Oral lichen planus patients who will meet inclusion criteria will be divided into 2 groups

-The intervention group (Group P): This group will be randomly allocated to take one capsule twice daily during meal time at morning and evening of probiotics complex obtained from Biovea for 4 -week study period. Moreover, patients in this group will be instructed to apply clobetasole propionate in orabase gel 2 times daily for 4 weeks. Patients will receive their supply of the gel and probiotics every 2 weeks. The control group (Group B): This group will be randomly allocated to apply clobetasol propionate in orabase gel 4 times daily after meal times and before sleeping for 4 weeks. At the 3rd week this group will be instructed to apply miconazole gel 4 times daily as a prophylaxis for two weeks.

Salivary sample collection: Unstimulated salivary sample was collected from all participants twice , once at baseline and another time after 4 weeks from the study period. Saliva was collected in graduated clear test tubes to be used in the evaluation of candidal counts before and after treatment .

Patient's visits was at baseline, 2 weeks and 4 weeks.

Inclusion Criteria:

• Patients who are diagnosed with symptomatic lichen planus whether bullous erosive or erythematous oral lichen planus.
• Male or female patient with age range between 20-75 years old were included.
• medically free individuals

Exclusion Criteria:

• the use of systemic antibiotics, corticosteroids or immunosuppressive agents within four weeks prior to enrollment in the study.
• Pregnant females
• patients with history of systemic disorder affecting the immune system
• active liver diseases and cancer
• allergy or intolerance to probiotics.
• any other oral lesions