INRA, UR Microbiology Unit, Clermont-Ferrand Research Centre, Saint Genès-Champanelle, France.
Aliment Pharmacol Ther. 2012 Apr;35(7):828-38. doi: 10.1111/j.1365-2036.2012.05007.x. Epub 2012 Feb 8.
The role of the gut microbiota in patho-physiology of irritable bowel syndrome (IBS) is suggested by several studies. However, standard cultural and molecular methods used to date have not revealed specific and consistent IBS-related groups of microbes.
To explore the constipated-IBS (C-IBS) gut microbiota using a function-based approach.
The faecal microbiota from 14 C-IBS women and 12 sex-match healthy subjects were examined through a combined strictly anaerobic cultural evaluation of functional groups of microbes and fluorescent in situ hybridisation (16S rDNA gene targeting probes) to quantify main groups of bacteria. Starch fermentation by C-IBS and healthy faecal samples was evaluated in vitro.
In C-IBS, the numbers of lactate-producing and lactate-utilising bacteria and the number of H(2) -consuming populations, methanogens and reductive acetogens, were at least 10-fold lower (P < 0.05) compared with control subjects. Concomitantly, the number of lactate- and H(2) -utilising sulphate-reducing population was 10 to 100 fold increased in C-IBS compared with healthy subjects. The butyrate-producing Roseburia - E. rectale group was in lower number (0.01 < P < 0.05) in C-IBS than in control. C-IBS faecal microbiota produced more sulphides and H(2) and less butyrate from starch fermentation than healthy ones.
A major functional dysbiosis was observed in constipated-irritable bowel syndrome gut microbiota, reflecting altered intestinal fermentation. Sulphate-reducing population increased in the gut of C-IBS and were accompanied by alterations in other microbial groups. This could be responsible for changes in the metabolic output and enhancement in toxic sulphide production which could in turn influence gut physiology and contribute to IBS pathogenesis.
多项研究表明，肠道微生物群在肠易激综合征（IBS）的病理生理学中起作用。然而，迄今为止使用的标准文化和分子方法并未显示出与 IBS 相关的特定和一致的微生物群。
采用基于功能的方法探索便秘型 IBS（C-IBS）的肠道微生物群。
通过严格厌氧培养功能群微生物和荧光原位杂交（16S rDNA 基因靶向探针）定量主要细菌群，对 14 例 C-IBS 女性和 12 名性别匹配的健康受试者的粪便微生物群进行检测。体外评估 C-IBS 和健康粪便样本的淀粉发酵。
与对照组相比，C-IBS 中乳酸产生菌和乳酸利用菌、H₂消耗菌群、产甲烷菌和还原乙酸菌的数量至少减少了 10 倍（P < 0.05）。同时，与健康受试者相比，C-IBS 中乳酸和 H₂利用硫酸盐还原菌的数量增加了 10 到 100 倍。C-IBS 中丁酸产生的罗斯伯里氏菌-直肠真杆菌群数量低于对照组（0.01 < P < 0.05）。C-IBS 粪便微生物群从淀粉发酵中产生更多的硫化物和 H₂，而丁酸较少。
在便秘型肠易激综合征肠道微生物群中观察到主要的功能失调，反映了肠道发酵的改变。硫酸盐还原菌在 C-IBS 肠道中增加，同时其他微生物群也发生改变。这可能是代谢产物变化和毒性硫化物产生增加的原因，这反过来又会影响肠道生理学并有助于 IBS 的发病机制。
