Sakulora™ (Lacticaseibacillus paracasei strain Shidare) improves bowel function: A randomized, double-blind, placebo-controlled trial
DOI:
https://doi.org/10.31989/ffhd.v16i2.1883Abstract
Introduction and objective: Heat-killed lactic acid bacteria with postbiotic effects have emerged as promising functional food ingredients for promoting intestinal health. SakuloraTM, which consists of heat-killed Lacticaseibacillus paracasei strain Shidare (strain Shidare) isolated from weeping cherry blossom, may exert postbiotic effects on the gut microbiota. However, its impact on the intestinal environment and intestinal mobility remains unclear. Therefore, the present study investigated the efficacy of SakuloraTM on intestinal serotonin and fecal IgA concentrations in mice and bowel function in healthy adults through a randomized, double-blind, placebo-controlled trial.
Methods: In the pre-clinical phase, mice were administered heat-killed strain Shidare, and intestinal serotonin and fecal IgA concentrations were assessed. Forty-four healthy adults with mild constipation were then randomly assigned to receive either SakuloraTM (containing 50 billion cells of the heat-killed strain Shidare) or a placebo daily for 2 weeks. The frequency of bowel movements in one week was used as the primary outcome.
Results: In murine models, the administration of heat-killed strain Shidare significantly increased intestinal serotonin and fecal IgA concentrations. In the clinical trial, the weekly frequency of bowel movements was significantly higher in the SakuloraTM group than in the placebo group. No significant improvements were observed in the secondary endpoints, including the gut microbiota and fecal short-chain fatty acids. No serious adverse events developed throughout the study period.
Novelty of the Study: The bowel movement-improving effect of the heat-killed strain Shidare was demonstrated for the first time, and its mechanism was suggested to be an increase in intestinal serotonin and IgA levels.
Conclusions: SakuloraTM containing heat-killed strain Shidare effectively improved the bowel function, supporting its potential as a safe functional food ingredient for maintaining digestive health in healthy individuals.
Trial Registration: UMIN-CTR: UMIN000054746
Keywords: Lacticaseibacillus paracasei; postbiotics; bowel function; intestinal environment
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Copyright (c) 2026 Tsuyoshi Takara, Naoko Suzuki, Kazuo Yamamoto, Shin-ichiro Iio, Hayata Noguchi, Toshihiro Kakinuma, Asami Baba, Hiroshi Shimoda, Takumi Watanabe, Akari Yoneda, Yuriko Namatame, Tetsuro Kan, Masafumi Nagata, Shogo Takeda
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