Bifidobacterium longum BB536 supplementation is associated with increased circulating choline plasmalogen concentrations in non-pregnant, non-lactating dairy cows.

CONTEXT: Plasmalogens are ether phospholipids implicated in neuroendocrine regulation, including reproductive function. Recent studies have suggested that circulating plasmalogen concentrations are associated with reproductive performance in dairy cows; however, practical strategies to increase these concentrations remain limited.

AIMS: We hypothesised that supplementation with Bifidobacterium longum increases circulating choline plasmalogen concentrations and that this response depends on physiological state.

METHODS

Commercial probiotic products were screened using liquid chromatography-mass spectrometry and metagenomics to identify candidates containing plasmalogen-producing bacteria. A product containing the characterised strain B. longum BB536 and products containing other B. longum strains were selected for in vivo evaluation. Selected products were administered to Holstein cattle, and circulating choline plasmalogen concentrations were measured using an enzyme-based fluorometric assay.

KEY

RESULTS

In long-term non-pregnant, non-lactating dairy cows, supplementation with B. longum BB536 significantly increased circulating choline plasmalogen concentrations, with a detectable rise approximately 1 week after the start of treatment and peak concentrations during Days 8-14 (P < 0.05). In contrast, no consistent increase was observed in pregnant, lactating dairy cows. Cross-sectional analysis across pregnancy stages showed significant variation in circulating choline plasmalogen concentrations, with lower concentrations during mid- to late gestation. No adverse effects were observed in ruminal pH, blood lactate concentrations, or bodyweight.

CONCLUSION

These findings suggest that supplementation with B. longum BB536 increases circulating choline plasmalogen concentrations in a state-dependent manner.

IMPLICATIONS: This study has provided new insight into the regulation of plasmalogens in cattle and suggests a potential nutritional approach for modulating reproductive function.