The Impact of Broad Bean Hull on Blood Glucose Control and Gut Health

The study aims to confirm in vivo the effects of consuming broad bean hull on blood glucose control and gut health. Although in vitro evidence is promising, its benefits remain confirmed in vivo in humans. No studies have previously attempted to assess the impact of broad bean hull consumption on glycaemic and gut health outcomes in humans. Therefore, this study will be novel and provide useful information on the potential of using BBH as a functional food for human health. From a health perspective, it is essential to establish the bioavailability and metabolism of dietary constituents in humans. Certain metabolites are absorbed early in the gastrointestinal tract, whereas others are transported to the colon, where they are extensively metabolised by the gut microbiota. This study will characterise the bioactive metabolites present in the plasma and faecal samples obtained. This will inform on their availability to the systemic circulation and their excretion profiles. Using targeted quantitative analysis (LC-MS and GC-MS), metabolites and their in vivo concentrations will be measured. The principal metabolites analysed will be those produced by the phenylpropanoid pathway and protein and carbohydrate metabolism products. These will include derivatives and metabolites of the simple phenols, benzoic acids, phenolic acids, phenylacetic acids, phenypropionic acids, phenylpyruvic acids, phenyllactic acids, mandellic acids, phenolic dimers, acetophenones, benzaldehydes, cinnamaldehydes, benzyl alcohols, cinnamyl alcohols, indoles, isoflavones, coumarins, chalcones, flavanones, flavones, flavonols, anthocyanidins. Furthermore, short-chain fatty acids will be analysed in the participants' faecal samples. It has been shown that many of these compounds are bioactive and exhibit anti-oxidant and anti-inflammatory activity at in vivo concentrations. Therefore, these studies will provide important information on bioavailability and metabolism and correlate the indices with health biomarkers. In addition, compounds such as the carcinogenic heterocyclic amines, genotoxic nitrosamines, indoles, polyamines, bile acids, and other protein metabolites considered detrimental to human health will also be measured. It is likely, the carbohydrate and phytochemical content of plant proteins may also protect against the formation of these toxic and potentially carcinogenic protein by-products.