Efeito probiótico de bactérias isoladas do leite materno humano como estratégia terapêutica em modelo de obesidade experimental

Abstract

Obesity is characterized by the excessive or abnormal accumulation of fat, posing health risks. Intestinal microbiota plays an important role in obesity, and thus, probiotics emerge as a treatment possibility, as they can modulate the host's microbiota and confer health benefits. Therefore, this study aims to evaluate the effect of bacteria isolated from breast milk as a therapeutic strategy in a mouse model of obesity. Initially, a screening was performed using eight-week-old male C57BL/6 mice, which were divided into groups treated with each of the nine bacteria isolated from breast milk (109 CFU/mL) and the obesity-inducing diet (DIO) for eight weeks. The bacteria that showed the best results in the obesity model were Lactobacillus gasseri (7) and Lacticaseibacillus rhamnosus (64). Next, the effect of administering L. gasseri, L. rhamnosus, and a mixture of the two bacteria was evaluated in a murine model of diet-induced obesity. Eight-week-old male C57BL/6 mice were divided into groups treated with the control diet (AIN-93M) or DIO and received 0,1mL of the probiotic (109 CFU/mL), daily, for eight weeks. The groups treated with the bacteria individually showed reduced body weight, improved glucose tolerance, decreased enterobacteria, increased lactic acid bacteria, decreased total cholesterol and HDL cholesterol, and improved cognition. However, the group treated with the mixture of the two bacteria did not show a protective effect in the obesity model. Next, we assessed whether the protective effect of the bacteria could be vertically transmitted to the offspring. Pregnant mothers were treated with the bacteria during gestation and the entire breastfeeding period, and after weaning, male mice were selected for obesity induction. We observed prevention of weight gain in the offspring of mothers who received probiotics during gestation and breastfeeding. We also observed in these animals an improvement in lipid and glycemic profiles and a decrease in liver inflammation. Thus, L. gasseri and L. rhamnosus showed a beneficial effect in the reduction of obesity when administered separately, representing a possible therapeutic strategy for this model.