Intake of olive-derived polyphenols classified as prenol lipids and phenylpropanoic acids is associated with increased abundance of Bacteroidales, a bacterial order that produces immunoinhibitory lipopolysaccharide, suggesting a potential dietary pathway to modulate gut-derived immune signaling.

When people eat olive-derived polyphenols, these compounds travel to the gut unchanged, where specific bacteria break them down using enzymes that cut off sugar parts. This process favors the growth of Bacteroidales bacteria, which produce a type of fat molecule that calms immune responses. The more diverse the polyphenols consumed, the more types of bacteria that can break them down become active, leading to a stronger presence of these immune-calming bacteria.