Evaluation of viability Bifidobacterium animalis subsp. lactis LKM512 in dogs

In dogs, gastric acid is not neutralised even when a meal is present in the stomach. Moreover, dogs take longer to digest their meals than humans do. Accordingly, the most important characteristic of any probiotics considered for use in dogs is high acid tolerance. The probiotic strain Bifidobacterium animalis subsp. lactis LKM512 (hereafter referred to as LKM512) not only exhibits potent acid tolerance, but also has the ability to adhere to intestinal mucin. The aim of the present study was to explore the potential of LKM512 as a probiotic in dogs. Specifically, we investigated whether LKM512 can survive in the large intestine in dogs. LKM512 preparations containing 10(10) cfu were administered daily for 14 days in five dogs. Faeces were collected on the day before administration (day 0) as well as on days 7 and 14, and 7 days after administration was halted (day 21). The numbers of viable LKM512 present in faeces were determined by both culture-based techniques and molecular analysis. Changes in intestinal bacterial populations were analysed by 16S rRNA gene semiconductor sequencing using the Ion Torrent Personal Genome Machine (PGM). On days 7 and 14, the numbers of viable LKM512 that were detected in faeces by culture-based techniques and molecular analysis were greater than the original daily dosage. 16S rRNA gene sequence analysis using the PGM indicated that relative proportions of Bifidobacterium spp. and Bifidobacteriaceae were significantly higher after administration than before. The present study demonstrated that LKM512 can survive strong gastric acid, and proliferate in the large intestine of dogs. Therefore, LKM512 may be a useful canine probiotic.