Microbiome-based therapeutics: Opportunity and challenges.

The autochthonous microbial communities comprising symbionts, commensals, and opportunistic pathogens living throughout the human body profoundly contribute to health by reducing disease susceptibility and maturing host immunity. The community compositions and functional repertoires of microbiomes present in the different body habitats are dynamic. The structural and functional balance of the human microbiome could be modulated by environmental factors, lifestyle, and host genetics. Several functions of the microbial community directly or indirectly modulate host cellular signaling pathways that are associated with energy assimilation, sensing and responding to environmental signals through the neuroendocrine pathways, and resistance against colonization of allochthonous microbiota with disease-causing potential. Both culture-dependent and independent characterizations of microbial community compositions and their functional attributes help us to recognize the importance of microbial diversity in individual's health and identify the microbes and their metabolites associated with health and diseases. Such an in-depth understanding of the human microbiome created avenues of microbiome-based translation research, which led to the discovery and development of large numbers of medical therapies. In this chapter, we discuss the current success of microbiome-based therapies for infectious and metabolic diseases, and the major bottleneck and challenges of translational research with the community of symbiotic microorganisms.