Published online Oct 7, 2018. doi: 10.3748/wjg.v24.i37.4254
Peer-review started: May 27, 2018
First decision: July 6, 2018
Revised: August 7, 2018
Accepted: August 24, 2018
Article in press: August 24, 2018
Published online: October 7, 2018
Recently, an upward trend has been observed in the incidence of ulcerative colitis (UC) leading to increased clinical attention on UC-associated carcinogenesis.
Existing treatment for UC in the prevention of carcinogenesis involves several risks and side effects with long-term usage. Finding new treatment regimens are essential.
To investigate the effects of VSL#3 on tumor formation, and fecal and intestinal mucosal microbiota in the azoxymethane/dextran sulfate sodium (AOM/DSS) induced mice model.
C57BL/6 mice were administered AOM/DSS to develop the UC-associated carcinogenesis model. The treatment group was gavaged with 5-ASA (75 mg/kg/d), VSL#3 (1.5 × 109 CFU/d), and 5-ASA + VSL#3 from the day of AOM injection for three months (five days/week). The tumor load was compared in each group, and tumor necrosis factor (TNF-α) and interleukin (IL)-6 levels evaluated in colon tissue. The stool and intestinal mucosa samples were collected to analyze the differences in the intestinal microbiota by 16s rDNA sequencing.
VSL#3 significantly reduced the tumor load in the AOM/DSS-induced mice model, and decreased the level of TNF-α and IL-6 in colon tissue. The model group had a lower level of Lactobacillus and higher level of Oscillibacter and Lachnoclostridium in fecal microbiota than the control group (UC-associated carcinogenesis not induced). Bacillus and Lactococcus were increased after the intervention with 5-ASA and VSL#3, while Lachnoclostridium and Oscillibacter were reduced. 5-ASA + VSL#3 increased the Lactobacillus and decreased the Oscillibacter. The intestinal mucosal microbiota analysis showed a lower level of Bifidobacterium and Ruminococcaceae_UCG-014 and higher level of Alloprevotella in the model group compared to the control group. Bifidobacterium was increased after supplementation with VSL#3. 5-ASA + VSL#3 increased the level of both Lachnoclostridium and Bifidobacterium.
In mice, VSL#3 can prevent UC-associated carcinogenesis, reduce the colonic mucosal inflammation levels, and is beneficial for rebalancing the fecal and mucosal intestinal microbiota.
VSL#3 may be a potential therapeutic agent for UC-associated carcinogenesis prevention based on the data presented here.