Paraprobiotics Mitigate Inflammation and Anxiety-Like Behavior in a Lipopolysaccharide-Induced Mouse Model

This study evaluated the effects of supplementing five different paraprobiotics on anxiety-like behavior, intestinal health, anti-inflammatory activity, and oxidative and nitrosative stress in an animal model of acute inflammation. Male adult Balb/C mice were divided into twelve groups and received either saline solution or paraprobiotic supplements daily for 15 days at a concentration of 100 mg/animal/day. Following the supplementation period, some groups were administered an inflammatory insult with lipopolysaccharide (LPS) at a dose of 15 mg/kg. After 24 h of LPS administration, the groups supplemented with B. lactis, S. thermophilus, and L. casei showed improved anxiety-like behavior compared to the LPS group. Serum interleukin IL-1β levels were reduced in all paraprobiotic-supplemented groups post-inflammation, with IL-6 levels specifically reduced by L. casei. IL-10 levels remained unchanged. In the gut, certain paraprobiotics mitigated cytokine alterations induced by LPS. Myeloperoxidase activity, elevated by LPS, was blocked by paraprobiotic supplementation in the blood, intestine, and brain. All paraprobiotic-supplemented groups exhibited significant reductions in nitrite/nitrate levels across various organs following LPS insult. No oxidative damage related to lipid peroxidation was observed in any group. Histological analysis revealed that LPS-induced intestinal damage was prevented in paraprobiotic-supplemented animals, as indicated by well-developed villi, intact brush borders, and absence of necrosis. Paraprobiotic supplementation modulated the inflammatory response, enhanced intestinal integrity and barrier function, and improved anxiety-like behavior in the mouse model of acute inflammation.