Are nutrition and physical activity associated with gut microbiota? A pilot study on a sample of healthy young adults

Background. The literature shows that gut microbiota composition is related with health, and a lot of individual and outer factors may determine its variability. In particular, nutrition and exercise seem to influence the presence in the gut of the two major bacterial phyla of Firmicutes and Bacteroidetes. Study design. An ongoing cross-sectional investigation is aimed to explore these associations in humans. Methods. Healthy Caucasian young adults were asked to provide a fecal sample in order to analyze their gut microbiome considering their Body Mass Index (BMI), adherence to Mediterranean diet and Physical Activity (PA) levels. Results. A total of 59 participants (49.1% males, mean age 23.1 +/- 3.14 years) were enrolled so far. Firmicutes (61.6 +/- 14.6) and Bacteroidetes (30.7 +/- 13.3) showed the highest relative abundance in fecal samples. The Pearson's analysis showed a significant negative correlation between PA and Firmicutes (r = -0.270, p = 0.03). Linear regression confirmed a significant decrease of this phylum with the increase of PA (R-2 = 0.07, p = 0.03). Conclusions. These preliminary results suggest the association between physical activity and gut microbiota composition in healthy humans.