Wholegrain foods made from a novel high-amylose barley variety (Himalaya 292) improve indices of bowel health in human subjects

Abstract

Himalaya 292 (Hordeum vulgare var. Himalaya 292) is a novel hull-less barley variety lacking activity of a key enzyme of starch synthesis giving a grain containing less total starch, more amylose and higher total dietary fibre. Animal trials have shown that Himalaya 292 contains more resistant starch and has greater positive impact on biomarkers of large-bowel health than comparable wholegrain cereal products. The present study compared the effects of foods made from wholegrain Himalaya 292 with those made from wholegrain wheat on faecal biomarkers of bowel health in human subjects. Seventeen male and female volunteers aged 31–66 years consumed similar quantities of Himalaya 292, whole-wheat or refined cereal foods daily for 4 weeks in a randomised cross-over design. Total dietary fibre intakes from weighed food records were 45, 32 and 21 g/d for the Himalaya 292, whole-wheat and refined cereal periods, respectively. Compared with the refined cereal foods, consumption of Himalaya 292 foods resulted in 33 % higher faecal weight, a lowering of faecal pH from 7·24 to 6·98, a 42 % higher faecal concentration and a 91 % higher excretion of butyrate, a 57 % higher faecal total SCFA excretion and a 33 % lower faecal p-cresol concentration. pH and butyrate concentration and excretion were also significantly different compared with wholemeal wheat. It is concluded that consumption of a diet that included foods made from Himalaya 292 supplied more fibre and improved indices of bowel health compared with refined cereal foods and, for some indices, similar wholemeal wheat foods at equivalent levels of intake.