<i>Lactobacillus rhamnosus</i> LC-STH-13 ameliorates the progression of SLE in MRL/lpr mice by inhibiting the TLR9/NF-κB signaling pathway

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease often treated with glucocorticoids, which can lead to complications such as osteoporosis and an increased infection risk. Hence, identifying safe and effective treatment strategies is crucial. <i>Lactobacillus</i> has shown promise in improving immune disorders. We investigated <i>Lactobacillus rhamnosus</i> LC-STH-13 for its probiotic properties. Female MRL/lpr mice, prone to lupus, were used to assess its impact on SLE development. The results showed that the intervention with <i>L. rhamnosus</i> LC-STH-13 significantly reduced the level of circulating anti-autoantibodies (<i>p</i> < 0.05) and rebalanced Th17/Treg cells (<i>p</i> < 0.05). Kidney tissue analysis revealed reduced immune cell infiltration and immune complex deposition in glomeruli. <i>L. rhamnosus</i> LC-STH-13 mitigated kidney inflammation <i>via</i> the TLR9/NF-κB pathway (<i>p</i> < 0.05) and attenuated complement-induced renal damage (<i>p</i> < 0.05). Furthermore, 16S rRNA sequencing data analysis indicated that <i>L. rhamnosus</i> LC-STH-13 can restore intestinal microecological imbalance caused by the development of SLE. These findings suggested that <i>L. rhamnosus</i> LC-STH-13 improves the development of SLE by regulating the TLR9/NF-κB pathway and intestinal microbiota, offering a foundation for exploring safe and effective treatments.