Changes in human fecal microbiota due to chemotherapy analyzed by TaqMan-PCR, 454 sequencing and PCR-DGGE fingerprinting.

Department of Nutritional Sciences, Vienna, Austria.
PLoS ONE (Impact Factor: 3.73). 01/2011; 6(12):e28654. DOI:10.1371/journal.pone.0028654
Source: PubMed

ABSTRACT We investigated whether chemotherapy with the presence or absence of antibiotics against different kinds of cancer changed the gastrointestinal microbiota.
Feces of 17 ambulant patients receiving chemotherapy with or without concomitant antibiotics were analyzed before and after the chemotherapy cycle at four time points in comparison to 17 gender-, age- and lifestyle-matched healthy controls. We targeted 16S rRNA genes of all bacteria, Bacteroides, bifidobacteria, Clostridium cluster IV and XIVa as well as C. difficile with TaqMan qPCR, denaturing gradient gel electrophoresis (DGGE) fingerprinting and high-throughput sequencing. After a significant drop in the abundance of microbiota (p = 0.037) following a single treatment the microbiota recovered within a few days. The chemotherapeutical treatment marginally affected the Bacteroides while the Clostridium cluster IV and XIVa were significantly more sensitive to chemotherapy and antibiotic treatment. DGGE fingerprinting showed decreased diversity of Clostridium cluster IV and XIVa in response to chemotherapy with cluster IV diversity being particularly affected by antibiotics. The occurrence of C. difficile in three out of seventeen subjects was accompanied by a decrease in the genera Bifidobacterium, Lactobacillus, Veillonella and Faecalibacterium prausnitzii. Enterococcus faecium increased following chemotherapy.
Despite high individual variations, these results suggest that the observed changes in the human gut microbiota may favor colonization with C. difficile and Enterococcus faecium. Perturbed microbiota may be a target for specific mitigation with safe pre- and probiotics.

0 0
  • [show abstract] [hide abstract]
    ABSTRACT: Cyclophosphamide is one of several clinically important cancer drugs whose therapeutic efficacy is due in part to their ability to stimulate antitumor immune responses. Studying mouse models, we demonstrate that cyclophosphamide alters the composition of microbiota in the small intestine and induces the translocation of selected species of Gram-positive bacteria into secondary lymphoid organs. There, these bacteria stimulate the generation of a specific subset of "pathogenic" T helper 17 (pTH17) cells and memory TH1 immune responses. Tumor-bearing mice that were germ-free or that had been treated with antibiotics to kill Gram-positive bacteria showed a reduction in pTH17 responses, and their tumors were resistant to cyclophosphamide. Adoptive transfer of pTH17 cells partially restored the antitumor efficacy of cyclophosphamide. These results suggest that the gut microbiota help shape the anticancer immune response.
    Science 11/2013; 342(6161):971-976. · 31.20 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Chemotherapy-induced mucositis is considered to be a major oncological problem, caused by the cytotoxic effects of cancer chemotherapy. In the last 10 years, there have been significant advances in the understanding of mucositis pathobiology. At the basic level, it is now well-understood that it is not just an epithelial process, but rather a complex interaction between epithelial and connective tissue compartments. There is also potential interaction between the oral microenvironment and the development of mucositis. Changes occur in the resident oral flora (commensal) throughout cancer treatment, and it is conceivable that these organisms and changes that occur may have an influence on the development of mucosal toxicity associated with cancer treatment. The aim of this review was to examine the potential contributions of oral microflora in the pathobiology of mucositis and identify pathways and interactions that could be targeted for therapeutic management of mucositis.
    Journal of Oral Pathology and Medicine 02/2014; · 2.06 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Gene-environment interactions underlie cancer susceptibility and progression. Yet we still have limited knowledge of which environmental factors are important and how they function during tumorigenesis. In this respect, the microbial communities that inhabit our gastrointestinal tract and other body sites have been unappreciated until recently. However, our microbiota are environmental factors that we are exposed to continuously, and human microbiome studies have revealed significant differences in the relative abundance of certain microbes in cancer cases compared to controls. To characterize the function of microbiota in carcinogenesis, mouse models of cancer have been treated with antibiotics. They have also been maintained in a germfree state or have been colonized with specific bacteria in specialized (gnotobiotic) facilities. These studies demonstrate that microbiota can increase or decrease cancer susceptibility and progression by diverse mechanisms such as by modulating inflammation, influencing the genomic stability of host cells, and producing metabolites that function as histone deacetylase (HDAC) inhibitors to epigenetically regulate host gene expression. One might consider microbiota as tractable environmental factors because they are highly quantifiable and relatively stable within an individual compared to our exposures to external agents. At the same time, however, diet can modulate the composition of microbial communities within our gut, and this supports the idea that probiotics and prebiotics can be effective chemoprevention strategies. The trajectory of where the current work is headed suggests that microbiota will continue to provide insight into the basic mechanisms of carcinogenesis and that microbiota will also become targets for therapeutic intervention.
    Carcinogenesis 12/2013; · 5.64 Impact Factor

Full-text (2 Sources)

Available from
May 9, 2012