Growth hormone, glutamine, and a modified diet enhance nutrient absorption in patients with severe short bowel syndrome

Abstract

Background: Massive loss of intestinal surface area results in the short bowel syndrome characterized by malabsorption of fluid, electrolytes, and other nutrients. Although the remaining bowel undergoes morphological and functional adaptation, often these changes are inadequate to support the individual by enteral feedings, and parenteral nutrition is required to prevent dehydration, electrolyte disturbances, and malnutrition. Substances such as growth hormone, glutamine, and fiber exert bowel-specific trophic effects and either directly or indirectly influence nutrient absorption. This study was undertaken to determine whether the co-administration of exogenous growth hormone, supplemental glutamine, and a modified fiber-containing diet could enhance nutrient absorption in patients who had undergone massive intestinal resection.

Methods: Ten patients (5 men, 5 women, aged 43 +/- 4 years) with short bowel syndrome were studied 6 +/- 1 years after surgical resection. All patients were admitted to the Clinical Research Center for a 28-day period; the first week served as a control period when nutritional (enteral and parenteral) and medical management simulated usual home therapy. Thereafter, eight patients received exogenous growth hormone, supplemental glutamine, and a modified high-carbohydrate, high-fiber diet. Two patients were treated with the modified diet alone. The efficiency of net nutrient absorption (percent absorbed) for total calories, protein, fat, carbohydrate, water, and sodium was calculated from the measured nutrient intake and stool losses.

Results: Three weeks of treatment with growth hormone, glutamine, and a modified diet increased total caloric absorption from 60.1 +/- 6.0% to 74.3 +/- 5.0% (p < or = .003), protein absorption from 48.8 +/- 4.8% to 63.0 +/- 5.4% (p < or = .006), and carbohydrate absorption from 60.0 +/- 9.8% to 81.5 +/- 5.3% (p < or = .02). Fat absorption did not change (61.0 +/- 5.3% to 60.3 +/- 7.9%, p = NS). Water and sodium absorption increased from 45.7 +/- 6.7% to 65.0 +/- 7.3% (p < or = .002) and from 49.0 +/- 9.8% to 69.6 +/- 6.5% (p < or = .04), respectively. These absorptive changes resulted in a decrease in stool output (1,783 +/- 414 g/d control period vs 1,308 +/- 404 g/d third week of treatment, p < or = .05). Treatment with diet alone did not influence nutrient absorption or stool output.

Conclusions: The combined administration of growth hormone, glutamine, and a modified diet enhanced nutrient absorption from the remnant bowel after massive intestinal resection. These changes occurred in a group of patients that had previously failed to adapt to the provision of enteral nutrients. This therapy may offer an alternative to long-term dependence on total parenteral nutrition for patients with severe short bowel syndrome.