建立頭皮微生物的採樣方法學並應用於大豆發酵液對於雄性禿改善之研究

Abstract

自人類微生物組計畫開展後，越來越多研究發現皮膚共生微生物對於維持皮膚的健康狀態扮演著相當重要的角色。頭皮作為一個毛囊密度最高的皮膚區域，其獨特的生理狀態使得定殖在頭皮上的微生物與其他皮膚部位有相當的差異，目前對於頭皮與微生物的相關研究相對較少，而與特定疾病的關聯性，如雄性禿，更是鮮少被討論。然而皮膚微生物研究時常受限於其低微生物量，取得穩定且具再現性的微生物樣本是研究皮膚微生物最基礎也最重要的步驟，佈滿毛髮的頭皮更是增加取樣的困難度，如何取得足量微生物檢體的採樣方法也是研究微生物相當重要的一環。 大豆為營養價值豐富的食物，根據不同的發酵方式可以增加大豆內機能性成分，強化其抗氧化及抗發炎等生物活性，有調查發現經常飲用大豆飲料可以防止中度到重度的落髮問題，現今市面上亦有許多大豆發酵成分的保養品，也有含大豆機能性成分的髮類養護產品。 本研究欲探討大豆發酵液是否能夠改善雄性禿，以及其頭皮中微生物的變化。首先對於大豆發酵液進行抗氧化活性實驗，發現樣品對於DPPH自由基清除能力約在60%左右。接著開發一個適用於頭皮微生物檢體的採樣流程，將其應用在雄性禿的受試者上，並使用real-time PCR定量常見的頭皮微生物。結果發現在受試者患部區域中的Malassezia globosa數量要明顯低於健康區域(p < 0.01)，而在使用大豆發酵液樣品兩個月後，受試者頭皮的健康區域中Propionibacterium acnes數量有增加的現象(p < 0.05)，並觀察到在患部區域毛髮密度、髮幹直徑都有改善的情形。除此之外亦發現頭皮中Staphylococcus epidermidis及Malassezia restricta與頭髮密度和頭皮敏感度具有關聯性。綜合以上所述，我們推論雄性禿以及頭皮的一些不適反應很可能與其頭皮中的共生微生物失衡有關，而本實驗大豆發酵液樣品作為改善雄性禿的頭皮養護品具有一定的潛力。

Since the Human microbiome project (HMP) was established, more and more studies have found that skin flora play a very important role in maintaining skin health. The scalp, as a part of skin, contains densely hair follicles, with unique physiological state that makes the microbial communities colonizing vary from other regions of body. Only few studies have recently focused on scalp and it’s commensal microflora while the connection with specific diseases, such as androgenetic alopecia(AGA), is even more rarely mentioned. Challenges with studing skin microbiome result in low biomass from human skin samples, and it makes sample collection even more difficult when it comes to hairy scalp. In consideration of the premises, obtaining stable and high amount of biomass is integral to skin microbiome research and the downstream steps. Soybeans contain several nutrients. The functional activities in soybeans, such as anti-oxidation and anti-inflammation could be improved depending on different fermentation methods. A survey has found that frequent soy bean drink consumption is protective against moderate to severe AGA. There are many skin-care products made with fermented soybean extract nowadays, as well as hair-care products which contain soybean functional compounds. The Purpose of this study is to investigate whether fermented soybean broth can improve AGA as well as influence common microbes on the scalp. Firstly, the in vitro antioxidant activity assay indicates that the fermented soybean broth presented above 60% of the DPPH free radical scavenging ability. Then we developed a microbiological sampling method which is suitable for scalp, and apply the method to AGA subjects. The amount of common microbes on the scalp of subjects was quantified by real-time PCR. Significantly lower amount of Malassezia globosa were detected from AGA region of subjects compare to healthy region (p < 0.01). And Propionibacterium acnes from heathy region increased (p < 0.05) after two months of sample intervention. We also observed significant improvement of hair density (p < 0.01) and hair diameter (p < 0.001) in AGA region. Apart from these, our results showed hair density was correlated with a higher amount of Staphylococcus epidermidis and Malassezia restricta. On the contrary, the opposite trend can be observed in scalp sensitivity score. In summary, we suggest that AGA and several uncomfortable sensations might be attributed to microbial dysbiosis on the scalp. And the result of human study suggests the potential of soybean fermentation extract as a promising hair care ingredient for AGA.