Nat. Rev. Endocrinol. doi:10.1038/nrendo.2016.150 Figure 2 Distribution of food-derived energy between the host and gut bacteria Figure 2 | Distribution of food-derived energy between the host and gut bacteria. Energy derived from ingested nutrients is directly and indirectly available to both gut bacteria and the host. Gut bacteria use this energy for bacterial multiplication, which results in population maintenance. In turn, bacteria generate energy as a part of bacterial catabolism and nutrient processing, which releases energy that is available to the host. The host, therefore, receives energy derived both directly from nutrient digestion and indirectly from gut bacteria to meet its metabolic needs. Part of the energy generated by both gut bacteria and the host is dissipated as heat and waste. Alternatively, during starvation, gut bacteria receive energy only from host energy stores. Fetissov, S. O. (2016) Role of the gut microbiota in host appetite control: bacterial growth to animal feeding behaviour Nat. Rev. Endocrinol. doi:10.1038/nrendo.2016.150