Dietary management of functional constipation in disorders of gut-brain interaction - A scoping review

Functional constipation is one of the most prevalent disorders of gut-brain interaction, but available dietary interventions haven't been comprehensively collated.

The aim of this scoping review was to synthesise the current evidence surrounding dietary-based interventions used to manage functional constipation in adults and to identify any gaps among published dietary management strategies that could warrant further research, namely a systematic review.

A comprehensive database search was conducted on MEDLINE, CINAHL and Web of Science capturing the notions of 'dietary management' and 'disorders of gut-brain interaction', from which two rounds of screening were performed.

Forty primary studies and twelve review papers were included in this review. These 52 papers non-exclusively cover a range of dietary domains including fibre supplementation (n = 15), microbiome modulation using prebiotics, probiotics or synbiotics (n = 26), functional foods (n = 10), fluid intake (n = 6) and other dietary approaches (n = 7). Fiber supplementation with psyllium is the current strongest dietary recommendation, with emerging strong evidence backing functional fruits like kiwifruit and prunes. Meanwhile the efficacy for all other approaches cannot be accurately deduced due to limited well-designed studies or conflicting evidence. However, improvements to constipation severity or symptoms have been observed with probiotics with both Bifidobacterium and Lactobacillus components, galacto-oligosaccharides, partially hydrolysed guar gum and various synbiotic formulations.

This paper contributes to the growing research around functional constipation where the open-ended approach allowed for identification and synthesis of all nutrition strategies trialed in the literature. We recommend further studies to be conducted on prebiotics, probiotics and synbiotics to determine its potential role in constipation management for this cohort.