Researchers tested whether a type of helpful bacteria called Enterococcus faecium could protect against colon cancer in laboratory rats. The bacteria, which naturally lives in our digestive system, was given to rats that were exposed to a cancer-causing chemical. The study found that rats receiving this bacteria had less damage to their intestines, less inflammation, and fewer signs of cancer development compared to rats that didn’t receive it. While these results are promising, this is early-stage research in animals, and much more testing is needed before we know if it could help prevent colon cancer in people.

The Quick Take

  • What they studied: Whether a specific probiotic bacteria (a type of ‘good’ bacteria) could prevent or slow down colon cancer development when given to animals exposed to cancer-causing chemicals
  • Who participated: Female laboratory rats were divided into groups. Some received only a cancer-causing chemical, while others received the chemical plus the probiotic bacteria at different time periods
  • Key finding: Rats that received the probiotic bacteria showed better protection of their intestinal lining, less inflammation, and fewer signs of pre-cancerous changes compared to rats that only received the cancer-causing chemical
  • What it means for you: This research suggests that certain probiotics might play a protective role against colon cancer, but this is very early-stage animal research. It’s too soon to recommend specific probiotics for cancer prevention in humans without much more research and clinical testing

The Research Details

This was an experimental laboratory study using female Wistar rats (a common research rat breed). The researchers divided the rats into different groups. Some groups received a chemical called DMH that causes colon cancer in animals, while other groups received both the cancer-causing chemical and doses of the probiotic bacteria Enterococcus faecium. Different groups received the bacteria for different lengths of time to see if timing mattered.

After the treatment period, the researchers examined the rats’ intestines and livers under microscopes, tested their blood, and looked for signs of cancer development, inflammation, and cell death. They specifically measured inflammation markers (IL-1β and TNF-α) and a growth factor (VEGF-A) that’s involved in cancer development.

Animal studies like this are important early steps in understanding how potential treatments might work before testing them in humans. By using a controlled laboratory setting with rats, researchers can carefully observe exactly what happens when probiotics are given to animals developing cancer. This helps scientists understand the biological mechanisms and decide whether human studies are worth pursuing

This is a controlled laboratory experiment, which is good for understanding how something works. However, the study has some limitations: it was done in animals, not humans; the exact number of rats used wasn’t clearly specified; and results in animals don’t always translate to humans. This type of research is considered preliminary and would need to be followed by human studies before making any health recommendations

What the Results Show

The main finding was that rats receiving the probiotic bacteria showed better preservation of their intestinal lining compared to rats that only received the cancer-causing chemical. The intestinal tissue looked healthier and more normal under the microscope.

Second, the bacteria appeared to reduce inflammation in the intestines. Inflammation is a key factor in cancer development, and the probiotic group showed lower levels of inflammatory markers compared to the group that only received the cancer-causing chemical.

Third, rats receiving the probiotic bacteria showed fewer pre-cancerous changes in their intestines, including fewer abnormal crypts (small pits in the intestinal lining where cancer often starts). The bacteria group also showed signs of better cell death (apoptosis) in abnormal cells, which is actually protective against cancer.

Finally, the probiotic bacteria appeared to protect the liver from damage and inflammation caused by the cancer-inducing chemical, suggesting benefits beyond just the intestines.

The study observed that rats receiving only the cancer-causing chemical had very low glycogen levels (a stored form of sugar) in their intestinal tissue, indicating significant intestinal damage. Rats that received the probiotic bacteria maintained more normal glycogen levels, suggesting their intestinal cells remained healthier. The protective effect appeared to work by reducing multiple inflammation-related pathways in the body

This research builds on previous observations that certain probiotic bacteria can support digestive health and may have anti-inflammatory properties. The specific finding that Enterococcus faecium might help prevent pre-cancerous changes is a new contribution, though other probiotics have shown similar protective effects in animal models. This study adds to growing evidence that the bacteria living in our digestive system (our microbiome) plays an important role in cancer prevention

This study was conducted only in laboratory rats, not humans, so we cannot assume the same effects would occur in people. The exact number of rats in each group was not clearly reported, making it harder to assess the strength of the findings. The study used a specific strain of bacteria (EF137v) at specific doses, so results might differ with other strains or doses. Additionally, this is a single study, and results would need to be confirmed by other independent research teams before drawing firm conclusions

The Bottom Line

Based on this single animal study, there is not yet enough evidence to recommend this specific probiotic for colon cancer prevention in humans. The findings are promising and suggest further research is warranted, but much more testing—including human clinical trials—would be needed before any health recommendations could be made. General probiotic use for digestive health may have other benefits, but cancer prevention claims require stronger evidence

This research is most relevant to: (1) Scientists and doctors researching cancer prevention and probiotics; (2) People with family histories of colon cancer who are interested in prevention strategies; (3) Researchers developing new probiotic treatments. This should NOT be used as a reason to start taking specific probiotics for cancer prevention without consulting your doctor, as the evidence is still very preliminary

This is early-stage research. If human studies eventually begin, it would likely take 5-10 years or more of research before any probiotic could be recommended for cancer prevention. Even then, it would likely be one part of a comprehensive prevention strategy that includes screening, diet, exercise, and other proven approaches

Want to Apply This Research?

  • Users interested in digestive health could track weekly digestive symptoms (bloating, regularity, discomfort) and any probiotic supplements taken, noting brand, strain, and dosage. This personal tracking helps identify which products seem to help individual users, though it’s not a substitute for medical advice
  • Users could use the app to set reminders for taking probiotic supplements if recommended by their doctor, and log any digestive changes they notice. They could also track other colon cancer prevention behaviors like fiber intake, water consumption, and physical activity
  • Over 4-8 weeks, users could rate their digestive comfort on a simple scale and note any changes. This helps them and their healthcare provider understand if a particular probiotic seems beneficial for their individual digestive health, while understanding that this is personal tracking, not medical treatment

This research is preliminary animal study findings and should not be used to guide personal health decisions. Colon cancer prevention requires a comprehensive approach including screening, healthy diet, exercise, and medical supervision. Anyone concerned about colon cancer risk should consult with their healthcare provider about evidence-based prevention strategies. This article is for educational purposes only and is not medical advice. Do not start, stop, or change any health treatments based on this single animal study without consulting your doctor.