Effects of lyophilized Lactiplantibacillus plantarum DC2 probiotic powder on gastrointestinal morphology and microbiota in mice

Abstract

Probiotics have potential benefits in modulating gastrointestinal function. However, their efficacy and application depend largely on specific bacterial strains and environmental contexts. In our previous study, a strain of Lactiplantibacillus plantarum ( L. plantarum ) DC2 exhibited superior functionality in pork fermentation processes and was granted a Chinese patent (ZL202110743486.8). However, its storage and application characteristics remain unclear. To evaluate its direct application potential for gastrointestinal regulation, in this study, the formula and process of lyophilized L. plantarum DC2 powder were optimized via single-factor design (SFD) and response surface methodology (RSM). The optimized protectant consisted of fat-free milk powder, trehalose, glycerine, and L-sodium glutamate. The survival rate and storage stability of lyophilized bacterial powder were maintained at optimal level under optimized conditions. Intragastric administration experiments revealed that the abundance of Lactobacillus in both the stomach and jejunum significantly increased, accompanied by shifts in intestinal morphological features and modulation of the intestinal microbial composition and abundance. In conclusion, a reliable lyophilization protocol was established for optimal survival rate and storage stability of lyophilized L. plantarum DC2 powder, which was capable of modulating intestinal morphology and gut microbial profiles in mice. This study lays a foundation for its further development as a probiotic candidate.