Scientists are discovering that the trillions of bacteria living in your gut play a huge role in ulcerative colitis, a disease that causes painful inflammation in the colon. People with this condition have different bacteria in their gut compared to healthy people—they have fewer helpful bacteria and more harmful ones. This imbalance triggers inflammation and prevents the gut from healing properly. Researchers are now testing new treatments like probiotics, special diets, and even transplanting healthy bacteria from donors to help restore balance and reduce symptoms. While these approaches show promise, scientists still need to do more research to figure out the best ways to use them.
The Quick Take
- What they studied: How the bacteria living in your gut contribute to ulcerative colitis and what new treatments might help by fixing the bacterial imbalance
- Who participated: This was a review article that examined existing research about ulcerative colitis and gut bacteria, rather than a study with human participants
- Key finding: People with ulcerative colitis have significantly fewer beneficial bacteria (like Faecalibacterium and Bifidobacterium) and more harmful bacteria (like E. coli) compared to healthy people, and this imbalance appears to cause the inflammation and symptoms
- What it means for you: If you have ulcerative colitis, treatments targeting your gut bacteria—such as probiotics, dietary changes, or other microbiome therapies—may help reduce symptoms and improve healing. However, these treatments are still being studied, so talk to your doctor before trying them
The Research Details
This was a review article, meaning researchers looked at and summarized findings from many other studies about ulcerative colitis and gut bacteria rather than conducting their own experiment. They examined what scientists currently know about how gut bacteria affect the disease, what causes the bacterial imbalance, and what new treatments are being tested.
The researchers focused on understanding the relationship between your gut bacteria and your immune system in people with ulcerative colitis. They looked at how healthy people’s bacteria help protect the gut lining and fight off harmful germs, and how this protection breaks down in people with the disease.
They also reviewed emerging treatments that try to fix the bacterial imbalance, including probiotics (beneficial bacteria you can take), prebiotics (food that feeds good bacteria), dietary changes, and fecal microbiota transplantation (transferring healthy bacteria from a donor to a patient).
This type of review is important because it brings together all the scattered research on this topic and helps doctors and scientists see the big picture. By summarizing what we know about how gut bacteria cause ulcerative colitis, researchers can identify the most promising treatment directions and spot gaps in our knowledge that need more study.
This is a review article published in a peer-reviewed scientific journal, meaning other experts checked the work before publication. However, because it summarizes other studies rather than conducting new research, it depends on the quality of those original studies. The findings represent current scientific understanding but are not definitive proof. More research is needed to confirm which treatments work best and for whom.
What the Results Show
The research shows that people with ulcerative colitis have a very different mix of bacteria in their gut compared to healthy people. Specifically, they have much lower levels of beneficial bacteria that normally help protect the gut and keep inflammation down. At the same time, they have higher levels of potentially harmful bacteria that can trigger inflammation.
This bacterial imbalance, called dysbiosis, appears to be a major factor in causing ulcerative colitis. When the helpful bacteria are missing, the gut lining becomes weaker and more vulnerable to damage. The harmful bacteria can then trigger the immune system to overreact, causing the painful inflammation that defines the disease.
The research also identified several factors that can cause this bacterial imbalance, including your genes (inherited traits), antibiotic use, diet, and environmental factors. This suggests that ulcerative colitis develops when multiple factors come together to disrupt the normal bacterial community.
The review found that several new treatments show promise for helping restore healthy bacteria and reduce symptoms. Probiotics (beneficial bacteria supplements) and prebiotics (foods that feed good bacteria) may help rebalance the gut. Dietary changes, particularly reducing processed foods and increasing fiber, appear to support beneficial bacteria growth. Fecal microbiota transplantation—transferring healthy bacteria from a donor—has shown encouraging early results in some patients, though it’s still being studied.
The research also highlights that the relationship between gut bacteria and the immune system is complex and not fully understood. Different people may respond differently to the same treatment, suggesting that personalized approaches based on individual bacterial profiles may be important in the future.
This research builds on decades of work showing that gut bacteria affect digestive health. Previous studies established that bacteria help digest food and protect the gut lining. This review adds to that knowledge by specifically showing how bacterial imbalance contributes to ulcerative colitis and by highlighting new treatment possibilities. It represents a shift toward treating the disease by fixing the underlying bacterial problem rather than just managing symptoms.
This review summarizes other studies, so its conclusions are only as strong as the original research. Many of the new treatments mentioned (like fecal transplants) are still in early testing stages with small numbers of patients. Scientists still don’t have a clear definition of what a ‘healthy’ gut microbiome looks like or how to standardize treatments. Additionally, most research has focused on certain populations, so results may not apply equally to everyone. More large-scale studies are needed to determine which treatments work best and for which patients.
The Bottom Line
If you have ulcerative colitis, discuss microbiome-based treatments with your gastroenterologist. Probiotics and dietary changes (increasing fiber and reducing processed foods) may help and are generally safe to try alongside standard treatments. These approaches show promise but are not yet proven as primary treatments—they should complement, not replace, medications prescribed by your doctor. Fecal microbiota transplantation is still experimental and should only be considered under medical supervision in clinical trial settings.
Anyone with ulcerative colitis or a family history of inflammatory bowel disease should pay attention to this research. People considering probiotics or major dietary changes should discuss them with their doctor first. This research is also relevant to people interested in gut health and disease prevention. However, if you don’t have ulcerative colitis, these specific treatments aren’t necessarily for you—focus instead on maintaining a healthy diet and gut bacteria through normal means.
If you try dietary changes or probiotics, you might notice some improvement in symptoms within 2-4 weeks, though full benefits may take several months. Fecal microbiota transplantation, if it works, may show results within weeks to months. Keep in mind that individual responses vary greatly, and some people may not respond to these treatments at all.
Want to Apply This Research?
- Track daily symptoms (bowel movements, pain level, energy) on a 1-10 scale and note what you ate each day. This helps identify which foods trigger symptoms and whether dietary changes or probiotics are helping. Record any supplements or probiotics you’re taking and their brand names.
- Start a food and symptom diary using the app to identify your personal trigger foods. Gradually increase fiber intake if tolerated, and consider adding a probiotic supplement (after discussing with your doctor). Use the app to set reminders for taking supplements consistently and to track any changes in symptoms over time.
- Review your symptom and food logs weekly to spot patterns. Compare your baseline symptoms from the first month to subsequent months to see if changes are helping. Share these tracked patterns with your doctor at appointments to guide treatment decisions. Set monthly goals for dietary improvements and track your progress toward them.
This article summarizes scientific research about ulcerative colitis and gut bacteria but is not medical advice. Ulcerative colitis is a serious condition that requires professional medical care. Do not start, stop, or change any medications or treatments without consulting your gastroenterologist or doctor. While probiotics and dietary changes may be helpful, they should complement—not replace—prescribed medical treatments. If you have ulcerative colitis symptoms, seek care from a qualified healthcare provider. Individual responses to treatments vary, and what works for one person may not work for another.