Scientists studied a type of bacteria called Streptococcus thermophilus to see if it could help prevent colon cancer. They found that this bacteria works by changing how other bacteria in your gut behave and by creating helpful substances like folate (a B vitamin). When researchers tested this bacteria in the lab, it slowed down the growth of cancer cells. While these results are promising, this is early-stage research done in test tubes, not yet proven in people. The findings suggest this bacteria could one day be used as a natural way to reduce colon cancer risk, but much more research is needed before doctors could recommend it.

The Quick Take

  • What they studied: Whether a specific probiotic bacteria (a type of ‘good’ bacteria) could help prevent colon cancer by changing the balance of bacteria in the gut and creating protective compounds
  • Who participated: This was laboratory research using human gut bacteria samples and colon cancer cells grown in dishes. No human volunteers participated in this study.
  • Key finding: The bacteria Streptococcus thermophilus IDCC 2201 appeared to slow down colon cancer cell growth and created helpful substances like folate that may protect against cancer
  • What it means for you: This research is very early-stage and only done in test tubes. It suggests a possible future benefit, but it’s not ready for people to use as a cancer prevention strategy yet. More research in animals and humans would be needed first.

The Research Details

Scientists conducted laboratory experiments to understand how a specific probiotic bacteria interacts with other bacteria in the human gut and how it affects colon cancer cells. They grew different bacteria together in dishes to see how they influenced each other, then tested whether the bacteria and their byproducts could slow down cancer cell growth. This type of research is called ‘in vitro’ study, meaning it happens in test tubes and dishes rather than in living organisms. The researchers used standard laboratory techniques to measure bacterial growth, identify chemical compounds produced by the bacteria, and assess cancer cell survival under different conditions.

Understanding how specific bacteria interact with each other and what protective compounds they produce is important because it helps scientists identify which probiotics might actually work against cancer. Rather than just testing if a bacteria helps or hurts, this research looked at the ‘why’ and ‘how’ behind the effects. This deeper understanding is necessary before any probiotic could be safely recommended to people.

This study was published in Scientific Reports, a well-respected scientific journal. However, because this is laboratory research only (not tested in animals or people yet), the results are preliminary. The study provides good mechanistic information about how the bacteria works, but cannot yet prove it would help prevent cancer in real people. The lack of human or animal testing is the main limitation for determining real-world effectiveness.

What the Results Show

The probiotic bacteria Streptococcus thermophilus IDCC 2201 showed the ability to slow the growth of most other bacteria found in the human gut. Interestingly, it had a special relationship with one type of bacteria called Bacteroides dorei, which it actually helped grow by providing nutrients. When researchers grew S. thermophilus together with other gut bacteria, the mixture produced increased amounts of folate, a B vitamin known to have protective properties. When this bacteria and its byproducts were exposed to colon cancer cells in dishes, the cancer cells grew more slowly, suggesting a potential protective effect.

The research identified specific mechanisms explaining how S. thermophilus works: it produces enzymes that break down plant fiber (xylan) and creates B vitamins that feed beneficial bacteria. These interactions create a chain reaction where the bacteria produce protective compounds like folate as a byproduct. The study also showed that the culture liquid containing the bacteria and its products had anti-cancer effects, meaning the protective compounds are transferable and could potentially be isolated for use.

This research builds on existing knowledge that gut bacteria influence colon cancer risk and that probiotics may offer protection. Previous studies suggested probiotics could help, but this research goes deeper by explaining the specific mechanisms and identifying which bacteria interactions matter most. The focus on nutrient cross-feeding between bacteria is a newer approach that provides more detailed understanding than earlier probiotic studies.

This study only used laboratory dishes and test tubes, not living animals or people. Results in test tubes often don’t translate to real-world benefits in humans. The study didn’t test whether eating this bacteria would actually prevent cancer in people. The sample size and specific bacterial strains tested were limited. Long-term effects and safety in humans remain unknown. The research cannot yet prove this bacteria would work as a cancer prevention strategy outside the laboratory.

The Bottom Line

This research is too early-stage to recommend S. thermophilus as a cancer prevention strategy. Current evidence suggests it may be worth further investigation, but people should not rely on this bacteria as a substitute for proven cancer prevention methods like screening, healthy diet, exercise, and avoiding smoking. If you’re interested in probiotics for general gut health, consult your doctor about established options with proven safety records.

This research is most relevant to scientists and doctors studying cancer prevention and probiotic therapy. People with family history of colon cancer or those interested in cancer prevention may find the findings interesting but should not change their behavior based on this preliminary research. Healthcare providers should be aware of this emerging research but cannot yet recommend it to patients.

This is fundamental research, not a treatment ready for use. It typically takes 10-15 years of additional research (laboratory studies, animal studies, and human clinical trials) before a promising laboratory finding becomes a medical recommendation. Realistic expectations are that this will inform future research directions rather than provide immediate benefits.

Want to Apply This Research?

  • Track daily probiotic intake and gut health markers (digestion quality, energy levels, bowel regularity) using a 1-5 scale to establish baseline patterns. Note any dietary changes and how you feel over 2-4 week periods.
  • While this specific bacteria isn’t yet available for consumer use, users can support gut health through proven methods: eat more fiber-rich foods, include fermented foods like yogurt and sauerkraut, stay hydrated, and maintain regular exercise. Log these habits in the app to build awareness of gut-supporting behaviors.
  • Create a long-term wellness dashboard tracking overall digestive health, diet quality, and lifestyle factors known to reduce colon cancer risk. Include reminders for age-appropriate cancer screenings and annual check-ups with healthcare providers. Monitor for any new research updates on this bacteria as studies progress.

This research is preliminary laboratory work and has not been tested in humans. It should not be used as a basis for medical decisions or as a substitute for proven cancer prevention strategies. Colon cancer prevention should focus on established methods including regular screening, healthy diet, exercise, avoiding smoking, and maintaining a healthy weight. Anyone with concerns about colon cancer risk should consult with their healthcare provider. This article is for educational purposes only and does not constitute medical advice.