Bifidogenic effect of dietary fiber and resistant starch from leguminous on the intestinal microbiota of rats

Objectives: The bifidogenic effect of leguminous containing diets on the intestinal microbiota of male Wistar rats was studied. Methods: Isoprotein (12.2 +/- 0.3%) and isoenergetic (373.2 +/- 4.2 kcal,1100 g) experimental diets, whose sources of dietary fiber and resistant starch were pea (Pisum sativum, L.), common bean (Phaseolus vulgaris, L.), chickpea (Cicer arietinum, L), and lentil (Lens culinaris, Med.), and a control diet (casein + microcrystalline cellulose) were offered ad libitum to recently weaned male albino Wistar rats (16 rats/treatment) for 28 d. Cecal appendices were removed and analyzed for Bifidobacterium, Lactobacillus, Enterobacter, Bacteroides, Clostridium, and total anaerobes. Results: The common bean diet showed the highest content of dietary fiber (17.0 +/- 0.2 g/100 g), which was significantly different (P < 0.05) from the others. Resistant starch content was similar for all diets. The control and chickpea groups showed significantly higher consumption of diet and food conversion efficiency than the others. The leguminous-containing diets produced a larger mass of cecal material that was statistically different from the control group. The pea group presented the highest count of Bifidobacteriton (9.4 +/- 0.7 log colony-forming units per gram of raw material), which was significantly different from the others, and the Lactobacillus count was similar for all groups. Animals fed leguminous-containing diets showed lower counts of Enterobacter and Bacteroides than did the control group and no statistical difference (P > 0.05) was found between groups with respect to counts of Clostridium and total anaerobes. Conclusions: The pea and chickpea groups stood out from the others with respect to growth of Bifidobacterium, especially the pea group. (c) 2005 Elsevier Inc. All rights reserved.