The effects of prebiotic bread containing oat ß-glucan and resistant starch on the glycemic index and glycemic load in healthy individuals

The enrichment of bread with non-digestible prebiotic ingredients may exert health-promoting effects and provide healthier food choices for those suffering from metabolic diseases, including obesity and diabetes. The purpose of this study was to investigate the effects of ß-glucan and resistant starch incorporation on the glycemic index (GI) and glycemic load (GL) of white bread.

Seven different formulations of prebiotic bread were produced using different proportions of ß-glucan (0.8, 1 and 1.2 per cent), resistant starch (5.5, 8 and 10.5 per cent) and the combination of resistant starch and ß-glucan in a ratio of 4:0.5.

The GI and GL of the prebiotic bread prepared with 1 per cent ß-glucan (w/w) were 55.7 and 7.8, respectively, whereas those of the prebiotic bread prepared with 8 per cent resistant starch (w/w) were 64.8 and 8.42, respectively, with both breads having significantly lower GI and GL values than the control (P < 0.05). It was concluded that the incorporation of 1 per cent ß-glucan may be beneficial in producing prebiotic bread with both low GI and low GL.

Although white bread is a main food source in human diet, its high GI and GL make it an unhealthy food choice. The incorporation of ingredients with prebiotic effects, such as ß-glucan and resistant starch, can improve the nutritional value of this product by lowering its GI and GL.