Background: Obesity threatens human health, and interventions to reduce obesity may have important effects on the gut microbiota. This study investigated alterations in gut microbial composition in response to aerobic exercise (AE) and intermittent fasting (IF).

Methods: We randomly divided mice into four groups of seven mice each: normal, obesity, exercise, and fasting. The normal group was fed a Chow Diet, whereas the other three groups were fed a High Fat Diet (HFD). After 13 weeks, the exercise group was subjected to aerobic treadmill running, and the fasting group started IF for 8 weeks. We then analyzed the composition of the fecal microbiome in all mice at the end of 21 weeks.

Results: Our investigation revealed that the HFD significantly influenced species (s)_Romboutsia ilealis, genus (g)_Dubosiella, and g_Blautia. AE predominantly affected family (f)_Rhizobiaceae and g_Rikenella, indicating its impact on enhancing microbial taxa associated with improved metabolic health profiles. On the other hand, IF prominently altered the abundance of s_Lactobacillus johnsonii and g_Colidextribacter, which are known for their roles in enhancing glucolipid metabolism and anti-inflammatory activity. Furthermore, the exercise group displayed increased diversity within f_Rhizobiaceae, potentially associated with anti-inflammatory benefits. The IF intervention was particularly effective in enriching s_Lactobacillus johnsonii, suggesting its pivotal role in regulating metabolic responses influenced by fasting.

Conclusion: The results demonstrated significant beneficial alterations in microbial composition following AE and IF interventions, which supports the use of personalized approaches for obesity management and overall health.