No abstract

Fatty acid research began about 90 years ago but intensified in recent years. Essential fatty acids (linoleic and α-linolenic) must come from diet. Other fatty acids may come from diet or may be synthesized. Fatty acids are major components of cell membrane structure, modulate gene transcription, function as cytokine precursors, and serve as energy sources in complex, interconnected systems. It is increasingly apparent that dietary fatty acids influence these vital functions and affect human health. While the strongest evidence for influence is found in cardiovascular disease and mental health, many additional conditions are affected. Problematic changes in the fatty acid composition of human diet have also taken place over the last century. This review summarizes current understanding of the pervasive roles of essential fatty acids and their metabolites in human health.

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...

We found no evidence of a beneficial effect of vitamin A for the treatment of RSV infection in children in the United States. There may be groups of children for which vitamin A has an adverse effect, resulting in longer hospital stays.