Effect of dietary oat and soy fiber on bowel function and clinical tolerance in a tube feeding dependent population

J Am Coll Nutr. 1994 Dec;13(6):565-8. doi: 10.1080/07315724.1994.10718448.


Objective: The role of fiber in tube feeding products has not clearly been defined. While some studies suggest that fiber can increase stool weight and bowel transit time in acutely ill patients, there is less information in stable patients receiving chronic enteral nutritional support.

Design: Using a crossover study design, we investigated the effect of 28.8 g/day of a 50% soy and 50% oat fiber combination in 10 medically stable residents of a chronic care facility. Subjects were randomized to initially receive 10 days of either Isocal HN or Ultracal, which are identical in composition except Ultracal contains 14.4 g/L of fiber. After the first 10-day study, subjects underwent a washout followed by a second 10-day study using the other product. Fecal dye markers were used to identify appropriate collection times.

Results: Fiber significantly increased the number of bowel movements per day (0.9 +/- 0.4 vs 0.5 +/- 0.2, p < 0.05) and fecal weights (57 +/- 31 vs 32 +/- 25 g/day, p < 0.05). Fiber also caused a significant increase in fecal nitrogen output (110 +/- 65 vs 75 +/- 74 mg/day, p < 0.05) and fecal energy (141 +/- 73 vs 76 +/- 62 kcal/day, p < 0.05). Fiber did not affect fecal moisture, gastric emptying, or intestinal transit time.

Conclusion: We conclude that the addition of a combination of soy and oat fiber to tube feeding material is well tolerated, and promotes regular bowel movements without altering the rate of gastric emptying or intestinal transit time.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Avena*
  • Cross-Over Studies
  • Defecation / physiology
  • Dietary Fiber / standards*
  • Digestive System Physiological Phenomena*
  • Dose-Response Relationship, Drug
  • Enteral Nutrition*
  • Feces / chemistry
  • Food, Formulated / standards
  • Gastric Emptying / physiology
  • Gastrointestinal Motility / physiology
  • Gastrointestinal Transit / physiology
  • Glycine max*
  • Humans
  • Male
  • Middle Aged
  • Nitrogen / analysis


  • Dietary Fiber
  • Nitrogen