Net digestive absorption and adaptive hyperphagia in adult short bowel patients

Abstract

Background and aims: Intestinal adaptation after small bowel resection in humans is debated. We have quantified in adult short bowel (remnant small bowel length <2 m) patients oral intake and net digestive absorption and their evolution over time.

Patients and methods: Oral intake and faecal output were studied over three days in 90 patients (39 and 51 without or with parenteral nutrition, respectively) and in 14 patients in early (<6 months) and late (>6 months) periods after digestive continuity. Nitrogen and fat output were measured using chemiluminescence and Van de Kamer techniques, respectively.

Results: In the whole group, 81% of patients had hyperphagia (spontaneous oral intake >1.5 x resting energy expenditure), independently and negatively related to fat absorption (p<0.01) and body mass index (p<0.001) but not braked by the presence of parenteral nutrition. Protein and fat absorption were related to small bowel length. We observed, in the late in comparison with the early period after digestive continuity: an increase in oral intake (1.6 v 2.3 resting energy expenditure), decrease in stool weight/oral intake ratio, no reduction in per cent fat absorption, and protein absorption improvement associated with a significant increase in the amount of protein absorbed (40 v 64 g/day; p<0.05), both being correlated with remnant small bowel length (p<0.01).

Conclusions: This study confirms an adaptive hyperphagia in adult short bowel patients. Over time, hyperphagia and amount of protein absorbed increased, the latter being related to remnant small bowel length, indicating a behavioural adaptation that allows expression of intestinal absorptive adaptation.

Figure 1

Correlation between net fat digestive absorption and remnant small bowel length according to the digestive circuit type of anastomosis (jejuno-ileocolic versus other types—that is, without remnant ileum and ileocaecal valve; p<0.05). Fat absorption was significantly correlated with remnant small bowel length (see table 3 ▶).

Figure 2

Correlation between fat absorbed and fat intake according to the digestive circuit type of anastomosis.

Figure 3

Correlation between net protein digestive absorption and remnant bowel length in the three digestive circuit type of anastomosis. Protein absorption was significantly correlated with remnant small bowel length (see table 3 ▶).

Figure 4

Correlation between protein absorbed and protein intake in relation to the digestive circuit type of anastomosis. There was no significant difference between the three digestive circuit types.

Figure 5

Fat and protein intake, faecal output, and net absorption before and after re-establishment of digestive continuity (n = 12; five jejuno-colic and seven jejuno-ileocolic anastomosis). Values are means (SD); **p<0.01, after versus before re-establishment of digestive continuity.

Figure 6

Body mass index (BMI), oral intake, net fat and protein digestive absorption (NDA), and serum albumin levels in short bowel patients (n = 14) at early (<6 months) and late (>6 months—that is, 19 (9–59) months) periods following re-establishment of digestive continuity. Values are means (SD); *p<0.05, **p<0.01, late versus early period.

Figure 7

Fat and protein intake, faecal output, and absorption in early (<6 months) and late (>6 months—that is, 19 (9–59) months) periods following re-establishment of digestive continuity (n = 14). Values are means (SD); *p<0.05, late versus early period following re-establishment of digestive continuity.

Figure 8

Relation between difference (late−early) in net protein digestive absorption (NDA) separating early (<6 months) and late (>6 months—that is, 19 (9–59) months) periods following re-establishment of digestive continuity and remnant small bowel length (n = 14).