Since the discovery and elucidation of deoxyribonucleic acid (DNA) and its structure in the 1950s by Watson and colleagues (Watson and Crick, 1953, Feughelman et al., 1955, Wilkins, 1956) strategies and multiple technological innovations have been made in efforts to better understand the complexity and diversity of genomes in a variety of ecosystems, including those in the health and disease. The term metagenome was first described by Jo Handelsman in 1998 as “the genomes of the total microbiota found in nature” (Handelsman et al., 1998). More recently, with the development and application of high throughput sequencing methods in combination with the growing recognition of the importance of the microbial community a National Science and Technology Council Committee of US government scientists was created in 2015 (Stulberg et al., 2016). The US government scientists defined microbiome as “a multispecies community of microorganisms in a specific environment (that is, host, habitat or ecosystem)” and microbiome research as “those studies that emphasize community-level analyses with data derived from genome-enabled technologies” (Stulberg et al., 2016).
Mounting evidence on microbiome and its impact on host health and metabolic functions has been generated by next-generation sequencing over the last few years. Remarkably, the microbiome is now referred to as the “new biomarker” of health (Shukla et al., 2017) mainly due to its role in maintaining host physiology (Sommer and Bäckhed, 2013, Barrett and Wu, 2017), maturation and “education” of the immune system (Kelly et al., 2007, Chung et al., 2012) and its potential to mediate host metabolic development (Cho et al., 2012, Cox et al., 2014). Since coevolution of mammals and their microbiota has occurred over millions of years (Ley et al., 2008) is not a surprise that this tight connection between host and its microbiota exists.
In veterinary medicine, symbiosis between ruminant host and microbial population is essential for animal survival and existence, mainly due to its role in converting plant and grain materials, consumed by the host, into available energy resources that are subsequently absorbed and metabolized by the host (Hungate, 1966). Given its complexity and importance to the ruminant existence, the bovine gastrointestinal tract microbiota has been extensively investigated (Khafipour et al., 2009, Jami and Mizrahi, 2012, Jami et al., 2013, Meale et al., 2016, DillMcFarland et al., 2017). However, it is becoming increasingly apparent that microbial communities in other anatomical sites, such as mammary gland (Oikonomou et al., 2012, Oikonomou et al., 2014, Addis et al., 2016) and airways (Holman et al., 2017), are also relevant for bovine health.
Presented at the 2021 Animal Nutrition Conference of Canada. For information on the next edition, click here.