Effects of Different Bowel Preparation Regimens and Age Factors on the Gut Microbiota: A Prospective Randomized Controlled Study.

BACKGROUND

Opinions about the impact of bowel preparation on the gut microbiota are divided. This study investigated the effects of different regimens on the gut microbiota post-bowel preparation and the differences in responses across different age groups.

METHODS

This single-center, prospective, randomized, controlled clinical trial included 194 patients. Patients were categorized into two groups: one group receiving polyethylene glycol (n = 108) and one receiving sodium picosulfate (n = 86) for bowel preparation. Fecal samples were collected at baseline and on days 7 and 14 post-bowel preparation. The microbiota's diversity and composition were analyzed using 16S ribosomal RNA gene sequencing, followed by comparative analyses.

RESULTS

The gut microbiota's abundance and diversity in patients significantly decreased post-bowel preparation, which did not recover to the level of pre-bowel preparation on Day 14. When comparing different regimens, the polyethylene glycol and sodium picosulfate groups recovered faster in richness and diversity, respectively. Patients aged < 65 years had higher richness and diversity of the gut microbiota, whereas the microbiota structure in those aged ≥ 65 years returned to the baseline state faster. The structure of beta diversity is significantly altered and did not return in the short term. However, in the elderly population aged ≥ 65 years, it can rebound quickly. This study also identified a number of significantly altered bacterial genera.

CONCLUSIONS

Following the use of different bowel preparation regimens, the gut microbiota recovers in diverse ways, with older people over 65 experiencing a faster recovery of the microbial structure.