Effect of oat β-glucan of different molecular weights on fecal bile acids, urine metabolites and pressure in the digestive tract - A human cross over trial

While the development of oat products often requires altered molecular weight (MW) of beta-glucan, the resulting health implications are currently unclear. This 3-leg crossover trial (n = 14) investigated the effects of the consumption of oat bran with High, Medium and Low MW beta-glucan (average 1000, 524 and 82 kDa respectively) with 3 consequent meals on oat-derived phenolic compounds in urine (UHPLC-MS/MS), bile acids in feces (UHPLC-QTOF), gastrointestinal conditions (ingestible capsule), and perceived gut well-being. Urine excretion of ferulic acid was higher (p < 0.001, p < 0.001), and the fecal excretion of deoxycholic (p < 0.03, p < 0.02) and chenodeoxycholic (p < 0.06, p < 0.02) acids lower after consumption of Low MW beta-glucan compared with both Medium and High MW beta-glucan. Duodenal pressure was higher after consumption of High MW beta-glucan compared to Medium (p < 0.041) and Low (p < 0.022) MW beta-glucan. The MW of beta-glucan did not affect gut well-being, but the perceptions between females and males differed.

Automated summary

The study found that consumption of low molecular weight beta-glucan led to higher excretion of ferulic acid in urine, and lower excretion of deoxycholic and chenodeoxycholic acids in feces. Consumption of high molecular weight beta-glucan resulted in higher duodenal pressure, while the molecular weight of beta-glucan did not affect perceptions of gut well-being, though perceptions differed between females and males.