The role of I-methionine in the reduction of recurrences of chronic bacterial prostatitis: A pilot study

Introduction: L-methionine has been used for many years as an aid in the treatment of urolithiasis and as a prevention of further occurrence of struvite crystal formation by the acidification of the urine. Acidification of urine has been also used as a technique to treat and prevent symptomatic urinary tract infections. The current pharmacological research in the field of bacterial prostatitis focuses on the combinations of available antibiotics with prostatic microenvironmental modifiers for the prevention and treatment of chronic bacterial prostatitis (CBP) clinical recurrences. We aimed to study whether, in addition to antibiotic therapy, acidification of urine and prostatic microenvironment decreases CBP recurrences. Materials and Methods: This study was conducted between February 01, 2019, and December 20, 2020. The patient population included subjects with a confirmed diagnosis of CBP (National Institutes of Health [NIH] category II), history of CBP recurrences, and prostate calcifications confirmed on the transrectal ultrasound (TRUS) examination of the prostate. Symptom severity was self-estimated with the NIH-Chronic prostatitis Symptom Index (CPSI) and the International Prostatic Symptom Score (IPSS) questionnaires. Participants were randomly assigned to two groups. All underwent TRUS and the Meares–Stamey “four-glass” test. Patients of both groups received antimicrobial treatment (according to the results of susceptibility tests) for 30 days, while patients of Group 2 received additionally l-methionine 500 mg b. i. d for 2 months. After 4 weeks of therapy, the NIH-CPSI and IPSS tests were repeated. Follow-up included also interview, physical examination, TRUS, and “four-glass” test. Patients were followed for 6 months. Results: A total of 10 patients (5+5) were investigated in both groups. No significant differences were found between groups regarding median age, prostate volume, and bacterial susceptibility. Microbiological eradication occurred in similar proportions between the two groups. Similarly, the resolution of clinical symptoms occurred in equivalent numbers of patients belonging to Groups 1 and 2. Analysis showed in both groups highly significant improvements of symptoms, assessed with both the NIH-CPSI and IPSS tests. No difference in the number and location of calcifications after treatment between groups was also found. One patient of Group 1 experienced a clinical recurrence within 6 months after conclusion of treatment. Conclusion: No clear recommendations can be made from this pilot study. Thus, the preventive effect of l-methionine remains unknown and evidence for its use in this setting is lacking, but randomized trials with large numbers of participants would help to determine the role of urinary acidification in the treatment or prevention of recurrent CBP.