Fructooligosaccharides protect against OVA-induced food allergy in mice by regulating the Th17/Treg cell balance using tryptophan metabolites.

Fructooligosaccharides (FOS) can change gut microbiota composition and play a protective role in food allergy (FA). Furthermore, the protective mechanism of FOS against FA is unclear. In this study, intestinal flora and tryptophan (Trp) metabolites were investigated in a mouse model with FA supplemented with FOS. Meanwhile, we injected aryl hydrocarbon receptor antagonists (AhR-A) into a mouse model of FA supplemented with FOS to investigate whether T helper cell (Th) 17/regulatory T (Treg) cell balance was affected. Our research studies showed that dietary intake of FOS provided moderate protection from the intestinal inflammation induced by ovalbumin (OVA). This protective effect disappeared in AhR-A mice. The OVA mice manifestations had significantly lower bacterial richness, when compared to the normal control (NC) mice. Among fecal bacteria, the abundance of Akkermansiaceae (family level) and Verrucomicrobia (phylum level) increased and Ruminococcacere (phylum level) decreased in the feces of allergic mice. These changes were reversed by FOS treatment. FOS modulated the gut microbiome profiles that were altered in OVA mice, which showed an increase in the abundance of Ruminococcacere (phylum level) and a decrease in the abundance of Akkermansiaceae (family level) and Verrucomicrobia (phylum level). Liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis of Trp metabolites showed significant reductions in the level of kynurenine (kyn) in the serum of OVA mice, as compared to NC and FOS mice. Conversely, the levels of Trp and 5-hydroxytryptamine (5-HT) were significantly increased in OVA mice. Correlation analysis revealed a negative relationship between the relative abundance of Verrucomicrobiae (class level) and Akkermansiaceae (family level) with kyn, and a positive relationship with 5-HT. FOS significantly reduced interleukin-17A (IL-17A) and retinoic acid-associated nuclear orphan receptor-γt (RORγt) in FOS mice but not in AhR-A mice. FOS increased the level of interleukin-10 (IL-10) and Forkhead box P3 (Foxp3) in FOS mice but not in AhR-A mice. These findings suggest that FOS ameliorates allergic symptoms and impacts Th17/Treg balance in mice by modulating the gut microbiota composition and Trp metabolites. FOS may serve as an effective tool for the treatment of FA by regulating immune and gut microbiota.

Adult Behavior of Tirumala limniace (Lepidoptera: Danaidae).

Tirumala limniace Cramer as an ornamental butterfly is utilized in butterfly garden, in this article we study their adult activities include flight, foraging, courtship, mating, and oviposition. We found that males spent 22.1% of its time flying, 14.1% foraging, 63.8% in courtship and mating. And females spent 30.8% of its time flying, 10.1% foraging, 57.1% in courtship and mating, and 2% ovipositing. Adults emerged from pupae when temperatures were above 23.5°C and eclosion took only ∼1 min, typically followed by a small amount of flight on the first day. Flight activity peaked from the ninth to the thirteenth day after eclosion, and there were two daily peak flight times: 10:00-13:00 and 15:00-18:00. The peak of flower-visiting activity was from the eighth to the thirteenth day after eclosion, and there were two daily peak foraging times: 11:00-12:00 and 16:00-17:00. Flight and foraging frequency and time were positively correlated and both were closely related to temperature, with very little flight or foraging below 18°C and an increase at temperatures above 22°C. Courtship and mating took place on the sixth day after eclosion, while oviposition occurred the following day. Oviposition occurred over 8 d, and the shortest time of a single oviposition was 2 s. The average life expectancy of males was 16.5 d, while that of females was 15 d.