Results from a new study suggest microbial diversity of the oral and intestinal mucosa in patients with acute myelogenous leukemia (AML) has a significant impact on the risk for infectious complication in the first 3 months of induction of chemotherapy.
The study from MD Anderson Cancer Center in Houston, Texas, reveals that the gut microbial diversity of cancer sufferers takes a battering from multiple and repeated antibiotics, and that this in turn may increase their risk of chemotherapy-related infection. Worse still, patients who experience neutropenia and fever during chemotherapy have a good chance of having this treated empirically, rather than waiting for susceptibility.
Dr Galloway-Peña and her group presented data from 34 patients with AML over their 26-day course of chemotherapy. Each patient provided an average of eight oral and six stool specimens for analysis. Standard supportive therapy for chemotherapy-induced infection includes beta-lactam antibiotics unless contraindicated due to patient sensitivities.
It is common for AML patients to experience neutropenic fever and all patients received prophylactic antibiotic cover, with many receiving other antibiotics as well. Patients received 5.4 antibiotics for a period of 6.5 days, on average. Therefore, some patients would have received multiple courses and/or multiple antibiotics to attend to their infections.
During the chemotherapy treatment period, oral microbial diversity significantly decreased and microbial diversity in stools was found to be significantly lower in baseline samples of those patients who went on to develop infections during chemotherapy. Importantly, of the 34 patients sampled those who maintained or increased their microbial diversity throughout their therapy had no infections within 90 days. However, of the 23 patients who experienced a decrease in diversity, nine patients developed infection.
Moreover, intestinal bacterial domination of pathogens increased over the course of chemotherapy. This lead investigators to postulate that monitoring and manipulation of the microbiome could be used to reduce infectious disease related toxicity of cancer therapy
From this study it would seem prudent to give all patients undergoing chemotherapy a high-dose, broad-spectrum probiotic to prevent the development of chemotherapy-induced gut infections. Previous studies using eight species of probiotics have shown benefit. This is a good start, but clinicians should be mindful of the expanse of the normal gut microbiology and give as many species/strains as practicable.
- Galloway-Peña J, Smith D, Ajami N, et al. A prospective cohort study of the oral and fecal microbiome during induction remission chemotherapy in acute myelogenous leukemia. Interscience Conference of Antimicrobial Agents and Chemotherapy (ICAAC) 2015: Microbiome and Biofilms Session. [Abstract]