Department of Microbiology and Preventive Medicine College of Veterinary Medicine Iowa State University Ames, IA 50011-1134, USA.
Interdepartmental Microbiology Program, Iowa State University, Ames, IA 50011-1027 USA.
FEMS Microbiol Ecol. 2018 Jul 1;94(7). doi: 10.1093/femsec/fiy096.
Microbial endocrinology represents the union of microbiology and neurobiology and is concerned with the ability of neurochemicals to serve as an evolutionary-based language between host and microbiota in health and disease. The recognition that microorganisms produce, modify and respond to the same neurochemicals utilized in the various signaling pathways of their mammalian hosts is increasingly being recognized as a mechanism by which the host and microbiota may interact to influence the progression of infectious disease as well as influence behavior through the microbiota-gut-brain axis. While the capacity for bacteria to produce neurochemicals has been recognized for decades, the degree to which this occurs in the environment of the gastrointestinal tract is still poorly understood. By combining techniques used in analytic chemistry, food science and environmental microbiology, a novel culture-based method was developed which generates a medium utilizing animal feed which resembles the contents of the small intestine. The usage of this medium allows for the in vitro growth of bacteria native to the gastrointestinal tract in an environment that is reflective of the small-intestinal host-based milieu. We describe a detailed protocol for the preparation of this medium and the quantification of neurochemicals by microorganisms grown therein. Catecholamines including dopamine and its precursor L-3,4-dihydroxyphenalanine (L-DOPA) as well as biogenic amines including tyramine and its precursor tyrosine, serve as prototypical examples of neurochemicals that are quantifiable with the methods described herein.
微生物内分泌学代表了微生物学和神经生物学的结合，它关注的是神经化学物质在宿主和微生物群之间作为一种基于进化的语言的能力，以维持健康和疾病状态。人们越来越认识到，微生物能够产生、修饰和响应与哺乳动物宿主各种信号通路中相同的神经化学物质，这是宿主和微生物群相互作用以影响传染病进展以及通过微生物群-肠道-大脑轴影响行为的一种机制。虽然几十年来人们已经认识到细菌能够产生神经化学物质，但对于这种情况在胃肠道环境中发生的程度仍知之甚少。通过将分析化学、食品科学和环境微生物学中的技术相结合，开发了一种新的基于培养的方法，该方法利用类似于小肠内容物的动物饲料来生成培养基。该培养基的使用允许在类似于小肠宿主环境的环境中体外生长肠道内的固有细菌。我们描述了一种详细的方案，用于制备这种培养基，并通过在其中生长的微生物来定量神经化学物质。儿茶酚胺包括多巴胺及其前体 L-3,4-二羟基苯丙氨酸（L-DOPA）以及生物胺包括酪胺及其前体酪氨酸，都是可以用本文所述方法定量的神经化学物质的典型例子。
