Effects of exopolysaccharides form Lactobacillus plantarum KX041 on high fat diet-induced gut microbiota and inflammatory obesity

Lactobacillus plantarum KX041 is a probiotics obtained from early screening, which can relieve inflammation and enrich the anti-obesity intestinal flora, and produce high yield of exopolysaccharides (EPS). The extraction, structure and physicochemical properties of EPS have been completed earlier. However, whether the functional activity of L. plantarum KX041 is related to the EPS is still unclear. In this study, combined in vivo and in vitro tests explored the effects of EPS on inflammatory obesity. In vitro tests, EPS relieased inflammation by inhibiting TLR4/p-NFκB, and inhibited adipocyte differentiation and reduced the transcriptional level of inflammation and lipid-synthesis genes (especially CD36 and peroxisome proliferators-activated receptors-γ PPARγ). In vivo tests demonstrated that EPS could alleviate weight gain, white adipocyte expansion, organ damage, insulin resistance, hyperlipidemia, and inflammatory response caused by high fat diet. Combined with in vitro tests, the transcription level of inflammation and lipid-synthesis genes in adipose tissue identified that IL-1β and PPARγ were the key genes for the effect of EPS on inflammatory obesity. Moreover, EPS increased the abundance of Akkermansia and Lachnospiraceae_NK4A136_group, and intestinal levels of isobutyrate, which is one of the key factors in alleviating inflammatory obesity. These insights may inform the development of functionalized dietary interventions in obesity.