# Evaluation of the safety of high-dose Lactobacillus gasseri CP2305 supplementation in healthy adults: A randomized, double-blind, placebo-controlled study

## TL;DR

This study shows that taking high doses of Lactobacillus gasseri CP2305 for four weeks is safe in healthy adults.

## Contribution

The study confirms the safety of high-dose Lactobacillus gasseri CP2305 intake in a placebo-controlled trial.

## Key findings

- No adverse clinical findings were observed in physical exams, blood tests, or urinalysis.
- Subjective symptoms and physician interviews showed no safety concerns.
- High-dose L. gasseri CP2305 intake (1.0 × 10¹¹ cells/day) was well-tolerated over four weeks.

## Abstract

Lactobacillus gasseri CP2305 (L. gasseri CP2305) has been reported to exert intestinal regulatory, anti-stress, and sleep-improving effects in healthy adults. This study aimed to evaluate the safety of an excessive intake of L. gasseri CP2305 in a randomized, double-blind, placebo-controlled, parallel-group trial.

Among 95 participants who provided written informed consent, 44 who met the eligibility criteria were randomly assigned to either the L. gasseri CP2305 group (n = 22) or the placebo group (n = 22). All participants ingested 20 tablets of either L. gasseri CP2305 or placebo daily for 4 weeks. The L. gasseri CP2305 group consumed 1.0 × 10 ¹ ¹ cells of L. gasseri CP2305 cells per day. To assess the safety of CP2305 tablets, physical examinations, hematological and biochemical blood tests, urinalysis, recording of subjective symptoms, and physician interviews were conducted.

One participant was excluded from the analysis; thus, the final analysis included data from 22 participants in the L. gasseri CP2305 group and 21 participants in the placebo group. No adverse clinical findings were observed in either group.

The results of this study demonstrate that no safety concerns were identified in the physical examinations, hematology, blood biochemistry, urinalysis, or subjective symptoms. These findings support the safety of L. gasseri CP2305 tablets even at high-dose intake (1.0 ×10 ¹¹ cells/day).

•A randomized, double-blind, placebo-controlled safety study was conducted in healthy adults.•Participants consumed Lactobacillus gasseri CP2305 tablets at a dose up to ten times the recommended daily intake for 4 weeks.•Safety was evaluated through physical examinations, hematology, blood biochemistry, urinalysis, and subjective symptoms.•No safety concerns were identified during the study period.•These findings confirm the safety of excessive intake of L. gasseri CP2305 tablets.

A randomized, double-blind, placebo-controlled safety study was conducted in healthy adults.

Participants consumed Lactobacillus gasseri CP2305 tablets at a dose up to ten times the recommended daily intake for 4 weeks.

Safety was evaluated through physical examinations, hematology, blood biochemistry, urinalysis, and subjective symptoms.

No safety concerns were identified during the study period.

These findings confirm the safety of excessive intake of L. gasseri CP2305 tablets.