Probiotic supplementation with Lactobacillus casei may help preserve intestinal microbial homeostasis, reduce chemotherapy-associated gastrointestinal toxicity, and support improved treatment outcomes in cancer patients receiving platinum-based chemotherapy.
Key Findings
Results
Chemotherapy induced significant gut microbial dysbiosis characterized by reduced alpha diversity and shifts in bacterial abundance.
Chemotherapy reduced abundance of beneficial bacteria including Lactobacillus, Bifidobacterium, and Faecalibacterium.
Chemotherapy increased abundance of opportunistic pathogens such as Escherichia-Shigella and Klebsiella.
Fecal samples were collected before and after chemotherapy and subjected to 16S rRNA sequencing to assess microbial diversity and taxonomic composition.
150 patients receiving platinum-based chemotherapy were enrolled and divided into control and probiotic intervention groups.
Results
Probiotic-treated patients maintained a relatively balanced gut microbiota and exhibited less pronounced dysbiosis after chemotherapy compared to controls.
The probiotic strain was identified as Lactobacillus casei using biochemical characterization and 16S rRNA gene sequencing.
The strain was isolated from a commercial formulation.
Its secreted metabolites were characterized using FTIR, GC-MS, HPLC, and NMR spectroscopy.
Probiotic-treated patients showed reduced microbial dysbiosis following chemotherapy compared to the control group.
Results
Overall gastrointestinal toxicity was significantly lower in probiotic-treated patients compared to controls.
Overall gastrointestinal toxicity was observed in 85% of control patients compared with 65% of probiotic-treated patients.
Diarrhea occurred in 60% of control patients and 35% of probiotic-treated patients.
Grade 3-4 gastrointestinal toxicity was reported in 40% of control patients compared with 20% of probiotic-treated patients.
Probiotic supplementation was also associated with lower incidence and severity of mucositis, nausea, and vomiting.
Results
Chemotherapy responders exhibited a more favorable microbial profile with greater abundance of beneficial commensal bacteria than non-responders.
Chemotherapy responders had greater abundance of beneficial commensal bacteria compared to non-responders.
This association suggests a link between gut microbial composition and chemotherapy treatment response.
The finding was identified through 16S rRNA sequencing of fecal samples collected before and after chemotherapy.
Results
Specific microbial taxa were identified as potential predictors of chemotherapy outcomes using receiver operating characteristic (ROC) analysis.
AUC value was 0.81 for Bacteroides ovatus as a predictor of chemotherapy outcomes.
AUC value was 0.78 for Faecalibacterium prausnitzii as a predictor of chemotherapy outcomes.
The combined response model achieved an AUC of 0.86 for predicting chemotherapy outcomes.
The combined microbial model achieved an AUC of 0.88 for predicting severe gastrointestinal toxicity.
What This Means
This research suggests that chemotherapy for cancer significantly disrupts the gut microbiome — the community of bacteria living in the digestive tract — by reducing beneficial bacteria and allowing harmful bacteria to flourish. In a study of 150 cancer patients receiving platinum-based chemotherapy, researchers found that this disruption was associated with gastrointestinal side effects like diarrhea, nausea, vomiting, and mouth sores, which are common and serious problems during cancer treatment.
This research suggests that supplementing with a probiotic strain of Lactobacillus casei during chemotherapy may help protect the gut microbiome and reduce these side effects. Patients who received the probiotic had notably lower rates of gastrointestinal complications: overall gut toxicity dropped from 85% to 65%, severe (Grade 3-4) toxicity dropped from 40% to 20%, and diarrhea rates fell from 60% to 35% compared to patients who did not receive probiotics. Additionally, patients who responded better to chemotherapy tended to have healthier gut microbiomes, and specific bacterial species (Bacteroides ovatus and Faecalibacterium prausnitzii) showed promise as predictors of how well patients might respond to treatment or how likely they were to develop severe side effects.
This research suggests that monitoring and supporting the gut microbiome during cancer treatment could be an important strategy for reducing side effects and potentially improving treatment effectiveness. The identification of specific bacterial markers that predict treatment outcomes opens the door to personalized approaches in cancer care, though further large-scale clinical trials would be needed to confirm these findings and establish standardized probiotic protocols for cancer patients.
Check Your Own Numbers
Upload your bloodwork. We'll cross-reference your results against this study and 4,700 others.
Li H, Hou C, Pan Y. (2026). Microbiome-based probiotic intervention to reduce chemotherapy-induced gastrointestinal toxicity.. Frontiers in cellular and infection microbiology. https://doi.org/10.3389/fcimb.2026.1887323