Cover Image
close this bookProtein-Energy Requirements of Developing Countries: Evaluation of New Data (UNU, 1981, 268 p.)
close this folderProtein requirements-children
close this folderProtein absorption of pre-school children with intestinal helminth parasites
View the document(introduction...)
View the documentObjective
View the documentExperimental details
View the documentSummary of main results
View the documentConclusions and comments

(introduction...)

Objective
Experimental details
Summary of main results
Conclusions and comments

Jin Soon Ju, W. I. Hwang, and T.G. Ryu
Department of Nutrition and Biochemistry, Korea University, College of Medicine, Seoul, Republic of Korea

Objective

The purpose of this study was to define the changes in protein digestibility and protein requirements that occur in pre-school children infested with intestinal parasites, mainly Ascaris lumbricoides.

Experimental details

1. Subjects
Six boys and four girls, 52 to 70 months old, were selected among pre-schoolers from agricultural villages in the northwestern part of South Korea, about 48 km from Seoul. Their characteristics are given in table 1. They were healthy and normal, except for the intestinal parasites, based on medical history, physical examination, and laboratory analyses of blood and urine specimens, including transaminase and alkaline phosphatase activities.

2. Study Environrnent
The tests were done in a field metabolic unit during the fall. Outdoor temperature ranged from 3 to 25 C, and indoor temperature from 18 to 24 C.

3. Physical Activity
The activities of these children were normal for their age.

4. Duration of the Study
The study iasted ten weeks, divided into three periods: a. The first feeding period (BfV) was before treatment with a vermicide and lasted four weeks. b. The second period lasted two weeks, with a free-choice diet comparable to what the subjects ate at home. Ten mg/kg of Combantrin was given on the first day of this period. c. The third period (AV), after the vermicide treatment, lasted four weeks.

TABLE 1. Characteristics of Subjects

 

Energy

 

Intake

Approximate requimments ***

Subject

Sex

Age
(years-
months)

Height
(cm)
m/hr)

Weight
(kg)

SA*
(m )

BMR *
(kcal/ m/hr)

BfV **

AV

Estimated

FAO/
WHO

             

(kcal/kg/day)

1

M

5-10

114.6

22.92

0.83

54.8

91.5

102.7

81.0

70.1

2

M

5- 9

11 5.6

20.5

0.80

55.4

86.9

102.7

88.2

74.2

3

M

5 - 9

107.5

1 7.67

0.72

59.9

101.8

100.0

102.5

80.3

Subjects 4 and 5 dropped
6

M

4- 4

107.3

18.64

0.73

60.7

92.9

102.5

96.9

75.7

7

M

4- 7

97.3

15.08

0.63

63.2

100.4

104.3

107.7

81 7

8

M

4- 7

96.3

14.83

0.62

64.2

101.2

106.8

109.5

82.6

9

F

5- 9

108.8

17.79

0.72

60.7

100.7

993

100,2

76.0

10

F

4- 8

95.8

15.92

0.63

61.2

103,7

99.6

98.8

80.1

11

F

4- 7

108.4

18.74

0.74

58.5

98.6

100.2

94,3

75,7

12

F

4 7

98.1

14.44

0.62

56.4

99.4

98.9

98.8

83.6

* Surface area (SA) and BMR were measured on the last day of the eighth experimental week. SA w0.425 x H0.725 x 71.84.
** BfV - before vermicide; AV ** after vermicide.
*** Approximate energy requirements: estimeted - BMR (kcal/day) x 1.7/body weight (BW); FAD/WHO = 1973 recommendations.

5. Dietary Intakes
Because of a generally low intake of animal protein, a daily supplemental feeding consisting of 150 ml of whole cow's milk was added to each subject's ordinary daily diet for one month before initiation of the study. The experimental diets were devised to provide approximately 100 kcal/kg/day and four levels of dietary protein (1.50, 1.75, 2.00, and 2.25 g/kg/day: diets A, B, C, and D, respectively), based on the local diet (see table 2). The four levels of dietary protein were fed in four consecutive weeks, both before and after treatment with the vermicide (BfV and AV, respectively). Three isoenergetic and isonitrogenous meals and light snacks were provided each day. Additional food intake, mainly rice, was allowed on request, especially in the AV period. A record was kept of each subject's food intake. Vitamin and mineral supplements were given once a day to meet requirements. Table 3 gives the estimated essential amino acid content and the chemical score of the experimental diets.

6. Indicators and Measurements

  1. Complete urine and faecal collections were made daily throughout the two experimental feeding periods. Total nitrogen (micro-Kjeldahl), urea nitrogen (Folin-Wu), and creatinine (diacetyl-monoxime) were measured in the urine collected during the last four days of each week with a given diet. Nitrogen was also measured in faeces pooled during the same four days and in aliquots of the diets.
  2. Fats (Soxhlet) and ash (combustion) in food and faeces were measured. Carbohydrates were calculated by subtracting protein, fat, ash, and moisture from total weights of food and faeces. Their energy contents were calculated using 4, 4, and 9 kcal per gram of carbohydrate, protein, and fat, respectively.
  3. Nude body weight was recorded daily after the subject had voided the first morning urine before breakfast.
  4. Venous blood samples were drawn before breakfast on the first and last days of the study. Haemoglobin, haematocrit, serum glucose, urea nitrogen, creatinine, SOOT, alkaline phosphatase, total proteins, albumin, and globulins were measured.
  5. Stool examinations for the quantitative determination of helminth eggs were performed each of the first three days in both experimental periods (BfV and AV). The parasites expelled on the first three days after treatment were identified and counted.
  6. The basal metabolic rate (BMR) was measured on day 14 of the AV period by the Douglas bag spirometer method.
  7. The faecal obligatory nitrogen losses were estimated from the Y intercept of the regression equation of faecal nitrogen (Y) on nitrogen intake (X) (table 4). Digestibilities of protein and energy were expressed as the percentage of intake that was absorbed.

TABLE 2. Food Ingredients in the Daily Diet of a 17-kg Child (g/day)

Foods

Dietary Periods

 

A

B

C

D

Rice

270

270

270

270

Wheat flour

-

13

-

-

Biscuits

-

30

-

20

Potato

80

80

80

30

Soybean curd

-

22

20

30

Soybean paste

-

25

-

9

Soy sauce

6

2.5

5

1

Radish

160

80

140

110

Spinach

-

25

-

30

Onion

5

10

10

10

Carrots

5

10

10

10

Seaweed

-

-

-

3

Candy

60

     
Sugar

-

12

70

46

Jam

50

30

-

10

Apple

-

-

80

100

Pear

75

100

100

100

Orange juice

100

100

100

100

Oil

1

2

1

1

Beef

10

2.5

-

15

Sausage

-

-

15

 
Dried small fish

-

2

1

1

Egg

-

-

-

30

Energy, kcal

1,660-

1,660

1,660

1,660

Protein, total g

26.2

34.1

29.5

38.3

g/kg

(1.5)

12.0)

(1.75)

12.25)

animal

3.6

4.3

2.6

7.5

Fibre,g

3.1

5.0

3.7

4.2

TABLE 3. Essential Amino Acid Composition of Experimental Diets (mg/g Protein)

   

Diet A

Diet B

Diet C

Diet D

Amino acid

FAO/WHO (S)

mg

(A/S) %

mg

(B/S) %

mg

(C/S) %

mg

(D/S) %

Isoleucine

40

45.5

114

45.3

113

47.2

118

46.0

115

Leucine

70

83.8

120

82.1

118

82.1

118

81.5

116

Lysine

55

49.1 *

89

50.8

92

49.9 *

91

51.9

94

Methionine +Cystine

35

34.2

98

32.0 *

91

33.9

97

32.5*

93

Phenylalanine +Tyrosine

60

82.0

137

80.4

134

79.7

133

79.2

132

Threonine

40

39.8

99

38.9

97

39.5

99

39.4

99

Tryptophan

10

11.6

116

12.1

121

11.7

117

12.4

124

Valine

50

57.2

114

54.9

110

55.9

112

55.8

112

Total

360

 

428.6

 

421.4

 

423.9

 

422.6

* First limiting amino acid.

An obligatory faecal nitrogen loss of 32 mg/kg/day was used to calculate "true" protein digestibility. True nitrogen balance was calculated assuming 5 mg N/kg/day for integumental and miscellaneous losses. The biological value (BV) of protein was estimated as:

BV = (intake-faecal-urinary + faecal and urinary obligatory losses) X 100/(intake-faecal + faecal obligatory loss)

where the obligatory faecal and urinary losses were assumed to be 32 and 48 mg N/kg/day, respectively. The net protein utilization (NPU) was calculated from the biological value and digestibility.

Summary of main results

1. Body Weight
Most children gained weight at a rate three times greater than the Korean standard for the corresponding age during the experimental period (an average gain of 0.99 kg in 11 weeks). This suggests that energy intakes were above requirements. There were no differences in weight gains before and after treatment.

2. Height
Most children gained 1.8 to 2.2 cm in ten weeks, which is more than the Korean standard of 1.2 cm for the corresponding age group. There were no differences before and after treatment.

3. Parasitological Observations
Table 5 gives the ova counts on each of the three days before and after treatment and the number of helminths identified in faeces during the three days after treatment.

TABLE 4. Estimation of Faecal Obligatory Nitrogen Losses

No. of subjects

Levels of nitrogen intake

Faecal nitrogen output (mg/kg/day)

 

Range
(mg/kg/day)

Mean
(mg/kg/day)

 
Before vermicide      
8

228 - 269

250.0 4.53*

79.46 5.21

9

270 - 300

286.8 3.47

84.86 7.03

10

308- 340

322.1 3.54

94.03 5.77

10

344 - 371

353.5 2.61

98.53 + 6.13

Y = 31.64 + 0.19x (for X = 0, Y = 32)
After vermicide      
9

262 - 276

269.8 1.70

83.90 4.23

8

282 - 311

299.3 3.44

92.66 4.16

9

315 - 362

346.9 4.70

96.61 5.65

9

356 - 397

381.1 3.32

111.90 6.17

Y=21.69+0.23x (for X=0, Y=22)

* Mean S.E.

4. Nitrogen Digestibility and Balance
Table 6 gives the "true" nitrogen digestibility and "true" nitrogen balance data, as well as the biological values and NPU. There were no differences before and after treatment. There was a poor correlation between nitrogen balance and nitrogen intake.

5. Urinary Urea and Creatinine Excretions
Table 7 gives the results obtained.

6. Absorption of Nutrients
Table 8 gives the apparent absorption of carbohydrates and fat, the "true" absorption of protein, and the estimated absorption of total dietary energy.

TABLE 5. Parasitological Findings in Stools

Subject

EPG* before vermicide

Worms excreted in 3 days after vermicide

EPG after vermicide

 

Day 3

Day 2

Day 1

 

Day 1

Day 2

Day 3

1 Al **

8,100

11,900

15,300

Al

8

Al

Neg.***

Neg.

Neg.

  Tt **

100

100

 

Tt

2

Tt

Neg.

Neg.

Neg.

2 Al

28,700

11,600

18,000

Al

8

Al

Neg.

Neg.

Neg.

  Tt

1,400

400

1,200

Tt

1

Tt

100

Neg.

Neg.

3 Al

22,600

32,000

35,100

Al

14

Al

Neg.

Neg.

Neg.

  Tt

500

500

300

Tt

2

Tt

100

Neg.

Neg.

Subjects 4 and 5 dropped
6 Al

28,300

44,900

4,300

AL

8

Al

Neg.

Neg.

Neg.

  Tt

400

       

Tt

Neg.

Neg.

Neg.

7 Al

6,500

10,200

19,200

Al

14

Al

Neg.

Neg.

Neg.

  Tt

3

       

Tt

Neg.

Neg.

Neg.

8 AL

6,100

9,800

2,700

Al

2

Al

Neg.

Neg.

Neg.

9 Al

4,200

13,700

18,100

Al

6

Al

Neg.

Neg.

Neg.

10 Al

11,000

10,900

5,000

Al

2

Al

Neg.

Neg.

Neg.

  Tt

200

400

 

Tt

2

Tt

Neg.

Neg.

Neg.

11 Al

300

600

4,300

Al

10

Al

Neg.

Neg.

Neg.

12 Al

200

400

200

Al

1

Al

Neg.

Neg.

Neg.

* EPG = number of eggs per gram of stool.
** Al = Ascaris lumbricoides; T = Trichuris trichiura.
*** Neg. = negative.

TABLE 6. Nitrogen Balance, BV, and NPU before and after Vermicidal Treatment

Diet No of subjects Nitrogen intake Faecal nitrogen (mg/kg/day) Urinary nitrogen Balance True
digestibility
(%)
BV NPU (kcal/kg/
day)
Energy
intake
Before vermicide
A 9 259.94 * 92.80 10.8.37 53.79 76.49 69.68 53.24 103.50
    8.21 6.70 6.48 9.44 2.67 3.05 2.91 2.74
C 10 276.36 92.48 130.67 48.26 78.17 61.50 48.05 98.0
    9.12 6.39 4.85 7.95 2.15 1.99 1.89 3.13
B 10 323.60 89.44 161.98 67.18 82.49 56.97 47.04 97.56
    7.72 6.97 3.84 7.05 1.91 1.73 1.98 2.36
D 11 340.53 91.95 191.09 52.49 82.43 49.05 40.55 92.15
    7.14 5.78 6.30 6.30 1.60 1.82 1.89 1.86
Average   302.12 91.65 150.10 55.39 79.90 59.30 47.22 98
      3.11 3.68 3.84 2.08 2.15 2.19 1.4
After vermicide
A 10 270.88 8522 117.28 63.38 80.36 68.17 54.76 102.49
    1.94 4.01 5.11 5.80 1.50 2.28 1.99 0.91
C 8 303.30 97.20 140.20 60.90 78.54 61.08 48.11 101.60
    2.94 6.60 4.15 7.15 2.09 1.96 2.37 0.89
B 9 353.49 92.93 178.79 76.77 82.77 55.28 45.73 101.98
    3.52 3.41 4.68 5.33 0.97 1.53 1.37 1.06
D 8 383.13 113.35 210.58 52.97 78.75 46.06 36.19 102.39
    4.00 6.97 6.98 2.99 1.69 1.36 0.91 0.90
Average   324.90 96.37 159.66 63.85 80.11 57.65 46.20 102
      3.03 6.65 3.03 1.56 1.78 1.67 0.5

* Mean S.E.

TABLE 7. Daily Urinary Excretion of Urea Nitrogen and Creatinine (mg/kg/day)

Item

Diets

 

A

C

B

D

Before vermicide  
Ures N (UuN)

77.97 + 5.50 *

91.15 4.05

112.38 2.96

139.57 5.37

Creatinine (UCr)

15.65 0.57

15.15 0.57

16.12 0.54

15.20 0.48

UtN **/nitrogen intake

9.42

0.47

0.50

0.56

UuN/UCr

4.98

6.00

6.98

9.18

UuN/nitrogen intake

0.39

0.33

0 35

0.41

UuN/UtN

0.72

0.70

0.70

0.73

After vermicide  
Urea N (UuN)

89.55 3.91

109.93 3.69

152.505.05

169.486.82

Creatinine (UCr)

15.13 0.43

15.71 0.46

15.90 0.56

16.72 0.69

UtN/nitrogen intake

0.43

0.46

0.51

0.55

Uun/UCr

5.93

7.00

9.59

10.15

UuN/nitrogen intake

0.33

0.36

0.43

0.44

UuN/UtN

0.76

0.78

0.85

0.80

* Mean S.E,
** UtN = total urinary nitrogen.

There were no differences at the various levels of protein intake or as a result of vermicidal treatment.

7. Analyses of Blood and Serum Samples
There were no significant changes during the study and all results were within normal ranges.

Conclusions and comments

  1. There were no changes in weight or height gains as a result of deworming.
  2. Deworming did not change the absorption of nitrogen, cabohydrates, and fats, or the total dietary energy.
  3. Nitrogen balance and the protein biological value and NPU were not affected by the parasites.
  4. The results coincide with our studies in adults, indicating that ascariasis and trichuriasis of the severity reported in our investigations do not interfere with the intake, absorption, and retention of protein.

TABLE 8. Absorption of Nutrients (Percentage of Intake)

Items
Energy, BfV 94.7 0.40* 95.5 0.28 95.4 0.45 93.8 1.50
  AV 95.0 0.40 94.8 0.56 95.0 0.36 94.3 0.54
CHO, BfV 98.9 0.23 99.3 0.23 99.0 0.28 97.0 1.74
  AV 98.9 0.27 99.6 0.29 99.7 0.35 99.7 0.21
Fat, BfV 93.3 1.02 94.5 0.40 95.4 0.55 92.9 0.74
  AV 96.5 0.25 93.5 0.48 96.6 0.39 93.6 0.55
Protein,** BfV 76.5 2.67 78.2 2.15 82.5 1.91 82.4 1.60
  AV 80.4 1.50 78.5 2.09 82.8 2.09 78.8 1.69

* Mean S.E.
** "True" absorption after accounting for estimates of obligatory faecal nitrogen.