Structural and Functional Dysbiosis of Fecal Microbiota in Chinese Patients With Alzheimer’s Disease Original paper
Researched by:
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Dr. Umar
ID
Dr. Umar
Read MoreClinical Pharmacist and Clinical Pharmacy Master’s candidate focused on antibiotic stewardship, AI-driven pharmacy practice, and research that strengthens safe and effective medication use. Experience spans digital health research with Bloomsbury Health (London), pharmacovigilance in patient support programs, and behavioral approaches to mental health care. Published work includes studies on antibiotic use and awareness, AI applications in medicine, postpartum depression management, and patient safety reporting. Developer of an AI-based clinical decision support system designed to enhance antimicrobial stewardship and optimize therapeutic outcomes.
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Dr. Umar
Read More
Researched by:
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Dr. Umar
ID
Dr. Umar
Read More
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Karen Pendergrass
Location
China
Sample Site
Feces
Species
Homo sapiens
What was studied?
This original research article investigated the Structural and Functional Dysbiosis of Fecal Microbiota in Chinese Patients With Alzheimer’s Disease, focusing on how gut microbiome changes relate to cognitive decline and immune markers. The study centered on the microbiome–gut–brain axis in Alzheimer’s disease, exploring whether specific microbial signatures—including shifts in butyrate-producing versus lactate-producing bacteria—could serve as biomarkers for early detection or therapeutic targeting. This exploration of dysbiosis in Alzheimer’s disease provides insight into how microbial imbalance may shape neuroinflammation, metabolic outputs, and cognitive impairment.
Who was studied?
The study enrolled 100 clinically diagnosed Alzheimer’s disease (AD) patients and 71 age- and gender-matched healthy controls, all living in Lishui, China. Participants were evaluated through the Mini-Mental State Examination (MMSE), the Wechsler Adult Intelligence Scale (WAIS), and Barthel Index scores. Exclusion criteria included recent antibiotic or probiotic use, active infections, autoimmune disease, inflammatory bowel disease, psychiatric comorbidity, and neurodegenerative disorders other than AD. Fecal samples and serum cytokines were collected to analyze microbiome structure and host immune profiles. All subjects underwent MRI to confirm brain atrophy in AD cases.
Most important findings
The study revealed profound structural and functional dysbiosis in AD patients. Alpha diversity (Shannon, Simpson, observed OTUs, ACE, Chao1) was significantly reduced, while beta diversity separated AD from controls across multiple distance metrics (page 5 PCoA plots). At the phylum level, Actinobacteria and Verrucomicrobia increased, whereas Firmicutes decreased. At the family and genus levels, the most notable shifts involved a loss of butyrate-producing bacteria and an expansion of lactate-producing taxa.
A simplified table illustrates the major microbiome shifts (from data on pp. 5–7):
| Microbial Category | Decreased in AD (Key SCFA/Butyrate Producers) | Increased in AD (Key Lactate/Propionate Producers) |
|---|---|---|
| Genera | Faecalibacterium, Roseburia, Gemmiger, Coprococcus, Butyricicoccus, Dialister | Bifidobacterium, Akkermansia, Collinsella, Enterococcus, Corynebacterium |
| Families | Ruminococcaceae, Lachnospiraceae, Clostridiaceae 1 | Bifidobacteriaceae, Verrucomicrobiaceae, Coriobacteriaceae, Enterococcaceae |
Key implications
This study establishes a clear microbial signature associated with Alzheimer’s disease, characterized by a shift from butyrate-producing to lactate-producing taxa, accompanied by altered metabolic potential and inflammatory cytokine patterns. The findings suggest that AD-related dysbiosis is not merely a consequence of aging but may contribute directly to neuroinflammation and cognitive decline. The taxa Faecalibacterium and Bifidobacterium, and particularly their ratio, show promise as non-invasive biomarkers for distinguishing AD patients from healthy aging individuals. The results underscore the potential for microbiome-targeted interventions—personalized probiotics, prebiotics, dietary modulation, or fecal microbiota transplantation—as therapeutic strategies for modifying disease trajectory.
Citation
Ling Z, Zhu M, Yan X, Cheng Y, Shao L, Liu X, Jiang R, Wu S. Structural and Functional Dysbiosis of Fecal Microbiota in Chinese Patients With Alzheimer’s Disease.Front Cell Dev Biol. 2021;8:634069. doi:10.3389/fcell.2020.634069 fcell-08-634069