Remarkable progress has occurred over the past two decades in identifying microbiomes affecting the human body in numerous ways. The microbiome is linked to gastrointestinal (GI) tract cancer. The purpose of this study was to determine if there is a common microbiome among GI tract cancers and how the microbiome affects the disease. To ensure ethnic consistency, Korean patients with GI tract cancer were selected. Fusobacterium nucleatum is an enriched bacteria in all cancer tissues. F. nucleatum is a Gram-negative obligate anaerobe that promotes colorectal cancer. Through Gene Set Enrichment Analysis (GSEA) and Differentially Expressed Genes (DEG) analyses, the upregulation of the G2M checkpoint pathway was identified in the F. nucleatum-high group. Cell viability and G2M checkpoint pathway genes were examined in MC 38 cells treated with F. nucleatum. F. nucleatum upregulated the expression of G2M checkpoint pathway genes and the cell proliferation of MC 38 cells. F. nucleatum facilitated cancer’s use of G2M checkpoint pathways and F. nucleatum could be a therapeutic target in Korean GI tract cancer.

Recent studies have identified a urinary microbiome, dispelling the myth of urine sterility. Intravesical bacillus Calmette–Guérin (BCG) therapy is the preferred treatment for intermediate to high-risk non-muscle-invasive bladder cancer (BCa), although resistance occurs in 30–50% of cases. Progression to muscle-invasive cancer necessitates radical cystectomy. Our research uses 16S rRNA gene sequencing to investigate how the urinary microbiome influences BCa and its response to BCG therapy. Urine samples were collected via urethral catheterization from patients with benign conditions and non-muscle-invasive BCa, all of whom underwent BCG therapy. We utilized 16S rRNA gene sequencing to analyze the bacterial profiles and metabolic pathways in these samples. These pathways were validated using a real metabolite dataset, and we developed predictive models for malignancy and BCG response. In this study, 87 patients participated, including 29 with benign diseases and 58 with BCa. We noted distinct bacterial compositions between benign and malignant samples, indicating the potential role of the toluene degradation pathway in mitigating BCa development. Responders to BCG had differing microbial compositions and higher quinolone synthesis than non-responders, with two Bifidobacterium species being prevalent among responders, associated with prolonged recurrence-free survival. Additionally, we developed highly accurate predictive models for malignancy and BCG response. Our study delved into the mechanisms behind malignancy and BCG responses by focusing on the urinary microbiome and metabolic pathways. We pinpointed specific beneficial microbes and developed clinical models to predict malignancy and BCG therapy outcomes. These models can track recurrence and facilitate early predictions of treatment responses.

Microbiome-derived metabolites have emerged as key mediators of the gut–brain axis, influencing cognitive function and neuroprotection. This study investigated whether Lactobacillus delbrueckii subsp. lactis CKDB001 alleviates scopolamine-induced memory impairment through metabolic modulation, and how its effects compare with those of donepezil. ICR mice were administered CKDB001 or donepezil for 4–5 weeks and evaluated through behavioral, microbiome, metabolomic, and molecular analyses. CKDB001 significantly improved spatial working memory in a dose-dependent manner, with the high-dose group showing improvements comparable to those of the donepezil-treated group, while passive avoidance showed a non-significant but positive trend. Both CKDB001 and donepezil modulated gut microbial composition, leading to a partial divergence from the scopolamine-disrupted community structure, with CKDB001 inducing dose-dependent intestinal colonization. Metabolomic profiling revealed that both treatments increased tryptophan-derived indole metabolites and altered lipid and short-chain fatty acid metabolite profiles, although these effects were more pronounced in CKDB001-treated mice. At the molecular level, both CKDB001 and donepezil reduced hippocampal tau phosphorylation, downregulated glycogen synthase kinase-3 (GSK-3) signaling, enhanced intestinal tight-junction proteins, and partially normalized acetylcholinesterase activity, with CKDB001 restoring AChE levels more closely toward the normal control. Together, these findings suggest that CKDB001 mitigates cognitive deficits through coordinated modulation of microbial, metabolic, and neuronal pathways, offering a microbiome-based therapeutic approach that may provide benefits comparable to donepezil with potentially fewer limitations.