Probiotics Against Methanogens and Methanogenesis

Ruminants transform plant biomass to high biological value foods. Ruminants’ gastrointestinal (GI) ecosystem serves as exceptionally functional system for saccharification and fermentation of consumed plant biomass and converts it into digestible microbial proteins, SCFAs, NH3, H2, CO2, and CH4. Ruminal Archaea helps indirectly by using H2, the end product of rumen fermentation, to reduce oxidized products such as CO2, SO4, and NO3 and certain organic compounds. Ruminant and nonruminants, pigs, equines, rabbits, and poultry also produce CH4 as a normal gut microbial metabolic activity. It is possible to reduce CH4 emission through various interventions without distressing the productivity potential of livestock. Probiotics or direct-fed microbials (DFM) (fungi, yeasts, and LAB) improve plant fiber utilization and reduce protozoa and protozoa-associated methanogens (PAM). Understanding of host-microbiome interaction will allow the development of novel strategies to mitigate enteric greenhouse gas (GHG) emission from animals.