Impact of a Cricket and Black Soldier Fly Larvae-Fortified Cracker on the Gut Microbiome and Iron Status in Malagasy Schoolchildren

Food insecurity, child malnutrition, and anemia remain significant public health problems globally, including in Madagascar where 40% of children under 5 years of age are chronically malnourished (stunted), 8% are wasted, and 46% are anemic (DHS, 2021). Interventions aimed at addressing this have often foundered on the fact that the foods that would address these nutrient deficiencies are physically unavailable, too expensive for poor households to purchase, or contribute to climate change or environmental degradation. Consequently, there is interest in the development of novel food products that could contribute to reducing malnutrition in all its forms, without the drawbacks of relying on existing food products. One possibility is to develop food products based on insects. Edible insects are low-cost, climate friendly, with nutritional profiles akin to meat. They contain high amounts of protein, iron, and zinc while also providing a novel source of prebiotic fiber. It is hypothesized that insect-based foods could improve children's health outcomes as measured by gut inflammation, anemia, and growth. The investigators and others have developed an insect-fortified cracker snack, suitable for the nutritional requirements of school-age children living in Southeast Madagascar. The investigators have already assessed the product's nutrient profile. They also have documented the safety tests done to date; these show that the snack is safe for human consumption. The test results have been submitted to the Malagasy regulatory authority for registering food and health products and the government has approved the insect powders as food for human consumption and issued "Certificates for Human Consumption". The investigators have also conducted an acceptability trial that showed that child participants like the organoleptic characteristics of the crackers and regularly consume the crackers in biologically meaningful quantities.

• Cricket and Black Soldier Fly Larvae-fortified Cracker (Dietary supplement), also known as Treatment Cracker: Children will receive a sachet containing 50g of insect crackers. 50 grams was chosen as the amount because the investigators know, from their earlier acceptability trial, that children are willing to consume this amount (in the acceptability trial, approximately 80% of children consumed 80% or more of the 50g of crackers that they were provided). Crackers will be provided Monday-Friday for approximately 14 weeks.
• Rice and Corn Cracker (Dietary supplement), also known as Control Cracker: Children will receive a sachet containing 50g of insect crackers. 50 grams was chosen as the amount because the investigators know, from their earlier acceptability trial, that children are willing to consume this amount (in the acceptability trial, approximately 80% of children consumed 80% or more of the 50g of crackers that they were provided). Crackers will be provided Monday-Friday for approximately 14 weeks.

Primary outcomes

• Gut mircrobiome [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will assess gut microbiome composition at baseline (0 weeks), midline (6 weeks), and endline (14 weeks) through 16S rRNA sequencing and quantification of fecal biomarkers.
• Iron via soluble transferrin receptor [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will assess iron status at baseline (0 weeks) and endline (14 weeks) through soluble transferrin receptor (mg/L).
• Intestinal inflammation via calprotectin [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will assess intestinal inflammation at baseline (0 weeks), midline (6 weeks), and endline (14 weeks) through the quantification of following fecal marker: calprotectin (µg/g).
• Intestinal inflammation via lactoferrin [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will assess intestinal inflammation at baseline (0 weeks), midline (6 weeks), and endline (14 weeks) through the quantification of following fecal marker: lactoferrin (µg/g).
• Intestinal inflammation via lipocalin [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will assess intestinal inflammation at baseline (0 weeks), midline (6 weeks), and endline (14 weeks) through the quantification of following fecal marker: lipocalin (ng/g).
• Intestinal inflammation via anlpha-1 antitrypsin [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will assess intestinal inflammation at baseline (0 weeks), midline (6 weeks), and endline (14 weeks) through the quantification of following fecal marker: anlpha-1 antitrypsin (mg/g).
• Intestinal inflammation via myeloperoxidase [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will assess intestinal inflammation at baseline (0 weeks), midline (6 weeks), and endline (14 weeks) through the quantification of following fecal marker: myeloperoxidase (µg/g).
• Systemic inflammation via quantification of circulating cytokines [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will also assess systemic inflammation at baseline (0 weeks), midline (6 weeks), and endline (14 weeks) through quantification of circulating cytokines, including IL-1β, IL-2, IL-4, IL-6, IL-10, IL-22, TNF-α, IFN-γ, CCL2, all expressed as pg/mL.
• Iron via quantification of hemoglobin [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will assess iron status at baseline (0 weeks) and endline (14 weeks) through quantification of hemoglobin (g/dL).
• Iron via inflammation adjusted ferritin [From enrollment to the end of treatment after 14 weeks of cracker consumption.]: The investigators will assess iron status at baseline (0 weeks) and endline (14 weeks) through inflammation adjusted ferritin (µg/L).

Sex: All, ages: 9 Years to 13 Years, accepts healthy volunteers

Inclusion criteria for children

* Child (male, female, intersex, non-binary), aged 9 to 13 years old who attends one of the selected schools
* Caregiver or legal guardian is willing to provide informed consent
* Child is willing to provide informed assent

Exclusion criteria for children

* Child age is outside the preferred age range (9 to 13 years)
* Not enrolled in the participating schools
* Unable or unwilling to comply with the study requirements
* Illness requiring medical treatment, malaria, severe anemia (hemoglobin (Hb) concentration below 8.0 g/dL as indicated by HemoCue 201+ system), severe acute malnutrition, fever, diarrhea, etc.
* Covid-exposure or symptoms: loss of smell or taste
* History of food allergies or adverse reactions to any edible insects
* Chronic severe medical condition or congenital anomalies requiring frequent medical attention or interfering with dietary consumption
* Caregiver does not give consent, or child does not assent

Inclusion criteria for parents • Willing to participate in completing surveys about demographics and household dynamics (assets, housing structure, etc.)

Exclusion criteria for parents

• Caregiver does not consent to participate

• John Hoddinott, DPhil, Study chair, Cornell University