The efficacy of prevention for colon cancer based on the microbiota therapy and the antitumor mechanisms with intervention of dietary <i>Lactobacillus</i>Original paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This animal study tested whether oral Lactobacillus probiotics (strains JY300-8 and JMR-01) prevent and treat colon cancer. It also probed the antitumor mechanism through gut microbiota and their metabolites. Probiotics were given for 20 days before tumour induction, then continued during treatment. Researchers combined 16S rRNA microbiome sequencing with untargeted metabolomics of feces, plus cell-culture proliferation assays on colon cancer cell lines.
Who was studied?
The main model was male BALB/c mice, 6 weeks old, split into three groups of 30: tumour control, living bacteria, and inactivated bacteria. Subcutaneous colon tumours were induced with CT26 cells. Cell experiments used murine CT26 cells and human colorectal adenocarcinoma lines HT29 and HCT116. This was a preclinical in vivo and in vitro study, not a human trial. Six fecal samples per group were profiled.
What were the most important findings?
Oral probiotics cut the tumour formation rate from 96.67% in controls to 13.33% with living bacteria and 16.67% with inactivated bacteria. Mean tumour volume fell by about 65.2% and 61.19% versus control. Survival at 30 days was 100% with living bacteria versus 93.33% in control and inactivated groups. In culture, probiotics inhibited HT29 and HCT116 growth by 72.02% and 66.76% at 48 hours. Probiotics depleted L-serine, lowering sphingosine and bile acids like deoxycholic acid, while enriching beneficial taxa.
What are the greatest implications of this study?
The results suggest Lactobacillus probiotics could be a safe strategy to help prevent and slow colon cancer, acting through gut microbiota and metabolites. A key proposed mechanism is serine restriction that lowers sphingosine and dampens sphingosine 1-phosphate signalling. Reducing cancer-promoting metabolites like deoxycholic acid and pyrimidine substrates may further constrain tumour growth. These findings come from mouse and cell models, so they cannot be assumed to apply to people. Human trials are needed.