The protective effects of high amylose maize (amylomaize) starch granules on the survival of Bifidobacterium spp. in the mouse intestinal tract.

The possibility of using high amylose maize starch granules as a delivery system for probiotic bacteria has been investigated using Bifidobacterium spp. LaftiTM 8B and LaftiTM 13B which were isolated from a healthy human. The Bifidobacterium cells were able to adhere to the amylomaize starch granules and were also able to hydrolyse the starch during growth. Initially, in vitro studies were carried out by studying the survival of strains Bifidobacterium LaftiTM 8B and LaftiTM 13B when exposed to pH 2.3, 3.5 and 6.5 as well as 0.03 and 0.05% w/v bile acids. Both strains were grown either in the absence or presence of high amylose maize starch granules, then mixed with the high amylose maize starch granules and exposed to acidic buffers or bile acid solutions. It was shown that growth in and the presence of high amylose maize starch granules led to enhanced survival of strains LaftiTM 8B and LaftiTM 13B. Subsequently, survival in vivo was monitored by measuring the faecal level of Bifidobacterium LaftiTM 8B after oral administration of the strain to mice. A sixfold better recovery of strain LaftiTM 8B from mice faeces after oral dosage was noted for cells grown in amylose-containing medium compared with controls. It was concluded that high amylose maize starch granules contributed to enhanced survival of Bifidobacterium sp. LaftiTM 8B and LaftiTM 13B.