Study · Scientific reports · 2021Conflicts declared

Chicken and pork eaters show different gut bacteria and metabolites

What it found

In 40 young men, those who usually ate chicken had more diverse gut bacteria and higher levels of skatole, indole and short-chain fatty acids in their feces than those who usually ate pork.

The study cannot show that chicken causes these differences.

What they found

Studies in people

Gut bacteria diversity

Chicken eaters had more diverse gut bacteria than pork eaters. Pork eaters had lower diversity scores.

Bacteria types

Chicken eaters had more Prevotella 9, Dialister, Faecalibacterium, Megamonas and Prevotella 2. Pork eaters had more Bacteroides, Faecalibacterium, Roseburia, Dialister and Ruminococcus 2.

Skatole and indole

Chicken eaters had higher levels of skatole and indole in their feces than pork eaters.

Short-chain fatty acids

Chicken eaters had higher total short-chain fatty acids, including acetic acid, propionic acid and branched chain fatty acids.

Links between bacteria and metabolites

Higher amounts of Prevotella 2 and Prevotella 9 were linked to higher levels of skatole, indole and short-chain fatty acids.

What the authors conclude

“Thus, intake of chicken diet may increase the risk of skatole- and indole-induced diseases by altering gut microbiota.”
Shi J, Zhao D, Zhao F, Wang C, Zamaratskaia G, Li C, 2021

Also in their conclusions

  • They say that eating chicken may increase the risk of diseases caused by skatole and indole by changing gut bacteria.
  • They note that long-term intake of a chicken diet may increase this risk.

How it was done

The authors wanted to see how different types of meat affect gut bacteria and the substances they make, since meat is a major source of tryptophan, which gut bacteria turn into skatole and indole.

They recruited 20 men who usually ate chicken and 20 men who usually ate pork, all aged 18 to 30. They collected stool samples and measured the bacteria present, short-chain fatty acids, skatole and indole.

What it can’t tell you

  • This study looked at people who already ate different meats, so it cannot prove that chicken or pork caused the differences seen.
  • It only included young men, so the results may not apply to women or other age groups.

The paper

Title
Chicken-eaters and pork-eaters have different gut microbiota and tryptophan metabolites
Type
Study
Evidence
Studies in people
Summarised from
Full text
Cite
Shi J, Zhao D, Zhao F, Wang C, Zamaratskaia G, Li C (2021). Chicken-eaters and pork-eaters have different gut microbiota and tryptophan metabolites. Scientific reports. doi:10.1038/s41598-021-91429-3Free full textPubMed 34099832DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error