The human intestinal microbiota is a community of 10(13)-10(14) microorganisms that harbor in the intestine and normally participate in a symbiotic relationship with human. Technical and conceptual advances have enabled rapid progress in characterizing the taxonomic composition, metabolic capacity and immunomodulatory activity of the human intestinal microbiota. Their collective genome, defined as microbiome, is estimated to contain > or =150 times as many genes as 2.85 billion base pair human genome. The intestinal microbiota and its microbiome form a diverse and complex ecological community that profoundly impact intestinal homeostasis and disease states. It is becoming increasingly evident that the large and complex bacterial population of the large intestine plays an important role in colorectal carcinogenesis. Numerous studies show that gut immunity and inflammation have impact on the development of colorectal cancer. Additionally, bacteria have been linked to colorectal cancer by the production of toxic and genotoxic bacterial metabolite. In this review, we discuss the multifactorial role of intestinal microbiota in colorectal cancer and role for probiotics in the prevention of colorectal cancer.
Animals ; Bacteroides/metabolism ; Colorectal Neoplasms/immunology/*microbiology ; Fatty Acids, Nonesterified/metabolism ; Humans ; Hydrogen Sulfide/metabolism ; Intestinal Mucosa/immunology/microbiology ; Metagenome ; *Probiotics ; Reactive Oxygen Species/metabolism ; Toxins, Biological/metabolism

OBJECTIVETo investigate the effect of perioperative application of intestinal probiotics to substitute oral intestinal antimicrobial agents on intestinal flora and immune function in surgical patients with colorectal cancer.

METHODSSixty patients with colorectal cancer undergoing elective laparoscopic radical surgery were randomized to receive preoperative bowel preparation using oral intestinal antimicrobial agents (n=20) or using oral intestinal probiotics (Jinshuangqi Tablets, 2.0 g, 3 times daily) since the fifth day before the operation and at 24 h after the operation for 7 consecutive days. Upon admission and 7 days after the operation, fecal samples and fasting peripheral venous blood were collected from the patients to examine the intestinal flora and serum levels of interleukin-2 (IL-2), IgA, IgG, and IgM, NK cell activity, T lymphocytes subsets CD3(+), CD4(+), CD8(+) and CD4(+)/CD8(+) ratio.

RESULTSAt 7 days after the operation, the patients receiving probiotics showed significantly increased counts of intestinal Bifidobacterium, Lactobacillus, and Enterococcus (P<0.05) and significantly lowered counts of Escherichia coli and Staphylococcus aureus (P<0.05). The serum levels of IL-2, IgA, IgG and IgM as well as CD4(+) cell percentage all increased significantly in probiotics group compared with those in patients with conventional intestinal preparation (P<0.05).

CONCLUSIONSPerioperative application of intestinal probiotics to replace preoperative oral intestinal antimicrobial agents can effectively correct intestinal flora imbalance and improve the immune function of surgical patients with colorectal cancer.

Aged ; Bifidobacterium ; Colorectal Neoplasms ; immunology ; microbiology ; Female ; Humans ; Intestines ; microbiology ; Intraoperative Period ; Male ; Middle Aged ; Premedication ; Probiotics ; therapeutic use ; Prospective Studies ; Single-Blind Method

OBJECTIVETo investigate the effect of preoperative use of viable Bifidobacterium supplement on the intestinal flora, immune status, inflammatory response and prognosis of patients undergoing colorectal cancer resection.

METHODSSixty patients with colorectal cancer were randomized into treatment group (n=30) and control group (n=30). Patients in the treatment group received oral viable Bifidobacterium with routine enteral nutrition and patients in the control group received routine enteral nutrition alone. The intestinal flora of stool was analyzed and stool SIgA, serum IgG, IgM, IgA, IL-6, and C-reactive protein (CRP) were detected.

RESULTSPostoperative Bifidobacterium/E.coli (B/E) ratio in the treatment group decreased significantly as compared to the preoperative ratio (2.01+/-0.36 vs 26.53+/-4.22, P<0.05). However, the ratios remained above one. Both preoperative and postoperative B/E ratios in the control group (0.72+/-0.14, 0.02+/-0.06) were significantly lower than those in the treatment group (P<0.05). Indexes of immunity and inflammation were not significantly different between the two groups (P>0.05). At day 9 after operation, stool SIgA was higher in the treatment group, while serum IgG, IgM, IgA, IL-6, CRP in the treatment group were lower (P<0.05). Postoperative septic complications in the treatment group was less than that in the control group (P<0.05), but other complications and hospital stay were comparable.

CONCLUSIONSIn patients with colorectal cancer, supplementation of viable Bifidobacterium before surgery can improve bacterial dysbiosis and immunity, and can reconstruct the balance of intestinal flora, and reduce infection complication of surgery.

Adult ; Aged ; Aged, 80 and over ; Antibodies ; blood ; Bifidobacterium ; C-Reactive Protein ; analysis ; Colorectal Neoplasms ; immunology ; microbiology ; therapy ; Female ; Humans ; Inflammation ; Interleukin-6 ; blood ; Male ; Middle Aged ; Postoperative Period ; Probiotics ; therapeutic use