The thyroid gland, a small, butterfly-shaped gland located in the front of the neck, plays an important role in regulating metabolism and energy utilisation by producing and distributing thyroid hormones. However, when the gland malfunctions, it can cause various problems, including digestive issues. Many individuals with chronic gastrointestinal problems struggle to find relief due to undiagnosed thyroid conditions.
Hypothyroidism is a condition where the body doesn’t produce enough thyroid hormone, which can slow down the body’s processes. This can lead to several symptoms such as fatigue, dry skin, depression, forgetfulness, constipation and weight gain. If you have an underactive thyroid, you may also experience digestive symptoms like bloating, chest pain, low stomach acid, poor absorption, food sensitivities, constipation, gallstones, anaemia and bacterial overgrowth in the small intestine.
T3, which is the active thyroid hormone, plays a crucial role in maintaining the health and repair of the intestines. Unfortunately, most conventional medicine only supports T4, which is the inactive thyroid hormone. This results in people continuing to suffer from inflammation, gut issues, and common low thyroid symptoms such as weight gain, fatigue, dry skin, and hair loss. This is why many clients who come to us start feeling better when we support T3. Chronic inflammation can hinder the conversion of T4 to T3, along with poor liver health and nutrient deficiencies. We can support all of this through dietary changes and supplements.
The thyroid gland can significantly impact the gastrointestinal system. It is a common misconception that chronic digestive trouble and weight changes are solely caused by diet.
Testing for Thyroid and Gut Health
If you notice weight gain, constipation, dry or dehydrated skin, and brittle hair, it may be worth looking more closely at your thyroid function.
The thyroid plays a central role in metabolism, energy and digestion, yet we often see suboptimal thyroid function missed, particularly when standard NHS testing appears “normal”.
In clinic, we use a comprehensive Thyroid Test Package which includes an at-home finger prick blood test measuring key markers such as TSH, Free T4, Free T3, thyroid antibodies, Active B12, Vitamin D, ferritin and hs-CRP. This provides a more complete picture of how the thyroid is functioning.
We often see raised cholesterol on our Comprehensive Blood Test Panels in clients who also have low thyroid function, and in many cases this has been missed for years. It is often treated as a standalone issue, and some clients have even been put on statins, when the root cause hasn’t actually been addressed. Thyroid hormones directly influence how well the liver processes cholesterol and produces bile, which is needed for fat digestion and clearing excess cholesterol through the gut. When thyroid function is low, bile flow tends to slow, so cholesterol is not cleared efficiently and starts to build up in the bloodstream. This is why we often see it alongside bloating, poor fat digestion or constipation. Clinically, when we improve thyroid function, we regularly see digestion improve and cholesterol come down as a result.
We also offer a comprehensive GI-MAP stool test for those experiencing digestive symptoms. This assesses factors such as infections, inflammation, enzyme production, fat digestion and the balance of bacteria in the gut, helping us understand what may be driving ongoing symptoms.
In terms of targeted support, my PCH Meta-Boost is one of the key supplements I use in clinic for women with thyroid-related symptoms. It contains nutrients including iodine, selenium, zinc, chromium and vitamin B6, which support thyroid hormone production, conversion and metabolic function.
If you are unsure where to start, the best first step is to book a Discovery Consultation with one of our practitioners. They will assess your symptoms and health history, and guide you on the most appropriate testing and next steps for you.
