Flaxseed diet caused inflammation by altering the gut microbiota of Peking ducks.

To study why flaxseed supplementation causes adverse effects on the performance of poultry, we investigated the gut microbiota of Peking ducks after consumption of a flaxseed diet. A total of 792, 12-day-old white Peking ducks were divided into four groups. In the control group, birds were provided with a basal diet. In the three experimental groups, the birds were fed flaxseed containing diet (10% flaxseed and 90% basal diet) for 30, 20 and 10 d, respectively. On day 42, ceca were collected to evaluate the bacterial diversity of the gut microbiota using microbial 16S rDNA gene profiling; serums were obtained to determine the levels of inflammatory mediators. The flaxseed diet decreased the alpha diversity and shifted the predominant genera of the gut microbiota. Flaxseed-fed groups had higher abundances of Escherichia/Shigella (p < 0.1) and Campylobacter (p < 0.05) than the control group. The abundance of pro-inflammatory bacteria such as Veillonellaceae increased (p < 0.05) at first and then decreased (p < 0.05) with prolonged flaxseed supplementation. The levels of prostaglandin E2 and Leukotriene B4 in serum showed the same pattern as that of the pro-inflammatory bacteria. In conclusion, flaxseed diets are associated with inflammation by altering the cecal microbiota dynamics.