Characterization of an Acidogenic Bacterial Consortium as Probiotic and Its Effect on Rumen Fermentation In Vitro and In Vivo

Probiotics are live microorganisms that promote host health through microbiota balance and immune modulation. We assessed an acidogenic bacterial consortium (ABC) with promising probiotic properties, focusing on its resilience during transit through the digestive tract in ruminants and determining its optimal in vitro dosage. The ABC exhibited antibiotic resistance, thrived at pH levels between 5 and 7 for 24 and 48 h, and showed a 77% survival rate in artificial gastric juice. Moreover, it not only endured bile salt exposure but also multiplied. The ABC exhibited 10.74% of coaggregation capabilities against E. coli. Optimal dosage determination revealed that 4 × 108 was the ideal concentration, as higher doses did not yield significant differences in dry matter digestion. In the in vivo trial with Limousin Heifers, the ABC led to enhanced total volatile fatty acid (VFA) production, increased daily weight gains, and improved feed conversion rates compared to the control group. These findings underscore the potential of the ABC as a probiotic to boost animal productivity and overall health.