Oral inoculation of probiotics Lactobacillus acidophilus NCFM suppresses tumour growth both in segmental orthotopic colon cancer and extra-intestinal tissue

Br J Nutr. 2012 Jun;107(11):1623-34. doi: 10.1017/S0007114511004934. Epub 2011 Sep 30.


Modulation of the cellular response by the administration of probiotic bacteria may be an effective strategy for preventing or inhibiting tumour growth. We orally pre-inoculated mice with probiotics Lactobacillus acidophilus NCFM (La) for 14 d. Subcutaneous dorsal-flank tumours and segmental orthotopic colon cancers were implanted into mice using CT-26 murine colon adenocarcinoma cells. On day 28 after tumour initiation, the lamina propria of the colon, mesenteric lymph nodes (MLN) and spleen were harvested and purified for flow cytometry and mRNA analyses. We demonstrated that La pre-inoculation reduced tumour volume growth by 50·3 %, compared with untreated mice at 28 d after tumour implants (2465·5 (SEM 1290·4) v. 4950·9 (SEM 1689·3) mm³, P<0·001). Inoculation with La reduced the severity of colonic carcinogenesis caused by CT-26 cells, such as level of colonic involvement and structural abnormality of epithelial/crypt damage. Moreover, La enhanced apoptosis of CT-26 cells both in dorsal-flank tumour and segmental orthotopic colon cancer, and the mean counts of apoptotic body were higher in mice pre-inoculated with La (P<0·05) compared with untreated mice. La pre-inoculation down-regulated the CXCR4 mRNA expressions in the colon, MLN and extra-intestinal tissue, compared with untreated mice (P<0·05). In addition, La pre-inoculation reduced the mean fluorescence index of MHC class I (H-2Dd, -Kd and -Ld) in flow cytometry analysis. Taken together, these findings suggest that probiotics La may play a role in attenuating tumour growth during CT-26 cell carcinogenesis. The down-regulated expression of CXCR4 mRNA and MHC class I, as well as increasing apoptosis in tumour tissue, indicated that La may be associated with modulating the cellular response triggered by colon carcinogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / metabolism
  • Adenocarcinoma / pathology
  • Adenocarcinoma / prevention & control*
  • Adenocarcinoma / secondary
  • Animals
  • Anticarcinogenic Agents / therapeutic use*
  • Apoptosis
  • Cell Line, Tumor
  • Colonic Neoplasms / metabolism
  • Colonic Neoplasms / pathology
  • Colonic Neoplasms / prevention & control*
  • Female
  • Gene Expression Regulation, Neoplastic
  • Genes, MHC Class I
  • Lactobacillus acidophilus*
  • Lymphatic Metastasis / pathology
  • Lymphatic Metastasis / prevention & control
  • Mice
  • Mice, Inbred BALB C
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism
  • Neoplasm Transplantation
  • Probiotics / therapeutic use*
  • RNA, Messenger / metabolism
  • Random Allocation
  • Receptors, CXCR4 / genetics
  • Receptors, CXCR4 / metabolism
  • Splenic Neoplasms / metabolism
  • Splenic Neoplasms / pathology
  • Splenic Neoplasms / prevention & control
  • Splenic Neoplasms / secondary


  • Anticarcinogenic Agents
  • CXCR4 protein, mouse
  • Neoplasm Proteins
  • RNA, Messenger
  • Receptors, CXCR4