Table 1.

Summary of the structure and formula of prebiotics.

Abbreviation	Chemical Composition	DP	Chemical Formula	References
Inulin	linear chain of fructose with β(2→1) linkages	3–60	n = up to 100	[59,60]
FOS	linear chain of fructose with β(2→1) linkages	<10	n = 1–5	[59,60]
GOS	Chain of galactosyl residues and a terminal glucose linked by β-(1–2), β-(1–3), β-(1–4), or β-(1–6) glycosidic bonds	2–8	n = 1–4	[60,103]
HMO	composed of five monosaccharides: glucose, galactose, N-acetylglucosamine, fucose, and N-acetylneuraminic acid or sialic acid	<7	2′fucosyllactose 3′-fucosyllactose 3′-sialyllactose 6′-sialyllactose Lacto-N-tetraose Lacto-N-neotetraose Lacto-N-fucopentaose I	[104,105]
Lactulose	consisting of galactose and fructose moieties	-		[106,107]
Lactosucrose	composed of galactose, fructose, and glucose monomers	-		[108]
AX	β-1,4-linked D-xylopyranoside units substituted with arabinose residues on the c(o)-2 or c(o)-3 position	1–60		[109]
XOS	xylose moeities linked by β-(1→4) glyosidic bonds	2–4	n = 2–4	[110,111,112]
Symbols used in Table 1: their meaning and chemical structure.