Ulcerative Colitis: Symptoms, Treatment, and the Role of the Gut Microbiota

What is Ulcerative Colitis?

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) characterized by inflammation and ulceration of the colonic mucosa. Unlike irritable bowel syndrome (IBS), which is a functional disorder without visible damage, ulcerative colitis leads to structural changes in the intestinal wall. This condition can manifest in various ways, from mild to severe, and significantly impairs patients' quality of life.

Symptoms of Ulcerative Colitis: How to Recognize It?

Symptoms of ulcerative colitis depend on the extent and location of the inflammation, but often include:

• Frequent loose stools, often mixed with blood, mucus, or pus.
• Abdominal pain and cramps, usually in the lower left side.
• Tenesmus (false urges to defecate).
• Weight loss and loss of appetite.
• Fatigue and weakness.
• Fever (during flare-ups).
• Anemia due to chronic blood loss.

Extraintestinal manifestations may include joint pain, skin rashes, and eye problems.

Inflammation and the Immune System: Key Mechanisms

The core of ulcerative colitis involves immune system dysfunction, where it mistakenly attacks the body's own intestinal tissues. This leads to chronic inflammation. Although the studies mentioned in the sources mainly concern irritable bowel syndrome (IBS), they highlight general principles of immune regulation and the resolution of inflammation that are also relevant to IBD.

For instance, the MER receptor tyrosine kinase (Mertk) plays a crucial role in regulating macrophage polarization and the resolution of inflammation [1]. Studies in mice have shown that Mertk-dependent immune regulation is essential for the therapeutic effects of fecal microbiota transplantation (FMT) in constipation-predominant IBS [1]. This indicates that modulating immune pathways may be a key element in treating inflammatory bowel conditions.

Other studies investigating traditional Chinese medicine in IBS have shown that it can improve the state of the gut microbiota and regulate the Toll-like receptors/nuclear factor-kappa B (TLRs/NF-κB) signaling pathway [2]. This pathway is central to the development of the inflammatory response, and its modulation can reduce intestinal inflammation [2]. Similar mechanisms may be involved in ulcerative colitis, where chronic inflammation is the primary issue.

The Role of the Gut Microbiota in Development and Treatment

Dysbiosis, or an imbalance in the gut microbiota, is considered an important factor in the pathogenesis of many gastrointestinal diseases, including ulcerative colitis and IBS. Restoring a healthy balance of microorganisms in the gut is a promising therapeutic direction.

Fecal Microbiota Transplantation (FMT): As previously mentioned, FMT has proven effective in alleviating IBS symptoms, which is partly related to Mertk-dependent immune regulation [1]. Although these data were obtained for IBS, the potential of FMT in modulating the immune response and restoring the microbiota makes it a subject of study for IBD as well.

Probiotics and Traditional Medicine: Multi-strain probiotics can significantly alleviate gastrointestinal symptoms associated with Helicobacter pylori therapy without affecting eradication success [3]. They reduce symptoms such as reflux, dyspepsia, and diarrhea, thereby improving patient comfort [3]. Traditional Chinese medicine can also regulate the gut microbiota, exerting a similar effect [3]. Traditional Chinese medicine formulas, such as Jianchang No. 1, have shown the ability to improve gut microbiota status and regulate inflammatory pathways in diarrhea-predominant IBS [2]. Another formula, Jianpi Yanggan Pill, has also demonstrated therapeutic potential in diarrhea-predominant IBS by targeting inflammation-related signaling pathways [4]. These findings indicate that targeted intervention in the microbiota and inflammatory pathways can be beneficial in various intestinal conditions.

Antibiotics: Certain antibiotics, such as rifaximin, are used to modulate the gut microbiota. A study showed that rifaximin is just as effective as a low-FODMAP diet in improving IBS symptoms [7]. Although rifaximin is not a primary treatment for ulcerative colitis, its ability to influence the bacterial composition of the gut underscores the importance of the microbiota. It is also known that antibiotics can temporarily alter the composition of the gut microbiota, which may have various health consequences [6].

Modern Approaches to Treating Ulcerative Colitis

Treatment for ulcerative colitis aims to suppress inflammation, relieve symptoms, prevent flare-ups, and improve quality of life. It often includes:

• Anti-inflammatory drugs: Aminosalicylates (5-ASAs) are the first line of therapy for mild to moderate forms.
• Corticosteroids: Used for rapid control of flare-ups, but not for long-term use due to side effects.
• Immunosuppressants: Azathioprine, mercaptopurine, and methotrexate help reduce immune system activity.
• Biologic therapy: Drugs that block specific inflammatory proteins (e.g., TNF-alpha, interleukins) are effective for moderate to severe forms.
• Small molecules: Newer targeted drugs, such as Janus kinase inhibitors (JAK inhibitors).
• Surgical intervention: In cases of severe, treatment-refractory colitis or when complications develop, removal of the colon may be necessary.

Dietary Recommendations: Although a low-FODMAP diet has been studied for IBS [7], general dietary approaches are also important in ulcerative colitis. Patients are often advised to avoid foods that may trigger symptoms and to maintain a balanced diet to support gut health. Consulting a nutritionist can help develop a personalized meal plan.

Prospects: Research into gut microbiota modulation, whether through FMT, probiotics, or traditional medicine, opens new horizons for adjunctive therapy in ulcerative colitis. Understanding the complex interactions between the microbiota, the immune system, and inflammation, as demonstrated in IBS studies [1, 2, 3, 4], may lead to the development of more effective and personalized IBD treatment strategies.

Conclusion

Ulcerative colitis is a serious chronic condition requiring a comprehensive treatment approach. Understanding its symptoms, the mechanisms of inflammation development, and the role of the gut microbiota is crucial for effective disease management. Modern medicine offers a wide range of therapeutic options, and ongoing research in microbiota and immune regulation promises new opportunities to improve patient prognosis and quality of life.

Sources

• [1] Mertk-dependent immune regulation is essential for therapeutic effects of fecal microbiota transplantation in a murine model of constipation-predominant irritable bowel syndrome. https://pubmed.ncbi.nlm.nih.gov/42480795/
• [2] Jianchang No. 1 formula alleviates diarrhea-predominant irritable bowel syndrome by improving gut microbiota and regulating Toll-like receptors/nuclear factor-kappa B signaling pathway in diarrhea-predominant irritable bowel syndrome rats. https://pubmed.ncbi.nlm.nih.gov/42639773/
• [3] Traditional Chinese medicine alleviates gastrointestinal symptoms during bismuth-containing quadruple therapy for Helicobacter pylori infection: An add-on perspective. https://pubmed.ncbi.nlm.nih.gov/41810439/
• [4] Network pharmacology reveals mechanisms of Jianpi Yanggan pill in treating diarrhea-predominant irritable bowel syndrome. https://pubmed.ncbi.nlm.nih.gov/42007093/
• [6] Impact of co-amoxiclav-induced gut microbiota modulation on seizure frequency in children with drug-resistant epilepsy. https://pubmed.ncbi.nlm.nih.gov/42183322/
• [7] Clinical trial: Rifaximin versus low-FODMAP diet in irritable bowel syndrome. https://pubmed.ncbi.nlm.nih.gov/41098003/

The information provided in this article is for reference purposes only and cannot replace professional medical advice. Always consult a qualified specialist for the diagnosis and treatment of diseases.