Infant feces-derived <i>Bifidobacterium breve</i> CCFM1078 inhibits the occurrence of rheumatoid cachexia by IRS1/PI3K/Akt signaling pathway

This study aimed to investigate the effects of infant feces-derived <em>Bifidobacterium breve</em> CCFM1078 on rheumatoid cachexia (RC). Twenty-four female Wistar rats were assigned to three groups: CON group (normal saline by gavage), CIA group (collagen-induced arthritis, normal saline by gavage), and CCFM1078 group (collagen-induced arthritis, 3×10⁹ CFU/rat/day<em> B breve </em>CCFM1078 gavage). The results demonstrated that <em>B. breve</em> CCFM1078 not only improved skeletal muscle function in CIA rats, but also modulated the gut microbiota, skeletal muscle metabolism and hormone levels, reduced inflammation in the knee joint and skeletal muscles, decreased activity of the NF-κB inflammatory signaling pathway, enhanced the IRS1/PI3K/Akt signaling pathway, promoted skeletal muscle differentiation, and maintained skeletal muscle fiber diameter, consequently slowing down the progression of RC. These findings suggested that <em>B. breve</em> CCFM1078 may have a beneficial role as part of a dietary intervention for RC, enhancing overall therapeutic effects.