Yeast-fermented spirulina as a functional feed additive: Impacts on growth efficiency and gut microbial diversity in native Indonesian ducks

The effects of supplementing with fermented spirulina (Arthrospira platensis) on the small intestine microbiota of native Indonesian Magelang ducks were examined in this study. The primary objective of this study was to evaluate the effects of different levels of yeast-fermented Spirulina supplementation on the small intestinal microbiota of Indonesian Magelang ducks, while growth performance was assessed as a supporting parameter. The ducks were supplemented with 5 , 10 , or 15 fermented spirulina, with a control group receiving no supplementation. The microbiome was described using 16S rRNA gene sequencing. The microbiome analysis revealed that supplementation significantly altered the microbial community, particularly increasing the population of Cetobacterium somerae, a beneficial bacterium known for its antiviral properties. © 2026 The Authors