Currently, great attention is being paid to the utilization of biomass, such as feather keratins. It is imperative to extract and dissolve keratins from animal keratinous materials for exploitation of innovative biopolymers. However, most of the current processes are based on strong acid and alkali hydrolysis, chemical cleavage and other violent reactions, which are not eco-friendly and/or result in severe degradation and destruction of feather keratins. In this study, high density steam flash-explosion (HDSF) as an innovative pretreatment of biomass was firstly employed to treat feather waste. In HDSF treatment, steam with a powerful seepage force first penetrates into fibrous tissues and cells of feathers, and then quickly expands and breaks free of the structure upon an explosive decompression at supersonic speed (within 0.0875 s). HDSF effectively destabilized β-sheet crystals and intermolecular disulfide bonds without causing substantial damage to the keratin protein chain, dramatically increasing the extraction and dissolubility of feather keratins in polar solvents like water, salt solution and weak bases, as well as enzymatic accessibility. HDSF treatment could be a sustainable and practical pretreatment for extraction of feather keratin for exploitation of biomaterials and conversion of feathers to nutrient animal feed instead of the current chemical hydrolysis and hydrothermal treatment.

The potential of the gut microbiome as a driver of individual cognitive differences in natural populations of animals remains unexplored. Here, using metagenomic sequencing of individual bumblebee hindguts, we find a positive correlation between the abundance of Lactobacillus Firm-5 cluster and memory retention on a visual discrimination task. Supplementation with the Firm-5 species Lactobacillus apis, but not other non-Firm-5 bacterial species, enhances bees’ memory. Untargeted metabolomics after L. apis supplementation show increased LPA (14:0) glycerophospholipid in the haemolymph. Oral administration of the LPA increases long-term memory significantly. Based on our findings and metagenomic/metabolomic analyses, we propose a molecular pathway for this gut-brain interaction. Our results provide insights into proximate and ultimate causes of cognitive differences in natural bumblebee populations.

The substantial discrepancy between the strong effects of functional foods and various drugs, especially traditional Chinese medicines (TCMs), and the poor bioavailability of these substances remains a perplexing problem. Understanding the gut microbiota, which acts as an effective bioreactor in the human intestinal tract, provides an opportunity for the redefinition of bioavailability. Here, we discuss four different pathways associated with the role of the gut microbiota in the transformation of parent compounds to beneficial or detrimental small molecules, which can enter the body’s circulatory system and be available to target cells, tissues, and organs.