Most CH4 mitigation strategies based on feed additives result in excess ruminal H2 being expelled and consequently not accompanied by improved rumen fermentation efficiency that could benefit animal productivity. The present study aimed to confirm previous in vitro results and evaluated the combined treatment of Asparagopsis taxiformis (AT), a potent methanogenesis inhibitor, and phloroglucinol, an organic compound that can be degraded by rumen bacteria using H2 as electron donor, yielding acetate as the terminal product. Eight Murciano-Granadina adult goats were used in a replicated 4x4 Latin square design. Four treatments were considered: i) control; ii) AT at 0.5% DM; iii) phloroglucinol at 20 g/kg DM diet (PHL) and iv) combination of AT and phloroglucinol (AT-PH). Each experimental period consisted of 10 days of adaptation to the treatments, followed by 3 days for CH4 and H2 measurements in open-circuit respiration chambers and 1 day for rumen fluid collection at 3h post-feeding for VFA analysis and rumen microbial community characterization. Results showed that PH treatment did not affect CH4 production, while AT and AT-PH significantly (P<0.001) reduced CH4 production by 30-40 %. The AT treatment increased H2 expelled, which was reduced by 74 % when AT was combined with PHL (P<0.001). Total VFA and acetate concentrations were significantly increased by AT-PHL compared to AT. Moreover, PHL supplementation decreased the concentrations of archaea, protozoa and anaerobic fungi. This study demonstrated that phloroglucinol could be used as means to capture ruminal H2 produced in excess in a methanogenesis inhibition scenario and redirect it towards acetate production, which could potentially lead to improvements in animal productivity.