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Background: Short-chain fatty acids (SCFAs), metabolites produced through the microbial fermentation of nondigestible dietary components, have key roles in energy homeostasis. Animal research suggests that colon-derived SCFAs modulate feeding behavior via central mechanisms. In humans, increased colonic production of the SCFA propionate acutely reduces energy intake. However, evidence of an effect of colonic propionate on the human brain or reward-based eating behavior is currently unavailable. Objectives: We investigated the effect of increased colonic propionate production on brain anticipatory reward responses during food picture evaluation. We hypothesized that elevated colonic propionate would reduce both reward responses and ad libitum energy intake via stimulation of anorexigenic gut hormone secretion. Design: In a randomized crossover design, 20 healthy nonobese men completed a functional magnetic resonance imaging (fMRI) food picture evaluation task after consumption of control inulin or inulin-propionate ester, a unique dietary compound that selectively augments colonic propionate production. The blood oxygen level-dependent (BOLD) signal wasmeasuredinaprioribrainregions involved in reward processing, including the caudate, nucleus accumbens, amygdala, anterior insula, and orbitofrontal cortex (n = 18 had analyzable fMRI data). Results: Increasing colonic propionate production reduced BOLD signal during food picture evaluation in the caudate and nucleus accumbens. In the caudate, the reduction in BOLD signal was driven specifically by a lowering of the response to high-energy food. These central effects were partnered with a decrease in subjective appeal of high-energy food pictures and reduced energy intake during an ad libitum meal. These observations were not related to changes in blood peptide YY (PYY), glucagon-like peptide 1 (GLP-1), glucose, or insulin concentrations. Conclusion: Our results suggest that colonic propionate production may play an important role in attenuating reward-based eating behavior via striatal pathways, independent of changes in plasma PYYand GLP-1. This trial was registered at clinicaltrials.gov as NCT00750438. [ABSTRACT FROM AUTHOR]

Background: Evidence suggests that the consumption of anthocyanin-rich foods beneficially affects cardiovascular health; however, the absorption, distribution, metabolism, and elimination (ADME) of anthocyanin-rich foods are relatively unknown. Objective: We investigated the ADME of a 13C5-labeled anthocyanin in humans. Design: Eight male participants consumed 500 mg isotopically labeled cyanidin-3-glucoside (6,8,10,3',5'-13C5-C3G). Biological samples were collected over 48 h, and 13C and 13C-labeled metabolite concentrations were measured by using isotope-ratio mass spectrometry and liquid chromatography-tandem mass spectrometry. Results: The mean ± SE percentage of 13C recovered in urine, breath, and feces was 43.9 ± 25.9% (range: 15.1-99.3% across participants). The relative bioavailability was 12.38 ± 1.38% (5.37 ± 0.67% excreted in urine and 6.91 ± 1.59% in breath). Maximum rates of 13C elimination were achieved 30 min after ingestion (32.53 ± 14.24 µg 13C/h), whereas 13C-labeled metabolites peaked (maximum serum concentration: 5.97 ± 2.14 µmol/L) at 10.25 ± 4.14 h. The half-life for 13C-labeled metabolites ranged between 12.44 ± 4.22 and 51.62 - 22.55 h. 13C elimination was greatest between 0 and 1 h for urine (90.30 ± 15.28 µg/h), at 6 h for breath (132.87 ± 32.23 µg/h), and between 6 and 24 h for feces (557.28 ± 247.88 µg/h), whereas the highest concentrations of Relabeled metabolites were identified in urine (10.77 ± 4.52 µmol/L) and fecal samples (43.16 ± 18.00 µmol/L) collected between 6 and 24 h. Metabolites were identified as degradation products, phenolic, hippuric, phenylacetic, and phenylpropenoic acids. Conclusion: Anthocyanins are more bioavailable than previously perceived, and their metabolites are present in the circulation for ≤48 h after ingestion. This trial was registered at clinicaltrials.gov as NCT01106729. [ABSTRACT FROM AUTHOR]