Lactiplantibacillus plantarum BGI-N6 mitigates obesity-linked inflammation and oxidative stress via gut microbiota-mediated metabolites.

Obesity-driven systemic inflammation is a critical contributor in the progression of metabolic diseases. While lactic acid bacteria (LAB) are recognized for countering diet-induced obesity, their specific role in mitigating the associated inflammatory pathways requires further elucidation. This study investigated the capacity of a novel LAB strain, Lactiplantibacillus plantarum BGI-N6 (N6), to alleviate obesity and its related inflammatory responses in a high-fat diet (HFD)-fed Sprague-Dawley (SD) rat model. N6 supplementation effectively attenuated body weight gain, fat deposition, and liver steatosis, while concurrently improving systemic metrics such as blood lipid profiles. Crucially, the treatment significantly reduced HFD-induced systemic inflammation and oxidative stress. Analysis of the gut microbiota demonstrated that N6 administration modulated gut microbiota composition, enhancing β-diversity and reducing the abundance of pro-inflammatory taxa, including Sutterella wadsworthensis, Bilophila wadsworthia, and Holdemania filiformis. These structural changes were accompanied by metabolic shifts, specifically an increased production of butyric and valeric acids and a decrease in propionic acid. Furthermore, N6 specifically downregulated bacterial biosynthesis pathways for lipopolysaccharide (LPS), an effect attributed to the reduced abundance of key gram-negative species such as Sutterella wadsworthensis, resulting in significantly lower serum LPS levels. Correlation analyses confirmed the strong association of these microbial and metabolic changes with improved metabolic and inflammatory parameters. Collectively, these findings demonstrate that N6 ameliorates obesity-induced inflammation and oxidative stress through a multi-faceted mechanism involving gut microbiota restructuring, SCFA modulation, and LPS reduction, underscoring its potential as a therapeutic probiotic for metabolic disorders.