The association between gut microbiome and erectile dysfunction: a community-based cross-sectional study in Japan.

We investigated the gut microbiome in subjects with erectile dysfunction (ED) in a community-based population. This cross-sectional study surveyed comprehensive health status in 408 men who participated in the Iwaki Health Promotion Project in 2015 in Hirosaki, Japan. The gut microbiome was assessed by tag sequencing of the 16S rRNA gene, which we extracted from fecal samples. Erectile function was evaluated with the five-item International Index of Erectile Function (IIEF-5), and the men were divided into two groups: low-IIEF-5 (≤ 16) and high-IIEF-5 (> 16). Of those, we selected age-adjusted 192 men (96 each) for analysis. We investigated the association of gut microbiome with IIEF-5 between the two groups. Median age was 50 years. No significant difference was seen in the history of hypertension, DM, CKD, and CVD between the low-IIEF-5 and high-IIEF-5 groups. However, the relative abundance of Alistipes (related with anti-inflammation) and Clostoridium XVIII (related with bowel movement) was significantly different between the two groups. Multivariate logistic analysis demonstrated that the relative abundance of Clostridium XVIII (OR, 2.06; 95% CI, 1.20-3.55, P = 0.009) and Alistipes (OR, 0.81; 95% CI, 0.66-0.99, P = 0.040) and, with an IPSS ≥ 8, were independent factors for low IIEF-5. We observed significant association between the low-IIEF-5 and high-IIEF-5 groups in Alistipes and Clostoridium XVIII. Further study is necessary to access the causal relationship between the gut microbiome and ED.