EFFECT OF OLESTRA UPON INTESTINAL MICROECOLOGY AS REFLECTED BY 5 MICROFLORA ASSOCIATED CHARACTERISTICS IN MAN

To determine the effect of olestra on microbial ecology of the gut fiv e microflora associated characteristics (MACs) were assessed in 93 sub jects in a 36 d parallel, placebo-controlled, double-blind study. Degr adation of tryptic activity, beta-aspartylglycine and mucin, and conve rsion of cholesterol to coprostanol and bilirubin to urobilinogen were determined in faecal samples collected at the end of an 8 d low fibre baseline period and 28 d treatment period. The test meal consisted of either a moderate (7 g) or high (24 g) level of fibre and olestra (24 g) or an equivalent amount of conventional fat. Olestra had no effect on degradation of tryptic activity or beta-aspartylglycine, and no co nsistent effect on mucin degradation. Olestra reduced significantly th e conversion of cholesterol to coprostanol and urobilin to urobilinoge n although the individual values were all within the range of healthy population after treatment. The lipophilic nature of cholesterol and u robilin is the most likely reason for the findings, as parts of the su bstrates partition into olestra and are not available to microorganism s.