Diet, gut microbiota and immune responses

Abstract

The fields of immunology, microbiology, nutrition and metabolism are rapidly converging. Here we expand on a diet-microbiota model as the basis for the greater incidence of asthma and autoimmunity in developed countries.

Metabolite-sensing receptors GPR43 and GPR109A facilitate dietary fibre-induced gut homeostasis through regulation of the inflammasome

“…GPR43 signals in response to acetate, propionate and to a lesser degree butyrate, and we had speculated that GPR43 was a metabolite-sensing receptor that might somehow facilitate the beneficial effects of dietary fibre for gut health. We also proposed that many diseases associated with western lifestyle may relate to insufficient intake of dietary fibre 8 . We found here that deficiency of dietary fibre did indeed compromise, whereas high-fibre diet promoted gut homeostasis.…”

“…For the most part, this has been studied in mice or humans that have been fed a high-fat diet 5,6 or that regularly consume a Western diet 3,7 ; however another proposal is that it is low consumption of dietary fibre that may negatively impact on health 4,8 . Dietary fibre has been promoted for its health benefits, and high-fibre consumption has been reported as beneficial in numerous diseases including inflammatory bowel diseases 9,10 .…”

Breast milk, microbiota, and intestinal immune homeostasis

“…The human diet provides energy to increase the proliferation of bacteria colonizing the intestine, particularly anaerobic bacteria residing in the distal small intestine, cecum, and the colon. The most recent iteration of the so called "Hygiene Hypothesis" is that Western life style, particularly Western diet, has influenced changes in colonizing bacteria which are implicated in the striking increase in many chronic diseases (52). Alterations in diet can influence the proliferation of large families of bacteria (phyla) based on the capacity of prokaryotic cells to adapt quickly to their nutritional environment (53).…”

The effect of microbial colonization on the host proteome varies by gastrointestinal location

“…The gut microbiota modulates various aspects of host physiology, including nutritional status, metabolism and immune-system maturation (Gill et al, 2006;Chow et al, 2010). Furthermore, the composition of the gut microbiota has been implicated in several human diseases, including type 1 diabetes (Wen et al, 2008), obesity Turnbaugh et al, 2006), asthma (Penders et al, 2007) and inflammatory bowel disease (Frank et al, 2007;Penders et al, 2007;Maslowski and Mackay, 2011). DNA sequencing technologies have enabled the profiling of microbial communities and their association with human health and disease (Eckburg et al, 2005;Gill et al, 2006;Ley et al, 2006).…”