Table 6. Posterior intestine and rectum morphometric parameters for European sea bass (Dicentrarchus labrax) juveniles at the end of the feeding trial (63days).

	Dietary treatments				Two-way ANOVA
	C	GMOS	PHYTO	GMOSPHYTO	GMOS	PHYTO	GMOS*PHYTO	Posterior vs Rectum
Fold length (μm)
Posterior gut	440.1±39.1	381.1±52.6	366.0±10.4	406.1±74.2	NS	NS	NS	p = 0.001
Rectum	668.4±59.4	645.1±19.9	645.9±66.2	706.5±51.0	NS	NS	NS
Fold area covered by mucus (%)
Posterior gut	10.3±0.2	8.8±1.5	9.2±0.9	8.7±2.4	NS	NS	NS	p = 0.001
Rectum	6.4±0.5	5.2±0.7	6.6±2.1	6.6±0.7	NS	NS	NS
Goblet cell area (μm2)
Posterior gut	81.5±15.2a	61.3±10.3b	56.2±8.2b	66.2±10.2ab	NS	F = 3.95; p = 0.05	F = 8.73; p = 0.006	p = 0.001
Rectum	114.5±4.0a	86.8±20.4b	96.8±26.7ab	109.6±8.4ab	NS	NS	F = 10.05; p = p = 0.003
Goblet cell minimum diameter (μm)
Posterior gut	6.5±0.6	5.7±0.5	5.4±0.6	5.9±0.8	NS	NS	F = 4.67; p = 0.038	p = 0.001
Rectum	8.3 ±0.3	7.1±1.2	7.6±1.3	8.3±0.4	NS	NS	F = 6.39; p = 0.017
Submucosa thickness (μm)
Posterior gut	34.8±0.8	34.4±3.0	36.1±2.0	34.1±0.4	NS	NS	NS	p = 0.001
Rectum	25.3±5.0a	19.2±0.9c	24.0±4.9a	21.4±3.3b	F = 51.31; p = 0.001	NS	F = 6.09; p = 0.014

Diets: C (control diet), GMOS (5000 ppm galactomannan oligosaccharides), PHYTO (200ppm phytogenic), GOSPHYTO (5000 ppm galactomannan oligosaccharides+200ppm phytogenic). Posterior gut (preileorectal valve segment) and rectum (postileorectal valve segment) as detailed in Fig 1. Data presented as mean ± SD. N = 4x3 (fish x tank). Different letters within a row denote significant differences among dietary treatments (p≤0.05; one-way ANOVA; Tukey). Two-way ANOVA analyses (p<0.05). NS = No significant. Quantitative differences between posterior and rectum segments, were calculated using T student or U Mann-Whitney tests (p<0.05).