Correlation between the maturational appearance of adult-type epithelium in the proximal and the distal SI.

<p>Appearance of FcRn^neg cells in the proximal SI and non-vacuolated cells in the distal SI in 17 days old rats treated with PHA or protease for 3 days, to induce precocious gut maturation, compared to control rats.</p

Replacement of vacuolated foetal-type epithelium by non-vacuolated adult-type epithelium in the distal part of the SI during postnatal development in rats.

<p>(<b>a)</b> Representative H & E stained sections (magnification 400x) showing the structural changes in the distal SI between the suckling (7d) and the post-weaning periods (28d). (<b>b)</b> Appearance of adult-type epithelium with non-vacuolated cells (in % of total villous length) in 7, 14, 21, 28 and 35 days old rats (mean ± SD, n = 6–7).</p

Replacement of FcRn^pos foetal-type epithelium by FcRn^neg adult-type epithelium in the proximal part of the SI during postnatal development in rats.

<p><b>(a</b>) Immunohistochemistry of FcRn shown in representative histological sections (magnification 400x) in the proximal SI from the suckling (7d) to the post-weaning periods (28d). For comparison, note the lack of staining for FcRn in the epithelium, while staining seen in the <i>lamina propria</i> in the distal SI of suckling 7 days old rats. (<b>b)</b> Appearance of adult-type epithelium with FcRn^neg enterocytes (in % of total villous length) in the proximal SI of 7, 14, 21, 28 and 35 days old rats (mean ± SD, n = 6–7).</p

Increased replacement of vacuolated foetal-type epithelium by non-vacuolated adult-type epithelium in the distal part of the SI in rats due to precociously-induced maturation.

<p><b>(a)</b> H & E stained sections (magnification 200x) from the distal SI in 17 days old rats gavage treated with PHA or protease for 3 days, to induce precocious gut maturation, compared to control rats gavaged water. (<b>b)</b> The proportion of adult-type non-vacuolated enterocytes appearing in the distal SI epithelium (in % of total villous length) in 17 days old rats treated with PHA or protease compared to control rats (mean ± SD, n = 6; * p < 0.05; **** p < 0.0001).</p

Expression of Blimp-1 in the small intestine during suckling and post-weaning periods.

<p>Immunohistochemical staining of Blimp-1 in representative histological sections (magnification 200x) from the proximal and distal SI in suckling (14d) and post-weaning (28d) rats. <b>Note:</b> Nuclear immunorreactivity of Blimp-1 antibodies in epithelial cells indicated by black arrows; intraepithelial and lamina propria cells–red arrows; crypt cells–green arrows and cells in muscle layer are indicated by blue arrows.</p

Correlation between the maturational appearance of adult-type epithelium in the proximal and the distal SI.

<p>Appearance of FcRn^neg cells in the proximal SI and non-vacuolated cells in the distal SI in 17 days old rats treated with PHA or protease for 3 days, to induce precocious gut maturation, compared to control rats.</p

Increased replacement of FcRn^pos foetal-type epithelium by FcRn^neg adult-type epithelium in the proximal parts of the SI after precociously induced maturation in rats.

<p>(<b>a)</b> Immunohistochemistry of FcRn in representative histological sections (magnification 200x) from the proximal SI in 17 days old rats gavaged with PHA or protease for 3 days to induce precocious maturation, compared to control rats. (<b>b)</b> The proportion of adult-type FcRn^neg enterocytes in the proximal SI epithelium (in % of total villous length) in 17 days old rats treated with PHA or protease, compared to control rats (mean ± SD, n = 6; *** p < 0.001).</p

Expression of mRNA for Fcgrt (FcRn) and Prdm1 (Blimp-1) in the SI of developing rats.

<p>Relative mRNA levels of Fcgrt <b>(a, c)</b> and Prdm1 <b>(b, d)</b> in the proximal and distal SI in 7, 14, 21, 28 and 35 days old rats (n = 4–6) during postnatal development (a, b) and in 17 days old rats treated with PHA or protease at 14–16 days of age (n = 3–4) to induce precocious gut maturation, compared to control rats (c, d). (mean ± SD, a–b and * p < 0.05; *** p < 0.001).</p

Gut organ growth and stomach pH of 17 d-old rats after gavage feeding a microbial-derived protease in increasing doses, or water (control) during 14–16 days of age.

<p>The organ results (mean ± SD, n = 5–6) are presented per gram body weight (g b.wt). Significant differences between protease-fed and control groups are indicated by</p><p>* <i>P</i> < 0.05,</p><p>**<i>P</i> < 0.01,</p><p>*** <i>P</i> < 0.001; SI = small intestine.</p><p>Gut organ growth and stomach pH of 17 d-old rats after gavage feeding a microbial-derived protease in increasing doses, or water (control) during 14–16 days of age.</p

Body weight, gut organ growth and stomach pH of 17 d-old rats after gavage feeding with microbial-derived enzymes, <i>i</i>.<i>e</i>., a protease, amylase, lipase, and a mixture thereof, or water (control) during 14–16 days of age.

<p>The results (mean ± SD, n = 7) are presented per grams body weight (g b.wt). Significant differences between enzyme-treated and control groups are indicated by</p><p>* <i>P</i> < 0.05,</p><p>** <i>P</i> < 0.01,</p><p>*** <i>P</i> < 0.001; SI = small intestine.</p><p>Body weight, gut organ growth and stomach pH of 17 d-old rats after gavage feeding with microbial-derived enzymes, <i>i</i>.<i>e</i>., a protease, amylase, lipase, and a mixture thereof, or water (control) during 14–16 days of age.</p