The Effect of Bifidobacterium Probiotics on Gut Microbiota Changes in Healthy Adults During Short-term Travel Along the Silk Road

Journeying along the historic Silk Road exposes travelers to dramatic dietary shifts, unfamiliar microbial environments, and the physical stresses of long-distance travel-all known to disrupt gut health and cause gastrointestinal complaints, including traveler's diarrhea and sleep disturbances. Such disruptions may also elevate the risk of acquiring antibiotic-resistant organisms.

This randomized, double-blind, placebo-controlled trial evaluated whether probiotic supplementation can help maintain gut microbial balance and support traveler well-being during trips to Silk Road regions. In addition to monitoring changes in gut microbiota composition, the study assessed gastrointestinal symptoms, sleep quality, anxiety levels, overall well-being, gut immune markers, functional profiles of the microbiome, and the presence of antibiotic resistance genes.

Study Overview

• Status: Recruiting
• Conditions: Healthy Adult Volunteer
• Intervention / Treatment: Other: Placebo; Other: Probiotic

Detailed Description

Journeys along the Silk Road-with their unique dietary shifts, unfamiliar water and food sources, novel microbial exposures, altered sleep patterns, and psychological adjustments-can significantly disrupt gut microbiota and impact overall health. Prior research has shown that even short-term travel can lead to substantial fluctuations in gut microbial composition, often accompanied by gastrointestinal symptoms and reduced well-being, underscoring the need for effective strategies to support gut homeostasis during such journeys.

Gastrointestinal distress, including traveler's diarrhea and non-diarrheal symptoms such as abdominal pain and irregular bowel movements, remains a common challenge. These issues can considerably diminish the travel experience. Furthermore, travel has been linked to an elevated risk of acquiring antimicrobial resistance genes, with the gut serving as a potential site for the exchange and amplification of resistant organisms.

Sleep disruptions-stemming from changes in routine and environment-also play an important role in traveler well-being. The gut-brain axis provides a mechanism through which sleep quality may influence gastrointestinal vulnerability, highlighting the interconnected nature of these systems.

Probiotics represent a promising intervention to support travelers. These beneficial microorganisms may enhance gut barrier function, modulate immune activity, inhibit pathogens, and produce metabolites that contribute to both gut and systemic health. Although some studies suggest probiotics can alleviate gastrointestinal symptoms and reduce the risk of diarrhea, robust evidence specific to the Silk Road travel context remains limited.

In this randomized, double-blind, placebo-controlled trial, effects of daily probiotic supplementation on gut microbiota stability, gastrointestinal symptoms, sleep quality, anxiety, and overall well-being in adults traveling the Silk Road will be evaluated. Immune markers, microbial functional pathways, and antibiotic resistance gene profiles will be identified to better understand the potential mechanisms of action. The investigators hypothesized that probiotic intake would help maintain microbial balance, reduce travel-related symptoms, and support physical and emotional well-being throughout the journey.

• Study Type: Interventional
• Enrollment (Estimated): 75
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Min Tze Liong, Ph.D.; Phone Number: 6046532114; Email: mintze.liong@usm.my
• Study Contact Backup: Name: Jie Yuan, M.Sc.; Phone Number: 822137027899; Email: peanut.yuan@diprobio.com

Study Locations

• China
  • Shanghai Municipality
    • Huangpu, Shanghai Municipality, China, 200001
      • Recruiting
      • Shanghai Jiao Tong University School of Medicine
      • Contact: Meiqin Cai, MD.; Phone Number: 86 62785846; Email: caimeiqin@sjtu.edu.cn
      • Contact: Email: peanut.yuan@diprobio.com
      • Principal Investigator: Meiqin Ca, MD.
• Malaysia
  • Pulau Pinang
    • George Town, Pulau Pinang, Malaysia, 11800
      • Not yet recruiting
      • Universiti Sains Malaysia
      • Contact: Min Tze Liong, Ph.D.; Phone Number: 6046532114; Email: mintze.liong@usm.my
      • Contact: Yuan Jie, M.Sc.; Email: peanut.yuan@diprobio.com
      • Sub-Investigator: Min Tze Liong, Ph.D

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Generally healthy adults
• Scheduled to undertake a short-term round trip (less than 7 days) to abroad
• Able to complete study procedures
• Willing to take intervention products

Exclusion Criteria:

• Use of antibiotics, probiotics, hormones, immunosuppressants, biologics or JAK inhibitors within four weeks prior to study
• Chronic or severe systemic diseases (including cardiovascular, hepatic, renal, malignant or psychiatric disorders)
• Uncontrolled parasitic infections
• Long-term use of corticosteroids, growth hormone, vitamin B12, lysine or inositol
• Major surgery within one month
• Allergy to probiotic components
• Other conditions deemed inappropriate by investigators

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Daily 6-drops of non-GMO corn starch in medium-chain triglyceride oil	Other: Placebo; Daily 6-drops of non-GMO corn starch in medium-chain triglyceride oil
Experimental: Probiotic; Daily 6-drops of Bifidobacterium longum subsp. infantis M-63, B. breve M-16V, and B. longum BB536 in non-GMO corn starch as excipient, in medium-chain triglyceride oil (1.5 × 109 CFU/day)	Other: Probiotic; Daily 6-drops of Bifidobacterium longum subsp. infantis M-63, B. breve M-16V, and B. longum BB536 in non-GMO corn starch as excipient, in medium-chain triglyceride oil (1.5 × 109 CFU/day)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microbiota profiles of fecal samples in generally healthy adults upon administration of probiotic as assessed via metagenomics sequencing	Differences in microbiota abundance in fecal sample of generally healthy adults upon administration of probiotic as compared to placebo	7 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gastrointestinal metabolites in generally healthy adults upon administration of probiotic as assessed using LC-MS	Differences in concentrations of gastrointestinal metabolites upon administration of probiotic compared to placebo	7 days
Respiratory symptoms duration and frequency in generally healthy adults upon administration of probiotic as assessed using questionnaire	Changes in duration and frequency of respiratory illnesses symptoms from generally healthy adults on probiotic or placebo after 7-days, via the use of standard clinical assessment questionnaire, scale 0-3 where higher scores indicate more severe symptoms	7 days
Gastrointestinal symptoms in generally healthy adults upon administration of probiotic as assessed using questionnaire	Differences in duration and frequency of gastrointestinal symptoms upon administration of probiotic compared to placebo via the use of standard clinical assessment questionnaire, scale 0-3 where higher scores indicate more severe symptoms	7 days
Allergy symptoms in generally healthy adults upon administration of probiotic as assessed using questionnaire	Differences in duration and frequency of allergy symptoms upon administration of probiotic compared to placebo via the use of standard clinical assessment questionnaire, scale 0-3 where higher scores indicate more severe symptoms	7 days
Anxiety in generally healthy adults upon administration of probiotic as assessed using questionnaire	Differences in anxiety via the GAD-7 questionnaire （scale 0-3 where higher scores indicate more severe outcomes), upon administration of probiotic compared to placebo	7 days
Sleep quality in generally healthy adults upon administration of probiotic as assessed using questionnaire	Differences in sleep quality via the PSQI questionnaire （scale 0-3 where higher scores indicate more severe outcomes) upon administration of probiotic compared to placebo	7 days
Well-being in generally healthy adults upon administration of probiotic as assessed using questionnaire	Differences in well-being via the WHO-5 questionnaire (scale 0-5 where higher scores indicate better outcomes）upon administration of probiotic compared to placebo	7 days

Collaborators and Investigators

• Sponsor: Universiti Sains Malaysia
• Collaborators: Shanghai Jiao Tong University School of Medicine
• Investigators: Principal Investigator: Meiqin Cai, MD., Shanghai Jiao Tong University School of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): October 16, 2025
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: September 8, 2025
• First Submitted That Met QC Criteria: September 15, 2025
• First Posted (Estimated): September 19, 2025

Study Record Updates

• Last Update Posted (Actual): December 10, 2025
• Last Update Submitted That Met QC Criteria: December 2, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: travel; probiotc; Silk Road
• Additional Relevant MeSH Terms: Dietary Supplements; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Probiotics
• Other Study ID Numbers: SJUPN-2025-013-HY1-KS2

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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