(P20-026-23) Dietary Inclusion of Yellow Mealworms (T. molitor) and Lesser Mealworms (A. diaperinus) Modifies Intestinal Microbiota Populations of Diet-Induced Obesity Mice

Objectives: Insect-based proteins have been identified as high-quality alternative proteins to support the shift toward more sustainable and healthy diets. In addition to protein, insects contain chitin and have unique fatty acid profiles. Studies have shown that mealworms may beneficially affect metabolism and aid in weight maintenance. However, limited information is known regarding the effects of mealworms on gut microbiota. We aimed to determine the effects of yellow mealworm (Tenebrio molitor)- or lesser mealworm (Alphitobius diaperinus)-based proteins on the intestinal microbiota of diet-induced obesity mice.

Methods: Male C57BL/6J mice were fed a high-fat diet (HFD; 45% kcal) to induce obesity and metabolic syndrome. Obese mice were then randomly assigned to treatments (n=10/group) and fed for 8 wk: HFD: HFD control based on casein; B50: HFD with 50% protein from A. diaperinus; B100: HFD with 100% protein from A. diaperinus; Y50: HFD with 50% defatted protein from T. molitor; Y100: HFD with 100% defatted protein from T. molitor. Lean mice (n=10) fed a low-fat-diet (LFD; 10% kcal from fat) were included. Fresh fecal samples were collected at baseline and every 2 wk during the dietary treatment phase, with cecal digesta collected at sacrifice. Total DNA of samples were analyzed for microbiota using 16S rRNA MiSeq Illumina sequencing.

Results: In fecal and cecal samples, mice fed mealworm diets had greater (P < 0.05) bacterial alpha diversity, with alpha diversity changes occurring in a time-dependent manner (P < 0.05). Beta diversity analyses of cecal samples showed a clear separation of treatments, especially for B100, with a time-based separation shown in fecal samples. Widespread differences were observed in specific bacterial taxa, with over 45 genera being altered (P < 0.05) by diet in cecal samples. In fecal samples, over 50 genera were altered (P < 0.05) by diet and over 40 were altered (P < 0.05) by time.

Conclusions: Dietary inclusion of mealworms changed the intestinal microbiota of obese mice, increasing alpha diversity measures and shifting a large number of bacterial taxa. More investigation is required to determine what components of mealworms are responsible for these changes and how they may be linked with the metabolic benefits observed in mealworm-fed mice.

Funding Sources: Funding was provided by Ÿnsect.