Probiotics on Immune Function and Intestinal Microbiota in Astronauts Under Closed Microgravity Environment

NCT02618005 | Completed

• 1 other identifier: Probiotics
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

Human immune function and intestinal microbiota are suggested to be altered within long-duration stay in space. Accumulated evidences on earth support that Lacticaseibacillus paracasei strain Shirota (LcS) is a promising probiotic strain on improvement of immune function and intestinal microbiota. This study aims to investigate the impact of long-duration spaceflight as well as intake of LcS on the international space station (ISS), on immune system and intestinal microbiota in astronauts.

Conditions

Immune Function and Intestinal Microbiota

Keywords

Astronauts; Probiotics; Immune function; Intestinal microbiota

Outcome Measures

Primary Outcomes (3)

• Longitudinal changes in the number of LcS in feces

  Number of LcS in feces will be assessed by PMA-qPCR, during pre-flight, in-flight and post-flight.

  9-18 months

• Longitudinal changes in the level of immune markers

  Levels of immune markers in blood/saliva will be assessed by ELISA and bioassay, during pre-flight, in-flight and post-flight.

  9-18 months

• Longitudinal changes in numbers and composition of intestinal microbiota

  Numbers and composition of bacteria in feces will be assessed by RT-qPCR/qPCR and next generation sequencer analysis, during pre-flight, in-flight and post-flight.

  9-18 months

Study Arms (2)

LcS group

EXPERIMENTAL

Consuming probiotic capsule

Dietary Supplement: Probiotic capsule

Control group

NO INTERVENTION

Interventions

Probiotic capsule DIETARY_SUPPLEMENT

Continuously take five capsules containing freeze-dried LcS on ISS for four weeks, from four weeks before the return (R-4W) to one day before the return (R-1d)

LcS group

Eligibility Criteria

• Age: 25 Years - 80 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Individuals who are scheduled to stay on the ISS for at least 3 months
• Individuals who fully understand the study protocol and provide written informed consent for the study participation

You may not qualify if:

• Individuals who routinely use antibiotic, laxative, and/or bowel regulating medicine
• Individuals who participate in other research that competes with this study in terms of the purpose and field, e.g., study with dietary management or intake of bifidobacteria/lactic acid bacteria, oligosaccharides, antibiotic, laxative, and/or bowel regulating medicine

Sponsors & Collaborators

• Yakult Honsha Co., LTD: lead
• Japan Aerospace Exploration Agency: collaborator

Study Sites (1)

Japan Aerospace Exploration Agency

Ibaraki, Japan

Location

MeSH Terms

Interventions

Probiotics

Intervention Hierarchy (Ancestors)

Dietary Supplements; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 1, 2015
• First Posted: December 1, 2015
• Study Start: October 1, 2015
• Primary Completion: April 1, 2022
• Study Completion: April 1, 2022
• Last Updated: November 25, 2025

Record last verified: 2025-11

Locations

JP (1)