Scientific reportsAug 6, 2025

Gut bacteria differences in aging Hispanic people with Alzheimer's linked to thinking problems and disease severity

Gut-Brain Axis Weekly Brief ↗PubMed ↗DOI ↗OA ↗

Updated Mar 6, 2026

Abstract

In a study of 100 participants, specific gut bacteria showed differing abundances between individuals with Alzheimer's disease (AD) and healthy controls.

Overall microbial diversity and richness did not significantly differ between AD patients and controls.
Faecalibacterium and Bacteroides were found in higher levels among healthy controls compared to those with AD.
Individuals with the had lower amounts of butyrate-producing bacteria.
An increase in potentially pro-inflammatory bacteria, such as Eggerthella and Lachnoclostridium, was observed in APOE E4 carriers.
dysbiosis may be linked to cognitive decline and progression of AD.

Simplified

Alzheimer's disease (AD) is a neurodegenerative disorder that begins with memory loss and can lead to death. In Puerto Rico, AD is the fourth leading cause of death, while in the United States, it ranks fifth. Research suggests the gut microbiome contributes to the pathophysiology of AD by promoting inflammation and amyloid buildup in the brain. This study examined the composition and diversity of the in Puerto Ricans with AD compared to controls and its relationship with cognitive impairment severity and APOE status. We recruited 100 participants (50 AD, 50 controls), who underwent clinical and cognitive assessments (MoCA/CDR). While overall microbial diversity and richness showed no significant differences, specific bacterial taxa exhibited subtle differential abundance. Faecalibacterium and Bacteroides were moderately significant and increased on controls compared to AD. Moreover, individuals carrying the exhibited lower abundances of butyrate-producing bacteria and an enrichment of potentially pro-inflammatory genera, including Eggerthella and Lachnoclostridium. These findings suggest that gut microbiota dysbiosis may contribute to cognitive decline and AD progression, highlighting the potential for microbiome-targeted therapeutic interventions in AD prevention and treatment.

Key numbers

33%

APOE E4 Carrier Prevalence

Among the total cohort of 100 participants.

44 of 50

Cognitive Impairment in Controls

Based on MoCA scores among control participants.

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Funding

Competing interests

Declarations. Competing interests: The authors declare no competing interests.

PubMed

Gut bacteria differences in aging Hispanic people with Alzheimer's linked to thinking problems and disease severity

Abstract

Key numbers

Full Text

Funding

Competing interests

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Abstract

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Full Text

Funding

Competing interests

Related papers

You found one interesting study. We’ll send the next 7.

What Lands in Your Inbox Each Week:

Recent issues from the gut-brain axis brief