Related Experiment Video

Updated: Jan 15, 2026

Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study
07:30

Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study

Published on: August 18, 2020

7.5K

Relationship between Gut microbiome and brain volumes among Japanese Men

Sabrina Ahmed1,2, Zhang Hexun3, Yuichiro Yano1,4

  • 1NCD Epidemiology Research Center (NERC), Shiga University of Medical Science, Otsu, Shiga, Japan.

Plos One
|October 7, 2025
PubMed

Insights

Gut microbiome diversity is linked to brain volumes in healthy older Japanese men. Specific bacteria, like Lachnospiraceae, were associated with higher white matter volume, and others with gray matter volume.

Area of Science:

  • Neuroscience
  • Microbiology
  • Public Health

Background:

  • Emerging evidence suggests a gut-brain axis, linking gut microbiome composition to brain health.
  • Previous studies focused on animal models or specific patient groups, leaving the association in healthy humans understudied.
  • Gut microbiome's influence on brain volumes in apparently healthy middle-aged to older adults requires further investigation.

Purpose of the Study:

  • To investigate the association between gut microbiome diversity and brain volumes (gray and white matter) in a population-based cohort of apparently healthy Japanese men.
  • To identify specific gut microbial taxa associated with variations in brain volumes.
  • To explore the gut-brain axis in the context of structural brain changes in aging.

Main Methods:

  • Cross-sectional study of 623 Japanese men from the Shiga Epidemiological Study on Subclinical Atherosclerosis (SESSA).
  • 16S ribosomal RNA gene sequencing of stool samples to analyze gut microbiome composition and diversity (alpha and beta diversity).
  • Brain magnetic resonance imaging with automated voxel-based morphometry to quantify gray and white matter volumes; statistical analyses included principal coordinate analysis, linear discriminant analysis, and multivariable linear regression.

Main Results:

  • Gray matter volume showed a positive association with gut microbiome alpha diversity (Shannon index) after adjusting for age and intracranial volume, but this was not significant after further adjustments.
  • Beta diversity analysis (weighted UniFrac distances) revealed distinct clustering of brain volumes, indicating differences in microbiome composition related to gray and white matter volumes.
  • Several bacterial genera were significantly associated with brain volumes; Lachnospiraceae (butyrate producer) was consistently linked to higher white matter volume, while Egarthellaceae, Bifidobacteraceae, and Selenomonadaceae were associated with greater gray matter volume.

Conclusions:

  • The study supports an association between gut microbiome diversity and brain volumes in middle-aged to older Japanese men.
  • Specific gut bacteria, such as Lachnospiraceae, may play a role in maintaining white matter volume.
  • These findings provide insights into the gut microbiome's potential influence on human brain structure and volume.

More Related Videos

Real-time Analysis of Gut-brain Neural Communication: Cortex wide Calcium Dynamics in Response to Intestinal Glucose Stimulation07:29

Real-time Analysis of Gut-brain Neural Communication: Cortex wide Calcium Dynamics in Response to Intestinal Glucose Stimulation

Published on: December 29, 2023

1.1K
Intracerebroventricular Delivery of Gut-Derived Microbial Metabolites in Freely Moving Mice07:49

Intracerebroventricular Delivery of Gut-Derived Microbial Metabolites in Freely Moving Mice

Published on: June 2, 2022

3.7K

Related Concept Videos

Brain Imaging01:14

Brain Imaging

Brain imaging technologies provide critical insights into both the structure and function of the human brain, enabling medical professionals and researchers to diagnose, study, and treat neurological disorders or psychiatric disorders more effectively.
These technologies include computerized axial tomography (CAT or CT scans), positron-emission tomography (PET scans),  magnetic resonance imaging (MRI),  functional magnetic resonance imaging (fMRI), and Transcranial Magnetic...
663
Biological Influences on Intelligence01:30

Biological Influences on Intelligence

Intelligence is often thought to be linked to brain size, but the relationship is more complex than that. While brain size does correlate modestly with some abilities, like verbal skills, the connection is weaker for others, such as spatial reasoning. Other factors, like brain structure, also play crucial roles. For instance, despite Einstein's smaller-than-average brain, his parietal cortex, which is involved in spatial reasoning, was 15% wider, suggesting that neural density might matter...
482
Physiology of Enteric Nervous System and Gut Health01:05

Physiology of Enteric Nervous System and Gut Health

The gastrointestinal tract, responsible for the digestion and absorption of nutrients, is safeguarded by the intestinal barrier, which consists of secretory, physical, and immune components. At the forefront is the secretory barrier, composed of essential elements such as mucus, gut microbiota, and defense proteins. They collaborate to break down food particles, facilitate nutrient absorption, and maintain optimal gut health. These secretory components ensure the smooth functioning of the...
870
Anatomy of the Intestines01:23

Anatomy of the Intestines

Although digestion of proteins, carbohydrates, and lipids may begin in the stomach, it is completed in the intestine. The absorption of nutrients, water, and electrolytes from food and drink also occurs in the intestine. The intestines can be divided into two structurally distinct organs—the small and large intestines.
Small Intestines
The small intestine is an ~7 meter-long tube with an inner diameter of just 2.5 cm. Since most nutrients are absorbed here, the inner lining of the...
86.7K
Organization of the Brain01:30

Organization of the Brain

The brain is an integral component of the nervous system and serves as the center for processing sensory inputs, making decisions, and directing bodily actions. This complex organ is organized into three primary sections: the hindbrain, midbrain, and forebrain, each responsible for a range of vital functions.
Hindbrain
The hindbrain, located at the base of the brain, plays a vital role in regulating automatic processes that sustain life. It includes the medulla oblongata, which is essential for...
2.3K
Biological Causes of Schizophrenia01:29

Biological Causes of Schizophrenia

Schizophrenia, a severe psychiatric disorder, arises from a complex interplay of biological factors, including genetic predisposition, structural brain abnormalities, neurotransmitter dysregulation, and developmental irregularities. These factors collectively contribute to the onset and progression of the disorder, which typically manifests in late adolescence or early adulthood.
Genetic Factors in Schizophrenia
The genetic basis of schizophrenia is strongly supported by family and twin...
491