Gut bacteria can boost response to immunotherapy
06 November 2017 09:27
Immunotherapy has a 25% success rate
Bacteria in the digestive system can affect how well some cancer patients respond to treatment, results from two new studies suggest.
According to the research, a "microbiome" found in the gut can help doctors determine whether immunotherapy drugs will be able to shrink cancerous tumours.
Tumours can trick the body into believing they are a cluster of healthy cells, causing the immune system not to act.
However, PD-1 inhibitor drugs - known as immunotherapy - block this process, sometimes for years at a time, and help the immune system fight the cancerous cells.
However, only a quarter (25%) of patients respond to the drugs.
Both studies have found that certain viruses, bugs and bacteria in the gut can boost the likelihood of a patient responding to PD-1 inhibitors, Science magazine reports.
Study one
Scientists at the Gustave Roussy Cancer Campus in Paris have found that taking antibiotics can hinder the effectiveness of immunotherapy.
Everyday medicines used to treat bacterial infections can disrupt gut bacteria, and cancer patients taking antibiotics are shown to relapse sooner.
Avoiding antibiotics can be seen to boost immunotherapy response rates to 40%, says Laurence Zitvogel, immunologist and leader of the study.
Study two
In Houston, Texas, research suggests patients with a variety of gut bacteria and those with specific types of microorganisms in the digestive system are more likely to respond well to immunotherapy.
Jennifer Wargo, of the MD Anderson Cancer Centre in Houston, says she is now planning to test patients' responses to faecal transplants in pill form.
In their separate efforts to manipulate gut bacteria, both research teams are hopeful that immunotherapy response rates will increase significantly.
Cancer patients can maintain a normal life and enjoy holidays and overseas trips by taking out pre-existing medical travel insurance.