White kidney bean extract as a nutraceutical: effects on gut microbiota, alpha-amylase inhibition, and user experiences

David Houghton, Oliver Shannon, Peter Chater, Jeffrey Pearson, Matthew Wilcox, Kyle Stanforth, Cara Jordan, Leah Avery, Alasdair Blain, Abraham Joel, Ruth Jefferies, Ruth Nolan, Andrew Nelson, Christopher Stewart, Fiona Malcomson

Research output: Contribution to journalArticlepeer-review

8 Downloads (Pure)


White kidney bean extract (WKBE) is a popular nutraceutical, often advocated as an anti-obesity agent. The main proposed mechanism for these effects is alpha-amylase inhibition, thereby slowing carbohydrate digestion and absorption. Thus, it is possible that WKBE could impact the gut microbiota and modulate gut health.
We investigated the effects of supplementing 20 healthy adults with WKBE for one week in a randomised, placebo-controlled crossover trial on the composition of the gut microbiota, gastrointestinal inflammation, gastrointestinal symptoms, and stool consistency/frequency. We also conducted in vitro experiments and used a novel gut model system to explore potential inhibition of alpha-amylase, and gained qualitative insight into participant experiences of using WKBE via focus groups. WKBE supplementation for seven days significantly decreased the relative abundance of Bacteroidetes and increased the relative abundance of Firmicutes, however there were no significant differences in post-intervention gut microbiota measurements between the WKBE and Control treatment periods. Further, there were no significant effects on gastrointestinal inflammation (faecal calprotectin) or symptoms related to constipation (e.g., abdominal pain, discomfort or bloating, or constipation), or stool consistency or frequency. Our in vitro and gut model system analyses showed no effects of WKBE on alpha-amylase activity. Altogether, our findings suggest that WKBE may modulate the gut microbiota in healthy adults, however the underlying mechanism is unlikely due to active site inhibition of alpha-amylase.
Original languageEnglish
JournalGut Microbiome
Publication statusPublished - 1 Jun 2023


Dive into the research topics of 'White kidney bean extract as a nutraceutical: effects on gut microbiota, alpha-amylase inhibition, and user experiences'. Together they form a unique fingerprint.

Cite this