Spine Community News:s The human body is a combination of trillions of human cells and an equal number of bacteria that live in our gastrointestinal tract. The microbiome refers to all the genetic material of all these bacteria, both good and bad. Humans are colonized with “our” bacteria soon after birth and remain constant over a lifetime. This is a symbiotic relationship with microorganisms receiving elements that promote their growth while humans receive vitamins and amino acids. However, environmental factors like diet, probiotics, prebiotics (supplements that support the growth of specific bacteria), viruses, and drugs, like antibiotics, can alter our microbiome composition.
Gut bacteria are constantly interacting with the immune system that resides in the gastrointestinal tract. In most circumstances, our normal microbiome protects against foreign bacteria and the maintenance of the normal gut immunity. When abnormal organisms gain access to the gut, immune responses can occur that may cause local inflammation (inflammatory bowel disease), or systemic inflammation (ankylosing spondylitis).1 In animals inflammatory conditions like ankylosing spondylitis develops when the animals are exposed to specific bacteria. Animals that are born into a germ-free environment however do not develop the inflammation.
The question remains whether modifications of diet or bacteria can result in improvement in a specific illness. A variety of clinical trials with diet modifications including the Mediterranean diet, polyunsaturated oils, and limited animal proteins have been reported to have some benefit but trial results have not been consistent. In regard to probiotics, benefits in decreased immune activation may be associated with the use of Bacteroides fragilis.2 The benefits however require the use of probiotics indefinitely. Our understanding of the microbiome is in its infancy. The potential to benefit human disease by modification of the microbiome does exist. What modifications, for which disease, by specific mechanisms remains to be determined.
David Borenstein, MD
Executive Editor TheSpineCommunity.com
- Clemente JC et al. The role of the gut microbiome in systemic inflammatory disease. BMJ 2018; 360:5145 doi:10.1136/bmj.5145
- Stebbings SM et al. The immune response to autologous bacteroides in ankylosing spondylitis is characterized by reduced interleukin 10 production. J Rheumatol 2009;36:797-800