Moderate Exercise Has Limited but Distinguishable Effects on the Mouse Microbiome

Area of Science:

• Microbiology
• Exercise Physiology
• Computational Biology

Background:

• The gut microbiome plays a crucial role in host health, influencing various physiological processes.
• Both exercise and the gut microbiome are independently linked to human health outcomes.
• The direct impact of exercise on the intestinal microbiota remains incompletely understood.

Purpose of the Study:

• To investigate the effects of voluntary exercise (VE) and moderate forced exercise (FE) on gut microbial diversity and inflammatory markers in mice over 8 weeks.
• To compare these effects against a sedentary control group.
• To explore the utility of machine learning in identifying exercise-associated microbial shifts.

Main Methods:

• Comparison of gut microbial diversity and inflammatory markers in mice undergoing VE, FE, or no exercise (sedentary).
• Analysis of operational taxonomic units (OTUs) and beta diversity using traditional statistical methods.
• Application of a random forests machine learning model to classify exercisers and non-exercisers based on microbial community data.

Main Results:

• Voluntary exercise (VE) mice exhibited increased food intake and lean body mass compared to sedentary controls; forced exercise (FE) mice did not show these changes.
• No significant differences in inflammatory markers were observed across the three groups.
• Traditional analyses of microbial profiles and beta diversity did not reveal significant alterations due to exercise.
• A machine learning model accurately classified voluntary exercisers (97% accuracy) and identified key bacterial taxa (Bacteroides, S24-7, Rikenellaceae, Lachnospiraceae, Lactobacillus) associated with exercise.

Conclusions:

• Aerobic exercise in mice did not lead to significant changes in overall gut microbial abundance or host inflammatory responses.
• Sophisticated computational approaches, like machine learning, can detect subtle microbial shifts associated with exercise.
• Further research is warranted to understand the impact of varying exercise intensities on the gut microbiome and host health.