Microbiome Bites May 17th: Meta-analysis of Published Microbiome Studies Finds Disease-Specific Microbiome Patterns
We usually cover multiple studies in these posts; however, I think this study warrants a dedicated post.
The scientific literature relating to the microbiome is growing at a rapid pace, with hundreds of clinical studies published.
These studies cover a wide variety of diseases and often use different methodologies making it difficult to generalize this knowledge.
Often, case-control studies report finding disease-associated “dysbiosis”, which is a somewhat-vague way of saying the gut microbiome of patients in the disease group being studied, looks different from the non-disease (healthy) group.
We currently lack a precise way of defining how the microbiome (as a whole) and the specific microbes therein (both good and bad), cause, respond to, or contribute to disease.
But that’s about to change…
This week, a group of researchers, headed by Eric Alm out of MIT, have introduced the MicrobiomeHD database to bioRxiv (pre-publication, not yet peer-reviewed).
The database includes 29 published case-control gut microbiome studies covering 10 different diseases.
The research team reanalyzed the raw data and disease metadata from each study and asked whether consistent and specific disease-related changes could be seen in gut microbiomes from multiple studies of the same disease.
What did they find?
Some diseases, such as colorectal cancer, are defined by an overabundance of disease-related bacteria.
While other diseases, such as inflammatory bowel disease (IBD), are characterized by a depletion of health-associated bacteria.
Some conditions, such as diarrhea, involve large-scale community changes.
Finally, and perhaps most-importantly, most bacterial associations are not specific to any one disease but general to all.
In-fact over 60% of bacteria associated with individual disease fall into this core group of health and disease-associated microbes.
This research could directly inform microbiome-based diagnostics and treatments.
For example, patients with diseases characterized by depletion of healthy bacteria may benefit most from prebiotic and probiotic treatments designed to supplement these missing bacteria. Conditions with large-scale community changes (like C. difficile infections) might respond better to fecal microbiota transplants.
Perhaps most-importantly, identifying a core set of health and disease-responsive bacteria suggests there’s a possibility of developing a general microbiome treatment for a variety of microbiome-related conditions.
A probiotic containing the core health and disease-associated bacteria could be on the cards.