Insects could be potential nutritional sources both for humans and animals. Among these, Hermetia illucens, with good amount of chitin and proteins, represents a suitable diet replacement for laying hens. Little is known about insect diet effects on the microbial ecology of the gastrointestinal tract and bacterial metabolites production. In this study we investigated the effect of H. illucens larvae meal administration on cecal microbiota and short chain fatty acids (SCFAs) production in laying hens. 16S rDNA sequencing showed strong differences between cecal microbiota of soybean (SD) and insect diet (ID) groups both in type and relative abundance (unweighted and weighted beta diversity) of microbial species. In particular, Bacteroides plebeius, Elusimicrobium minutum, Alkaliphilus transvaalensis, Christensenella minuta, Vallitalea guaymasensis and Flavonifractor plautii represented the principal contributors of changes in gut microbiota composition of ID group (FDR p-values < 0.05). Of these, F. plautii, C. minuta and A. transvaalensis have the potential to degrade the chitin’s insect meal and correlated with the observed high levels of gut SCFAs produced in ID group. These microorganisms may thus connect the chitin degradation with high SCFAs production. Our results suggest H. illucens as a potential prebiotic by well feeding gut microbiota.

The gut microbiota plays a crucial role in the bi-directional gut–brain axis, a communication that integrates the gut and central nervous system (CNS) activities. Animal studies reveal that gut bacteria influence behaviour, Brain-Derived Neurotrophic Factor (BDNF) levels and serotonin metabolism. In the present study, we report for the first time an analysis of the microbiota–gut–brain axis in zebrafish (Danio rerio). After 28 days of dietary administration with the probiotic Lactobacillus rhamnosus IMC 501, we found differences in shoaling behaviour, brain expression levels of bdnf and of genes involved in serotonin signalling/metabolism between control and treated zebrafish group. In addition, in microbiota we found a significant increase of Firmicutes and a trending reduction of Proteobacteria. This study demonstrates that selected microbes can be used to modulate endogenous neuroactive molecules in zebrafish.

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Pet rabbits (n = 125) from Southern Italy were submitted to a serological screening for Encephalitozoon cuniculi, using an enzyme-linked immunosorbent assay (ELISA) and a carbon immunoassay (CIA). Seventy-eight examined rabbits showed clinical signs suggestive of encephalitozoonosis (head tilt, ataxia, paralysis, cataracts, uveitis, polyuria and polydipsia), whereas 47 were healthy rabbits. Antibodies anti-E. cuniculi were found in 84/125 (67.2%) sera analysed. The results of the chi-squared test showed that sex and health status had no significant effect (P > 0.05) on E. cuniculi seropositivity; however, rabbits older than 4 months had a seropositivity for E. cuniculi significantly (P < 0.05) higher than that of rabbits aged up to 4 months. The results of the present survey reinforce the assumption that rabbit may be indicated as the main reservoir of E. cuniculi; therefore, routine screening examinations in pet rabbits are strongly advised considering the zoonotic potential of this parasite.

This paper has been updated to correct a spelling error concerning an author name. It previously showed as Giuseppe Griseo, however the correct spelling is Giuseppe Criseo.