Lactose and Casein Cause Changes on Biomarkers of Oxidative Damage and Dysbiosis in an Experimental Model of Multiple Sclerosis

Background and Objectives: Experimental autoimmune encephalomyelitis (EAE) in rats closely reproduces multiple sclerosis (MS), a disease characterized by neuroinflammation and oxidative stress, that also appears to extend to other organ compartments. The origin of MS is a matter for discussion, but it would seem that altering certain bacterial populations present in the gut may lead to a proinflammatory condition due to the bacterial lipopolysaccharides (LPS) in the so-called brain-gut axis. The casein and lactose in milk confer anti-inflammatory properties and immunomodulatory effects. The objectives of this study were: to evaluate the effects of administration of casein and lactose on the oxidative damage and the clinical status caused by EAE, and to verify whether both, casein and lactose, had any effect on the LPS and its transport protein -LBP-. Methods: Twenty male dark Agouti rats were divided into: control rats (control), EAE rats and EAE rats to which casein and lactose, EAE+casein and EAE+lactose, respectively, were administered. Fifty-one days after casein and lactose administration, the rats were sacrificed and different organs were studied (brain, spinal cord, blood, heart, liver, kidney, small and large intestine). In the latter, products derived from oxidative stress were studied (lipid peroxides and carbonylated proteins) as well as the glutathione redox system, various inflammation factors (total nitrite, Nuclear Factor-kappa B p065, the Rat Tumour Necrosis Factor-α) and the LPS and LBP values. Results and Conclusion: Casein and lactose administration improved the clinical aspect of the disease at the same time as reducing inflammation and oxidative stress, exerting its action on the glutathione redox system or increasing GPx levels.