Researchers discovered that children diagnosed with acute lymphoblastic leukemia (ALL), the most common childhood cancer, have different types of bacteria in their stomachs compared to healthy children. Using advanced DNA testing, scientists found that ALL patients had more harmful bacteria and fewer helpful bacteria that produce short-chain fatty acids. These differences suggest that changes in gut bacteria during childhood development might be connected to how this cancer develops. The findings could eventually help doctors understand cancer risk better, though more research is needed to confirm these connections.
The Quick Take
- What they studied: Whether children with acute lymphoblastic leukemia (a type of blood cancer) have different bacteria in their gut compared to healthy children
- Who participated: 30 children newly diagnosed with ALL (19 with B-cell type, 11 with T-cell type) and 176 healthy children without cancer for comparison
- Key finding: Children with ALL had more harmful bacteria like Enterococcus faecium and fewer helpful bacteria that make short-chain fatty acids, which are important for gut health
- What it means for you: This research suggests gut bacteria changes might play a role in cancer development, but it doesn’t mean bacteria cause cancer. Parents shouldn’t worry that their child’s bacteria caused their illness. This finding may eventually help doctors identify children at higher risk, but much more research is needed first.
The Research Details
Scientists used a technique called shotgun metagenomics, which is like reading the complete instruction manual of all bacteria in a sample. They collected gut bacteria samples from 30 children newly diagnosed with ALL and compared them to samples from 176 healthy children. The researchers identified which bacteria were present, how many of each type existed, and what functions those bacteria performed in the gut.
This approach is more detailed than older methods because it can identify bacteria more precisely and understand what they do. The study looked at two main types of ALL (B-ALL and T-ALL) to see if they had different bacterial patterns. The researchers carefully analyzed the data to find meaningful differences between the cancer patients and healthy children.
Understanding the gut bacteria in children with ALL is important because the gut microbiome affects immune system development and overall health. If certain bacteria patterns are connected to cancer development, this knowledge could eventually help doctors identify at-risk children earlier or develop new prevention strategies. This research uses advanced technology that provides more detailed information than previous studies, making the findings more reliable.
This study has good strengths: it used advanced DNA sequencing technology, had a reasonable number of participants, and compared cancer patients to healthy controls. However, readers should know this is an observational study, meaning it shows associations but cannot prove that bacteria changes cause cancer. The study was done at one point in time (at diagnosis), so it doesn’t show how bacteria changed over time. More research is needed to confirm these findings and understand whether bacteria changes happen before cancer develops or as a result of it.
What the Results Show
When comparing all ALL patients together to healthy children, clear differences emerged in bacterial composition. Children with ALL had higher amounts of potentially harmful bacteria, including Enterococcus faecium (a bacteria that can cause infections) and bacteria normally found in the mouth like Rothia dentocariosa. In contrast, healthy children had more beneficial bacteria that produce short-chain fatty acids—special compounds that help keep the gut healthy and support the immune system.
Beyond just which bacteria were present, the researchers found functional differences in what these bacteria do. In healthy children, the bacteria were better at breaking down carbohydrates (sugars) and making folate (a B vitamin). In ALL patients, the bacteria were more focused on breaking down proteins and amino acids. These differences suggest the gut environment in ALL patients is fundamentally different at the time of diagnosis.
When researchers compared the two main types of ALL (B-ALL and T-ALL) to each other, they found surprisingly few differences. The bacterial communities were quite similar between these two cancer types. The main difference was in pathways related to bile acid metabolism (how the body processes bile acids from the liver). This suggests that the major change in gut bacteria happens in ALL generally, rather than being specific to one cancer subtype.
These findings align well with previous research using older bacterial identification methods (16S rRNA testing), which also found bacterial differences in ALL patients. However, this new study using shotgun metagenomics provides more detailed information and confirms earlier findings with greater precision. Some minor differences between this study and previous ones likely reflect the improved technology’s ability to detect bacteria more accurately.
This study has several important limitations. First, it’s a snapshot at one moment in time (diagnosis), so researchers cannot determine whether bacterial changes happened before cancer developed or as a result of it. Second, the study cannot prove that bacteria changes cause cancer—only that they’re associated with it. Third, the study was relatively small (30 ALL patients) and conducted at one location, so results may not apply to all children with ALL worldwide. Finally, other factors like diet, antibiotics, and living conditions weren’t fully analyzed, and these could affect bacterial composition.
The Bottom Line
Based on this research alone, there are no specific dietary or probiotic recommendations for preventing or treating ALL. This is early-stage research showing associations, not proven causes. Parents of children with ALL should follow their oncologist’s treatment recommendations. Future research may eventually lead to new prevention or treatment strategies, but that’s not yet available.
This research is most relevant to: (1) researchers studying cancer development and the microbiome, (2) oncologists caring for children with ALL, and (3) parents wanting to understand their child’s condition. Healthy children and their families should not make changes based on this single study. This research does not suggest that normal variations in gut bacteria cause cancer.
This is foundational research, not a treatment or prevention strategy. It may take 5-10 years or more of additional research before findings translate into practical applications for patients. Realistic expectations are that this work will inform future studies, not provide immediate benefits.
Want to Apply This Research?
- For families affected by ALL, track dietary intake and gastrointestinal symptoms (bowel regularity, bloating, digestive comfort) to share with the medical team, as these may be affected by both cancer treatment and gut bacteria changes.
- While waiting for more research, families can support overall gut health through a balanced diet rich in fiber and whole foods, which supports beneficial bacteria growth. However, any dietary changes for a child with ALL should be discussed with their oncology team first.
- Long-term, families should maintain records of any gastrointestinal changes during and after cancer treatment, as this information helps doctors understand treatment side effects and may inform future personalized medicine approaches.
This research describes associations between gut bacteria and acute lymphoblastic leukemia but does not prove that bacteria cause cancer. Parents should not assume their child’s bacterial composition caused their illness. This is early-stage research and should not be used to make medical decisions. All treatment and prevention decisions for children with ALL should be made in consultation with qualified oncologists and medical professionals. If you have concerns about your child’s health or cancer risk, speak with your pediatrician or oncologist.