我們已經證明人體微生物總體中兩種主要細菌:丙酸桿菌（嗜酸性桿菌）和表皮葡萄球菌（表皮葡萄球菌），都可以利用甘油作為發酵的碳源，同時在細菌發酵的過程中產生電(提升電壓)，以及表皮葡萄球菌利用甘油發酵產生比丙酸桿菌利用甘油發酵所產生的電力高。並且細菌發電這機能顯著會被糠醛給抑制，然而糠醛同時是種有效的細菌發酵抑制劑，所以表示這細菌發電是通過發酵來的。 人體表皮膚電導大小與皮膚上表皮葡萄球菌的數量成比例，在局部皮膚塗抹(2%)甘油的話會增加人體表皮膚電導。另外在前額塗抹酒精殺菌後，會減少人體表皮膚電導以及腦電波中事件相關電位P300。相反的，在前額上局部塗抹甘油後會增加P300，這意味著腦電波P300可能是被細菌甘油發酵所影響。未來將發展皮膚貼片，可以感知在人體皮膚微生物總體中，不同細菌所產生的電差異。 ;We have demonstrated that both Propionibacterium (or Cutibacterium ) acnes (P. acnes) and Staphylococcus epidermidis (S. epidermidis), two major bacterium in the human microbiome, can utilize the glycerol as a carbon source for fermentation. Electricity (electric voltage) was produced during the bacterial fermentation. Glycerol fermentation of S. epidermidis yielded higher electricity than that of P. acnes. Bacterial electricity can be considerably blocked by furfural, a potent fermentation inhibitor, indicating that the production of bacterial electricity is mediated by fermentation. The magnitude of human skin conductance is proportional to the number of S. epidermidis in skin. Topical application of 2% glycerol onto skin remarkably enhanced the magnitude of human skin conductance in hands. Removal of bacterial by alcohol in forehead reduced the skin conductance as well as brain wave P300 of the human event-related potential (ERP). Conversely, topical application of glycerol onto forehead promoted the P300, suggesting that glycerol fermentation of bacteria modulated the brain waves. An electronic skin patch was fabricated to dynamically detect human skin conductance in real time. Future works will include employee the electronic skin patches to sense the electricity differentially produced various bacteria in the human skin microbiome.
