During the American Society for Microbiology Microbe 2017 New Orleans meeting, Contagion®
interviewed David Relman, MD, ASM Microbe 2017 Vice-Chair, Professor in Medicine, and Microbiology & Immunology at Stanford University on microbiome research and its potential utility in medicine.
CONTAGION®: Where Do You Think The Future of Medicine is Going with the Microbiome-Based Therapies?
This is a hard one to predict given so many uncertainties. First, microbiome research may help with diagnostics and prognostics to find patients at greater risk for developing infections like Clostridium difficile
. A second area may be in treatment, but I’m cautious as it is still not so simple. There are a few examples of therapeutically beneficial small molecules made by bacteria that have been identified. The third area is in prevention. It will be possible at some point to sort out what confers stability or resilience on a person that is about to enter hospitalization, take a drug, experience a surgical procedure, or is at risk of some disease condition. An intervention may involve provision of groups of organisms thought to be beneficial, followed by feeding of those organisms to keep them there. It is important to remember that data indicate that it is actually hard to instill an organism and get it to stay. So, we must know how to feed and promote said therapeutic groups of organisms.
C: Can We Get These Organisms Through a Pill, Instead of Insertion From Below?
Fecal transfer is being done in a pill, but it turns out you need more organisms to have an effect if you administer it orally than if you administer it rectally, but you need lots of pills, like 20-30 big pills a day, to get past the stomach. Some day we should be able to do this, for sure. There are many companies and researchers trying to sort out the minimum ecosystem needed, eg. 14 different strains for 14 different people. Then, the bacteria have to be fed appropriately or else they will be eliminated by selective advantage. The reason C. difficile
transplants work so well is that they are given to the person precisely at the time they are beginning their recovery from a bout with C. difficile
colitis. Most significantly, these people have a damaged ecosystem in their gut that is teetering and more vulnerable to elimination. If its left alone, it creates an inflammatory environment that most healthy bacteria cannot tolerate, while C. difficile
thrives. So, now that we understand this, the organisms must be fed properly during this time along with antibiotics targeting C. difficile
C: Can An Individual Also Experience Bacterial Effects From Frozen Vegetables in a "Food as Medicine" Paradigm?
Definitely this can help indirectly, in the sense that many fruits and vegetables will properly feed your beneficial organisms by providing fiber, and potentially directly, [by] providing therapeutic beneficial organisms. Freezing does not kill everything—organisms with spores, capsules, or strong cell walls can survive and then thrive. For example, in a study presented at this conference, a small molecule was identified in Lactobacillus
that inhibits the growth of antibiotic-resistant organisms. A few years ago, there was a study identifying a small molecule named lactocillin that is made by a different Lactobacillus
species that normally lives in the vagina. [The molecule] doesn’t affect healthy bacteria, but it does have potent antibacterial activity against a range of Gram-positive vaginal pathogens.