Fatty Acid Supplement Prevents Weight Gain in First Human Study
the MPR take:
An increased intake of dietary fiber has been associated with reduced appetite and weight loss via short chain fatty acids (SCFAs) like propionate produced by microbial fermentation of dietary fiber in the colon, but a significant amount (>30g/day) is needed for these benefits and compliance is typically poor due to gastrointestinal side effects. These SCFAs have been found to stimulate the release of peptide YY (PYY) and glucagon like peptide-1 (GLP-1), contributing to short-term signal of satiation and satiety to the appetite centers of the brain.
To assess the acute effects of inulin-propionate ester on appetite regulation, hormone release, and energy update, 20 volunteers were served a standardized meal containing either 10g of inulin-propionate ester or 10g inulin control; this was followed by a standardized lunch and buffet dinner, with food served in excess and instructions to eat until they felt full. Acute inulin-propionate ester supplementation significantly reduced food intake by a mean reduction of 13.8%; propionate production from in vitro fecal fermentation was significantly greater from inulin-propionate ester compared with inulin, while no significant differences in acetate or butyrate production were observed.
Next, 60 volunteers with non-alcoholic fatty liver disease were assigned to either 10g/day of the supplement inulin-propionate ester or placebo; the participants were instructed to mix the content into their normal diet over 24 weeks and maintain usual dietary and physical activity habits. None of the participants in the long-term inulin-propionate ester group experienced substantial weight gain (≥5% baseline weight) compared to 17% in the placebo group. This inulin-propionate group also saw a significantly greater reduction in distribution of intra-abdominal adipose tissue and intrahepatocellular lipid content.
Because this is the first study on humans and the sample size was small, replication of the results is needed in larger trials before supplementation with SCFAs can be recommended to reduce weight gain.
The colonic microbiota ferment dietary fibres, producing short chain fatty acids. Recent evidence suggests that the short chain fatty acid propionate may play an important role in appetite regulation. We hypothesised that colonic delivery of propionate would increase peptide YY (PYY) and glucagon like peptide-1 (GLP-1) secretion in humans, and reduce energy intake and weight gain in overweight adults.