Microbial and Metabolic Gut Profiling across Seven Malignancies Identifies Fecal <i>Faecalibacillus intestinalis</i> and Formic Acid as Commonly Altered in Cancer PatientsOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study used whole-genome shotgun sequencing and gas chromatography/mass spectrometry to profile gut microbial and metabolic signatures across seven different malignancies. The researchers compared taxonomic and metabolomic configurations in cancer patients against sex- and age-matched healthy controls. The goal was to identify both common and cancer-type-specific gut microbiome and metabolite alterations.
Who was studied?
The study included patients with colorectal cancer (40), stomach cancer (45), breast cancer (71), lung cancer (34), melanoma (50), lymphoid neoplasms (60), and acute myeloid leukemia (40). Each cancer group was compared against its own sex- and age-matched healthy control group. In total the analysis spanned 300 cancer patients across seven malignancy types plus their matched controls.
What were the most important findings?
Beta-diversity differed between every cancer group and its healthy controls, while alpha-diversity differed only for the lymphoid neoplasm and acute myeloid leukemia groups. Of 203 unique species identified, 179 were under-represented and 24 were over-represented in cancer patients relative to controls. Faecalibacillus intestinalis was under-represented across all seven cancer groups, and Anaerostipes hadrus was under-represented in all groups except stomach cancer, with a marked reduction in the gut microbiome cancer index in every group except acute myeloid leukemia. Among the short-chain fatty acids and amino acids tested, formic acid concentration was significantly altered.
What are the greatest implications of this study?
The consistent depletion of Faecalibacillus intestinalis and altered formic acid levels across seven distinct cancer types suggest these may represent shared, cross-cancer markers of gut dysbiosis rather than disease-specific findings. This points toward a common gut microbial and metabolic signature that could inform future pan-cancer diagnostic or monitoring approaches. Because the pattern held despite differences in cancer biology and location, it strengthens the case for a generalizable link between gut dysbiosis and malignancy.