What is Big Think?  

We are Big Idea Hunters…

We live in a time of information abundance, which far too many of us see as information overload. With the sum total of human knowledge, past and present, at our fingertips, we’re faced with a crisis of attention: which ideas should we engage with, and why? Big Think is an evolving roadmap to the best thinking on the planet — the ideas that can help you think flexibly and act decisively in a multivariate world.

A word about Big Ideas and Themes — The architecture of Big Think

Big ideas are lenses for envisioning the future. Every article and video on bigthink.com and on our learning platforms is based on an emerging “big idea” that is significant, widely relevant, and actionable. We’re sifting the noise for the questions and insights that have the power to change all of our lives, for decades to come. For example, reverse-engineering is a big idea in that the concept is increasingly useful across multiple disciplines, from education to nanotechnology.

Themes are the seven broad umbrellas under which we organize the hundreds of big ideas that populate Big Think. They include New World Order, Earth and Beyond, 21st Century Living, Going Mental, Extreme Biology, Power and Influence, and Inventing the Future.

Big Think Features:

12,000+ Expert Videos


Browse videos featuring experts across a wide range of disciplines, from personal health to business leadership to neuroscience.

Watch videos

World Renowned Bloggers


Big Think’s contributors offer expert analysis of the big ideas behind the news.

Go to blogs

Big Think Edge


Big Think’s Edge learning platform for career mentorship and professional development provides engaging and actionable courses delivered by the people who are shaping our future.

Find out more

Arthritis and Gut Bacteria

November 13, 2013, 12:01 AM

It's well known that the 10 to 100 trillion bacterial cells that live in the human intestinal tract (comprising the gut microbiome) help digest food, provide essential micronutrients, and keep harmful bacteria from overwhelming us. Disturbances in the gut microbiome (so-called dysbiosis) have been associated with various illnesses, such as colorectal cancer, obesity, and IBS (irritable bowel syndrome),  with a possible role, also for Alzheimer's disease and other abnormalities of the brain.

To this list, we can now add rheumatoid arthritis (RA).

Earlier this month, Jose Scher and his colleagues, in a report published in eLIFE, presented evidence (based on DNA sequencing of 16S ribosomal genes) that sufferers of newly diagnosed, as-yet-untreated RA have a gut biome that is significantly enriched in Prevotella copri, a bacterium that exists as a minority species in the normal microbiota.

Overall, 75% of new-onset untreated rheumatoid arthritis (NORA) patients had P. copri versus 11.5% for chronic, treated AR patients and 21.4% of healthy controls.

To see if the Prevotella-associated metagenome is sufficient to predispose to increased inflammatory responses, antibiotic-treated mice were colonized with P. copri by oral gavage. Analysis of DNA extracted from fecal samples two weeks post-gavage confirmed robust colonization with P. copri. Said the researchers:

In comparison to fecal DNA from mice gavaged with media alone, P. copri-colonized mice had reduced Bacteroidales and Lachnospiraceae... Consistent with a previous report of a Prevotella taxon exacerbating an inflammatory phenotype (Elinav et al., 2011), exposure of P. copri-colonized mice to 2% dextran sulfate sodium (DSS) in drinking water for 7 days resulted in more severe colitis as assessed by enhanced weight loss, worse endoscopic score, and increased epithelial damage on histological analysis when compared to littermate controls gavaged with media alone... These data suggest that a Prevotella-defined microbiome may have the propensity to support inflammation in the context of a genetically susceptible host.

It is well established that RA is a multifactorial disease that occurs in sequential phases. Typically, the disease is preceded by a prolonged period of autoimmunity (i.e., presence of circulating auto-antibodies), in a pre-clinical state that lasts many years, during which time one sees no clinical or histologic evidence of inflammatory arthritis. With the onset of clinical disease, auto-antibodies increase along with circulating pro-inflammatory cytokines. This has led to the so-called "second-event" hypothesis in RA, which proposes that an environmental factor of some kind triggers systemic joint inflammation in the context of pre-existent autoimmunity. A change in the gut microbiome (of a kind that favors Prevotella copri) might be the final triggering event.

The report by Scher et al. by no means proves a causal role for gut bacteria in development of RA, but it adds new handwriting on the wall (saying that gut bacteria may very well play a role in development of RA) and points the way to new research and/or additional prevention and treatment options (perhaps involving probiotics and/or fecal transplant technology). If nothing else, it underscores the importance of gut bacteria (which outnumber human cells ten-to-one) in keeping our bodies healthy and points up the fact that the human body is, at the end of the day, an ecosystem that (like any other ecosystem) relies on a delicate balance between competing and cooperating elements for its ongoing successful existence.


Arthritis and Gut Bacteria

Newsletter: Share: