The soluble fibers are degraded in the large intestine by the means of the bacterial enzymes. The bacteria present in the large intestine secretes enzymes that helps in the degradation of the many soluble fibers which are not digested in the stomach and the small intestine. The bacteria present in the large intestine of the humans include the Lactobacillus, E. coli, Clostridium, Enterococcus and many more.
Hence, the answer is 'bacterial enzymes'.