Quantification of in Vivo Colonic Short Chain Fatty Acid Production from Inulin

Abstract

Short chain fatty acids (SCFA), including acetate, propionate, and butyrate, are produced during bacterial fermentation of undigested carbohydrates in the human colon. In this study, we applied a stable-isotope dilution method to quantify the in vivo colonic production of SCFA in healthy humans after consumption of inulin. Twelve healthy subjects performed a test day during which a primed continuous intravenous infusion with [1-13C]acetate, [1-13C]propionate and [1-13C]butyrate (12, 1.2 and 0.6 μmol·kg−1·min−1, respectively) was applied. They consumed 15 g of inulin with a standard breakfast. Breath and blood samples were collected at regular times during the day over a 12 h period. The endogenous rate of appearance of acetate, propionate, and butyrate was 13.3 ± 4.8, 0.27 ± 0.09, and 0.28 ± 0.12 μmol·kg−1·min−1, respectively. Colonic inulin fermentation was estimated to be 137 ± 75 mmol acetate, 11 ± 9 mmol propionate, and 20 ± 17 mmol butyrate over 12 h, assuming that 40%, 10%, and 5% of colonic derived acetate, propionate, and butyrate enter the systemic circulation. In conclusion, inulin is mainly fermented into acetate and, to lesser extents, into butyrate and propionate. Stable isotope technology allows quantifying the production of the three main SCFA in vivo and proved to be a practical tool to investigate the extent and pattern of SCFA production.

The effects of dietary supplementation with inulin and inulin‐propionate ester on hepatic steatosis in adults with non‐alcoholic fatty liver disease

“…9 It could be suggested that the elevated ratio of colonic propionate : acetate promoted by IPE supplementation may have prevented the accumulation of liver fat observed in the inulin-control group by impairing hepatic acetate metabolism. This proposed mechanism is concordant with the results from Wolever and colleagues, who showed using stable isotope technology that propionate inhibits incorporation of colonic [1,[2][3][4][5][6][7][8][9][10][11][12][13] C] acetate into plasma lipids in humans. 7 Studies using rat hepatocytes have also highlighted that propionate inhibits lipid synthesis when acetate is a major source of acetyl-CoA.…”

“…The blood samples were collected >12 hours after volunteers were requested to ingest their final supplement, which may explain why we were unable to detect large differences in circulating SCFAs postsupplementation. Nevertheless, previous research using stable isotope methodology has showed that inulin is predominantly fermented in the human colon into acetate (82%), with considerably less propionate and butyrate produced (6% and 12%, respectively) . Dietary supplementation with inulin‐type fructans (ITF) has generally been associated with positive effects on metabolic health.…”

“…Nevertheless, previous research using stable isotope methodology has showed that inulin is predominantly fermented in the human colon into acetate (82%), with considerably less propionate and butyrate produced (6% and 12%, respectively). 10 Dietary supplementation with inulin-type fructans (ITF) has generally been associated with positive effects on metabolic health. The evidence for this beneficial effect is primarily derived from rodent studies, where dietary supplementation with ITF has consistently been shown to prevent the accumulation of liver fat and metabolic dysregulation induced by a high fat diet.…”

Low abundance of colonic butyrate-producing bacteria in HIV infection is associated with microbial translocation and immune activation

“…While the RA and location of BPB species likely has an important impact on the amount of butyrate produced in the colon, other factors such as diet can play a large role. For instance, soluble fibers with high degrees of polymerization, such as inulin, are fermented in the gut which results in SCFA production [71-73]. Using a limited dietary questionnaire, our study observations suggest that HIV-1 infection may disrupt the normal association between diet and RA of BPB species, thereby potentially contributing to the dysbiosis of the intestinal microbiome seen during HIV-1 infection.…”

Effect of Non-Thermal Ultrasound on Inulin from Jerusalem Artichoke and Its Application in Dairy Industry

“…First, undigested carbohydrates are broken down into smaller carbonhydrates by microbial hydrolysis, which is mainly done by Bifidobacterium in the large intestine. The monosaccharides are then fermented to phosphoenolpyruvate (PEP) by the Embden-Meyerhof-Parnas pathway (Boets, Deroover et al 2015). The Embden-Meyerhof-Parnas pathway is the major pathway of glycolysis, and this pathway will convert monosaccharides to PEP which are then converted into pyruvate by pyruvate kinase in glycolysis (White, Drummond et al).…”