Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 administration to Long–Evans rats has interactive effects with sex and diet on anxiety-related feeding behaviors and specific endocrine outcomes

Abstract

Anxiety symptomatology and metabolic functioning are intricately related, with associated mechanisms yet to be fully delineated. Nutritional manipulations may influence these outcomes in a sex-specific manner. This study characterized the interactive effects of the Cerebiome® probiotic and the D12079B-formulated Western diet (WD) on anxiety- and feeding-related behaviors and physiological outcomes in 80 male and female Long–Evans rats born to dams also administered either the probiotic or placebo during gestation and lactation. In WD-fed rats, the probiotic attenuated the increase in daily calorie intake observed in placebo rats. Subsequently, in the novelty-suppressed feeding task (NSFT), probiotic standard diet (SD) males spent more time in the center of an open field, suggesting a reduced anxiety-related state. Independent of diet and sex, probiotic administration resulted in more feeding bouts and food pellet contacts in the center compared to placebo. Furthermore, independent of probiotic and sex, WD rats lost less weight following the 24 h fast prior to behavioral testing and consumed more calories during the NSFT compared to SD rats. At sacrifice, rats given Cerebiome® had higher adrenal neuropeptide Y expression than placebo, and females had higher adrenal glucocorticoid receptor expression than males. In plasma, leptin was increased with WD and ghrelin was increased in SD females. These findings demonstrate that the Cerebiome® probiotic and this specific WD differentially affect behavioral and physiological indicators of health. We additionally demonstrate that concurrently administered nutritional factors interact to affect study outcomes based on sex, supporting the inclusion of both sexes in similar preclinical nutrition research.