Table 1.

Effects of fructooligosaccharides (FOSs) in different chemical structures on reviewed parameters.

Biological activity	Effect${}^{\mathrm{a}}$	Structure ofmolecule	Effect mechanism${}^{\mathrm{b}}$	References
Positive effect ondigestion	$+$	oligomeric FOS	direct	Xu et al. (2002), Shim (2005)
Improved gut	$+$	oligomeric FOS	direct	Xu et al. (2002), Shim (2005)
microbiota		longer-chain FOS	direct	Zhao et al. (2013)
composition		scFOS	direct	Zhao et al. (2019)
		scFOS	indirect	Le Bourgot et al. (2019)
	o	oligomeric FOS	direct	Mountzouris et al. (2006)
		longer-chain FOS	direct	Loh et al. (2006), Eberhard et al. (2007)
Effect on pH value	$+$	oligomeric FOS	direct	Houdijk et al. (2002), Shim et al. (2005)
	o	oligomeric FOS	direct	Tsukahara et al. (2003)
Positive intestinal	$+$	oligomeric FOS	direct	Xu et al. (2002, 2005), Tsukahara et al. (2003)
morphologic effects		scFOS	indirect	Le Bourgot et al. (2017)
	o	oligomeric FOS	direct	Shim (2005)
		scFOS	indirect	Le Bourgot et al. (2014)
Immunological activity	$+$	oligomeric FOS	direct	Chang et al. (2018)
		scFOS	direct	Le Bourgot et al. (2014), Le Bourgot et al. (2016)
		scFOS	indirect	Le Bourgot et al. (2016, 2017, 2019)
	o	oligomeric FOS	direct	Herich et al. (2002), Shim (2005)
Effect on growthperformance	$+$	oligomeric FOS	direct	Chang et al. (2018), Xu et al. (2002), Estrada et al. (2001), Shim (2005)
		scFOS	direct	Apper et al. (2016)
		scFOS	indirect	Le Bourgot et al. (2016)
		longer-chain FOS	direct	Zhao et al. (2013)
	o	oligomeric FOS	direct	Xu et al. (2005)
		scFOS	direct	Le Bourgot et al. (2017)
			indirect	Le Bourgot et al. (2014, 2017), Apper et al. (2016)

${}^{\mathrm{a}}$ $+$: positive effect on traits/parameters; o: no significant effect was observed. ${}^{\mathrm{b}}$ Direct: experiment animals were fed with diet containing FOS; indirect: maternal diet included FOS.