Fig. 4

The design of a clinical trial with the application of heat-killed GMNL-653-containing shampoo and examinations of scalp conditions among recruited participants. A All participants were requested to use the shampoo without heat-killed GMNL-653 (control shampoo) for the first month. Then, heat-killed GMNL-653-containing shampoo was used for the following 4 month. The collection time points of scalp conditions and scalp microbiota data were indicated by tick. B Data of oil count and hair volume were collected from front, middle, and back of scalp using Sebumeter 815 and Aram TSII. C Data of dandruff were collected from whole scalp by dandruff tapes and analyzed by Image J. Scalp samples for microbiota analysis were collected from whole scalp by wet cotton swabs containing 1 ml PBS buffer with 0.1% Triton X