This study aimed to evaluate the impact of consumption of avocado oil (AO) and pulp (AP) on anxiety-like behavior, cerebral oxidative stress and alteration of the fecal microbiota in the mother and male Wistar rats offspring treated during gestation and lactation. Anxiety-like behavior was measured through the elevated plus maze (EPM) and open field test (OFT) tests. Cerebral malondialdehyde (MDA) and glutathione (GLUT) levels were measured in mothers and offspring. The fatty acid profile was determined for maternal milk and brain. Data showed a shorter time spent on the open arms of EPM in mothers and offspring for those fed AO and AP (P <
0.001). Moreover, the AO offspring adolescent and adult spent less time in the central area (P <
0.05). Furthermore, offspring adults from the AO moved about less and offspring from the AP ambulated more (P <
0.001). MDA was increased in mothers and decreased in the offspring in AO and AP and GLUT was lower in mothers and higher in adolescent and adult offspring in AP (P <
0.05). Polyunsaturated fatty acids in the brain and breast milk in AO and AP were decreased (P <
0.05). Furthermore, there was an increase in the abundance of intestinal bacteria related to the production of inflammatory metabolites that compromised brain function in offspring treated with avocado. These results suggest that avocado induces anxiogenic-like behavior and increases cerebral oxidative stress in mothers and offspring of rats treated during pregnancy and lactation, negatively altering the fecal microbiota of the offspring. So, we report for the first time how the consumption of avocado oil and pulp interferes with a developing organism when consumed in the early stages of life in rats.