Postbiotics from Lacticaseibacillus rhamnosus IOB820 Combat Obesity in HFD Mice by Modulating Gut Microbiota and...

Aims: To evaluate whether Lacticaseibacillus rhamnosus (L. rhamnosus) IOB820 and its postbiotics can combat high-fat diet (HFD)-induced obesity, improve metabolic parameters, and modulate gut microbiota and systemic inflammation in a mouse model. Methods: Seventy 4-week-old male C57BL/6J mice were divided into a normal diet group, an HFD control group, two postbiotic dose groups, two live bacteria dose groups, and an orlistat control group. After 10 weeks of intervention with live L. rhamnosus IOB820 or its postbiotics, body weight, metabolic parameters (blood glucose, lipid profile, hepatic steatosis), pro- and anti-inflammatory cytokines (TNF-α, IL-6, IL-1β, IL-10), gut microbiota composition (α, β diversity and taxonomic shifts), and fecal short-chain fatty acid (SCFA) levels were assessed. Results: Both live L. rhamnosus IOB820 and its postbiotics significantly alleviated HFD-induced weight gain and improved metabolic outcomes. The treatments also reduced systemic inflammation, as indicated by decreased levels of TNF-α, IL-6, and IL-1β and elevated IL-10. These effects were accompanied by restoration of gut microbial diversity, enrichment of beneficial taxa, and increased fecal SCFA concentrations. Conclusions:L. rhamnosus IOB820 and its postbiotics effectively mitigate obesity and related metabolic disturbances in HFD-fed mice. Their beneficial effects are likely mediated through modulation of gut microbiota composition and enhancement of SCFA-driven anti-inflammatory responses.