An unfermented gel component of psyllium seed husk promotes laxation as a lubricant in humans

Abstract

Background: In addition to increasing stool weight, supplements of psyllium seed husk produce stools that are slick and gelatinous. Objective: Our purpose was to test the hypothesis that a gelforming fraction of psyllium escapes microbial fermentation and is responsible for the characteristics that enhance laxation. Design: Fifteen healthy adults consumed controlled diets for two 7-d periods, one of which included 8.8 g dietary fiber provided by 15 g/d of a psyllium seed husk preparation. All stools were collected and evaluated and diet was monitored throughout. Results: Psyllium significantly increased the apparent viscosity of an aqueous stool extract, stool moisture, and wet and dry stool weights. A very viscous fraction, not present in low-fiber stool and containing predominantly 2 sugars that are also found in abundance in psyllium husk, was isolated from psyllium stool. Conclusions:In contrast with other viscous fibers that are fermented completely in the colon, a component of psyllium is not fermented. This gel provided lubrication that facilitated propulsion of colon contents and produced a stool that was bulkier and more moist than were stools resulting with use of comparable amounts of other bowel-regulating fiber sources.Am J Clin Nutr 2000;72:784-9. KEY WORDSPsyllium seed husk, Plantago ovata, dietary fiber, laxation, colon function, constipation, fermentation INTRODUCTIONMost dietary fiber sources promote laxation by increasing colonic contents, which stimulates propulsion. Unfermented or incompletely fermented fiber and the accompanying moisture it holds are 2 contributors to this increased stool mass (1). Slowly or incompletely fermented fibers also contribute to stool weight by providing substrate for microbial growth. The greater bacterial mass and accompanying water further increase stool weight (2, 3). In most studies, the additional stool mass produced by consumption of more dietary fiber contains the same proportion of moisture as do low-fiber stools (4).Psyllium seed husk (PSH) is a partially fermented dietary fiber from Plantago ovata that increases stool weight and promotes laxation by its presence in stool and by increasing the moisture content of stool (5-8). Available evidence indicates that PSH does not increase fecal bacterial mass (8), although excretion of muramic acid, an amino sugar unique to bacteria, was increased when PSH was part of a rat diet (9).In a preliminary human study, we observed that PSH consumption results in the passage of slick, gelatinous stools (Marlett and Fischer, unpublished observations, 1992), similar to those we observed in the rat study (9). The purposes of this experiment were to isolate the fraction in feces responsible for the gel characteristic of stool, to determine and relate the sugar composition of this fraction to the sugar composition of PSH, and to evaluate the laxative properties of PSH under controlled diet conditions. Our overall objective was to test the hypothesis that this gelatinous material represents unfermented PSH, which con...

The active fraction of psyllium seed husk

“…A controlled-diet study was conducted to obtain stools from subjects consuming PSH (Marlett et al 2000). Fourteen healthy men and women (18-30 years old) completed the study that tested a dose of 8·8 g PSH as 15 g Metamucil®/d.…”

“…Marteau et al (1994) were unable to extract the gel from human stools using differing concentrations of ethanol. Our approach was to solubilise the fresh stool in alkali (Marlett et al 2000). At this pH a negatively-charged environment is created in which the polysaccharide moieties repel one another, and the solution is no longer viscous.…”

Optimization of Method for Determination of Swelling Factor of Ispaghula Seeds

“…grade) and calibrated pipettes. Distilled water, chloroform water, hydrochloric acid (0.1N), sodium hydroxide (0.1N), alcohol (10,20, and 90%), ethyl acetate and solvent ether were used as solvents. All the chemicals used were of Analytical grade (Loba).…”

“…Traditionally, Isphaghula is widely used for other medicinal purposes such as lipase inhibitor [14], hypolipidemic agent [15], arthritis, constipation [16][17][18][19][20][21][22], skin diseases and in cosmetic preparations [23][24][25][26][27][28]. Its activity has been found comparable to misoprostal and loparamide for its antidiarrheal activity [29][30][31].…”

Utilização De Fitoterápicos No Tratamento De Constipação Intestinal

“…Outro estudo demonstrou que as fibras de Psyllium não são fermentadas no cólon intestinal, o que resulta na lubrificação e aumento da expulsão do conteúdo do cólon, além da formação de fezes mais volumosas e úmidas do que aquelas formadas com a utilização de outras fibras (MARLETT; KAJS;FISCHER, 2000).…”