Bifidobacterium bifidum 1,2-alpha-L-fucosidase (AfcA)

Bifidobacterium bifidum is a prominent member of the infant gut microbiota, distinguished by its specialized machinery for degrading human milk oligosaccharides (HMOs) (Sakanaka et al., 2019). The primary enzyme involved in the breakdown of 2'-fucosyllactose (2'-FL), the most prevalent HMO, is the extracellular 1,2-alpha-L-fucosidase, often designated as AfcA (Katayama et al., 2004). This enzyme is a member of the glycoside hydrolase family 95 (GH95) and is typically anchored to the bacterial cell wall, allowing it to process 2'-FL in the extracellular environment (Ashida et al., 2009). By cleaving the alpha-1,2-fucosyl linkage, AfcA releases fucose and lactose, which can then be internalized by the bacterium or shared with other beneficial microbes through a process known as cross-feeding (Turroni et al., 2010). This enzymatic activity is critical for the successful colonization of B. bifidum in the neonatal gut, which in turn promotes immune system maturation and provides protection against enteric pathogens (Garrido et al., 2013). In clinical practice, 2'-FL is utilized as a prebiotic to selectively enhance the activity of these glycosidases, thereby supporting a healthy microbiome and reducing the risk of conditions like necrotizing enterocolitis and allergic diseases (Sakanaka et al., 2019). While these enzymes and their parent organisms are generally safe, therapeutic use in severely immunocompromised individuals carries a small risk of opportunistic infection (NIH, 2025).

Other names

1,2-alpha-L-fucosidaseGH95 fucosidaseBifidobacterium bifidum extracellular glycosidases acting on 2'-fucosyllactosealpha-L-fucosidase AfcAExtracellular 1,2-alpha-L-fucosidase

Hydrolysis of alpha-1,2-fucosyl linkages in 2'-fucosyllactose to release fucose and lactose.