Scientists studied a type of helpful bacteria called Lactobacillus crispatus that naturally lives in women’s bodies. They discovered this bacteria might do more than just protect against infections—it could also help prevent heart and liver problems. In lab tests and mouse studies, the bacteria produced special compounds that fight harmful germs and improved how the body handles sugar and fat. While these results are promising, researchers need to test this in humans before we know if it could become a treatment for heart and liver disease.

The Quick Take

  • What they studied: Whether a common type of good bacteria found in women’s bodies could protect against heart disease, liver disease, and infections
  • Who participated: Three specific strains of bacteria were tested in laboratory dishes and in mice fed an unhealthy diet. No human participants were involved in this study.
  • Key finding: When mice received this bacteria daily for 2 weeks and then twice a week for 12 weeks, their livers got healthier, their bodies handled sugar better, and their hearts worked better compared to mice that didn’t get the bacteria
  • What it means for you: This research suggests the bacteria might someday help prevent or treat heart and liver problems, but it’s still in early stages. Scientists need to test it in humans before anyone should consider it as a treatment. This is not yet ready for real-world use.

The Research Details

Researchers started by analyzing the genetic code of 60 different bacteria samples to find the best ones. They selected 3 strains that looked most promising based on their genes. Then they studied these 3 strains in detail, looking at what special compounds they could make. They tested whether the bacteria could survive stomach acid and bile (digestive fluid), and whether they could kill harmful bacteria in lab dishes. Finally, they gave the bacteria to mice that had been fed an unhealthy diet to see if it would help their hearts and livers.

The study used both test-tube experiments (called in vitro) and living animal experiments (called in vivo). This two-step approach helps researchers understand both how the bacteria work and whether those benefits actually happen in a living body.

This type of research is important because it helps scientists understand the potential of bacteria before testing them in humans, which is much more complex and takes longer.

Understanding how bacteria work at the genetic level helps scientists predict which strains might be helpful. Testing in mice first is important because it shows whether the bacteria actually produce benefits in a living system, not just in a dish. This research approach is the standard way scientists develop new treatments before they can be tested in people.

This study has several strengths: it used complete genetic analysis, tested multiple approaches (lab dishes and living animals), and measured several health markers. However, the study only tested mice, not humans, so we don’t know if the same benefits would happen in people. The sample size of bacteria strains tested (3 out of 60) is small. The study was published in a respected scientific journal, which suggests it went through expert review. The main limitation is that this is very early-stage research.

What the Results Show

The bacteria produced several types of natural antibiotics and compounds that can kill harmful germs. In lab tests, the bacteria’s liquid byproducts killed common dangerous bacteria including E. coli, Staph aureus, and others. The bacteria could survive the harsh conditions of the stomach (very acidic) and bile, which means they could potentially be taken by mouth and reach the intestines alive.

In mice with heart and liver problems from eating an unhealthy diet, the bacteria made a real difference. After 14 weeks of treatment, the mice that received the bacteria had less fat buildup in their livers, their bodies handled sugar better (improved insulin sensitivity), and their hearts worked better than mice that didn’t get the bacteria.

The genetic analysis showed the bacteria can make several helpful compounds: natural antibiotics called bacteriocins, lactic acid (which helps fight bad bacteria), short-chain fatty acids (which are good for gut health), and other beneficial molecules. These compounds work together to protect against infections and support healthy metabolism.

The bacteria showed the ability to break down bile salts, which is important for digestion and metabolism. The bacteria can also make folate, a B vitamin that the body needs. These additional functions suggest the bacteria might help the body in multiple ways beyond just fighting infections. The broad-spectrum antibacterial activity (meaning it kills many types of harmful bacteria) suggests it could protect against various infections.

Previous research already knew that this bacteria protects against infections in the reproductive tract and gut. This study is the first to show it might also help with heart and liver health. The findings build on earlier work showing the bacteria’s protective effects, but extend those benefits to metabolic and heart health—which is new territory. The genetic findings about antimicrobial compounds confirm what scientists suspected about how this bacteria works.

The biggest limitation is that this study only tested mice, not humans. Mice don’t always respond the same way humans do to treatments. The study tested only 3 bacterial strains out of 60 available, so results might not apply to all strains. The mice were given a specific dose (108 CFU) on a specific schedule, and we don’t know if different doses or schedules would work better or worse in humans. The study didn’t compare this bacteria to other potential treatments. Finally, the study was relatively short (14 weeks in mice), so we don’t know about long-term effects.

The Bottom Line

This research is too early to recommend this bacteria as a treatment. It shows promise in mice, but human studies are needed first. If you’re interested in heart and liver health, focus on proven strategies: eat a healthy diet, exercise regularly, maintain a healthy weight, and talk to your doctor about your risk factors. Do not take supplements containing this bacteria specifically for heart or liver health without talking to your doctor first.

This research is most relevant to scientists and doctors studying new treatments for heart disease and fatty liver disease. People with heart disease, liver disease, or metabolic problems should be aware this is being researched but should not expect it to be available as a treatment soon. This is particularly relevant to women’s health researchers since the bacteria naturally occurs in women’s bodies.

This research is in the very early stages. It typically takes 5-10 years or more to go from promising lab and animal results to human testing, and then several more years to develop an actual treatment. Don’t expect this to become available as a medical treatment for at least several years, and possibly much longer.

Want to Apply This Research?

  • Track heart and liver health markers: record your weight weekly, note any changes in energy levels, and if your doctor monitors your cholesterol or liver enzymes, log those results when available. This creates a baseline for comparing against future treatments.
  • Use the app to build habits that support heart and liver health right now: set reminders for daily exercise (30 minutes), track meals to ensure you’re eating vegetables and whole grains, and monitor alcohol consumption. These proven strategies are more important than waiting for new treatments.
  • Create a long-term health dashboard that tracks weight, energy levels, exercise consistency, and diet quality. When this bacteria becomes available for human testing (which may take years), you’ll have baseline data to compare against. Set a reminder to check for updates on this research annually.

This research is preliminary and has only been tested in mice, not humans. These findings do not constitute medical advice or a recommendation to use any product. Do not start, stop, or change any treatment based on this research without consulting your healthcare provider. If you have heart disease, liver disease, or metabolic disorders, work with your doctor on proven treatments. This bacteria is not currently available as a medical treatment for these conditions. Always consult a qualified healthcare professional before using any supplement or probiotic product, especially if you take medications or have existing health conditions.