Exploring the gut microbiome's influence on cancer-associated anemia: Mechanisms, clinical challenges, and innovative therapies.

Abstract

Background: Anemia is a prevalent and challenging complication in patients with hematologic and solid malignancies, which stems from the direct effects of malignancy, treatment-induced toxicities, and systemic inflammation. It affects patients' survival, functional status, and quality of life profoundly. Recent literature has highlighted the emerging role of the gut microbiome in the pathogenesis of cancer-associated anemia. The gut microbiota, through its intricate interplay with iron metabolism, inflammatory pathways, and immune modulation, may either exacerbate or ameliorate anemia depending on its composition, and functional integrity. Dysbiosis, characterized by disruption in the gut microbial ecosystem, is very common in cancer patients. This microbial imbalance is implicated in anemia causation through diminished iron absorption, persistent low-grade inflammation, and suppression of erythropoiesis.

Aim: To consolidate current evidence regarding the interplay between gut microbiome and anemia in the setting of malignancies. It aims to provide a detailed exploration of the mechanistic links between dysbiosis and anemia, identifies unique challenges associated with various cancer types, and evaluates the efficacy of microbiome-focused therapies. Through this integrative approach, the review seeks to establish a foundation for innovative clinical strategies aimed at mitigating anemia and improving patient outcomes in oncology.

Methods: A literature search was performed using multiple databases, including Google Scholar, PubMed, Scopus, and Web of Science, using a combination of keywords and Boolean operators to refine results. Keywords included "cancer-associated anemia", "gut microbiome", "intestinal microbiota", "iron metabolism", "gut dysbiosis", "short-chain fatty acids", "hematopoiesis", "probiotics", "prebiotics", and "fecal microbiota transplantation". Articles published in English between 2000 and December 2024 were included, with a focus on contemporary and relevant findings.

Results: Therapeutic strategies aimed at restoration of gut microbial homeostasis, such as probiotics, prebiotics, dietary interventions, and fecal microbiota transplantation (FMT), can inhibit anemia-causing pathways by enhancing microbial diversity, suppressing detrimental flora, reducing systemic inflammation and optimizing nutrient absorption.

Conclusion: Gut dysbiosis causes anemia and impairs response to chemotherapy in cancer patients. Microbiome-centered interventions, such as probiotics, prebiotics, dietary modifications, and FMT, have shown efficacy in restoring microbial balance, reducing inflammation, and enhancing nutrient bioavailability. Emerging approaches, including engineered probiotics and bacteriophage therapies, are promising precision-based, customizable solutions for various microbiome compositions and imbalances. Future research should focus on integrating microbiome-targeted strategies with established anemia therapies.