Lactiplantibacillus plantarum KX041 regulates lipid accumulation and intestinal flora to alleviate inflammatory obesity and its application in dairy products

Lactobacillus exhibits considerable potential in preventing metabolic disorders. The identification and characterization of novel Lactobacillus species hold significant practical value for the development of functional dairy products. Lactiplantibacillus plantarum KX041 is presumed to have potential probiotic functions due to its ability to produce functional extracellular polysaccharides. Therefore, this study aims to further investigate the effects and underlying mechanisms of both live and heat-inactivated L. plantarum KX041 on inflammatory obesity, and to preliminarily assess its application potential in dairy fermentation. In vitro, L. plantarum KX041 significantly inhibited adipocyte differentiation and reduced intracellular lipid accumulation, particularly at a concentration of 40%. The mechanism involved downregulating the mRNA expression of CEBPA and Fabp4. In vivo, activity and inactivated of L. plantarum KX041 can improve adipose accumulation (FAS and FABP2, CEBPA), intestinal barrier dysfunction (Occludin), systemic inflammation (IL-6) by regulating the transcription level of key genes. Additionally, L. plantarum KX041 improved inflammatory obesity by mitigating symptoms such as insulin resistance, liver dysfunction, and hyperlipidemia. Furthermore, 16S rRNA sequencing and correlation analysis suggested intestinal microbiota community structure is significantly associated with the levels of SCFAs. L. plantarum KX041 may enhance the production of acetic and butyric acids by promoting Lactobacillus colonization and reducing the abundance of Ruminiclostridium_9. Finally, based on its favorable functional properties and fermentation performance, L. plantarum KX041 shows promise as a candidate single-strain starter culture for the development of functional dairy products.