MOS (Mannan-oligosaccharides)

Why this ingredient is used

Mannan-oligosaccharides (MOS) are prebiotic fibres derived from the cell wall of yeast (Saccharomyces cerevisiae). Unlike FOS which feeds beneficial bacteria, MOS works by binding to pathogenic bacteria (E. coli, Salmonella) and preventing them from attaching to the gut wall, effectively flushing them out. MOS also stimulates the gut immune response. It is less common than FOS in pet food but appears in premium brands (Purina ProPlan, some Eukanuba formulas) as a gut health differentiator. The inclusion rate is typically 0.1 to 0.5 percent.