BackgroundMalnutrition causes several changes in body composition and physiological liver function and is commonly related to systemic inflammation, cognitive deficits, and metabolic changes. Kefir is a symbiotic association of yeast and bacteria fermenting milk, used as food supplementation, and is now recognized for its beneficial health properties. In this context, the present study aims to verify the effects promoted by Kefir supplementation in a model of mice malnutrition, evaluating its metabolic effects and liver modulation. MethodsMale Swiss mice were divided into four groups with 8 animals each. After the adaptation period, the animals were subjected to two phases of treatment: the caloric restriction phase to promote malnutrition and the renutrition phase. A calorie restriction of 20 % compared to the control group was adopted. Metabolic profile, adipose tissue, liver, biochemical parameters, and gene expression of CAT and SOD were evaluated. ResultsThe main findings demonstrate an improvement in body weight and biochemical parameters followed by a greater recovery of adipocyte area in the (FR + Kefir) group when compared to the malnourished (FR) group. The data showed an increase in the expression of genes associated with oxidative stress suppression such as superoxide dismutase (SOD) and catalase (CAT) in the groups supplemented with kefir. ConclusionsOral supplementation was able to increase body weight recovery, and adiposity, enabling improvements in metabolism and reducing liver inflammation.