Oral Administration of Water Extract from Euglena gracilis Alters the Intestinal Microbiota and Prevents Lung Carcinoma Growth in Mice

Abstract

The antitumor effects of a partially purified water extract from Euglena gracilis (EWE) and EWE treated by boiling (bEWE) were evaluated using orthotopic lung cancer syngeneic mouse models with Lewis lung carcinoma (LLC) cells. Daily oral administration of either EWE or bEWE started three weeks prior to the inoculation of LLC cells significantly attenuated tumor growth as compared to the phosphate buffered saline (PBS) control, and the attenuation was further enhanced by bEWE. The intestinal microbiota compositions in both extract-treated groups were more diverse than that in the PBS group. Particularly, a decrease in the ratio of Firmicutes to Bacteroidetes and significant increases in Akkermansia and Muribaculum were observed in two types of EWE-treated groups. Fecal microbiota transplantation (FMT) using bEWE-treated mouse feces attenuated tumor growth to an extent equivalent to bEWE treatment, while tumor growth attenuation by bEWE was abolished by treatment with an antibiotic cocktail. These studies strongly suggest that daily oral administration of partially purified water extracts from Euglena gracilis attenuates lung carcinoma growth via the alteration of the intestinal microbiota.

Lung cancer progression alters lung and gut microbiomes and lipid metabolism

“…According to the methods used in previous studies [ 21 ], LLC cells (1 × 10 6 ) suspended in 100 μL of phosphate-buffered saline (PBS) were injected into the tail vein of C57BL/6J female mice under anesthetic on day 0 using a 29-G syringe needle. At each time point (days 0, 7, 14, 21, 28, and 32 after tail vein injection of LLC cells), the mice were sacrificed by cervical dislocation following exposure to saturated CO 2 .…”

Euglena, a Gravitactic Flagellate of Multiple Usages

“…It also has anti-inflammatory, -oxidant, and -obesity properties [ 186 , 187 ]. An oral administration of a partially purified water extract from E. gracilis was found to prevent lung carcinoma growth in mice by decreasing the myeloid-derived cell number [ 188 , 189 ]. Paramylon nanofibers from the WZSL mutant of E. gracilis had an anti-fibrotic effect on liver damage induced by CCl 4 in mice [ 190 ].…”

Research Progresses on the Physiological and Pharmacological Benefits of Microalgae-Derived Biomolecules

“…The EPS treatment regulated the expression levels of differentially expressed genes and activated various cancer and apoptosis-related proteins, which include mitogen-activated protein kinase (MAPK), TNF-1α, PI3K, and Akt. The changes in the expression levels of 13 proteins that are involved in signal transduction pathways were found in cells that were treated with Chlorella EPS [ 31 ].…”