The Effect of Psyllium Husk on Intestinal Microbiota in Constipated Patients and Healthy Controls

Abstract

Psyllium is a widely used treatment for constipation. It traps water in the intestine increasing stool water, easing defaecation and altering the colonic environment. We aimed to assess the impact of psyllium on faecal microbiota, whose key role in gut physiology is being increasingly recognised. We performed two randomised, placebo-controlled, double-blinded trials comparing 7 days of psyllium with a placebo (maltodextrin) in 8 healthy volunteers and 16 constipated patients respectively. We measured the patients’ gastrointestnal (GI) transit, faecal water content, short-chain fatty acid (SCFA) and the stool microbiota composition. While psyllium supplement had a small but significant effect on the microbial composition of healthy adults (increasing Veillonella and decreasing Subdoligranulum), in constipated subjects there were greater effects on the microbial composition (increased Lachnospira, Faecalibacterium, Phascolarctobacterium, Veillonella and Sutterella and decreased uncultured Coriobacteria and Christensenella) and alterations in the levels of acetate and propionate. We found several taxa to be associated with altered GI transit, SCFAs and faecal water content in these patients. Significant increases in three genera known to produce butyrate, Lachnospira, Roseburia and Faecalibacterium, correlated with increased faecal water. In summary, psyllium supplementation increased stool water and this was associated with significant changes in microbiota, most marked in constipated patients.

Mechanisms of Action of Prebiotics and Their Effects on Gastro-Intestinal Disorders in Adults

“…Moreover, the SCFAs concentration was also different between healthy and constipated subjects. After psyllium administration, microbial species associated with the production of SCFAs, such as Fecalibacterium and Phascolarctobacterium, increased, while Christensenella, associated with hard stools, decreased [111].…”

“…↑ Fecalibacterium and Phascolarctobacterium growth, associated with SCFAs production [111]. ↓ Christensenella, associated with hard stools [111]. ↑ Butyrate fecal concentration [112].…”

“…These results show that the synergistic action of more than one prebiotic could perhaps have greater effects on gastrointestinal symptoms [129]. A recent meta-analysis that evaluated the effects of FOS and GOS on IBS symptoms showed that both types of prebiotics did not have important effects on symptoms except for GOS that provided a significant effect on global IBS symptoms but not on abdominal pain [130] Moreover, psyllium is usually used in chronic constipation due to its capability to retain water in the small intestine, tinning the stool and increasing the defecation frequency [111]. Psyllium has little effects on healthy subjects' microbiota, but it has a great beneficial effect in constipated individuals.…”

Psyllium Supplementation is Associated with Changes in the Fecal Microbiota of Horses

“…Changes in human gut microbial populations have been documented with psyllium supplementation, particularly for constipated individuals for which psyllium supplementation was associated with increased stool water and signi cant changes in fecal microbial populations (8).…”

Microbiota, Food, and Health

“…This approach in combination with 16s rRNA gene profiling allowed the detailed study of the infant microbiome and the evaluation of the functional community-wide metabolic status of the infants representing different gut microbial environments with regard to factors including delivery or feeding mode and use of antibiotics. Jalanka and coworkers [7] addressed, in a double-blind study setting, the impact of dietary psyllium consumption with anticipated prebiotics effects on fecal microbiota composition as well as gut environmental conditions in participants with and without constipation. In this Special Issue article, psyllium was found to increase fecal water and to induce changes in gut microbiota composition.…”