Association between Hypothyroidism and Small Intestinal Bacterial Overgrowth
Talk about the complicated web that makes up our physiology!! In this small study, it was determined that 54% patients with hypothyroidism due to autoimmune thyroiditis had small bowel bacterial overgrowth (SMBO). So what are the connections? First, we know that anti-secretory therapy for ulcers leads to bacterial overgrowth as well.
Then, we know that SMBO has been linked to fatty liver (at first seems like a stretch, but SMBO will lead to leaky gut, allowing larger molecules to get absorbed and head straight to the liver, where the liver now has to deal with the burden). We also know that a large percentage of patients with autoimmune thyroiditis have celiac disease, which further disrupts the integrity of the GI tract.
So, we end up with an upregulation of the immune system as a result of the leaky gut, increasing our likelihood of an autoimmune condition. This can be a perfect example of a feed forward cycle, where an initial disruption in physiology leads to other problems, with these “other problems” feeding back into the cycle and making the initial disruption worse!!