Edible insects prevent changes to brain monoamine profiles from malnourishment in weaned rats

ABSTRACT

Background: Childhood malnutrition can have devastating consequences on health, behavior, and cognition. Edible insects are sustainable low cost high protein and iron nutritious foods that can prevent malnutrition. However, it is unclear whether insect-based diets may help prevent changes to brain neurochemistry associated with malnutrition.

Materials and Methods: Weanling male Sprague–Dawley rats were malnourished by feeding a low protein-iron diet (LPI, 5% protein and ∼2 ppm Fe) for 3 weeks or nourished by feeding a sufficient protein-iron diet (SPI, 15% protein 20 ppm FeSO₄) for the duration of the study. Following 3 weeks of LPI diet, three subsets of the malnourished rats were placed on repletion diets supplemented with cricket, palm weevil larvae, or the SPI diet for 2 weeks, while the remaining rats continued the LPI diet for an additional 2 weeks. Monoamine-related neurochemicals (e.g. serotonin (5-HT), dopamine (DA), norepinephrine) and select monoamine metabolites were measured in the hypothalamus, hippocampus, striatum, and prefrontal cortex using Ultra High-Performance Liquid Chromatography.

Results: Five weeks of LPI diets disrupted brain monoamines, most notable in the hypothalamus. Two weeks supplementation with cricket and palm weevil larvae diets prevented changes to measures of 5-HT and DA turnover in the hippocampus and hypothalamus. Moreover, these insect diets prevented the malnutrition-induced imbalance of 5-HT and DA metabolites in the hippocampus, striatum, and hypothalamus.

Conclusion: Edible insects such as cricket and palm weevil larvae could be sustainable nutrition intervention to prevent behavioral and cognitive impairment associated abnormal brain monoamine activities that results from early life malnutrition.

KEYWORDS:

• Malnutrition
• crickets
• palm weevil larvae
• serotonin
• dopamine
• monoamines
• hypothalamus
• hippocampus
• striatum
• prefrontal cortex‌

Acknowledgements

The authors acknowledge Aspire Food Groups for providing the cricket and palm weevil larvae samples and Tina Herkful at Envigo-Tekland for diet preparation. We thank Dr. Mark Lyte with assistance with UHPLC equipment and Allyse Fristo (Shoeman) for her contributions to the analyses.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available on request from the corresponding author.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research was funded by the Doris A. Adams Endowment funds from the College of Human Sciences at Iowa State University, Ames, Iowa, USA.

Notes on contributors

Ella E. Bauer

Ella E. Bauer is a PhD candidate at the Laboratory of Behavioural and Nutritional Neuroscience in the Department of Food Science and Human Nutrition, Iowa State University, USA. Her research focuses on how dietary factors influence human health and behaviour with experience investigating these factors through the lens of the microbiome-gut-brain axis using preclinical models.

Isaac Agbemafle

Isaac Agbemafle holds a PhD in Human Nutrition and Statistics from Iowa State University, USA. Currently, he is a lecturer in Human and Biochemical Nutrition at the Fred N. Binka School of Public Health, University of Health and Allied Sciences, Ghana. His research focuses on the use of nutritious underutilized foods for improving infant and young child developmental milestones, nutritional status and microbiome.

Manju B. Reddy

Manju B. Reddy is a professor and Doris A. Adams Endowed Chair in Food Science and Human Nutrition at Iowa State University, USA. Her work focuses on iron deficiency anaemia, toxicity, and the direct impact of nutrition on developmental milestones in children.

Peter J. Clark

Peter J. Clark is an assistant professor and principal investigator at the Laboratory of Behavioural and Nutritional Neuroscience in the Department of Food Science and Human Nutrition, Iowa State University, USA. His research focuses on the impact of nutrition and physical activity status on neural plasticity, mood, cognitive performance and brain metabolic adaptations.