Romo Jesus A, Markey Laura, Kumamoto Carol A
Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111, USA.
Graduate Program in Molecular Microbiology, Graduate School of Biomedical Sciences and Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111, USA.
J Fungi (Basel). 2020 Jul 3;6(3):100. doi: 10.3390/jof6030100.
Prior antibiotic treatment is a risk factor for infection (CDI); the commensal gut microbiota plays a key role in determining host susceptibility to the disease. Previous studies demonstrate that the pre-colonization of mice with a commensal fungus, , protects against a lethal challenge with spores. The results reported here demonstrate that the cecum contents of antibiotic-treated mice with colonization contained different levels of several lipid species, including non-esterified, unsaturated long-chain fatty acids compared to non--colonized mice. Mice fed olive oil for one week and challenged with spores showed enhanced survival compared to PBS-fed mice. The amount of olive oil administered was not sufficient to cause weight gain or to result in significant changes to the bacterial microbiota, in contrast to the effects of a high-fat diet. Furthermore, the direct exposure of bacteria in laboratory culture to the unsaturated fatty acid oleic acid, the major fatty acid found in olive oil, reduced the transcription of genes encoding the toxins and reduced the survival of bacteria in the post-exponential phase. Therefore, the effects of on the metabolite milieu contributed to the attenuation of virulence.
先前的抗生素治疗是感染（艰难梭菌感染，CDI）的一个风险因素；肠道共生微生物群在决定宿主对该疾病的易感性方面起着关键作用。先前的研究表明，用共生真菌对小鼠进行预定植可保护其免受艰难梭菌孢子的致命攻击。此处报告的结果表明，与未定植艰难梭菌的小鼠相比，定植了艰难梭菌的抗生素治疗小鼠的盲肠内容物中几种脂质种类的含量不同，包括非酯化的不饱和长链脂肪酸。与喂食磷酸盐缓冲盐水（PBS）的小鼠相比，喂食橄榄油一周并受到艰难梭菌孢子攻击的小鼠存活率提高。与高脂饮食的影响相反，给予的橄榄油量不足以导致体重增加或引起细菌微生物群的显著变化。此外，在实验室培养中，将艰难梭菌直接暴露于橄榄油中的主要脂肪酸不饱和脂肪酸油酸，可降低编码毒素的基因的转录，并降低细菌在指数后期的存活率。因此，艰难梭菌对代谢物环境的影响导致了其毒力的减弱。
