The Safety and Efficacy of Probiotic for Improving Intestinal and Immune Function

Safety and Efficacy of Streptococcus Salivarius Subsp. Thermophilus ST36 on Intestinal and Immune Function Improvement.

To evaluate the safety and efficacy of Streptococcus salivarius subsp. thermophilus ST36 in healthy adults on immune function and intestinal health.

Study Overview

• Status: Completed
• Conditions: Adults Aged 18-45 Years
• Intervention / Treatment: Dietary supplement: Probiotic; Dietary supplement: Placebo

• Study Type: Interventional
• Enrollment (Actual): 98
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Henan
    • Zhengzhou, Henan, China, 210095
      • Xu fei

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 1) Age 18-45 years; 2) Willing to undergo 3 follow-up visits during the intervention period; 3) Willing to provide 2 blood, urine, and stool samples during the intervention period; 4) Willing to self-administer Streptococcus salivarius subsp. thermophilus ST36/placebo once daily during the intervention period; 5) Good eyesight, able to read and write, and can wear glasses; 6) Have good hearing and be able to hear and understand all instructions during the intervention;

Exclusion Criteria:

• 1) Suffering from digestive disorders, mainly gastrointestinal disorders (celiac disease, ulcerative colitis, Crohn's disease); 2) Has a severe neurological condition (epilepsy, stroke, severe head trauma, meningitis within the past 10 years, brain surgery, brain tumor, prolonged coma - excluding general anesthesia); 3) Has received/is receiving treatment for the following psychiatric disorders: alcohol/drug/substance abuse dependence, schizophrenia, psychosis, bipolar disorder; 4) Take medication for depression or low mood; 5) Suffering from internal organ failure (heart, liver, or kidney failure, etc.); 6) Radiotherapy or chemotherapy in the past; 7) Surgery/procedure under general anesthesia within the past three years, or planned to undergo a procedure/procedure under general anesthesia within the next 3 months during this trial; 8) Have had hepatitis (hepatitis B, hepatitis C), HIV or syphilis in the past.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Probiotic group; 30B CFU/strip/day ST36, before meals; Storage: Store in a cool, dry place without sun exposure.	Dietary supplement: Probiotic; The experimental phase of this study will last 8 weeks and each subject will have three visits (day 0, week 4 and week 8).
Placebo Comparator: Placebo group; Dextrin, one strip/day, before meals; Storage: Store in a cool, dry place without sun exposure.	Dietary supplement: Placebo; The experimental phase of this study will last 8 weeks and each subject will have three visits (day 0, week 4 and week 8).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Antimicrobial peptide levels in stool samples	Antimicrobial peptides refer to fecal calprotectin and LL-37(Cathelicidin Antimicrobial Peptide). The change in their concentrations at the end of the intervention was detected compared to baseline.	8 weeks

Collaborators and Investigators

• Sponsor: Wecare Probiotics Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): April 10, 2025
• Primary Completion (Actual): May 6, 2025
• Study Completion (Actual): August 20, 2025

Study Registration Dates

• First Submitted: January 14, 2025
• First Submitted That Met QC Criteria: January 14, 2025
• First Posted (Actual): January 17, 2025

Study Record Updates

• Last Update Posted (Estimated): August 29, 2025
• Last Update Submitted That Met QC Criteria: August 22, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Substandard Drugs; Pharmaceutical Preparations; Dietary Supplements; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Counterfeit Drugs; Probiotics
• Other Study ID Numbers: WK2025002

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No