The gut microbiota metabolizes bile acids, thereby influencing human health and diseases including obesity, colitis and cancer. In this Review, Patterson and colleagues discuss host–microbiota interactions and their influence on the bile acid pool as well as therapeutic implications.

In this Review, Rogers, Mileto and Lyras explore the impact of enteric bacterial infections at and beyond the epithelial barrier. They highlight how different bacterial pathogens disrupt structural first line defences of the gut, the influence this has on the systemic dissemination of gut contents, the acute inflammatory processes that are triggered and the collective implication of these events on the regeneration of efficient barrier functions.

Like the gut, the lung harbours a diverse, interacting assortment of microbiota. In this review, Natalini, Singh and Segal examine the role of the lung microbiome in health and disease and discuss future work that is needed to produce novel diagnostic and therapeutic tools aimed at improving lung health.

This study reveals a role of contractile injection systems in regulated cell death and developmental processes.

This study analysed sorption, stability and persistence of SARS-CoV-2 RNA in sewers.

This new study reports that a fungal ectosymbiont metabolizes resin monoterpenes of the host tree and that the volatile products possibly function as cues for beetles to locate breeding sites with beneficial fungal symbionts.

This Genome Watch highlights recent metagenomics studies in fish that reveal unique microbiomes with low functional diversity, which could help to improve our understanding of host–microorganism dynamics in non-mammalian species.

This study set out to increase our understanding of how viruses might mediate responses of microbial communities to climate warming.

This study evaluates the efficacy of exogenous pegylated IFNλ in the treatment of patients with COVID-19.