This randomized, double-blind, placebo-controlled study will enroll 60 individuals with mild-to-moderate anxiety depression. Following a 3-month intervention and a 1-month follow-up period, the study aims to: 1) evaluate the efficacy of probiotics by comparing anxiety, depression, and sleep scores to baseline; and 2) investigate the safety and underlying mechanisms by analyzing changes in serum biomarkers, gut microbiota, and related metabolites.

Inclusion Criteria:

• 1) Age: 18-60 years old; Gender: male or female.
• 2) Meets the diagnostic criteria of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) for a mild-to-moderate depressive or anxiety symptoms.
• 3) Hamilton Depression Rating Scale (HAM-D-24) score ≥ 8 or Hamilton Anxiety Rating Scale (HAM-A-14) score ≥ 7 at screening.
• 4) Has no used of anxiolytic or antidepressant medications (including traditional Chinese patent medicines), with the exception of Escitalopram Oxalate, within 2 weeks prior to the first dose.
• 5) For participants of childbearing potential (male or female): Must agree to use least one medically approve form of contraception (e.g., intrautering device [IUD], oral contraceptives, or condoms) throughout the trial. For female participants of childbearing potential: Must have a negative urine pregnancy test at screening and must be non-lactating.
• 6) The participant is willing and be able to provide written informed consent to participate in the study.

Exclusion Criteria:

• 1) HAM-D-24 score ≥ 35 or HAM-A-14 score ≥ 29.
• 2) Presence of significant suicidal ideation.
• 3) History or current diagnosis of neuropsychiatric disorders such as schizophrenia or epilepsy.
• 4) History of head trauma (with loss of consciousness for >10 minutes), other unstable major somatic diseases, or any somatic condition that could cause psychiatric symptoms.
• 5) Suspected intellectual disability.
• 6) History of alcohol or substance abuse prior to enrollment.
• 7) Cranial magnetic resonance imaging (MRI) reveals organic lesions.
• 8) Participants who are deemed unsuitable for the study by the investigator for any other reason.