To investigate the dietary effects of six different edible marine algae on the intestinal microflora and the level of serum lipids, diets containing 1% and 5% of the algae were administered to male rats for one week. These algae increased fecal weight. Cecal weight was increased by the diets containing 5% kombu Laminaria sp., 5% wakame Undaria pinatifida, and 5% mozuku (okinawa mozuku Cladosiphon okamuranus). In the case of the 5% aosa (hitoegusa Monostroma nitidum) diet, cecal pH value was higher. Most of the algae suppressed cecal ammonia. These marine algae had similar effects on serum lipid, such as the suppression of levels of serum triglycerides and free fatty acids, though these algae had no effect on serum cholesterol levels. On the other hand, these marine algae showed different effects on cecal microflora. The ratio of bifidobacteria to total viable counts increased in rats fed diets containing mekabu (sporophyll of wakame).
