Researchers discovered that a specific type of helpful bacteria called Lactobacillus plantarum Lac16 can reduce intestinal inflammation in mice with a condition similar to inflammatory bowel disease. The bacteria work by changing the mix of microbes in the gut and producing a substance called isobutyric acid, which calms down the immune system’s overactive response. When scientists transferred the beneficial bacteria to other mice, the protective effects transferred too, suggesting this approach could potentially help people with inflammatory bowel disease in the future.

The Quick Take

  • What they studied: Whether a specific probiotic bacteria (Lac16) could reduce intestinal inflammation and how it works in the body
  • Who participated: Laboratory mice that were given a chemical to create intestinal inflammation similar to what happens in inflammatory bowel disease
  • Key finding: Mice treated with Lac16 bacteria showed significant improvement in inflammation symptoms, including less weight loss, shorter recovery time, and reduced disease activity compared to untreated mice
  • What it means for you: This research suggests that probiotics might help people with inflammatory bowel disease, but human studies are still needed before doctors can recommend this treatment. If you have IBD, talk to your doctor before trying new supplements.

The Research Details

Scientists used laboratory mice to test whether Lactobacillus plantarum Lac16 could help with intestinal inflammation. They created inflammation in the mice using a chemical called dextran sodium sulfate (DSS), which damages the intestinal lining similar to what happens in inflammatory bowel disease. Some mice received the Lac16 bacteria while others didn’t, allowing researchers to compare the effects.

To understand how the bacteria worked, researchers used special mice without their normal gut bacteria and transplanted bacteria from treated mice into untreated mice. This helped them prove that the bacteria themselves—not something else—were causing the improvement. They also tested the specific chemical (isobutyric acid) that the bacteria produce to see if it alone could reduce inflammation.

This research approach is important because it shows not just that the bacteria help, but exactly how they help. By using multiple types of mouse models and testing the specific chemical produced by the bacteria, the scientists could prove a clear cause-and-effect relationship rather than just observing that something helped.

This study was published in mBio, a respected scientific journal. The researchers used multiple experimental approaches to verify their findings, including special mouse models and direct testing of the active chemical. However, this research was done in mice, not humans, so results may not directly apply to people. The study is well-designed but represents early-stage research that needs human testing before clinical use.

What the Results Show

Mice treated with Lac16 bacteria showed dramatic improvements in intestinal inflammation. They experienced less weight loss, their colons remained longer and healthier, and their overall disease activity scores were significantly lower than untreated mice. The bacteria also helped repair the intestinal barrier—the protective lining that keeps harmful substances out of the bloodstream.

The researchers found that Lac16 changed the composition of bacteria in the gut, increasing helpful bacteria like Alloprevotella and Dubosiella while reducing potentially harmful bacteria like Bacteroides and Helicobacter. More importantly, the bacteria produced increased amounts of short-chain fatty acids, particularly isobutyric acid, which appears to be the key protective substance.

When scientists transplanted bacteria from treated mice into untreated mice, the benefits transferred as well. This proved that the protective effects came from the bacteria and the changes they made to the gut environment, not from other factors. When they tested isobutyric acid directly, it reduced inflammation both in living mice and in laboratory cell cultures, confirming this chemical as the main protective agent.

The study found that Lac16 changed how immune cells called macrophages behave, shifting them toward an anti-inflammatory state. The bacteria also suppressed overactivation of a protein complex called NLRP3 inflammasome, which is involved in triggering excessive immune responses. These changes work together to calm down the intestinal inflammation.

This research builds on previous studies showing that probiotics can help with inflammatory bowel disease. However, this study goes further by identifying the specific mechanism—the production of isobutyric acid and its effect on the NLRP3 inflammasome. This provides a clearer understanding of why certain probiotics work and could help scientists develop better treatments.

This research was conducted entirely in mice, so results may not directly translate to humans. The study used a chemical-induced inflammation model that may not perfectly replicate the complex nature of inflammatory bowel disease in people. Additionally, the sample size of mice used is not specified in the available information. The study doesn’t address whether this approach would work for people with different genetic backgrounds or other health conditions.

The Bottom Line

Based on this research, Lactobacillus plantarum Lac16 shows promise as a potential treatment for inflammatory bowel disease, but human clinical trials are needed before it can be recommended. Current confidence level: Low to Moderate (early-stage research). If you have inflammatory bowel disease, discuss probiotic options with your gastroenterologist rather than self-treating.

People with inflammatory bowel disease (Crohn’s disease or ulcerative colitis) should be aware of this research as it may lead to future treatments. Researchers studying gut health and probiotics should also pay attention. However, this research is not yet ready for general public use. People without IBD don’t need to change their behavior based on this single study.

In the mouse studies, improvements appeared relatively quickly after treatment began. However, if this approach is eventually tested in humans, it may take months to see significant benefits. Any human clinical trials would likely take several years to complete before this could become an available treatment.

Want to Apply This Research?

  • If you have IBD and work with your doctor on probiotic treatment, track daily symptoms including: number of bowel movements, presence of blood in stool, abdominal pain level (1-10 scale), and overall energy level. Record these in a daily log to share with your healthcare provider.
  • Work with your doctor to identify if a specific probiotic supplement containing Lactobacillus plantarum might be appropriate for your situation. If recommended, take it consistently as directed while maintaining other prescribed treatments. Don’t stop other medications without medical guidance.
  • Over 4-12 weeks, monitor whether your IBD symptoms improve, stay the same, or worsen. Keep records of medication changes, diet modifications, and symptom patterns. Share this information with your gastroenterologist at regular appointments to determine if the probiotic is helping or if adjustments are needed.

This research was conducted in laboratory mice and has not yet been tested in humans. While the findings are promising, they do not constitute medical advice or approval for human use. If you have inflammatory bowel disease or suspect you might, consult with a gastroenterologist before starting any new supplements or probiotics. Do not discontinue prescribed medications based on this research. Probiotics may interact with certain medications or conditions. This article is for educational purposes only and should not replace professional medical guidance.