The Evidence for Microbes in the Small Intestine as the Mechanism for Post-Finasteride Syndrome: Self-Reported Case Study

A self-reported case study of a 35-year-old male with Post-Finasteride Syndrome (PFS) suggests that microbes in the small intestine may sustain PFS. Despite normal standard blood tests and a negative hydrogen and methane breath test, a hydrogen sulphide (H2S) breath test was strongly positive. The patient responded well to H. pylori triple therapy, indicating a mechanism beyond stomach acid suppression. Stool analysis revealed high levels of Ruminococcus gnavus and beta-glucuronidase, suggesting a dual-population of fermenting and H2S-producing bacteria in the small intestine. This microbial activity may disrupt hormone excretion and inhibit mitochondrial function, contributing to PFS symptoms. The report recommends further studies with a larger sample of PFS patients.