The Microbiome

Independent Research: How the Canine Gut Microbiome Changes With Age

A 2024 peer-reviewed study compared the gut microbiome and faecal metabolome of junior, adult and senior Sapsaree dogs. Researchers found clear age-related differences in both microbial composition and metabolite profiles, suggesting that the gut ecosystem changes substantially across the canine lifespan.

Peer reviewed Open access

Independent Research: How the Canine Gut Microbiome Changes With Age

Year

2024

Study type

Peer-reviewed cross-sectional multi-omics study

Sample

18 Sapsaree dogs, 6 per age group

Measured

Faecal microbiome composition, sequencing-method differences and faecal metabolome across junior, adult and senior dogs

The research question

Age influences almost every major biological system in the body.

The gut microbiome is unlikely to be an exception.

Researchers therefore asked whether dogs at different life stages show different microbial communities and metabolite profiles.

The study compared three groups of Sapsaree dogs:

junior dogs

adult dogs

and

senior dogs

The central question was:

Does the canine gut microbiome and metabolome change systematically with age?

The researchers also compared short-read and long-read sequencing approaches to see how strongly the analytical method influenced what was detected.

What did the researchers do?

Eighteen Sapsaree dogs were divided into three groups of six.

Junior

1 year old.

Adult

4 to 6 years old.

Senior

10 to 12 years old.

Faecal samples were collected from each dog.

The researchers analysed the microbiome using two sequencing approaches.

Short-read sequencing

Illumina sequencing was used to analyse bacterial DNA with relatively high depth and accuracy.

Long-read sequencing

Oxford Nanopore sequencing generated much longer reads, allowing different taxonomic resolution but with a different error profile.

The faecal metabolome was also analysed using gas chromatography-mass spectrometry.

This allowed the researchers to compare:

microbial composition

with

metabolite profiles

across the three age groups.

What did they measure?

The study examined several layers of the gut ecosystem.

Microbial composition

Researchers compared bacterial populations at phylum and genus level.

Microbial diversity

They examined whether overall microbial diversity differed between age groups.

Sequencing-method differences

The same samples were analysed using both Illumina and Nanopore platforms.

This allowed the researchers to see whether the analytical method affected which bacterial genera were detected.

Faecal metabolites

A broad range of metabolites was measured.

These included compounds associated with amino-acid metabolism, carbohydrate metabolism and microbial fermentation.

Microbiome-metabolome relationships

The researchers then examined correlations between bacterial groups and metabolite patterns.

What was observed?

Age was associated with clear differences in both the microbiome and metabolome.

Firmicutes decreased with age

Firmicutes were the dominant bacterial phylum overall, but their relative abundance declined from junior to senior dogs.

Actinobacteria and Proteobacteria increased in older groups

Both were more abundant in adult and senior dogs than in juniors.

Lactobacillus was lower in senior dogs

Lactobacillus was one of the common genera detected by both sequencing platforms and showed lower relative abundance in senior dogs.

The metabolome differed clearly by age

Faecal metabolite profiles clustered according to age group.

Junior, adult and senior dogs each showed different dominant metabolites.

Junior dogs had higher levels of several compounds

These included:

gamma-aminobutyric acid

cadaverine

uracil

benzofuran

and D-cellobiose

Senior dogs showed a different metabolic profile

Compounds including:

D-serine

glyceric acid

propanoic acid

and glycolic acid

were relatively more prominent in senior dogs.

Microbiome and metabolome changes were linked

The age-related metabolite patterns broadly correlated with age-related microbiome changes.

This suggests that ageing alters not only which microorganisms are present but also the chemical environment associated with them.

What does this study tell us?

This study supports the idea that the canine gut ecosystem is dynamic across the lifespan.

A senior dog does not necessarily have the same microbiome or metabolite profile as a younger dog.

That matters for several reasons.

First, it reinforces the importance of individual context when interpreting microbiome data.

A bacterial profile that is typical in a young dog may not be typical in an older one.

Second, it suggests that age can influence both:

who is present

and

what is happening chemically within the gut

This fits with the wider multi-omics view of the microbiome.

Composition and function should be considered together.

The study also has practical implications for nutrition research.

If the baseline gut environment changes with age, then the response to diet, fibre, probiotics or other gut-directed interventions may also differ between life stages.

For a study of common bacterial species and variation among healthy dogs, read the core microbiome research.

What doesn't this study tell us?

Several limitations are important.

Small sample size

Only 18 dogs were studied, with six in each age group.

Single breed

All dogs were Sapsaree.

The findings may not generalise directly to other breeds or body sizes.

Cross-sectional design

Different dogs were compared at different ages.

The study did not follow the same dogs from youth into old age.

Therefore, some differences may reflect individual or cohort effects rather than ageing itself.

Diet differed between age groups

Junior dogs were fed a different food from adult and senior dogs.

Diet can strongly influence the microbiome, so some apparent age effects may also reflect dietary differences.

Sequencing method affected results

Illumina identified more bacterial genera than Nanopore.

The same biological sample therefore looked somewhat different depending on the analytical method.

Association is not causation

Age-related microbial and metabolite differences do not establish that those changes cause age-related health effects.

The study is best viewed as evidence that age is an important variable when interpreting canine microbiome and metabolome data.

Original research

Study details

Study

Gut microbiome and metabolome library construction based on age group using short-read and long-read sequencing techniques in Korean traditional canine species Sapsaree

Authors

Seon-Hui Son
Min-Geun Kang
Anna Kang
Yonggu Kang
Kimoon Kim
Min-Jin Kwak
Minho Song
Younghoon Kim

Institutions

Seoul National University, Republic of Korea

Chungnam National University, Republic of Korea

University of Florida, USA

Reference

Son SH, Kang MG, Kang A, Kang Y, Kim K, Kwak MJ, Song M, Kim Y. Gut microbiome and metabolome library construction based on age group using short-read and long-read sequencing techniques in Korean traditional canine species Sapsaree. Frontiers in Microbiology. 2024;15:1486566.

Published 5 December 2024.

Eighteen Sapsaree dogs were divided into junior, adult and senior groups. Faecal samples were analysed using Illumina short-read sequencing, Oxford Nanopore long-read sequencing and metabolomics.

DOI: 10.3389/fmicb.2024.1486566

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