Efficient tumor targeting by anaerobic butyrate-producing bacteria.

Butyrate as an important short chain fatty acid has been shown to affect different kinds of cancer cells. Butyrate exerts its anti-cancerous effects by several mechanisms and has lead to successful outcomes in phase I and II clinical trials. Moreover, since solid tumors grow rapidly, multiple regions of hypoxia and anoxia forms within them that provide good niches for the growth of anaerobic bacteria. It has been shown that bacterial tumor targeting is an applicable strategy for tumor-selective therapy. Therefore, we propose that nonpathogenic anaerobic butyrate-producing bacteria may be a versatile tool in tumor therapy as they can grow in anoxic and hypoxic regions of tumors and influence tumor cells by producing butyric acid. Moreover, this approach may overcome the existing problems of butyrate delivery to the sites of tumor and enhance its bioavailability. Also reversion of cancer drug resistance by butyrate will be plausible. Tumor targeting with nonpathogenic anaerobic bacteria with a higher capacity to produce butyrate could be the focus of future research.