Serum lipids and cholesterol metabolism during guar gum, plantago ovata and high fibre treatments.

Short-term viscous dietary fibres, plantago ovata and guar gum preparations, decreased serum cholesterol, mainly LDL cholesterol, as compared to low fibre or nonviscous high fibre periods, through enhancing cholesterol elimination as fecal bile acids. These changes were associated with significant increases in serum levels of cholesterol precursors, both in methylsterols and demethylated precursor sterols, while that of cholestanol (saturated cholesterol derivative) was decreased. In addition, cholesterol precursor contents were positively related, cholestanol negatively, to fecal cholesterol elimination both on and off viscous fibres. These findings indicate increased cholesterol synthesis, also seen by sterol balance data. As compared to low fibre diet, nonviscous high fibre diet conserved bile acids and decreased cholesterol absorption. Thus, it had no effect on cholesterol synthesis as indicated by fecal total steroids or serum levels of cholesterol precursors.