Researchers tested whether combining probiotics (good bacteria) and omega-3 fatty acids (found in fish oil) could help reduce obesity and improve health in mice eating a high-fat diet. Over six weeks, mice that received both treatments together showed better results than mice receiving either treatment alone or no treatment. They gained less weight, had healthier livers, better blood clotting, and more diverse gut bacteria. While this is promising, these are early results from mouse studies, and scientists will need to test whether the same benefits work in humans.

The Quick Take

  • What they studied: Whether giving probiotics and omega-3 fatty acids together could help mice lose weight and improve their health when eating unhealthy, high-fat food
  • Who participated: Male laboratory mice (C57BL/6J strain) divided into five groups: normal diet, high-fat diet only, high-fat diet with probiotics, high-fat diet with omega-3, and high-fat diet with both probiotics and omega-3
  • Key finding: Mice receiving both probiotics and omega-3 together gained significantly less weight, had better liver health markers, improved blood clotting ability, and healthier gut bacteria compared to mice eating high-fat food without these supplements
  • What it means for you: This research suggests that combining probiotics and omega-3 supplements might help people manage weight and improve liver and heart health, but these are early findings from animal studies. More research in humans is needed before making dietary changes based on this study alone

The Research Details

Scientists divided male mice into five groups and fed them different diets for six weeks. One group ate normal, healthy food. The other four groups ate high-fat food, but some also received probiotics (beneficial bacteria), omega-3 supplements (fish oil), or both. The researchers measured how much weight the mice gained, checked their blood and liver health using blood tests, examined their gut bacteria using genetic testing, and compared the results between groups.

This type of study is called a controlled experiment because the scientists carefully controlled what each group ate and measured specific outcomes. By comparing groups that received different treatments, they could see which combinations worked best. The study lasted six weeks, which is a reasonable amount of time to see changes in mice (though mice have faster metabolisms than humans).

This research design is important because it allows scientists to test whether two treatments work better together than separately. Many health problems involve multiple systems in the body, so combining treatments might be more effective than using just one. By measuring multiple health markers (weight, liver function, blood clotting, and gut bacteria), the researchers could see how these treatments affect different parts of the body.

This study was published in PLoS ONE, a well-respected scientific journal that requires peer review (other scientists check the work). The researchers used a standard mouse strain commonly used in research, which makes results easier to compare with other studies. However, the sample size wasn’t specified in the abstract, which makes it harder to assess statistical power. The study was conducted in controlled laboratory conditions, which is good for identifying cause-and-effect relationships but may not perfectly reflect real-world conditions in humans.

What the Results Show

The most important finding was that mice receiving both probiotics and omega-3 together showed better results than mice receiving either treatment alone. These mice gained significantly less weight compared to mice eating high-fat food without supplements. Their liver function improved, as shown by better ALT levels (a blood marker that indicates liver health). The combined treatment also improved blood clotting markers, including prothrombin time and activated partial thromboplastin time, which are important for preventing dangerous blood clots.

Genetic analysis of the mice’s gut bacteria showed that the combined treatment increased the diversity of beneficial bacteria in their digestive systems. A more diverse gut microbiome (the community of bacteria in your digestive tract) is generally associated with better health. The mice that received both treatments had noticeably more diverse bacterial communities compared to the high-fat diet group without supplements.

Interestingly, mice receiving only probiotics or only omega-3 showed some improvements, but not as much as the group receiving both treatments together. This suggests that the two treatments may work together in ways that are more powerful than either one alone.

The study also showed that both probiotics and omega-3 individually had some positive effects on the mice’s health, even though the combination was most effective. The high-fat diet group without any supplements showed the worst health markers, confirming that diet quality matters significantly for these health measures. The normal diet group (eating healthy food without supplements) performed well, suggesting that a good diet is the foundation for health.

Previous research has shown that omega-3 fatty acids can lower triglycerides (a type of fat in the blood) and reduce heart disease risk. Other studies have demonstrated that probiotics can improve gut health and nutrient absorption. This study builds on that knowledge by testing whether combining these two approaches produces better results than using either one alone. The findings align with the growing scientific understanding that gut health and heart health are connected.

This study was conducted in mice, not humans, so results may not directly apply to people. Mice have different body sizes, metabolisms, and lifespans than humans, which can affect how treatments work. The study lasted only six weeks, which is relatively short for observing long-term health effects. The abstract doesn’t specify the exact number of mice in each group, making it difficult to assess whether the sample size was large enough to draw strong conclusions. The study only included male mice, so results may not apply equally to females. Finally, this was a controlled laboratory study, so real-world factors like exercise, stress, and food variety weren’t included.

The Bottom Line

Based on this mouse study, probiotics and omega-3 supplements together appear promising for managing weight and improving liver and heart health in people eating high-fat diets. However, confidence in these recommendations is moderate because this is early research in animals. Before making significant dietary changes, consult with a healthcare provider. The most reliable approach remains eating a balanced diet with plenty of vegetables, whole grains, and lean proteins, along with regular physical activity.

This research is most relevant to people struggling with obesity, high cholesterol, or liver health concerns. It may also interest people with heart disease risk factors. However, this study doesn’t yet provide strong enough evidence for healthy people to start taking supplements. People with bleeding disorders, those taking blood thinners, or anyone with allergies to fish or dairy should consult their doctor before trying these supplements.

In the mouse study, significant improvements appeared within six weeks. If similar effects occur in humans, you might expect to see changes in weight and blood markers within 6-12 weeks, though individual results vary greatly. Long-term benefits would likely take several months to become apparent.

Want to Apply This Research?

  • Track weekly weight, energy levels, and digestive health (bloating, regularity) if you decide to try probiotics and omega-3 supplements. Record these measurements in the app to monitor trends over 8-12 weeks.
  • If interested in trying this approach, start by adding omega-3 rich foods (fatty fish like salmon, sardines, or walnuts) to your diet 2-3 times per week, and consider a probiotic-rich food like yogurt or kefir daily. Track these additions in your food log.
  • Use the app to log supplement intake (if taking them), monitor weight weekly, track digestive symptoms, and note energy levels. Set a reminder to check in monthly with your doctor about blood work to monitor liver function and cholesterol levels.

This research was conducted in mice and has not yet been tested in humans. These findings are preliminary and should not replace medical advice from your healthcare provider. Before starting probiotics or omega-3 supplements, especially if you take medications, have bleeding disorders, or are pregnant or nursing, consult your doctor. This study does not constitute medical advice, and individual results may vary significantly. Always discuss dietary supplements with a qualified healthcare professional before beginning use.