Abstract:

This study was conducted to investigate the effects of soybean oligosaccharides (SBOS) on intestinal microbes
in vitro. Jejunum, ileum and cecal digesta collected from Huanjiang mini-pigs were used as the inoculum, and SBOS at
different concentrations namely 0, 0.5%, 1.0%, 2.0%, 5.0% and 8.0%, and 2.0% glucose were used as the substrates during
the in vitro fermentation. The slurry was fermented for 48 h in an anaerobic in vitro system, and then the intestinal microbes
were determined by terminal restriction fragment length polymorphism (T-RFLP) and real time-polymerase chain reaction
(RT-PCR) techniques. The results showed that SBOS increased the intestinal microbial diversity when compared with the
control group. With increasing addition of SBOS, the beneficial bacteria were increased firstly and then decreased, while
the bacterial pathogens were suppressed firstly and then enriched; 2.0% of SBOS, the optimal level, increased (P < 0.05)
Bifidobacterium in ileum and cecum, but decreased (P < 0.05) Escherichia and Streptococcus in cecum when compared with
the glucose group. These findings suggested that 2.0% SBOS could enrich beneficial intestinal microbes, but suppressed
bacterial pathogens in Huanjiang mini-pigs, which could effectively promote the diversity of the intestinal flora.

Key words: soybean oligosaccharides, fermentation, intestinal microbes