# Management of Scalp Biofilm in Local Dermatosis: From In Vivo Visualization to Optimal Treatments
## 4 Discussion  
The interactions between pathogenic microbes and the host's skin are central to maintaining homeostasis and the initiation of disease [21]. Bacteria undergo metabolic changes to adapt to scalp skin surfaces, which involve producing a substance to bind bacterial communities and controlling specific genes [22]. This leads to the formation of networks that support multicellular functions, ultimately resulting in the development of biofilms, a community-like living state. Biofilms provide survival benefits to bacterial community members, such as increased virulence, pathogenesis, and resistance to antibiotic agents, when viewed from the host's perspective [23]. The visualization and removal strategies of pathogenic biofilms provide opportunities for studies of the various host-microbiome interactions and maintenance of scalp health. We evaluated the bacteria on the surface of the scalp, and _Staphylococcus aureus (S. aureus)_ and _Culobacterium acnes (C. acnes)_ were observed in high levels in the first layer of coenocytes with aggregative features (Figure 4). However, to advance the evaluation of the biofilm's physiological effect on scalp skin, analyses of scalp biofilm components such as peptidoglycan, analyses of the population of bacteria and fungi, and examinations of skin irritation biomarkers are needed [22]. The examination of cultivable microorganisms associated with the skin, such as _Staphylococcus aureus (S. aureus)_, _Staphylococcus epidermidis (S. epidermidis)_, _Propionibacterium acnes (P. acnes)_, _Malassezia_ spp., _Candidida albicans_, and various others, has occurred over a number of years and has revealed intricate molecular processes crucial to their interactions with the skin [24; 25; 26; 27; 28]. Numerous studies in microbiology and dermatology have consistently indicated strong connections between _P. acnes_ and acne vulgaris, _S. aureus_ and atopic dermatitis (AD), and _Malassezia_ species and dandruff. Furthermore, there has been extensive research on the biofilm-forming abilities of many skin-associated microbes, and there are ongoing efforts to prevent such biofilm formation [29]. In this study, the levels of _S. epidermidis_, _C. acnes_, and _Malassezia_ were increased in the high sRA-positive group. In particular, the relative total amount of _Malassezia_ is significantly different compared with that of the sRA-negative group, which means that _Malassezia_ has a dominant effect in controlling biofilm staining on the scalp. The skin microbiota's single-species biofilms, such as _S. aureus_, _S. epidermidis_, and _P. acnes_, have been extensively studied in vitro, but there is relatively limited research on _Malassezia_ spp. biofilms. Furthermore, important interactions between different species have been discovered among the skin prokaryotes, including _S. epidermidis_, inhibiting the growth of _P. acnes_ and _S. aureus_ biofilms [30; 31]. However, these interactions between species have not yet been linked to fungal skin commensals, particularly _Malassezia_[22]. Following attachment to scalp skin, the bacteria secrete a range of substances to enhance the attachment and growth capabilities of the emerging community, collectively known as the extracellular matrix [32]. The extracellular components of the bacterial biofilm comprise various biopolymers, such as polysaccharides, DNA, proteins, and lipids [33]. Mineral scaffolds have been demonstrated to have an impact on the formation of the extracellular matrix [34]. Diverse bacterial and fungal skin microbiomes, such as _S. aureus_, _C. acnes_, and _Malassezia_ species, contribute to the formation of scalp skin biofilms [22; 33]. The compositions of homogenous biofilms from each bacterial and fungi species were investigated. The structure and matrix composition of _Cultibacterium acnes_ biofilms were reported depending on _C. acnes_ subtypes [35].