Evaluate the efectiveness and safety of Bifidobacterium bifidum BBi32 as a food supplement compared to a placebo in improving intestinal andimmune functions in healthy adults.

Inclusion Criteria:

1. Willing to attend 3 follow-up visits during the intervention period
2. Agree to provide blood, urine, and stool samples twice during the intervention period
3. Good eyesight, able to read and write, and capable of wearing glasses if needed
4. Good hearing and able to fully comprehend all instructions during the intervention

Exclusion Criteria:

1. Presence of digestive diseases, particularly gastrointestinal disorders (e.g., celiac disease, ulcerative colitis, Crohn's disease)
2. History of serious neurological conditions (e.g., epilepsy, stroke, severe head trauma, meningitis within the last 10 years, brain surgery, brain tumor, or prolonged coma-not including general anesthesia)
3. History of or currently receiving treatment for mental health disorders such as alcohol/drug/substance abuse, schizophrenia, psychosis, or bipolar disorder
4. Currently taking medication for depression or low mood
5. Presence of internal organ failure (e.g., heart, liver, or kidney failure)
6. History of radiation therapy or chemotherapy treatments
7. Underwent general anesthesia within the past three years or are scheduled for general anesthesia within the next 3 months during the trial period
8. History of hepatitis (B or C), HIV, or syphilis