503P - Effect of probiotics on gut microbiota diversity during chemotherapy treatment in patients with gastrointestinal cancer

Background

Chemotherapy is an essential treatment modality for cancer patients, but it often leads to detrimental effects on the gut microbiome, such as dysbiosis and decreased diversity. These disruptions can result in opportunistic infections, autoimmunity, chronic inflammation. In recent years, there has been growing interest in the use of probiotics to counteract these negative effects and maintain gut microbiome diversity during chemotherapy. Studies have shown that probiotics can modulate the composition and function of the gut microbiota. In this study, we aimed to evaluate the effect of probiotics on gut microbiome diversity during chemotherapy treatment in patients with gastrointestinal cancer.

Methods

Between April 2022 and February 2024, 13 patients diagnosed with gastrointestinal cancer who were intended to receive chemotherapy based on fluoropyrimidine, oxaliplatin, and/or irinotecan received a 20 billion colony-forming units (CFU) of a mixture containing five strains including 335mg of Lactobacillus acidophilus NCFM®, Lactobacillus paracasei Lpc-37^TM, Bifidobacterium lactis Bi-04^TM, Bifidobacterium lactis Bi-07^TM, and Bifidobacterium bifidum Bb-02^TM. Patients were instructed to take the product orally once daily for 30 days and had their gut microbiota composition evaluated before the first cycle of chemotherapy and one month after the first chemotherapy infusion. The gut microbiota composition was measured from fecal samples using 16S ribosomal RNA gene sequencing. The results were evaluated through the relative abundance and alfa diversity of phyla of the species in the gut microbiota.

Results

The median age of patients was 61 years (range 33-72). Most patients were diagnosed with tumors in the lower gastrointestinal tract, colorectal (53,84%, n=7). The most commonly prescribed treatment regimen was the combination of Capecitabine and Oxaliplatin (53,84%; n=7). No significant alterations were observed in the overall alpha diversity of phyla in samples collected before and after chemotherapy (p=0.21).

Conclusions

Probiotics did not demonstrate a statistically significant effect on gut microbiome diversity in patients undergoing chemotherapy treatment.

Clinical trial identification

U1111-1296-2263.

Legal entity responsible for the study

The authors.

Funding

São Paulo Research Foundation (FAPESP), #2021/12587-2.

Disclosure

All authors have declared no conflicts of interest.