Malnutrition weakens the immune system. As a result, this makes it easier for parasites such as worms to colonize the intestine. For those affected, this situation is more than life-threatening. How the human organism can manage the fatal combination of immunodeficiency and the lack of micronutrients is discussed by clinical chemists from the University of Bonn and parasitologists from the National Institutes of Health in Bethesda (USA) (1).
In mice, scientists have shown that certain immune cells (ILCs – inborn lymphoid cells) prefer to use fatty acids in emergency situations, such as vitamin A deficiency or worm infestation, to maintain their function in conjunction with worm infections or malnutrition.
This adaption allows the immune system to maintain its vital barrier immunity, even with low food intake and parasite attack, according to the experts. They assume that this ability has been acquired in the course of evolution and has thus ensured the survival of humanity in acute periods of lack.
(1) C. Wilhelm et al. Critical role of fatty acid metabolism in ILC2-mediated barrier protection during malnutrition and helminth infection, The Journal of Experimental Medicine, DOI: 10.1084/jem.20151448, available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4986525/