Effects of probiotics on alcohol-conditioned behaviors and hippocampal morphology in male rats.

Alcohol Use Disorder (AUD) is a complex condition marked by physical and psychological dependence, often accompanied by lasting changes in brain regions such as the hippocampus that contribute to memory and cognitive impairments. Emerging evidence highlights the role of gut microbiota dysbiosis in AUD and suggests a link between the gut-brain axis, neuroinflammation, and behavioral alterations. Probiotics have been proposed as potential modulators of microbial balance and inflammatory responses, with possible benefits for alcohol-related deficits. This study examined the effects of probiotic treatment on alcohol-conditioned behavior, withdrawal symptoms, selected fecal bacterial populations, and hippocampal alterations in a rat model of ethanol withdrawal. Ninety-six male Wistar rats were assigned to different drinking and treatment conditions and divided into groups for behavioral, neuroanatomical, and microbiological assessments. Conditioned place preference (CPP) was used to evaluate alcohol-related learning, while hippocampal volume, cell density, and fecal Lactobacillus and Enterobacteriaceae levels were measured. Ethanol exposure reduced fecal Lactobacillus levels and was associated with decreased hippocampal volume and altered cell density. Probiotic treatment partially restored Lactobacillus levels and reduced withdrawal severity, but did not significantly restore hippocampal structural parameters. Probiotics reduced CPP acquisition in control rats and accelerated CPP extinction in ethanol-exposed rats, suggesting a limited modulatory effect on alcohol-related behaviors.