Role of Colonic Short Chain Fatty Acids in Obesity

Effect of Inulin and Resistant Starch on Postprandial Short Chain Fatty Acid, Glucose, Insulin and Gut Hormone Responses in Lean and Overweight Subjects.

The excess production of colonic short-chain-fatty-acids (SCFA) has been implicated in the promotion of obesity, but colonic fermentation of dietary-fiber to SCFA may also play a role in preventing diabetes. The investigators aimed to compare the effects of two fermentable fibers (inulin and resistant-starch) on postprandial SCFA, glucose, insulin, free-fatty acids (FFA) and gut hormone responses and to compare the responses in healthy overweight and obese (OWO) vs lean (LN) participants. Methods: Using a randomized, single blind, crossover design, 13 OWO and 12 LN overnight fasted participants were studied on 3 separate occasions. On each day they consumed a 300 mL drink containing 75g glucose (Control) or 75g glucose plus 24g inulin (IN), or 28.2g resistant-starch (RS). A standard lunch was served 4 h after the test drink.

Inclusion Criteria:

• non-pregnant
• body mass index >=20 and <=35

Exclusion Criteria:

• history of diabetes mellitus
• history of cardiovascular disease
• history of bowel disease
• history of kidney disease
• history of liver disease
• use of antibiotics within 3 months of enrolment
• unusual dietary habits
• fasting glucose >6.9mmol/L
• hematocrit below normal range for age and sex