Resistant starch and sodium butyrate reduce body fat in rodents

Abstract

Introduction: Obesity levels in the United States have significantly increased in the last forty years. Lifestyle and pharmacological treatments have been largely ineffective in treating obesity for most people. Both Resistant Starch (RS) and Dietary Sodium Butyrate (SB) are bioactivties which have shown the ability to decrease body fat levels of rodents without increasing physical activity or decreasing energy intake. Glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) are gut hormones that may be involved in increased energy expenditure at a cellular level with dietary RS and SB. Objective: To discern if SB and RS both work through the increase of plasma GLP-1 and PYY. Also to see if a combination of RS and SB would lead to an increased or even an additive effect on the reduction of body fat levels in rodents. Methods: 60 Sprague Dawley rats were fed isocaloric diets of either control, SB, RS or a combination of RS and SB for 60 days. Measurements included food intake, body weight, abdominal fat, plasma PYY and GLP-1, and gastrointestinal tract weights. Results: There was no difference in caloric consumptions between any groups. According to factorial results, SB and RS both lowered abdominal fat. While the combination of RS and SB showed the lowest levels of abdominal body fat levels by t tests compared to control, there was not an additive effect of SB and RS. GLP-1 and PYY levels were not increased in the SB fed group. Conclusions: SB effects on body fat reduction are not associated with increased plasma GLP-1 and PYY levels as found in RS fed rodents. The combination of SB and RS have a greater effect on body fat than either alone, but the lack of an additive effect suggests a saturation level in a cellular mechanism by which both RS and SB may increase energy expenditure.