Clostridium butyricum MIYAIRI 588 Reduces Colorectal Adenomatous Polyp Recurrence: A Randomized Crossover Trial.

Objectives: Colorectal adenomatous polyps frequently recur after removal and are precursors to colorectal cancer, highlighting the need for effective preventive strategies. This study evaluated the efficacy of probiotic Clostridium butyricum MIYAIRI 588 (CBM588) in preventing colorectal adenoma recurrence in high-risk patients. Methods: We conducted a randomized, single-blind, two-year crossover trial in patients with a history of adenomatous polyps. Participants received CBM588 in either the first or second year, with the alternate year as observation, and underwent annual surveillance colonoscopies. Outcomes (adenoma recurrence and polyp counts) were analyzed by intention-to-treat (ITT) and per-protocol (PP) approaches. Results: A total of 398 participants were enrolled. In first-year ITT analysis, the CBM588-first group had a lower mean polyp count (0.78 vs. 1.00) and lower adenoma recurrence rate (30.00% vs. 35.35%) than the control-first group, though these differences were not statistically significant (p = 0.10 and p = 0.26, respectively). In contrast, first-year PP analysis showed significant reductions in the CBM588-first group's mean polyp count (0.80 vs. 1.25, p < 0.05) and adenoma recurrence rate (29.76% vs. 44.71%, p < 0.05) compared to control. After crossover, the group receiving CBM588 in the second year experienced similar benefits, and by year two both groups had comparable outcomes. No carryover effect was evident. The number needed to treat to prevent one adenoma in one year was 19 in ITT and 7 in PP. CBM588 was well tolerated, with no serious adverse events. Conclusion: CBM588 demonstrated potential to reduce colorectal adenoma recurrence in high-risk patients, supporting its role as a feasible, non-invasive preventive strategy.