This study is a randomized, double-blind, placebo-controlled trial aimed primarily at investigating the effects of Weizmannia coagulans BC99 on alleviating anxiety and depression and the gut microbiota.

Inclusion Criteria:

1. Adults aged 18-65 years.
2. Individuals experiencing scientific research, employment-related, or occupational stress, including graduate students or community-dwelling adults with job-related pressure.
3. A Hamilton Depression Rating Scale (HAMD-17) score ≥ 8 and/or a Hamilton 4) Anxiety Rating Scale (HAMA-14) score ≥ 7 at screening.

5)Ability and willingness to voluntarily participate in the study and to provide written informed consent prior to enrollment.

Exclusion Criteria:

1. A confirmed previous diagnosis of other psychiatric disorders, including intellectual disability, bipolar disorder, treatment-resistant depression, or suicidal ideation.
2. Pregnant or breastfeeding women.
3. Individuals with known food or drug allergies, or those with alcohol abuse or psychotropic substance abuse.
4. Use of antibiotics or probiotics known to affect gut microbiota for more than one week within one month prior to enrollment.
5. Participants who withdrew from the study, discontinued intervention, or were unable to complete the study for any reason.

Double (Participant, Investigator)