Its ID gene (16S) · each bar is one letter A C G T ? Not read clearly in the reference sequence NCBI 16S

What's this?

Zoomed in: letters 116–139

Its ID gene: the stretch scientists read to tell microbes apart. Each bar is one letter of its DNA. Every species has its own order of letters, so the pattern works like a fingerprint. Close relatives share most of it.

16S rRNA gene, V4 region: the 254 letters between the standard primers (515F/806R), which are the same in every species. One reference sequence; strains can differ by a letter or two. 2 letters weren’t read clearly in it, so they’re grey, not guessed. NCBI NR_024750.1

NCBI Taxonomy 116085

Plate · Bacillota

Coprococcus catus

NCBI now calls it Pseudocoprococcus catus.

What it can do

All 13 things it can and can’t do →

Can make butyrate
Can make propionate
Can change bile acids

Healthy guts 51% of healthy people carry it Its slice 131st largest in a healthy gut · <1% Genome 3.6M letters Products 0 list it on the label

Lab traits Cell shape: not yet known

All of its DNA, to scale

Its genome

Genome · 3.6 million letters · 43% G+C

Shortest we have Mycoplasmoides genitalium 0.6M

⋮ 1,443 shorter

Coprococcus average 3.4M

Coprococcus catus 3.6M

⋮ 908 longer

Longest we have Bradyrhizobium altum 9.8M

Mid-sized for a gut microbe: longer than 61% of the 2,354 we have genomes for.

43% G+C, higher than 37% of gut microbes.

To scale: if its ID gene were 1 cm long, its genome would stretch 24 meters. Yours would stretch 21 kilometers. One reference genome; strains vary. NCBI GCF_019734885.1

Capabilities, not measurements of anyone's gut

What it can do

Makes

Can make butyrate A short-chain fatty acid that feeds the cells lining the colon.
Can make propionate A short-chain fatty acid, mostly used by the liver.

Changes

Can change bile acids Modifies the bile acids the liver makes to digest fat.

Not seen in its genomes: make lactic acid, ferment fiber, eat inulin, eat resistant starch, eat pectin, use lactose, feed on gut mucus, make B vitamins, make hydrogen sulfide, make methane.

All 13 capabilities and their evidence

Capability	Verdict	Genome analysis	Lab tests	Published research
Can make butyrate	Can	2 of 2 genomes	—	Papers say yes
Can make propionate	Can	2 of 2 genomes	—	Papers say yes
Can make lactic acid	Not seen	0 of 2 genomes	—	No papers
Can ferment fiber	Not seen	0 of 2 genomes	—	No papers
Can eat inulin	Not seen	0 of 2 genomes	—	No papers
Can eat resistant starch	Not seen	0 of 2 genomes	—	No papers
Can eat pectin	Not seen	0 of 2 genomes	—	No papers
Can use lactose	Not seen	0 of 2 genomes	—	No papers
Can feed on gut mucus	Not seen	0 of 2 genomes	—	No papers
Can change bile acids	Can	1 of 2 genomes	—	No papers
Can make B vitamins	Not seen	0 of 2 genomes	—	No papers
Can make hydrogen sulfide	Not seen	0 of 2 genomes	—	No papers
Can make methane	Not seen	0 of 2 genomes	—	No papers

AGORA2 (Heinken et al. 2023) via VMH, CC BY 4.0 · BacDive (DSMZ), CC BY 4.0 · NJC19 (Lim et al., Scientific Data 2020), CC0

What’s typical · a description, not a comparison

In healthy guts

Everyone · 12,213 people · 129 studies

How common

Found in 51% of healthy people.

How big a slice of the gut

largest Segatella copri 6.2%
2nd largest Phocaeicola vulgatus 5.0%
3rd largest Faecalibacterium prausnitzii 4.7%
4th largest Bacteroides uniformis 3.2%
5th largest Agathobacter rectalis 2.5%
6th largest Alistipes putredinis 2.3%
7th largest Bifidobacterium longum 2.1%
8th largest Ruminococcus bromii 1.8%
⋮
top 10% Coprococcus catus 0.09%
2,169 other microbes, each a sliver 56.6%
15.6%

On average, 0.09% of the microbes in a healthy gut: larger than 90% of species’ slices.

By age and sex

Every group, drawn the same way. Only some samples record age or sex, so each group says how many people it comes from. Tap one to see it above.

By age

367 people · 1.1% carry it under 0.01% of the microbes

198 people · 5 studies 30% carry it 0.05% of the microbes top 25%

57 people · 33% carry it 0.02% of the microbes top 45%

1,283 people · 27 studies 59% carry it 0.07% of the microbes top 15%

142 people · 15 studies 54% carry it 0.05% of the microbes top 25%

By sex

2,063 people · 50% carry it 0.08% of the microbes top 15%

1,530 people · 29 studies 47% carry it 0.08% of the microbes top 15%

Compared within studies that had both

In conditions

Compared with healthy people in the same studies, it’s less common in 10 conditions and more common in none. Only studies that had both are counted.

A difference is an association: it doesn’t mean this microbe causes, prevents or treats any of these.

Strongest first, then the biggest gap · Each figure is 10 people

Chronic fatigue syndrome 302 people · 3 studies Less common in people with it Healthy 70% With it 39%
COVID-19 259 people · 3 studies Less common in people with it Healthy 57% With it 38%
Crohn's disease 1,313 people · 8 studies Less common in people with it Healthy 39% With it 25%
Colorectal cancer 475 people · 10 studies Less common in people with it Healthy 69% With it 58%
Ulcerative colitis 820 people · 7 studies Less common in people with it Healthy 41% With it 31%
Chronic kidney failure 347 people · 2 studies Less common in people with it Healthy 70% With it 40%
Neuroblastoma 95 people · 2 studies Less common in people with it Healthy 54% With it 30%
Clostridium infections 24 people · 1 study Less common in people with it Healthy 67% With it 0%
Diarrhea 65 people · 1 study Less common in people with it Healthy 70% With it 11%
High blood pressure 50 people · 1 study Less common in people with it Healthy 93% With it 40%

PubMed · human studies and reviews first

Recent research

All research on it

Review AIMS microbiology · 2026
The role of lactate metabolism in shaping intestinal microbiota and health.
PubMed ↗
Observational PloS one · 2026
Comparative analysis of gut microbiome alterations in early- and late-onset preeclampsia: A case control study.
PubMed ↗
Observational Microbiology spectrum · 2026
Gut microbial community structure, metabolic signature, and resistome in dyslipidemia: implications for cardiovascular disease management.
PubMed ↗
Randomized trial Microbiome · 2025
Fecal microbiota transplantation for hypertension: an exploratory, multicenter, randomized, blinded, placebo-controlled trial.
PubMed ↗
Observational Nutrients · 2024
Specific Gut Microbiome Signatures in Children with Cow's Milk Allergy.
PubMed ↗

Source: PubMed, U.S. National Library of Medicine · 38 linked papers, last 10 years

Coprococcus catus

What it can do

Its genome

What it can do

In healthy guts

Where these numbers come from

In conditions

Where these numbers come from

Also compared · 46 conditions

No meaningful difference · 46

Recent research