Salmon changes your stool

Salmon consumers had less of the unfavorable bacteria

Researchers at the Centre for Nutrition studied 67 healthy adults with overweight, asking them to consume either cod, salmon, or no fish for five days weekly across eight weeks. The investigation initially focused on whether fish intake affects blood glucose regulation.

"It was a bit surprising that only salmon had a positive effect on blood glucose, while cod had no effect," notes researcher Odrunn Anita Gudbrandsen. Upon examining stool samples from 15 participants in each dietary group, salmon consumers demonstrated altered intestinal flora with notably fewer Bacteroidetes bacteria—a type frequently increased in type 2 diabetes patients.

Not as big of a change in those eating meat

When compared to meat-consuming participants, the bacterial composition shift did not occur similarly. Gudbrandsen explains: "It is difficult to say whether it is the high salmon intake or the absence of meat that causes the change in the salmon group." However, since cod consumers showed no comparable changes, researchers believe salmon specifically drives these findings.

"Normal" food can influence our health

Despite these discoveries, stool consistency and type remained unchanged throughout the study period. All participants remained healthy with normal gut function. Gudbrandsen emphasizes the importance of understanding how everyday foods influence health through intestinal flora, noting that researchers plan investigating whether lower fish consumption produces similar effects.