Intestinal morphologic and functional changes occur in human for whom TPN is the sole nutritional source, although the findings in humans are substantially less significant than observed in animal models. The loss of mucosal structure may be sufficient to cause increased intestinal permeability, the clinical significance of which remains to be defined. Enteral nutrition is important in restoring and probably preventing morphologic intestinal changes associated with TPN, and a peptide and free amino acid-based formula supplemented with glutamine and arginine may have some added role. Our findings also suggest sepsis is associated with gut adaptation rather than degradation.

There is growing evidence that taurine is a biologically valuable nutrient. However, there are few published data concerning the taurine content of different foods. We measured the taurine content of 29 meats, including both cooked and uncooked samples, nine dairy products, 17 infant or adult-feeding solutions and 48 plant foods (including vegetables, nuts or seeds, fruits and legumes. Taurine was detected in meats, dairy products, and infant feeding solutions but not in plant products or adult feeding solutions. Using these data, we compared calculated and measured daily taurine intakes in six defined diets. We present sample daily diets for omnivores, lacto-ovovegetarians and vegans (strict vegetarians), together with calculated taurine intakes.

A B S T R A C T The requirement for dietary histidine was investigated in four normal and three chronically uremic men. Subjects lived in a metabolic unit where they were fed three isonitrogenous diets in the following order: a 40-g protein diet (28±SD 8 days), a semisynthetic amino acid diet deficient in histidine (35±2 days), and an amino acid diet which contained histidine (31±5 days). With ingestion of the histidine-deficient diet, nitrogen balance gradually became negative, and serum albumin decreased in six subjects. Plasma histidine fell by 82±6%; muscle histidine decreased by 62± 19%; the hematocrit fell by 25+9%; and serum iron rose. Subjects felt unwell, and in five cases a skin lesion consisting of fine scales, dry skin, and mild erythema developed. After administration of the histidine-repletion diet, nitrogen balance became positive in six subjects; serum albumin increased in five cases; plasma and muscle histidine rose; serum iron fell abruptly; a reticulocytosis ensued; and the hematocrit rose. The clinical symptoms and skin lesions disappeared. These observations indicate that histidine is an essential amino acid in normal and chronically uremic man. The absence of dietary histidine is associated with failure of normal erythropoiesis.

Nutritional status and lymphocyte transformation were examined in 30 clinically stable men who underwent maintenance hemodialysis for 1 to 141 months. The men displayed decreased relative body weight, triceps and subscapular skinfold thickness, midarm circumference, midarm muscle circumference, serum total protein, albumin, transferrin, IgG, IgA, IgM, and C3 concentrations. There were many abnormalities in the plasma amino acid pattern. Lymphocyte transformation stimulated by phytohemagglutin or pokeweed mitogen was reduced. Many nutritional parameters correlated with each other and with the rate of lymphocyte transformation. There was a tendency (p = 0.06) for higher mortality in the malnourished patients during a mean follow-up period of 43.3 months. These findings suggest that clinically stable men undergoing maintenance hemodialysis are typically malnourished. Poor nutritional status may be a cause of impaired lymphocyte function. Malnutrition or wasting may indicate that the patient is at risk for a higher mortality rate.