Project description:Purpose: Gut microbiota is associated with the progression of brain tumor. However, the alterations in the gut microbiota during glioma growth and temozolomide (TMZ) therapy remains to be understood. Methods: C57BL/6 male mice were implanted with GL261 glioma cells. TMZ/sodium carboxymethyl cellulose (SCC) was administered by gavage for five consecutive days (from 8 to 12 days after implantation). Fecal samples were collected before (T0) and on days 7 (T1), 14 (T2), and 28 (T3) after implantation. The gut microbiota was analyzed using 16S ribosomal DNA sequencing followed by absolute and relative quantitation analyses. Results: Nineteen genera were altered during glioma progression with the most dramatic changes in Firmicutes and Bacteroidetes phyla. During glioma growth, Lactobacillus abundance decreased at the earlier stage of glioma development (T1), and then gradually increased (T2, T3); Intestinimonas abundance exhibited a persistent increase; Anaerotruncus showed a transient increase and then a subsequent decrease. Twenty genera altered following TMZ treatment. The enrichment of Akkermansia and Bifidobacterium was observed only at the early stage following TMZ treatment (T2), but not at the later stage (T3). Additionally, the decrease of Anaerotruncus was slighter in TMZ group at T3 comparing to the vehicle group. The abundance of Intestinimonas increased constantly during the progression of glioma, but was unaffected by TMZ. Conclusions: Glioma development and progression resulted in altered gut microbiota. TMZ reversed the decrease of Anaerotruncus in glioma at T3, and increased the abundance of Bifidobacterium with no influence on the increase of Intestinimonas. Short-term and long-term effects of TMZ treatment on the bacterial communities may be differential. This study will improve understanding the role of gut microbiota in glioma, and help develop gut microbiota as a potential therapeutic target.
