# Safety Evaluation of the High‐Dose Intake of Heat‐Killed Lacticaseibacillus paracasei MCC1849 in Healthy Adults

**Authors:** Natsumi Wada, Kumiko Kato, Satoshi Arai, Soichiro Sato, Noriyuki Iwabuchi, Manabu Nakano, Masahiko Tokushima, Miyuki Tanaka

PMC · DOI: 10.1002/fsn3.71071 · Food Science & Nutrition · 2025-11-17

## TL;DR

This study shows that taking a high dose of a heat-killed postbiotic called MCC1849 is safe for healthy adults over four weeks.

## Contribution

The study provides new evidence on the safety of high-dose MCC1849 intake in healthy adults.

## Key findings

- No adverse events were observed in participants taking 250 billion cells of MCC1849 daily for 4 weeks.
- There were no significant changes in blood, urine, or anthropometric measurements after the intervention.
- MCC1849 intake was found to be safe for use in functional foods.

## Abstract

Heat‐killed Lacticaseibacillus paracasei MCC1849 (MCC1849) is a postbiotic used as a functional food ingredient. It has been shown to affect immune regulation both in vivo and in several clinical trials. Based on a previous safety evaluation, the intake of MCC1849 by healthy adults did not raise safety concerns. However, the effects of high‐dose intake have not been investigated. In this study, the safety associated with a high‐dose MCC1849 was evaluated in 20 healthy adults for 4 weeks. The participants received 250 billion cells of MCC1849 per day. Safety evaluations included anthropometric and blood pressure measurements, hematological and biochemical tests, urinalysis, and adverse event monitoring. No clinical differences were detected in anthropometric measurements, blood pressure, or blood and urine parameters between the baseline and post‐intervention measurements. No adverse events associated with MCC1849 intake were observed. In conclusion, an intake of 250 billion cells of MCC1849 per day for 4 weeks was found to be safe in healthy adults. These results suggest that the intake of MCC1849 is safe for use as functional foods, such as for immune‐enhancing effects.

This study evaluated the safety of a high‐dose intake of heat‐killed Lacticaseibacillus paracasei MCC1849, a type of postbiotic. No adverse events related to the test food were observed in anthropometric and blood pressure measurements, blood and urine analysis, or medical interviews. These results suggest that the intake of MCC1849 is safe.

## Linked entities

- **Species:** Lacticaseibacillus paracasei (taxon 1597)

## Full-text entities

- **Chemicals:** MCC1849 (-)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

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## References

12 references — full list in the complete paper: https://tomesphere.com/paper/PMC12623149/full.md

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Source: https://tomesphere.com/paper/PMC12623149