Selenium plays an extremely important role in our body's defense system, mainly due to its antioxidant properties. Chronic inflammatory processes can deplete this natural defense over time, increasing the severity of diseases. One of the main types of inflammatory bowel disease is ulcerative colitis, which is also characterized by the depletion of antioxidant defenses. This research looked at whether selenium supplementation could help reduce inflammation and improve patients' condition.

What is ulcerative colitis?

Ulcerative colitis is an inflammatory bowel disease that mainly affects the lining of the large intestine. The exact causes of the disease are still unknown and treatment is usually aimed at reducing symptoms. 
However, the drugs used to relieve symptoms can have many side effects, so several therapeutic strategies are being investigated that have the potential to improve patients' condition and are less harmful.

How might selenium help?

Since the 1980s, many researchers have observed that serum selenium concentrations in patients with ulcerative colitis are quite low. (1) And previous studies have shown that selenium concentrations correlate with disease activity and severity. (2) 
Based on a study in animal models, higher selenium intake increased the proportion of regulatory T-immune cells and reduced levels of the inflammatory marker IL-17, significantly reducing colonic inflammation and symptoms of histological damage.(3)
It is therefore hypothesized that selenium supplementation may alleviate the symptoms and severity of the disease, but there have been no high-quality human randomized trials  testing this in humans until now. (4)

The new study

Only participants who had not taken any medicines, selenium supplements or multivitamins in the past 1 month were selected. Patients were instructed not to change their normal diet during the study. There were no significant differences between participants in other health-relevant factors such as weight, smoking, alcohol consumption or drug use.
Those who met the inclusion criteria were randomly divided into two groups. One group was given an oral selenium capsule containing 200 mcg selenomethionine and the others were given a placebo capsule of the same size and appearance. In the end, 100 participants completed the 10-week study, with 44 and 45 successfully completing the two groups.
The main aspect studied was a SCCAI test assessing disease activity. The SCCAI is based on six clinical parameters that assess general well-being in addition to ulcerative colitis symptoms. Higher scores indicate the severity of the disease state in the past 2 weeks. 
Clinical improvement was defined as a reduction of at least 3 SCCAI scores from baseline, and clinical remission as a SCCAI score of less than 2 at week 10. 
Secondary factors examined included another questionnaire test assessing participants' quality of life, two inflammatory markers (IL-10 and 17) and changes in serum selenium levels.Results
At baseline, there were no significant differences between the two groups and inflammatory markers (IL-10 and IL-17) were similar.

• The 10 weeks of selenium supplementation reduced the SCCAI test score by an average of 1.8 points, so the patients' condition improved, while it worsened in the placebo group. 
• 38% of the selenium-supplemented group (19 participants) enjoyed clinical improvement, i.e. a reduction of 3 points, while only 6% of the placebo group (3 participants) did. 
• The clinical remission at the end of the study was 20% in the selenium-supplemented group (10 participants) compared to only 4% (2 participants) in the placebo group.
• The pro-inflammatory marker IL-17 was significantly reduced by selenium supplementation, while it remained unchanged in the placebo group. There was no significant change in IL-10 levels.
• As expected, selenium supplementation increased blood levels of selenium.

The researchers found that selenium supplementation of 200mcg/day for 10 weeks can improve clinical symptoms and even lead to remission in patients with mild to moderate active ulcerative colitis.

 
Other studies with similar results

In a study published in 1997, supplementation with 2 x 300 mcg selenium per day for 4 weeks significantly improved clinical symptoms of ulcerative colitis. (5) 
Consistent with these results, another study demonstrated that a combined supplement of 500 mg curcumin, 250 mg green tea extract and 100 mcg selenomethionine reduced colitis symptoms and disease activity after 8 weeks in patients with mild to moderate colitis. (6)

Summary

Unfortunately, inflammatory bowel disease can severely limit what food you can eat, and patients often don't dare to eat enough for fear of symptoms. This in itself increases the risk of micronutrient deficiencies, but chronic inflammatory processes can exhaust the body even more.
Research suggests that 85% of people with inflammatory bowel disease suffer from some form of micronutrient deficiency... (7)
Trace minerals such as selenium tend to receive little attention, even though there are many areas of selenium deficiency and it is easy to develop a deficiency. If you have an inflammatory disease of the digestive tract, you need to take extra care to prevent deficiencies of selenium and other trace elements, as this can aggravate the disease condition.