What is Stunting and Why It Matters
Stunting means a child is much shorter than expected for their age because of long-term problems like poor nutrition and illness. It affects about 149 million children under five worldwide. Stunted children often face health problems, learning difficulties, and even higher risks of obesity and chronic diseases later in life. Global efforts aim to reduce stunting, but progress is slow, and events like the COVID-19 pandemic have made things worse.
Parasites as an Overlooked Factor
Parasites—tiny organisms that live inside the body—are an important but often overlooked cause of stunting. They are common in areas with poor sanitation and limited healthcare. These infections do not just make children sick; they interact with poor diets and the intestines, creating a cycle that stops children from growing properly. Instead of asking if parasites cause stunting, experts now focus on how they do it.
Parasites can make children lose their appetite, feel stomach pain, and eat less. They also cause diarrhea, which leads to loss of nutrients through the intestines and makes it harder for the body to absorb nutrients. Over time, infection with parasites and repeated diarrhea damage intestinal cells, leading to a condition called environmental enteric dysfunction, where the structure and function of the intestines are distorted. The combination of dysfunctional intestines, poor eating, nutrient loss, and poor absorption keeps children from growing well.
Intestinal Bacteria and Parasite Interactions
Healthy intestinal bacteria help children digest food and fight infections. Parasites can upset this balance, promoting the growth of harmful bacteria that make intestinal problems worse. If a child’s intestinal bacteria are not well developed, they may also be more likely to develop intestinal parasitic infections. Scientists are testing products like probiotics (good bacteria) to fix this. It is suggested that these products partly act by preventing parasites and other harmful microbes from attaching to and multiplying in the intestines. However, it is still unclear how much they help with preventing stunting, but several research projects are currently underway, especially in low-income areas where stunting is prevalent.
Whole-Body Effects of Parasites and Long-Term Changes in Growth
Parasites do not just harm the intestine—they affect the whole body. They cause inflammation, which uses up energy that should go toward growth. They also lower important growth hormones and cause anemia (low iron), which makes children tired and weak. If mothers have anemia during pregnancy, babies may start life at a disadvantage, making stunting even more likely.
Parasites may even change how genes work through changes in the cell called epigenetic changes, which can affect growth and health for life. For example, infections during pregnancy might change a baby’s development. These changes can make it harder to recover from stunting later on, even if nutrition improves.
What Needs to Happen Next
Scientists still do not fully understand all the ways parasites affect growth. More research is needed to figure out how parasites, nutrition, intestinal health, and genetics are connected—and how to break the cycle. Solutions will likely need to combine better nutrition, parasite control, and intestinal health support to help children grow properly. This is why there have been initiatives like the UKRI GCRF Action Against Stunting Hub, which employed an interdisciplinary approach to improve understanding of how biological, biochemical, social, and environmental factors interact to cause stunting and how this can inform the development of more effective interventions to prevent stunting. These initiatives have also underscored the importance of global collaborative efforts and context-specific approaches.
Written by ISID Emerging Leader, Dr. Benjamin Kadia