合组的H₂S浓度（10.32±1.5 ppm）在统计学上高于B. theta组（0.19±0.03 ppm）和D. vulgaris组（3.46±0.28 ppm；P<0.05）。在体内研究中，B. theta组的H₂浓度（44.3±6.0 ppm）显著高于对照组（31.8±4.3）和组合组（34.2±8.7，P<0.05）。本研究表明，硫酸盐还原菌可将可用的H₂转化为H₂S，导致所测得的氢气水平取决于产氢菌和耗氢菌的作用。
