Effects of dietary fibers or probiotics on functional constipation symptoms and roles of gut microbiota: a double-blinded randomized placebo trial

source extracted confidence: high 2026-04-09
#adult #humans #dietary-fiber #gastrointestinal-microbiome #psyllium

Effects of dietary fibers or probiotics on functional constipation symptoms and roles of gut microbiota: a double-blinded randomized placebo trial

Lai et al., 2023 | Gut Microbes | Rct

Citation

Lai Hao, Li Yunfeng, ... Liu Xin. Effects of dietary fibers or probiotics on functional constipation symptoms and roles of gut microbiota: a double-blinded randomized placebo trial. Gut Microbes. 2023;15(1):2197837. doi:10.1080/19490976.2023.2197837

Abstract

Dietary fibers/probiotics may relieve constipation via optimizing gut microbiome, yet with limited trial-based evidences. We aimed to evaluate the effects of formulas with dietary fibers or probiotics on functional constipation symptoms, and to identify modulations of gut microbiota of relevance. We conducted a 4-week double-blinded randomized placebo-controlled trial in 250 adults with functional constipation. Intervention: A: polydextrose; B: psyllium husk; C: wheat bran + psyllium husk; D: Bifidobacterium animalis subsp. lactis HN019 + Lacticaseibacillus rhamnosus HN001; Placebo: maltodextrin. Oligosaccharides were also included in group A to D. 16S rRNA sequencing was used to assess the gut microbiota at weeks 0, 2, and 4. A total of 242 participants completed the study. No time-by-group effect was observed for bowel movement frequency (BMF), Bristol stool scale score (BSS), and degree of defecation straining (DDS), while BSS showed mean increases of 0.95-1.05 in group A to D (all P < 0.05), but not significantly changed in placebo (P = 0.170), and 4-week change of BSS showed similarly superior effects of the interventions as compared placebo. Group D showed a marginal reduction in plasma 5-hydroxytryptamine. Group A resulted in a higher Bifidobacterium abundance than placebo at week 2 and 4. Fourteen genera showed intervention-specific increasing or decreasing trends continuously, among which Anaerostipes showed increasing trends in groups B and C, associated with BMF increase. Random forest models identified specific baseline microbial genera panels predicting intervention responders. In conclusion, we found that the dietary fibers or probiotics may relieve hard stool, with intervention-specific changes in gut microbiota relevant to constipation relief. Baseline gut microbiota may predispose the intervention responsiveness. ClincialTrials.gov number, NCT04667884.

Key Findings

ClincialTrials.gov number, NCT04667884.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 250
Age Range See abstract
Condition See abstract

MeSH Terms

  • Adult
  • Humans
  • Dietary Fiber
  • Gastrointestinal Microbiome
  • Psyllium
  • RNA, Ribosomal, 16S
  • Constipation
  • Probiotics
  • Bifidobacterium animalis
  • Gastrointestinal Diseases
  • Double-Blind Method

Evidence Classification

  • Level: Rct
  • Publication Types: Randomized Controlled Trial, Journal Article, Research Support, Non-U.S. Gov't
  • Vertical: probiotics-constipation

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09