In vitro and in vivo evaluation of the effects of low molecular weight chitosan and chitooligosaccharides on the growth of certain intestinal bacteria

10.29822/JFST.202209_49(3).0002

Shun-Hsien Chang；Shu-Lin Chan；Guo-Jane Tsai

chitosan ； chitosan hydrolysate ； LMWC ； chitooligosaccharide ； fructooligosaccharide ； probiotic

臺灣水產學會刊

49卷3期（2022 / 09 / 01）

157 - 171

英文

The effects of three samples including chitosan hydrolysate, low molecular weight chitosan (LMWC) and chitooligosaccharide (COS) isolated from chitosan hydrolysate, on the growth of some intestinal bacteria were investigated in vitro using laboratory media and in vivo by oral feeding of Wistar rats as an animal model. The antimicrobial activity of three samples was evaluated in vitro against one strain of pathogenic Clostridium perfringens and 12 strains of probiotics, including 5 strains of Lactobacillus and 7 strains of Bifidobacterium. Overall, LMWC had the highest antibacterial activity, followed by chitosan hydrolysate, and COS activity was weak. Among the 13 tested strains, C. perfringenes was most susceptible to LMWC and chitosan hydrolysate, with minimum lethal concentrations (MLC) of 25 μg/mL and 50 μg/mL, respectively; while Bifidobacterium was the most resistant. Wistar rats were divided into 5 groups given normal saline as a control, or fructooligosaccharide (FOS) as a positive control, chitosan hydrolysate, LMWC and COS as the experimental groups, and the feeding dose was 3 g /kg body weight/ day. Although FOS and 3 test samples did not significantly alter the body weight gain, liver weight, and plasma cholesterol and triglyceride levels in rats, FOS and 3 test samples significantly increased the number of Bifidobacterium in the caecum and feces. In addition, FOS, chitosan hydrolysate and COS significantly reduced the number of C. perfringens in the caecum and feces. Functionally similar to FOS, COS can be utilized by species of Bifidobacterium and Lactobacillus.