Juvenile Idiopathic Arthritis and the Gut

One study argues for analysis of the microbiome as a predictive tool.

Image Credit: National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health

I received a request to evaluate the research I could find on integrative, functional, and herbal treatments in Juvenile idiopathic arthritis. For new readers, Juvenile idiopathic arthritis is a non-specific catchall name encompassing everyone under the age of 16, experiencing arthritis of unknown cause, for six weeks or longer. You can learn more from its Diagnosis Description here. There are several sub-types of Juvenile idiopathic arthritis, with a growing body of evidence to suggest that different sub-types represent different disease processes. I list all the sub-types and write about one of them here. The study classification criteria for Juvenile idiopathic arthritis—including the sub-types—is currently undergoing a major overhaul that I think will have far-reaching implications for improved diagnostics. You can learn more about that here.

I Could Talk About Poop All Day: I’ve Had Jobs Where I Did

Fecal analysis and correction of gut flora has long been a focus of naturopathy. Examining poop is a common healthcare tool that’s non-invasive and can yield a great deal of information about a body’s health status. In the mid-aughts, even before I became a nurse, I was captivated by the concept of fecal transplants. Since then, I’ve followed the research on the gut microbiome implications of cesarean deliveries—bypassing the microbial colonization of the newborn that occurs during a vaginal delivery via a necessarily sterile procedure. Potential fix? Just smear that new baby with mom’s stool—and hopefully they eat some of it. I also wrote about how humans are fundamentally food-then-poop tubes here. I simply love learning about what poop can tell us.

A Little Anatomical Background

The gastrointestinal tract is anatomically considered to be external to the body. If you think of it in that way, the sheer variety of external exposures, through food and drink, matches or exceeds the daily exposures that your skin comes in contact with, or your lungs. And just like your lungs, your body has to make an exchange of nutrients that comes at a cost—exposure to potentially harmful things. Intestinal bacteria, their interaction with each other and the gut environment, can help with that exchange and protection, or can impede that exchange and fail to protect the body. In addition, immunity and the intestinal tract are tightly linked because of the need for a layer of immune protection surrounding this external tube traveling right through the middle of you.

I included the picture above because I find it so helpful to visualize the inner lining of the middle portion of the small intestine (jejunum) due to the astronomically large absorptive surface area it has. The larger the absorptive surface area, the larger the exposure to potentially harmful substances. The inner lining is packed with folds of specialized tissue called villi, which are, in turn, covered by many tinier protrusions. This article claims that if all of this surface area were flattened out, it would be the size of a tennis court. All of this absorptive surface area is designed to wring as much nutrients out of the food you eat as it possibly can, row by row by row by row. It can’t do this without the complex flora inhabiting its surface. The composition of that flora is influenced by the food you eat and drink, the stress you experience, the exercise you get, the exposure you have to infectious viruses and bacteria, and a whole host of other factors.

The Study

Qian et. al examined the stool of 40 study participants with Juvenile idiopathic arthritis (JIA) and 42 age, sex, and ethnicity matched controls (2020). This Venn diagram succinctly sums up the differences and overlap they found:

(Qian et. al, 2020)

“Venn diagram based on genera. The two groups have 83 shared genera, with 3 unique genera in the JIA group and 8 unique genera in the control group.” For bacteria and other gut biota, a genus, or genera, is more specific than the family-level taxonomy and less specific than the species-level taxonomy. The authors found that analysis at the genus level was the most meaningful. What strikes me is how much overlap there is, with relatively few differences to evaluate.

The authors found differences in the quantity of bacteria in the 83 genera that overlap between participants with Juvenile idiopathic arthritis and healthy controls. And specifically zeroed in on 12 shared genera that could be predictive for Juvenile idiopathic arthritis. Predictive, meaning a piece of the diagnostic puzzle. Here are those 12 genera, in the quantities they appear in the study participants and control group, compared.

(Qian et. al, 2020)

Two other notable points:

1. The authors did not include children with systemic Juvenile idiopathic arthritis in this study because they are convinced by the evidence that systemic Juvenile idiopathic arthritis is auto-inflammatory, not autoimmune. For more on auto-inflammation vs. autoimmunity, there’s a good article here.

2. The authors cite two studies that found that gut microbes end up in synovial fluid and liver tissue, respectively, with evidence that these interlopers trigger an autoimmune reaction. What? I’ve tabled this for further exploration in a future post.

What does this study have to do with integrative, functional, and herbal treatments?

This study is not characterized as any of the above, and it’s not a treatment. However, studies like these, when there are enough of them, can provide the scientific basis for stool analysis in suspected Juvenile idiopathic arthritis, which can lead to this type of analysis being part of the diagnostic picture. Although integrative, functional and herbal approaches to autoimmune disease do not focus exclusively on gut health, this is a large part of their focus, so I wanted to write a post that establishes some baseline knowledge of how the small intestine, particularly, functions. This week, I confined my search to PubMed and I struck out on the integrative, functional and herbal treatment evidence, as it relates to Juvenile idiopathic arthritis. Where I search defines what I find, and I have a few other avenues to explore in the coming weeks to see what evidence I can find.

Reference

Qian X, Liu YX, Ye X, Zheng W, Lv S, Mo M, Lin J, Wang W, Wang W, Zhang X, Lu M. Gut microbiota in children with juvenile idiopathic arthritis: characteristics, biomarker identification, and usefulness in clinical prediction. BMC Genomics. 2020 Apr 7;21(1):286. doi: 10.1186/s12864-020-6703-0. PMID: 32264859; PMCID: PMC7137182.