Kerianalee Rivera-Cruz^1, Patricia Pujols¹ , Jan Bilbao Del Valle¹ , Alfredo Ghezzi¹ , Imilce A. Rodriguez-Fernandez¹

¹College of Natural Sciences, Department of Biology, University of Puerto Rico, Rio Piedras

INTRODUCTION: People over 65 years old have an increased alcohol use disorder, which complicates existing age-related health problems. Additionally, there are important sex differences in alcohol consumption and susceptibility influencing our understanding of the consequences of alcohol consumption in an aged population. Therefore, considering these sex-related variations is important when studying the effects of alcohol on older individuals. Alcohol consumption alters the gut microbiota playing an important role in the system known as the gut-brain axis. It remains to be elucidated if sex differences and the gut microbiome can play a role in alcohol tolerance, and if this is affected during aging. The fruit fly Drosophila Melanogaster serves as a genetically amenable model to study this. Many of the genes involved in these processes are conserved and can be translated to mammals. Flies display aging phenotypes including microbial dysbiosis and do sedate in response to alcohol exposure. The overall goal of this project is to characterize the sex- and age-specific effects of alcohol exposure on the gut microbiota-brain axis. To study the sex-specific differences we took young female and male flies and exposed them to 50% ethanol and quantified the sedation time. We found that males take double the time to sedate than females indicating sex-specific differences in ethanol sensitivity. We then measured changes in the gut microbiome by homogenizing dissected guts in PBS and plating them on selective plates to quantify Colony Forming Units (CFUs). We found that a second exposure to ethanol reduces the number of microbial colonies. Future experiments focus on performing these experiments in old female and male flies, characterizing the microbiome of flies exposed to ethanol, and understanding the role of sex hormones.

METHODS: To study the sex-specific differences we took young female and male flies and exposed them to 50% ethanol and quantified the sedation time. We then measured changes in the gut microbiome by homogenizing dissected guts in PBS and plating them on selective plates to quantify Colony Forming Units (CFUs

RESULTS: Preliminary data in the lab indicates that older flies present an increase in alcohol sensitivity and tolerance. We found that males take double the time to sedate than females indicating sex-specific differences in ethanol sensitivity. We found that a second exposure to ethanol reduces the number of microbial colonies.

CONCLUSION: Future experiments focus on performing these experiments in old female and male flies, characterizing the microbiome of flies exposed to ethanol, and understanding the role of sex hormones

ACKNLOWLEDGMENTS: KRC thanks funding by IDgene program, the Dra. Imilce lab, Rodríguez-Martínez’s lab, García-Arrarás’s lab at UPRRP. IARF thanks funding provided by NIH-NIGMS COBRE (5P20GM103642-10) and the Catalyzer Research Grant (#2023-00056) Puerto Rico Science, Technology & Research Trust (PRST).