Effects of lipid-based nutrient supplements on the immunity of 6- month old infants : a randomised controlled trial

Abstract

Background: Nutrition has the ability to modulate immune function. Both innate immunity and adaptive immunity may be affected. There are however, very little data available where infants are concerned. In developing countries infants often do not meet their nutritional requirements making them more susceptible to infectious diseases. Therefore there is a global shift towards reducing morbidity and mortality in infants through nutritional interventions such as administering small quantity lipid-based nutrient supplements (SQ-LNS). Objective: To determine the effect of two SQ-LNS on the immunity of South African peri-urban 6- month-old infants. Design: In a randomised controlled trial two groups of infants (n = 250 each) were supplemented with two SQ-LNS products for six months in Jouberton, Klerksdorp in the Matlosana Municipality in South Africa. The control group (n = 250) did not receive any supplements during the intervention period, but received a six month long intervention with SQ-LNS A upon completion of the study. Both products comprised of similar micronutrients and essential fatty acids (EFA), but SQ-LNS B also included long- chain polyunsaturated fatty acids (LCPUFA), phytase, lysine and additional vitamin C and trace elements. During weekly surveillance, the incidence and duration of infectious morbidity symptoms were recorded by fieldworkers using a questionnaire. In addition, the effect of the intervention on immune function was assessed by comparing the immunoglobulin G (IgG) response to immunisation against measles between the intervention and control groups. Results: Both SQ-LNS A and B reduced the overall sick days with fever by 19.2% (P < 0.001) and 9.8% (P = 0.006); of coughing by 9.2% (P < 0.001) and 5.7% (P = 0.001) and of wheezing by 78.0% (P < 0.001) and 53.1% (P < 0.001), respectively. SQ-LNS A reduced the number of incidences of wheezing by 57.4% (P = 0.006) and decreased the overall sick days with runny nose by 6.6% (P = 0.002), whereas SQ-LNS B increased the overall sick days with runny nose by 4.5% (P = 0.035). Both SQ-LNS A and SQ-LNS B increased the overall days of diarrhoea by 29.6% (P < 0.001) and 68.4% (P < 0.001) and both groups showed an increase in the number of incidences of diarrhoea by 24.6% (P = 0.002) and 25.5% (P = 0.001), respectively. The SQ-LNS A group had 4.8 times more overall sick days of vomiting (P < 0.001) and the SQ-LNS B group had 2.4 times more overall sick days of vomiting compared to the control group (P < 0.001). Both intervention groups had 2.4 times more incidences of vomiting compared to the control group (P < 0.001). Both SQ-LNS A and B increased the overall days with rash/sores by 13.0% (P = 0.012) and 99.6% (P < 0.001), and increased the number of incidences of rash/sores by 36.2% (P = 0.031)and 41.9% (P = 0.013), respectively. Measles IgG response was significantly reduced by SQ-LNS-B (B: - 608.337 95% CI: -1178.974, -37.699). Conclusion: These novel findings are a significant advancement to current knowledge. It is one of the first soy-based SQ-LNS intervention studies in infants. Both SQ-LNS products reduced fever and certain respiratory symptoms. However, there was an increase in diarrhoea, vomiting and rash/sores in both groups, although the symptoms were mostly mild and not serious. Smaller quantities taken more frequently may provide the benefits without the side effects of the products. Nevertheless, the results should be interpreted taking the main outcomes of this study, linear growth and psychomotor development into consideration. This study showed the need not only for more trials to be done on this topic but also to monitor and record morbidity data frequently and accurately.

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and 41.9% (P = 0.013), respectively. Measles IgG response was significantly reduced by SQ-LNS-B (B: - 608.337 95% CI: -1178.974, -37.699).

Conclusion: These novel findings are a significant advancement to current knowledge. It is one of the first soy-based SQ-LNS intervention studies in infants. Both SQ-LNS products reduced fever and certain respiratory symptoms. However, there was an increase in diarrhoea, vomiting and rash/sores in both groups, although the symptoms were mostly mild and not serious. Smaller quantities taken more frequently may provide the benefits without the side effects of the products. Nevertheless, the results should be interpreted taking the main outcomes of this study, linear growth and psychomotor development into consideration. This study showed the need not only for more trials to be done on this topic but also to monitor and record morbidity data frequently and accurately.