Changes in fecal composition and colonic function due to cereal fiber

Area of Science:

• Gastroenterology
• Human Nutrition
• Dietary Fiber Research

Background:

• Dietary fiber is crucial for digestive health.
• Understanding the impact of specific fiber sources like wheat fiber on colonic function is important.
• Previous research suggests a link between fiber intake and reduced risk of colon cancer.

Purpose of the Study:

• To investigate the effects of increased dietary wheat fiber on colonic function in healthy individuals.
• To quantify changes in fecal parameters and gut transit time.
• To explore the implications of these changes for colon cancer prevention.

Main Methods:

• Six healthy volunteers consumed metabolically-controlled diets for three weeks.
• Dietary fiber intake was increased from 17 g/day to 45 g/day, primarily from wheat fiber.
• Colonic function was assessed by measuring fecal weight, transit time, and output of various components (water, fat, nitrogen, calcium, electrolytes, volatile fatty acids, bile acids).

Main Results:

• Fecal weight increased significantly from 79 g/day to 228 g/day, mainly due to water retention.
• Mean transit time decreased from 57.8 hours to 40.3 hours.
• Increased output of fecal fat, nitrogen, calcium, volatile fatty acids, and bile acids was observed.

Conclusions:

• Increased wheat fiber intake significantly alters colonic function by increasing fecal bulk and accelerating transit time.
• The observed changes in fecal composition, including increased bile acid output, warrant further investigation regarding their role in colon cancer risk.
• Dietary wheat fiber demonstrates a notable impact on digestive physiology, supporting its potential role in gastrointestinal health.