Plate · Bacteroidota

genus · NCBI 816

Bacteroides

Formerly Capsularis.

Species44

Products0 across its species

Samples53,839

Also known as CapsularisRistella

The genus

Species in this genus

Include unnamed strains (8)

Species	Healthy guts ↓ 0–100%	Products
Bacteroides uniformis	87%	0
Bacteroides ovatus	76%	0
Bacteroides thetaiotaomicron	69%	0
Bacteroides caccae	62%	0
Bacteroides xylanisolvens	59%	0
Bacteroides stercoris	50%	0
Bacteroides fragilis	44%	0
Bacteroides cellulosilyticus	35%	0
Bacteroides finegoldii	27%	0
Bacteroides eggerthii	24%	0
Bacteroides intestinalis	21%	0
Bacteroides nordii	21%	0
Bacteroides salyersiae	18%	0
Bacteroides faecis	17%	0
Bacteroides clarus	15%	0
Bacteroides bouchesdurhonensis	3.3%	0
Bacteroides congonensis	2.3%	0
Bacteroides cutis	1.6%	0
Bacteroides faecalis	1.1%	0
Bacteroides mediterraneensis	<1%	0
Bacteroides propionicigenes	<1%	0
Bacteroides fluxus	<1%	0
Bacteroides togonis	<1%	0
Bacteroides stercorirosoris	<1%	0
Bacteroides ndongoniae	<1%	0
Bacteroides oleiciplenus	<1%	0
Bacteroides gallinarum	<1%	0
Bacteroides acidifaciens	<1%	0
Bacteroides caecigallinarum	<1%	0
Bacteroides gallinaceum	<1%	0
Bacteroides rodentium	<1%	0
Bacteroides faecium	<1%	0
Bacteroides ilei	<1%	0
Bacteroides caecicola	<1%	0
Bacteroides pyogenes	<1%	0
Bacteroides caecimuris	<1%	0
Bacteroides muris (ex Fokt et al. 2023)	<1%	0
Bacteroides neonati	<1%	0
Bacteroides graminisolvens	<1%	0
Bacteroides heparinolyticus	<1%	0
Bacteroides coprosuis	0%	0
Bacteroides reticulotermitis	0%	0
Bacteroides timonensis	0%	0
Bacteroides zoogleoformans	0%	0
Across the genus	94%	0

* Counted in the same healthy people as the species (whole-genome samples). All bars use the same 0–100% scale. A product with two Bacteroides species counts once in the genus total.

What they are

Its species' DNA

A C G T ? Not read clearly in the reference sequence

Genome sizes · 42 Bacteroides species

Shortest we have Mycoplasmoides genitalium 0.6M

⋮ 902 shorter than any Bacteroides

Bacteroides coprosuis 2.8M

Bacteroides caecigallinarum 3.4M

Bacteroides zoogleoformans 3.4M

Bacteroides pyogenes 3.5M

Bacteroides heparinolyticus 3.6M

Bacteroides gallinaceum 3.7M

Bacteroides graminisolvens 3.8M

Bacteroides clarus 3.9M

Bacteroides cutis 3.9M

Bacteroides ilei 4.0M

Bacteroides togonis 4.0M

Bacteroides stercoris 4.0M

Bacteroides mediterraneensis 4.1M

Bacteroides propionicigenes 4.1M

Bacteroides eggerthii 4.2M

Bacteroides rodentium 4.3M

Bacteroides fluxus 4.3M

Bacteroides uniformis 4.7M

Bacteroides caecimuris 4.8M

Bacteroides acidifaciens 4.8M

Bacteroides finegoldii 4.9M

Bacteroides gallinarum 4.9M

Bacteroides ndongoniae 4.9M

Bacteroides neonati 5.0M

Bacteroides fragilis 5.2M

Bacteroides bouchesdurhonensis 5.3M

Bacteroides reticulotermitis 5.5M

Bacteroides caccae 5.5M

Bacteroides salyersiae 5.6M

Bacteroides nordii 5.7M

Bacteroides faecalis 5.8M

Bacteroides intestinalis 6.1M

Bacteroides stercorirosoris 6.3M

Bacteroides thetaiotaomicron 6.3M

Bacteroides faecis 6.4M

Bacteroides congonensis 6.4M

Bacteroides ovatus 6.5M

Bacteroides xylanisolvens 6.6M

Bacteroides faecium 6.8M

Bacteroides timonensis 7.0M

Bacteroides oleiciplenus 7.1M

Bacteroides cellulosilyticus 7.3M

⋮ 27 longer than any Bacteroides

Longest we have Bradyrhizobium altum 9.8M

Bacteroides genomes run from 2.8M to 7.3M: large for gut microbes.

One reference genome per species; strains vary.

Their ID genes, lined up: shared stretches form solid stripes

16S gene, V4 region, from one reference sequence per species, aligned so the same positions line up. A blank is a gap: letters other species have and this one lacks. Switch to “Only where they differ” to fade the letters they share. Grey letters weren’t read clearly; they never count as a difference.

From its species' genomes and lab tests

What its species can do

A species counts when most of its strains can. Not measured in anyone's gut. 10 of its 44 species aren't in either source yet.

Can ferment fiber 30 of 34 species B. uniformis, B. ovatus, B. thetaiotaomicron, B. caccae, B. xylanisolvens, B. stercoris and 24 more
Can use lactose 28 of 32 species B. uniformis, B. ovatus, B. thetaiotaomicron, B. caccae, B. xylanisolvens, B. stercoris and 22 more
Can make propionate 24 of 26 species B. uniformis, B. ovatus, B. thetaiotaomicron, B. caccae, B. xylanisolvens, B. stercoris and 18 more
Can make lactic acid 24 of 26 species B. uniformis, B. ovatus, B. thetaiotaomicron, B. caccae, B. xylanisolvens, B. stercoris and 18 more
Can eat pectin 8 of 26 species B. uniformis, B. ovatus, B. thetaiotaomicron, B. caccae, B. xylanisolvens, B. stercoris and 2 more
Can eat inulin 7 of 26 species B. uniformis, B. ovatus, B. thetaiotaomicron, B. caccae, B. stercoris, B. fragilis and 1 more
Can change bile acids 5 of 26 species B. thetaiotaomicron, B. fragilis, B. eggerthii, B. intestinalis, B. nordii
Can feed on gut mucus 3 of 26 species B. thetaiotaomicron, B. caccae, B. fragilis
Can make butyrate 0 of 26 species None of its species
Can eat resistant starch 0 of 26 species None of its species
Can make B vitamins 0 of 26 species None of its species
Can make hydrogen sulfide 0 of 26 species None of its species
Can make methane 0 of 26 species None of its species

What’s typical · a description, not a comparison

In healthy guts

Everyone · 12,213 people · 129 studies

How common

Found in 94% of healthy people.

How big a slice of the gut

largest Bacteroides 9.8%
2nd largest Phocaeicola 9.1%
3rd largest Segatella 6.4%
4th largest Bifidobacterium 6.2%
5th largest Faecalibacterium 5.4%
6th largest Alistipes 5.2%
7th largest Blautia 3.6%
8th largest Ruminococcus 3.0%
650 other microbes, each a sliver 32.3%
18.9%

On average, 9.8% of the microbes in a healthy gut: the largest slice of any genus.

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 · 49% carry it 6.2% of the microbes 5th largest

198 people · 5 studies 100% carry it 22.0% of the microbes largest

57 people · 77% carry it 13.0% of the microbes 3rd largest

1,283 people · 27 studies 96% carry it 12.2% of the microbes largest

142 people · 15 studies 95% carry it 10.8% of the microbes largest

By sex

2,063 people · 95% carry it 14.4% of the microbes largest

1,530 people · 29 studies 94% carry it 13.0% of the microbes largest

Compared within studies that had both

In conditions

Compared with healthy people in the same studies, it’s less common in 7 conditions and more common in 2 conditions. 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

HIV infection 508 people · 7 studies Less common in people with it Healthy 91% With it 83%
Crohn's disease 1,658 people · 15 studies Less common in people with it Healthy 90% With it 81%
Chronic fatigue syndrome 302 people · 3 studies As many carry it in people with it Healthy 100% With it 99%
Carriers have more, in 3 of 3 studies (16% → 23% of their gut microbes).
Ulcerative colitis 1,015 people · 13 studies As many carry it in people with it Healthy 84% With it 82%
Carriers have more, in 9 of 9 studies (9.8% → 13% of their gut microbes).
Diarrhea 263 people · 2 studies Less common in people with it Healthy 99% With it 75%
Neuroblastoma 95 people · 2 studies Less common in people with it Healthy 92% With it 70%
Polycystic ovary syndrome 105 people · 2 studies As many carry it in people with it Healthy 100% With it 100%
Carriers have about 3 times as much, in 2 of 2 studies (4.3% → 13% of their gut microbes).
Depression 65 people · 2 studies As many carry it in people with it Healthy 100% With it 100%
Carriers have about half as much, in 2 of 2 studies (12% → 6.8% of their gut microbes).
Clostridium infections 24 people · 1 study Less common in people with it Healthy 100% With it 42%
Diffuse large B-cell lymphoma 35 people · 1 study Less common in people with it Healthy 100% With it 46%
Cystic fibrosis 52 people · 1 study Less common in people with it Healthy 98% With it 46%
Pancreatic cancer 24 people · 1 study More common in people with it Healthy 39% With it 92%
Growth hormone-secreting pituitary tumor 28 people · 1 study More common in people with it Healthy 22% With it 61%

PubMed · human studies and reviews first

Recent research

No recent human studies or reviews yet. Probiome follows PubMed for the few hundred most-studied microbes; rarer species often only show up in large surveys. Search PubMed for this genus ↗