The gut microbiome: scourge, sentinel or spectator?

The gut microbiota consists of trillions of prokaryotes that reside in the intestinal mucosa. This long-established commensalism indicates that these microbes are an integral part of the eukaryotic host. Recent research findings have implicated the dynamics of microbial function in setting thresholds for many physiological parameters. Conversely, it has been convincingly argued that dysbiosis, representing microbial imbalance, may be an important underlying factor that contributes to a variety of diseases, inside and outside the gut. This review discusses the latest findings, including enterotype classification, changes brought on by dysbiosis, gut inflammation, and metabolic mediators in an attempt to underscore the importance of the gut microbiota for human health. A cautiously optimistic idea is taking hold, invoking the gut microbiota as a medium to track, target and treat a plethora of diseases

“We are what we eat”: How diet impacts the gut microbiota in adulthood

The important role of the microbes residing in our gut, collectively called the microbiota, in human health is widely acknowledged. There are numerous factors that have an impact on the microbiota in the gut of which diet is considered a crucial one. In this chapter we highlight our current knowledge on the ecology of the microbiota in adults and how it is affected by diet. We summarize observations from different cross-sectional and intervention studies that focused on the impact of diet on microbiota composition and activity. Special attention is paid to which microbial metabolites can be produced in the gut; how these are affected by different dietary components such as carbohydrates, fat, and proteins; and how these are associated to human health. Finally, we provide recommendations for future intervention studies in order to improve our understanding of the complex interplay between microbes, diet, and ourselves