Figure 2.

Number of observed OTUs detected at week zero (T0) and week eight (T8) in civilian and navy trainee groups. Number of OTUs at T0 and T8 in different categories: cigarette smoking (a), alcohol consumption (b), sleep duration (c), physical exercise (d), and body mass index (BMI) (e). Values are expressed as means ± SEM. Asterisk (*) indicates statistically significant (p < 0.05) differences between groups based on Wilcoxon matched-pairs signed-rank test. At T8, the navy trainees had stopped smoking and drinking alcohol, and had been instructed to do physical exercise for 5 h per day and obey the 8 h sleep schedule.