Probiotics can treat skin diseases. Different probiotics can treat different skin diseases, for example, Nitrosomonas eutropha and Lactobacillus buchneri can improve skin aging; Streptococcus thermophiles, Enterococcus faecalis and Streptococcus salivarius can improve acne; Vitreoscilla filiformis, Streptococcus thermophilus and Lactobacillus johnsonii can improve atopic dermatitis, Bifidobacteria infantis and Lactobacillus pentosus can improve psoriasia; Lactiplantibacillus plantarum kefir, Lactobacillus fermentum and Saccharomyces cerevisiae can improve wound healing; Lactobacillus paracasei can improve dandruff; Bifidobacterum breve BR03 and Lactobacillus salivarius can improve rosasea.