Lactobacillus paragasseri SBT2055 attenuates obesity via the adipose tissue-muscle-gut axis in obese mice

The anti-obesity effects of Lactobacillus paragasseri (L. paragasseri) have been reported, but the exact mechanisms have not been elucidated. There are also no reports on the impact of L. paragasseri on the gut microbiota environment. Recently, the incidence of sarcopenia due to obesity has increased regardless of age, exacerbating metabolic disorders caused by obesity. Therefore, we investigate the beneficial effects of L. paragasseri SBT2055 (LG2055) on obesity along with obese sarcopenia and gut microbiome changes. C57BL/6 J mice were fed a high-fat diet (HFD) and LG2055 (1×10⁸ or 1×10¹⁰ CFU/mice, low-dose LG2055 (LP) or high-dose LG2055 (HP), respectively was administered orally. LG2055 supplementation significantly reduced white adipose tissues compared to the HFD group and modified plasma lipid profiles to normal levels. The anti-obesity efficacy of LG2055 was due to increased lipid excretion into feces by reducing the mRNA levels of fatty acid binding protein 1 (Fabp1), fatty acid binding protein 2 (Fabp2), fatty acid transport protein 4 (Fatp4), cluster of differentiation 36 (Cd36), and apolipoprotein 48 (ApoB48) in the small intestine. The body fat reduction inhibits ectopic lipid accumulation in the muscles, leading to improvements in muscle mass, grip strength, hind leg thickness, muscle protein levels, and muscle fiber size in both LP and HP groups. LG2055 increased gut microbiota diversity and elevated the levels of Bacteroidota, resulting in a lower Firmicutes/Bacteroidota ratio compared to the HFD group. Changes in the Bacteroidota showed a negative correlation with body fat and plasma free fatty acid (FFA) while exhibiting a positive correlation with lean body mass, grip strength, and hind leg thickness. Our results demonstrated the anti-obesity effects of LG2055 through the white adipose tissue (WAT)-muscle-gut axis, suggesting its potential as an anti-obesity agent.