A Prebiotic-Supplemented Formula Improves Gut Microbiota and Intestinal Inflammatory Microenvironment in Patients with Colorectal Adenoma: A Double-Blind, Placebo-Controlled Trial.

Abstract

Background: Colorectal cancer is preventable, and patients with colorectal adenomas are at high risk of colorectal cancer.

Objectives: This study aimed to evaluate the effects of a complex prebiotic formulation on the gut microbiota and inflammation levels in patients with colorectal adenoma.

Methods: A randomized double-blind placebo-controlled trial assigned patients with adenomatous polyps to either the prebiotic intervention group (N = 51) or the placebo control group (N = 49). Blood and stool samples were collected at baseline and week 12; mixed-effects models were used to analyze the impact of the prebiotic on gut microbiota and inflammatory markers.

Results: Both groups showed an increase in Bacteroidetes abundance over 12 wk, but the increase was smaller in the intervention group [β = -5.507; 95% confidence interval (CI): -11.390, 0.375; P = 0.066]. Unidentified Ruminococcaceae increased in the intervention group (β = 2.072; 95% CI: -0.130, 4.274; P = 0.065), but declined in the control group. A significant increase in interleukin-10 concentrations was observed in the intervention group (β = 0.778; 95% CI: 0.132, 1.425; P = 0.019), in contrast to a downward trend in the control group. Notably, baseline tumor necrosis factor-α concentrations appeared to modify the intervention's microbial effects. Specifically, for each 1 pg/mL increase, the intervention was associated with increased Actinobacteria (β = 0.624; 95% CI: 0.100, 1.148; P-interaction ₌ 0.020), Bifidobacteriaceae (β = 0.608; 95% CI: 0.114, 1.103; P-interaction = 0.017), and Bifidobacterium (β = 0.608; 95% CI: 0.114, 1.103; P-interaction = 0.017). However, these associations did not remain statistically significant after false discovery rate adjustment.

Conclusions: The prebiotic intervention effectively increased the abundance of beneficial bacteria, while simultaneously reducing inflammatory levels in individuals with colorectal adenoma. This trial was registered at XXX as ChiCTR2100046390.