Edible canna rhizomes contain extremely high levels of resistant starch among cereals and potatoes. We previously showed that feeding canna rhizome starch to mice may increase intestinal barrier function and improve the intestinal environment. Here, we investigated the effects of canna starch intake in a murine food allergy model. Five-week-old female BALB/c mice were divided into four groups: Control and OVA groups fed on the control diet (AIN-93G) ad libitum and Canna and OVA-Canna groups fed on the canna diet (AIN-93G with 10% replaced with canna starch). The OVA and OVA-Canna groups were sensitized to ovalbumin (OVA), and the anaphylactic response was assessed by measuring body temperature. Body temperature was significantly lower in the OVA group than in the non-sensitized group, but no decrease was observed in the OVA-Canna group. Fecal weight, fecal mucin content, and goblet cells of colorectal tissue were significantly increased in the Canna and OVA-Canna groups compared with those in the Control and OVA groups. Allergen uptake into the liver was also increased in the OVA group and decreased in the OVA-Canna group to the same level as in the non-sensitized group. These results indicate that canna starch supplementation in a murine food allergy model suppresses anaphylactic symptoms by improving the intestinal environment and reducing allergen uptake by increasing intestinal barrier function.

Background/Objectives: Nopalea cochenillifera (L.) Salm-Dyck cladodes are rich in dietary fiber, polyphenols, and minerals, which are known to exert antioxidant and immunomodulatory effects. However, the mechanisms and active constituents have not been fully elucidated. In this study, we investigated the effects of continuous N. cochenillifera consumption on lipid metabolism, immune function, and the gut microbiota in mice. Methods: The feed was made using freeze-dried and powdered cladodes of N. cochenillifera. Male C57BL/6J mice were assigned to four groups: control diet (C), control diet plus 10% N. cochenillifera (CN), high-fat diet (FC), and high-fat diet plus 10% N. cochenillifera (FN). Results: Cactus supplementation reduced the body and liver weights that were elevated by the high-fat diet. Serum total cholesterol and free fatty acids were increased in the FC group compared with the C group, while cactus intake lowered these levels and enhanced fecal cholesterol excretion. Cactus consumption also elevated fecal total IgA and mucin contents. IL-4 expression in Peyer’s patches was significantly increased in the FN group compared with the FC group. Gut microbiota analysis showed significant differences in β-diversity, along with increased α-diversity and higher abundance of Lachnospiraceae, following cactus intake. Conclusions: These findings suggest that N. cochenillifera intake increases gut microbiota diversity, which enhances intestinal barrier function and thereby contributes to improved lipid metabolism and immune regulation.