# Anti-Inflammatory Effects of Lactiplantibacillus plantarum Strain FS4722 Through MAPK and NF-κB Signaling Pathways and Its Lyophilization Optimization

## TL;DR

This study shows that a specific probiotic strain reduces inflammation through key pathways and improves its survival after freeze-drying.

## Contribution

The study identifies the anti-inflammatory mechanisms of L. plantarum FS4722 and optimizes its lyophilization for high viability.

## Key findings

- L. plantarum FS4722 suppresses inflammatory cytokines via inhibition of MAPK and NF-κB pathways in macrophages.
- The fermented supernatant of FS4722 shows stronger anti-inflammatory effects than the reference probiotic LGG.
- Optimized lyoprotectant formulation achieves 82.32% survival rate after lyophilization and maintains activity over 28 days.

## Abstract

Probiotics hold considerable promise for treating and preventing inflammatory disease; however, their application is often limited by unclear anti-inflammatory mechanisms and reduced viability following lyophilization. In this study, I thoroughly evaluated the anti-inflammatory potential of Lactiplantibacillus plantarum FS4722 (L. plantarum FS4722) and substantially enhanced strain viability through optimization of the lyoprotectant formulation. Functional assays demonstrated that the fermented supernatant, heat-inactivated bacterial suspension, and cell lysate derived from L. plantarum FS4722 effectively suppressed transcription and expression of inflammatory cytokines in LPS-stimulated RAW 264.7 macrophages. The fermented supernatant exhibited the strongest inhibitory effects, surpassing the reference probiotic Lacticaseibacillus rhamnosus GG (LGG). Mechanistic investigations revealed that anti-inflammatory activity is primarily mediated via inhibition of the MAPK and NF-κB signaling pathways. Furthermore, using component screening combined with response surface methodology, the lyoprotectant formulation (10.00% trehalose, 1.00% sodium carboxymethyl cellulose, and 5.00% skim milk) was optimized, resulting in a lyophilization survival rate of 82.32% while maintaining cellular integrity; in this accelerated stability assessment, the strain retained 78.89% of its activity after 28 days of storage at 4 °C. Collectively, this study provides a robust and efficient approach for probiotic formulation while systematically elucidating the underlying anti-inflammatory mechanisms, thereby offering practical guidance for the development and clinical application of high-performance probiotic products.