Researchers discovered that a special combination of helpful gut bacteria and plant fibers might reduce obsessive-compulsive disorder (OCD) symptoms in rats. When rats were given a mixture containing a beneficial bacteria called Faecalibacterium prausnitzii along with two types of plant fibers (FOS and GOS) for six weeks, they showed fewer repetitive behaviors and less anxiety. The treatment worked by improving the connection between the gut and brain, reducing inflammation in the brain, and helping the gut produce more healthy compounds. While this is exciting early research, it was only tested in rats, so scientists need to do more studies in humans before we know if it could help people with OCD.

The Quick Take

  • What they studied: Whether a combination of special gut bacteria and plant fibers could reduce OCD-like behaviors (repetitive actions and anxiety) in rats
  • Who participated: Laboratory rats that were given a drug to create OCD-like symptoms, divided into groups that either received the bacteria-fiber treatment or no treatment
  • Key finding: Rats treated with the special bacteria and plant fibers showed significant improvements in repetitive behaviors, compulsive actions, and anxiety compared to untreated rats. The treatment also reduced brain inflammation and improved gut health markers.
  • What it means for you: This early-stage research suggests that gut health might play a role in OCD symptoms, but these results are from rats only. Much more research in humans is needed before this could become a treatment option for people with OCD.

The Research Details

Scientists used laboratory rats to test whether a special combination of helpful bacteria and plant fibers could reduce OCD-like symptoms. First, they gave some rats a drug called quinpirole that causes repetitive and anxious behaviors similar to OCD in humans. Then they divided the affected rats into groups: some received a treatment containing Faecalibacterium prausnitzii (a beneficial gut bacteria) mixed with two plant fibers called FOS and GOS, while others received no treatment. The treatment lasted six weeks. Throughout the study, researchers measured the rats’ behaviors using specific tests, like how much they explored new areas and how much they buried marbles (a sign of compulsive behavior). They also examined the rats’ brains and gut tissue to understand how the treatment worked at a biological level.

This research approach is important because it helps scientists understand the connection between gut health and mental health, specifically OCD. By using animal models first, researchers can safely test new ideas before considering human trials. The study measured both behavior (what the rats actually did) and biology (what happened in their brains and guts), which gives a more complete picture of how the treatment might work.

This is a controlled laboratory study, which is a solid foundation for early research. The researchers used specific, measurable tests to assess behavior and examined biological markers to understand the mechanism. However, because this was only tested in rats, the results may not directly apply to humans. The study appears to be well-designed with appropriate controls, but the sample size of rats was not specified in the available information, which limits our ability to assess statistical power.

What the Results Show

Rats that received the bacteria and plant fiber treatment showed dramatic improvements in OCD-like behaviors. They buried fewer marbles (a sign of compulsive behavior), spent more time exploring open areas (showing less anxiety), and had less excessive self-grooming compared to untreated rats. These improvements suggest the treatment reduced both the compulsive and anxiety-related aspects of OCD-like symptoms. Importantly, the treatment didn’t affect normal movement or weight gain, meaning it specifically targeted the problematic behaviors without causing other side effects. The researchers also found that treated rats had lower levels of inflammation-causing molecules in their brains, particularly TNF-α and IL-6, which are thought to contribute to OCD symptoms.

The treatment improved several gut health markers in the rats. The beneficial bacteria helped the gut produce more short-chain fatty acids (acetate, propionate, and butyrate), which are compounds that support brain health and reduce inflammation. The intestinal lining also improved, with better structure and more protective cells. Additionally, the colon showed increased production of a substance called tryptophan hydroxylase, which is important for making serotonin—a brain chemical that affects mood and anxiety. These changes suggest the treatment works by improving the gut-brain connection.

This research builds on growing evidence that gut bacteria influence mental health and brain function. Previous studies have suggested links between gut health and anxiety, depression, and other mental health conditions. This study is among the first to specifically examine whether beneficial bacteria combined with plant fibers might help with OCD-like symptoms. The findings align with the emerging understanding that the gut-brain axis—the communication system between the digestive system and the brain—plays an important role in psychiatric disorders.

This study was conducted only in rats, so we cannot assume the same results would occur in humans. Rats’ biology and behavior are different from humans in important ways. The study did not specify the exact number of rats used, which makes it harder to evaluate how reliable the results are. Additionally, the treatment was given for only six weeks, so we don’t know if the benefits would last longer or if there might be long-term effects. The study also doesn’t tell us what dose would be appropriate for humans or whether the same bacteria and fibers would work the same way in people.

The Bottom Line

Based on this rat study, we cannot yet recommend this treatment for people with OCD. This is early-stage research that needs to be followed by human studies. If you or someone you know has OCD, continue working with a mental health professional using proven treatments like cognitive-behavioral therapy and medications that have been tested in humans. While maintaining good gut health through diet is generally beneficial, this specific bacteria-fiber combination has not been proven safe or effective in humans.

This research is most relevant to scientists studying the gut-brain connection and OCD researchers looking for new treatment approaches. People with OCD or their families might find it interesting as a sign of future possibilities, but should not change their current treatment based on this rat study. Healthcare providers treating OCD should be aware of this emerging research direction but should continue using established treatments.

In rats, the treatment showed effects over a six-week period. If this were to be tested in humans, it would likely take much longer to see results, and the timeline could be very different. Any human studies would need to start with small safety trials before larger effectiveness studies could be conducted, which typically takes several years.

Want to Apply This Research?

  • Users interested in gut-brain health could track daily probiotic/prebiotic intake and mood/anxiety levels using a simple daily log (1-10 scale) to monitor their own patterns, while noting that this specific bacteria combination hasn’t been tested in humans yet.
  • Users could experiment with increasing their intake of prebiotic foods (like garlic, onions, bananas, and whole grains) that feed beneficial gut bacteria, while tracking any changes in mood or anxiety. They should continue any prescribed OCD treatments and discuss dietary changes with their healthcare provider.
  • Over 6-8 weeks, users could maintain a journal tracking gut health indicators (digestion quality, energy levels) alongside mood and anxiety symptoms, while understanding this is personal observation only and not a replacement for professional mental health care.

This research was conducted in laboratory rats and has not been tested in humans. The findings do not constitute medical advice or a proven treatment for obsessive-compulsive disorder. OCD is a serious mental health condition that requires professional diagnosis and treatment. If you or someone you know has OCD, please consult with a qualified mental health professional such as a psychiatrist, psychologist, or licensed therapist. Current evidence-based treatments for OCD include cognitive-behavioral therapy and medications that have been proven safe and effective in human studies. Do not change, stop, or start any OCD treatment without consulting your healthcare provider. While maintaining good gut health is generally beneficial, the specific bacteria and fiber combination studied here has not been proven safe or effective in humans and should not be used as a substitute for professional OCD treatment.