近日,，來自國外的研究者揭示了大腦血清素（也稱為快樂荷爾蒙）的水平,，這種快樂荷爾蒙（happy hormone）在個體早年的時候受腸道內(nèi)大量的細菌所調(diào)節(jié)，這項研究刊登在了國際著名雜志Molecular Psychiatry上,。這項研究揭示了正常成年人大腦功能的發(fā)育依賴于其腸道內(nèi)的微生物,。血清素主要調(diào)節(jié)情緒和情感，其水平可以隨著壓力,、焦慮以及大多臨床的抗抑郁藥物所改變,。
UCC的研究者使用無菌小鼠模型來研究其在早年的時候機體細菌的存在,，是否可以影響小鼠成年后的大腦血清素水平。這項研究同時也揭示了這種影響是受性別依賴的,，相比雌性動物來說,，雄性動物更易受影響。早期研究中研究者揭示了微生物組-腸道-大腦軸的存在對于維持機體健康以及影響大腦和行為至關(guān)重要,。
研究者John F Cryan表示,，作為神經(jīng)科學家，這些發(fā)現(xiàn)非常有意思,，腸道的細菌對于維持大腦和腸道之間的定向交流至關(guān)重要,。而且這也為我們治療腦部障礙提供了基于微生物的一些治療措施。
這項研究蘊含多種健康效應(yīng),，包括微生物的操作對于大腦功能具有深遠的影響,。研究者對于其發(fā)現(xiàn)非常興奮，他們發(fā)現(xiàn)了微生物群落對于一般的健康必不可少,，同時研究者也揭示了微生物對于我們的精神心理健康也是很重要的,。（生物谷Bioon.com）
編譯自：Early Gut Bacteria Regulate Happiness
編譯者：T.Shen
doi:10.1038/mp.2012.77
PMC:
PMID:
The microbiome-gut-brain axis during early life regulates the hippocampal serotonergic system in a sex-dependent manner
G Clarke, S Grenham, P Scully, P Fitzgerald, R D Moloney, F Shanahan, T G Dinan and J F Cryan
Bacterial colonisation of the intestine has a major role in the post-natal development and maturation of the immune and endocrine systems. These processes are key factors underpinning central nervous system (CNS) signalling. Regulation of the microbiome–gut–brain axis is essential for maintaining homeostasis, including that of the CNS. However, there is a paucity of data pertaining to the influence of microbiome on the serotonergic system. Germ-free (GF) animals represent an effective preclinical tool to investigate such phenomena. Here we show that male GF animals have a significant elevation in the hippocampal concentration of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid, its main metabolite, compared with conventionally colonised control animals. Moreover, this alteration is sex specific in contrast with the immunological and neuroendocrine effects which are evident in both sexes. Concentrations of tryptophan, the precursor of serotonin, are increased in the plasma of male GF animals, suggesting a humoral route through which the microbiota can influence CNS serotonergic neurotransmission. Interestingly, colonisation of the GF animals post weaning is insufficient to reverse the CNS neurochemical consequences in adulthood of an absent microbiota in early life despite the peripheral availability of tryptophan being restored to baseline values. In addition, reduced anxiety in GF animals is also normalised following restoration of the intestinal microbiota. These results demonstrate that CNS neurotransmission can be profoundly disturbed by the absence of a normal gut microbiota and that this aberrant neurochemical, but not behavioural, profile is resistant to restoration of a normal gut flora in later life.
