Tissue-specific polyphenol enrichment following oral supplementation with spray-dried Lacticaseibacillus casei-Maoberry juice in rats

• Probiotic-Maoberry powder was developed via spray drying and retained high polyphenol content and antioxidant capacity. • No adverse effects on body weight or oxidative stress markers were observed in healthy rats after 21-day supplementation. • Hepatic polyphenol levels increased significantly, suggesting tissue-specific accumulation without systemic elevation. • Microbial metabolism likely facilitated polyphenol biotransformation and bioavailability in vivo . Maoberry ( Antidesma bunius ) is a polyphenol-rich fruit with antioxidant and hepatoprotective potential. This study investigated whether co-administration with Lacticaseibacillus casei 01 could enhance in vivo polyphenol bioavailability and tissue-specific accumulation through microbial metabolism in the gut. Pasteurized Maoberry juice was supplemented with L. casei 01, spray-dried, and reconstituted daily for oral gavage in male Sprague-Dawley rats at a dose of 10 11 –10 12 CFU/kg body weight for 21 days. Rats were divided into control and probiotic-Maoberry juice powder (PM) groups ( n = 7). No significant differences were observed in body weight gain or malondialdehyde levels in serum, liver, or intestine ( p > 0.05), confirming the safety of the intervention and the absence of oxidative stress. Notably, liver polyphenol content significantly increased in the PM group ( p ≤ 0.01), while serum and intestinal levels remained unchanged ( p > 0.05). These results indicated selective hepatic accumulation of polyphenols, likely mediated by microbial biotransformation within the gut. The findings supported the potential of probiotic-Maoberry juice powder as a functional food ingredient for targeted antioxidant delivery.