Research published in the journal Thyroid establishes for the first time that individuals with Hashimoto’s thyroiditis, the most common autoimmune disease in the United States and the primary cause of hypothyroidism in Americans, have significantly different gut microbiota, compared to the healthy population. This imbalanced mix of bacteria that contributes to symptoms and disease is known as gut dysbiosis.
Microbiota are the bacteria in the microbiome, an environment of microorganisms that all rely on each other. Gut microbiota — formerly called “gut flora” and sometimes “gut bacteria” — refers to the bacteria in your digestive and intestinal system.
The study compared a group of Hashimoto’s patients with a control group of healthy people. The researchers collected fecal samples and analyzed the gut microbiota of study participants. The researchers found that the general mix of bacteria was similar in both groups, but certain bacteria were seen at higher or lower levels in Hashimoto’s patients, as compared to the healthy control group.
While the list of bacterial changes seen in Hashimoto’s patients is long, there are a few notable highlights:
- One bacterium found to be in short supply in the Hashimoto's patients was faecalibacterium, which is usually abundant in the human gut microbiota. These bacteria ferment dietary fiber to produce butyrate, which helps immune function, and energy pathways.
Another bacterium that was decreased in Hashimoto’s is bacteroides. Low levels of bacteroides are associated with obesity, irritable bowel syndrome, and multiple sclerosis.
The ratio of firmicutes to bacteroides bacteria was significantly increased in people with Hashimoto’s compared to healthy controls. A low ratio is considered a marker for good health.
Decreases in Bifidobacterium were also seen. Bifidobacteria help maintain healthy immune function and protect the intestinal lining.
Researchers already know that certain infections are triggers for Hashimoto’s, including helicobacter pylori infection (the bacteria that causes ulcers), and viral infections such as hepatitis C virus, human parvovirus B19, enteroviruses (such as Coxsackie virus), and Epstein-Barr virus (the virus that causes mononucleosis).
Based on this research, the experts theorize that gut dysbiosis, with elevated levels of certain bacteria, and lower levels of others, are another trigger for Hashimoto’s. They believe that inflammation in the mucosal lining of the intestine exposes immune cells to bacteria and “dietary antigens” (foods you are allergic or sensitive to, and foods that cause inflammation). This leads to activation of the immune system, and ultimately, to development of autoimmune diseases.
What should Hashimoto’s patients do?
While more research is needed to put this information to effective use in terms of prevention and treatment of Hashimoto’s thyroiditis, there are some commonsense actions that you can take.
Avoid substances that create gut inflammation. These include alcohol, excessive caffeine, and inflammatory foods like sugar, gluten, soy, and for some people, dairy, eggs, or other foods that commonly trigger allergies and sensitivities.
Identify and treat any infections. You can start with a comprehensive stool analysis to identify parasitic, yeast, or bacterial infections, which can then be treated with supplements or medications as needed.
Ensure good digestion, which for many people, requires supplements such as digestive enzymes, bile acids, slippery elm, aloe vera, and fish oils.
Get enough prebiotics. Prebiotics promote the growth of beneficial bacteria. You can get prebiotics in supplements, and in the top prebiotic-rich foods, which include:
- Raw chicory root
- Raw Jerusalem artichoke/sunchoke
- Raw dandelion greens
- Reintroduce good bacteria to help restore balance. The most effective way is to take a probiotic supplement. You can learn more about probiotics in this article. You can also add more fermented foods to your diet.