Gastrointestinal hormone modulation after a double-blind interventional study with unavailable carbohydrates

Abstract

The intake of unavailable carbohydrates—functional ingredients—has presented an inverse relationship with the risk for non-communicable diseases. Inulin and unripe banana flour (UBF) (source of resistant starch—55%) are among these ingredients. The aim of this work was to evaluate the impact of regular and discontinued intake of inulin or UBF on the plasma levels of gastrointestinal hormones and energy intake in healthy volunteers. A medium-term clinical assay was conducted with healthy volunteers, both males and females (n=33), who were oriented to consume soup with added inulin (INU group), UBF (UBF group) or maltodextrin (Control group) three times a week for six weeks. Prototypes of two different types of frozen soups were provided by a food industry. The plasma concentration of satiety-related gastrointestinal hormones was evaluated before and at the end of the intervention. Blood collection was performed 180min after the consumption of breakfast ad libitum. The energy intake was evaluated at the subsequent meal (180min). UBF consumption (8g) caused significant changes in the plasmatic levels of the gastrointestinal hormones when compared to the period before the intervention: there was a lower increase in ghrelin (T0, T60, T120 and T180min) and a decrease in insulin (T0 and T180min), hormones related to hunger, when at high levels, as well as an increase in peptide YY (PYY) at all timepoints. When comparing the Control and UBF groups at the end of the intervention, the latter presented a reduction in ghrelin (T0, 120 and 180min) and insulin (T0 and 180min) and an increase in PYY (T30 and 180min). The consumption of inulin (8g), compared to the period before and at the end of the intervention, resulted in a lower increase in ghrelin (T0, T120 and T180min) and a decrease in insulin (T180min). PYY also increased at all timepoints, which indicates higher satiety. When the Control and INU groups were compared at the end of the intervention, the INU group presented reductions in ghrelin (T0, 120 and 180min) and insulin (T180min) and an increase in PYY (T180min). At the subsequent meal, there was a reduction in energy intake of approximately 15% (129kJ) for the UBF and 12% (130kJ) for the INU groups. Both inulin and UBF present positive effects on gastrointestinal hormones and energy intake and may be used for producing products that stimulate healthy eating habits.