Researchers tested whether specific friendly bacteria called Lactobacillus could protect rat hearts from damage caused by cisplatin, a powerful cancer-fighting drug. They found that cisplatin damaged heart cells by creating harmful molecules and triggering inflammation. However, when rats received the probiotic bacteria before cisplatin treatment, their hearts showed significantly less damage. The bacteria appeared to work by reducing harmful molecules, decreasing inflammation, and preventing heart cells from dying. While these results are promising, this research was done in rats, so scientists need to test whether the same benefits would occur in people receiving cancer treatment.

The Quick Take

  • What they studied: Can a mixture of three types of friendly bacteria (probiotics) protect the heart from damage caused by cisplatin, a common cancer drug?
  • Who participated: 28 male laboratory rats divided into four groups: a control group with no treatment, a group receiving only cisplatin, a group receiving both probiotics and cisplatin, and a group receiving only probiotics.
  • Key finding: Rats that received probiotics before cisplatin treatment had significantly less heart damage compared to rats that received cisplatin alone. The probiotics reduced harmful molecules in the heart by about 32% and improved the heart’s natural defense system.
  • What it means for you: This research suggests probiotics might help protect hearts during cancer treatment, but these results are from animal studies. People receiving cisplatin should not change their treatment without talking to their doctor, as human studies are still needed to confirm these findings.

The Research Details

Scientists divided 28 rats into four equal groups to test how probiotics affect cisplatin-related heart damage. One group served as the control (no treatment), one received only cisplatin, one received probiotics plus cisplatin, and one received only probiotics. The researchers then measured various markers in the rats’ hearts and blood to see what happened. They looked for signs of damage like harmful molecules, inflammation, and cell death. They also examined heart tissue under a microscope to see physical damage.

The probiotics used were three specific types of Lactobacillus bacteria: rhamnosus, fermentum, and brevis. These are friendly bacteria that naturally live in human and animal digestive systems. The researchers gave these bacteria to the rats before exposing them to cisplatin, which is a chemotherapy drug used to treat various cancers.

The study measured multiple indicators of heart health including oxidative stress (harmful molecules), inflammation markers, and proteins that control whether cells live or die. They also checked blood tests that show heart damage, similar to tests doctors use on human patients.

This research approach matters because cisplatin is an effective cancer drug, but it can damage the heart as a serious side effect. Finding a safe, natural way to protect the heart during cancer treatment could help patients tolerate their cancer therapy better and reduce long-term health problems. Testing in animals first is the standard scientific approach before trying new treatments in humans.

This study was published in Scientific Reports, a reputable scientific journal. The researchers used clear measurements and statistical analysis to show their results were significant (p < 0.01 means there’s less than a 1% chance the results happened by accident). However, this is an animal study, so results may not directly apply to humans. The study used a relatively small number of rats (28 total), and only male rats were tested, so results might differ in females or in people.

What the Results Show

Cisplatin caused significant damage to rat hearts by creating harmful molecules called free radicals and triggering inflammation. Specifically, cisplatin increased harmful oxidative stress markers by about 74% and decreased the heart’s natural protective antioxidant system by about 33%. The drug also activated cell death pathways, causing heart cells to die and creating visible damage when researchers examined heart tissue under a microscope.

When rats received the probiotic bacteria before cisplatin treatment, the damage was substantially reduced. The probiotics lowered harmful molecules by approximately 32%, increased the heart’s natural defense system by about 12%, and reduced markers of cell death. Heart tissue from rats receiving probiotics showed much less physical damage compared to rats receiving cisplatin alone.

The probiotics also improved blood markers that indicate heart damage. When cisplatin damages the heart, certain enzymes and proteins leak into the bloodstream. Rats receiving probiotics had significantly lower levels of these damage markers, suggesting their hearts were better protected. The combination of reduced harmful molecules, improved natural defenses, and decreased cell death all contributed to better overall heart health in the probiotic-treated group.

The study found that probiotics alone (without cisplatin) did not harm the rats’ hearts and appeared safe. The researchers also discovered that the protective effect of probiotics involved multiple mechanisms: reducing inflammation, decreasing DNA damage in heart cells, and improving the balance between proteins that promote cell death and those that promote cell survival. These multiple protective pathways suggest probiotics work through several different ways to protect the heart.

Previous research has shown that cisplatin causes heart damage through oxidative stress and inflammation, which matches what this study found. Other studies have suggested that probiotics may have antioxidant and anti-inflammatory properties, but this is one of the first studies specifically testing whether probiotics can protect against cisplatin-induced heart damage. The findings align with growing evidence that gut health and probiotics may influence heart health through multiple biological pathways.

This study was conducted only in rats, so results may not directly apply to humans. Only male rats were tested, so it’s unclear if female rats or women would respond the same way. The study used a relatively small sample size (28 rats total, 7 per group), which limits how confident we can be in the results. The researchers didn’t test different doses of probiotics or different timing of when to give them, so the optimal approach for humans remains unknown. Additionally, this was a short-term study, so long-term effects in humans are unclear. Finally, the study didn’t compare probiotics to other potential protective treatments that might already be used in cancer care.

The Bottom Line

Based on this animal research, probiotics containing Lactobacillus appear promising for protecting the heart during cisplatin treatment, but human studies are needed before making clinical recommendations. Confidence level: Low to Moderate (animal study only). People currently receiving cisplatin should not start probiotics without discussing it with their oncologist, as interactions with cancer treatment are unknown. Future human studies should test whether these specific probiotic strains provide the same protection in cancer patients.

This research is most relevant to cancer patients receiving cisplatin therapy, their doctors, and researchers developing ways to reduce cancer treatment side effects. People with heart disease or those at risk for heart problems during cancer treatment should be especially interested in this research. However, people should not self-treat based on this animal study alone. Healthy people without cancer have no reason to use probiotics specifically for heart protection based on this research.

In this rat study, protective effects were observed relatively quickly after probiotic administration. However, the timeline for human benefits is unknown. If human studies confirm these findings, it might take weeks to months of probiotic use during cancer treatment to see protective effects. Long-term benefits and whether protection continues after stopping probiotics remain unknown.

Want to Apply This Research?

  • Users receiving cisplatin could track heart-related symptoms weekly: shortness of breath, chest discomfort, unusual fatigue, or swelling in legs/feet. If probiotics are used (with doctor approval), note the specific strains and dosage, along with any changes in these symptoms or blood test results showing heart damage markers.
  • If a healthcare provider approves probiotic use during cisplatin treatment, users could set daily reminders to take the probiotic supplement at the same time each day. They could also track dietary sources of probiotics (yogurt, fermented foods) and note any digestive changes, as probiotics can affect digestion.
  • Create a monthly check-in to review heart health markers from blood tests ordered by the oncologist (troponin, creatine kinase levels). Compare these results over time while using probiotics. Also track overall energy levels, exercise tolerance, and any heart-related symptoms. Share this information with both the oncologist and cardiologist to monitor for any changes in heart function during cancer treatment.

This research was conducted in laboratory rats and has not been tested in humans. Cisplatin is a serious cancer medication that requires careful medical supervision. Anyone receiving cisplatin or other chemotherapy should not start probiotics or make any changes to their treatment plan without explicit approval from their oncologist. While these findings are promising, they do not constitute medical advice or a recommendation for clinical use. Probiotics may interact with certain medications or conditions. Always consult with your healthcare team before starting any supplement, especially during active cancer treatment. This summary is for educational purposes only and should not replace professional medical guidance.