Table 2.

In vivo studies on the evaluation of the prebiotic effect of AX.

Animal model	Diet/experimental time	Findings	Reference
Male chickens	Control diet (CT), diet supplemented with XOS, wheat bran-derived AXOS, wheat endosperm alkali-solubilized AX. 2 w	All treatments increased bifidobacteria. AX decreased body weight gain after 2 weeks of feeding compared with CT.	[89]
Male C57bl6/J mice	Control diet, high-fat (HF) diet, HF diet supplemented with AX. 4 w	HF diet supplemented with AX restored microbiota with a major effect on Roseburia spp., Bacteroides-Prevotella spp., and bifidobacteria. Improvement of gut barrier function, decrease in adipocyte size, fatty acid uptake, fatty acid oxidation and inflammation, and decrease in key lipogenic enzyme activity in the subcutaneous adipose tissue.	[39]
Male germ-free Fisher 344 albino rats inoculated with human faecal microbiota	Control diet, diet supplemented with long-chain AX (LC-AX) and diet supplemented with inulin (IN). 6 w	LC-AX and IN increased SCFA levels (propionate and butyrate, resp.). Stimulation of butyrate-producing bacteria and bifidobacteria, respectively. Reduction of mucin-degrading Akkermansia muciniphila and more mucin production by the host. Less weight gain.	[90]
Male Wistar rats	Diets supplemented with WU-AX, WE-AX, and AXOS. 14 days	WU-AX supplementation increased butyrate production and butyrate-producing bacteria. WE-AX and/or AXOS reduced pH, suppressed relevant markers of proteolytic breakdown, and induced selective bifidogenic response. Combination of WU-AX, WE-AX, and AXOS showed a synergic effect.	[91]
Male C57bl6/J mice	Control diet, high-fat (HF) diet, HF diet supplemented with AXOS. 8 w	AXOS supplementation exerted a bifidogenic effect. Improvement of the HF-induced body weight gain, fat mass development, hyperinsulinemia, insulin resistance, endotoxemia, and inflammatory disorders in a model of HF diet-induced obesity.	[13]
Pigs	Low dietary fiber and high-fat diet (WSD), AX-rich diet (AXD), and resistant starch diet (RS). 3 w	AXD feeding shifted the microbial composition towards butyrogenic species in the faeces and increased the large-intestinal butyrate pool size.	[59]

w: week.