Mode of Action of Psyllium in Reducing Gas Production from Inulin and its Interaction with Colonic Microbiota: A 24 hours, Randomised, Placebo-Controlled Trial in Healthy Human Volunteers

Alhasani, Alaa; Modasia, Amisha; Anodiyil, Mohamed; Corsetti, Maura; Aliyu, Abdulsalam; Crooks, Colin; MARCIANI, LUCA; Reid, Joshua; Yakubov, Gleb; Avery, Amanda; Harris, Hannah; Warren, Frederick; Spiller, Robin

Abstract

Background: Recent studies show that the increase in breath hydrogen (BH2) and symptoms after ingestion of inulin is reduced by co-administering psyllium.

Objectives: To determine if slowing delivery of inulin to the colon by administering it in divided doses would mimic the effect of psyllium. Primary endpoint was the BH2 area under the curve AUC0-24hours. Secondary endpoints included BH2 AUC0-6h, 6-12h, and 12-24h. Exploratory endpoints included the correlation of BH2 AUC0-24h with dietary FODMAPs intake and in vitro fermentation results.

Methods:17 Healthy adults were randomised to a single-blind, 3-arm, crossover trial. All consumed 20g inulin (I) powder dissolved in 500mL water and mixed with either 20g maltodextrin (control) or 20g psyllium (PI) consumed as a single dose or 20g inulin given in divided doses (DDI), 62.5mL every 45 minutes over 6h. 24-h BH2, dietary FODMAP intake, stool microbiota, and gas production in vitro were measured. Responders were defined as those whose AUC0-24h BH2 was reduced by psyllium, while non-responders showed no reduction.

Results: Compared to control, PI did not reduce average BH2 AUC0-24h while DDI increased it, p<0.0002. DDI and PI both significantly reduced BH2 AUC0-6h compared to the control, p<0.0001. However, subsequently, DDI significantly increased BH2 from 6-12h (p<0.0001) and overnight (12-24h) (p<0.0001), while PI did so only overnight (p=0.0002). Non-responders showed greater release of arabinose during in-vitro fermentation and higher abundance of two species, Clostridium spp. AM22_11AC and Phocaeicola dorei, which also correlated with BH2 production on PI. Dietary FODMAP intake tended to correlate inversely with BH2 AUC0-24h (r=-0.42, p=0.09) and correlated with microbiome community composition.

Conclusions: DDI, like psyllium, reduces early BH2 production. Psyllium acts by delaying transit to the colon but not reducing colonic fermentation over 24h. Dietary FODMAP intake correlates with BH2 response to inulin and the microbiome.

Citation

Alhasani, A., Modasia, A., Anodiyil, M., Corsetti, M., Aliyu, A., Crooks, C., MARCIANI, L., Reid, J., Yakubov, G., Avery, A., Harris, H., Warren, F., & Spiller, R. (2024). Mode of Action of Psyllium in Reducing Gas Production from Inulin and its Interaction with Colonic Microbiota: A 24 hours, Randomised, Placebo-Controlled Trial in Healthy Human Volunteers. Journal of Nutrition, https://doi.org/10.1016/j.tjnut.2024.12.017

• Journal Article Type: Article
• Acceptance Date: Dec 18, 2024
• Online Publication Date: Dec 26, 2024
• Publication Date: Dec 26, 2024
• Deposit Date: Dec 19, 2024
• Publicly Available Date: Dec 27, 2025
• Journal: Journal of Nutrition
• Print ISSN: 0022-3166
• Electronic ISSN: 1541-6100
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1016/j.tjnut.2024.12.017
• Public URL: https://nottingham-repository.worktribe.com/output/43095816
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0022316624012446