Published online Oct 7, 2014. doi: 10.3748/wjg.v20.i37.13258
Revised: April 2, 2014
Accepted: June 2, 2014
Published online: October 7, 2014
Gastric cancer is still the second leading cause of cancer death worldwide, accounting for about 10% of newly diagnosed neoplasms. In the last decades, an emerging role has been attributed to the relations between the intestinal microbiota and the onset of both gastrointestinal and non-gastrointestinal neoplasms. Thus, exogenous microbial administration of peculiar bacterial strains (probiotics) has been suggested as having a profound influence on multiple processes associated with a change in cancer risk. The internationally accepted definition of probiotics is live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. The possible effects on the gastrointestinal tract following probiotic administration have been investigated in vitro and in animal models, as well as in healthy volunteers and in patients suffering from different human gastrointestinal diseases. Although several evidences are available on the use of probiotics against the carcinogen Helicobacter pylori, little is still known about the potential cross-interactions among probiotics, the composition and quality of intestinal flora and the neoplastic transformation of gastric mucosa. In this connection, a significant role in cell proliferation is played by polyamines (putrescine, spermidine, and spermine). These small amines are required in both pre-neoplastic and neoplastic tissue to sustain the cell growth and the evidences here provided suggest that probiotics may act as antineoplastic agents in the stomach by affecting also the polyamine content and functions. This review will summarize data on the most widely recognized effects of probiotics against neoplastic transformation of gastric mucosa and in particular on their ability in modulating cell proliferation, paying attention to the polyamine metabolism.
Core tip: Studies linking probiotics and gastric neoplasms have mainly been addressed to evaluate the potential of probiotics as alternative regimen against Helicobacter pylori, a carcinogen tightly connected to gastric cancer. The effects of probiotics on gastric cell proliferation are still under investigation and interest has also been paid on the polyamines metabolism. Polyamines (putrescine, spermidine and spermine) are pivotal in regulating different metabolic functions, including cell proliferation. In this review, the authors try to summarize data on gastric cancer and the proposed abilities by probiotics in affecting the gastric integrity and cell proliferation, also in relation to the polyamine metabolism.