Trace amines (TA) are endogenously produced in mammals, have a low concentration in the central nervous system (CNS), but trigger a variety of neurological effects and intervene in host cell communication. It emerged that neurotransmitters and TA are produced also by the microbiota. As it has been shown that TA contribute to wound healing, we examined the skin microbiome of probands using shotgun metagenomics. The phyla Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes were predominant. Since SadA is a highly promiscuous TA-producing decarboxylase in Firmicutes, the skin microbiome was specifically examined for the presence of sadA-homologous genes. By mapping the reads of certain genes, we found that, although there were less reads mapping to sadA than to ubiquitous housekeeping genes (arcC and mutS), normalized reads counts were still >1000 times higher than those of rare control genes (icaA, icaB, and epiA). At protein sequence level SadA homologs were found in at least 7 phyla: Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, Acidobacteria, Chloroflexi, and Cyanobacteria, and in 23 genera of the phylum Firmicutes. A high proportion of the genera that have a SadA homolog belong to the classical skin and intestinal microbiota. The distribution of sadA in so many different phyla illustrates the importance of horizontal gene transfer (HGT). We show that the sadA gene is widely distributed in the human skin microbiome. When comparing the sadA read counts in the probands, there was no correlation between age and gender, but an enormous difference in the sadA read counts in the microbiome of the individuals. Since sadA is involved in TA synthesis, it is likely that the TA content of the skin is correlated with the amount of TA producing bacteria in the microbiome. In this way, the microbiome-generated TA could influence signal transmission in the epithelial and nervous system.

痕量胺（TA）是哺乳动物内源产生的，在中枢神经系统（CNS）中浓度较低，但会触发多种神经系统作用并干预宿主细胞的通讯。结果表明，微生物群也产生神经递质和TA。如已表明TA有助于伤口愈合，我们使用we弹枪宏基因组学研究了先证者的皮肤微生物组。以放线菌，变形杆菌，硬毛和拟杆菌为主。由于SadA是Firmicutes中高度混杂的产生TA的脱羧酶，因此需要专门检查皮肤微生物组是否存在悲伤同源基因。通过绘制某些基因的读图，我们发现，尽管映射到悲伤 而不是普遍存在的管家基因（弧线 和 突变），归一化的读取计数仍比稀有对照基因（>协会， ICAB和 EpiA）。在蛋白质序列水平上，在至少7个门中发现了SadA同源物：Firmicutes，放线菌，变形杆菌，拟杆菌，Acidobacteria，Chloroflexi和Cyanobacteria，以及Firmicutes门的23属。具有SadA同源物的属中很大一部分属于经典的皮肤和肠道菌群。的分布悲伤在许多不同的门上，都说明了水平基因转移（HGT）的重要性。我们表明悲伤该基因广泛分布在人的皮肤微生物组中。比较时悲伤 先证者的阅读次数，年龄和性别之间没有相关性，但是 悲伤读取个体微生物组中的计数。以来悲伤由于参与TA合成，皮肤的TA含量可能与微生物组中产生TA的细菌数量有关。这样，微生物组产生的TA可能会影响上皮和神经系统中的信号传输。