Rye Bread Better Than Laxative

HELSINKI, FinlandA recent study published in the Journal of Nutrition found rye bread relieved mild constipation and improved colonic metabolism compared with white-wheat bread and commonly used laxatives without increasing gastrointestinal adverse effects (2010; DOI:10.3945/jn.109.118570).

The effects of rye bread and cultured buttermilk with Lactobacillus rhamnosus GG (LGG) on bowel function and colon metabolism were investigated and compared with laxatives in 51 constipated adults. They were randomized to receive whole-grain rye bread (minimum 240 g/d), LGG (2 x 1010 CFUs/d), whole-grain rye bread (minimum 240 g/d) + LGG (2 x 1010 CFUs/d), white-wheat bread (maximum 192 g/d) or laxatives (as usual for a participant) for three weeks.

Rye bread, compared with white-wheat bread, shortened total intestinal transit time (TITT) by 23 percent (P=0.040), increased weekly defecations by 1.4 (P=0.014), softened feces (P=0.037), eased defecation (P=0.018), increased fecal acetic acid and butyric acid contents by 24 percent (P=0.044) and 63 percent (P<0.001), respectively, and reduced fecal beta-glucuronidase activity by 23 percent (P=0.014). Compared with laxatives, rye bread reduced TITT by 41 percent (P=0.006), fecal beta-glucuronidase activity by 38 percent (P=0.033) and fecal pH by 0.31 units (P=0.006). LGG did not relieve constipation or significantly affect colonic metabolism. Gastrointestinal adverse effects did not significantly differ among the study groups.