Microbially Matured Phytomedicines from Sesame Hull (Sesamum indicum L.) Cell-Wall Oligosaccharides: Lactobacillus-Generated Pre-Postbiotics with Antioxidant, Enzyme-Inhibitory and Anti-Helicobacter pylori Activity in a Functional Beverage

Many bioactive constituents of medicinal plants depend on microbial biotransformation for their pharmacological activity, positioning postbiotics from plant substrates as microbially matured phytomedicines. An emerging framework integrates prebiotic phytochemicals with probiotic strains to modulate gut microbiota and host health. In this study, we explored the functional properties of heat-inactivated Lactobacillus strains following the fermentation of oligosaccharides obtained from sesame hulls (Sesamum indicum L.), underutilised agro-industrial residues. Cell-wall oligosaccharides were obtained by alkaline or enzymatic (Celluclast® 1.5 L (Novonesis, Copenhagen, Denmark)) extraction with Ultraflo® L (Novonesis, Copenhagen, Denmark) hydrolysis and fermented with Lactobacillus acidophilus, L. casei, or L. paracasei. Heat-inactivated pre-postbiotic preparations were profiled for antioxidant capacity, inhibition of metabolic enzymes implicated in obesity and type 2 diabetes, and anti-Helicobacter pylori urease activity. Moreover, these preparations were incorporated into a barley malt (Hordeum vulgare L.) beverage. Bioactivity was strain- and substrate-dependent: L. casei-derived postbiotics most strongly inhibited pancreatic lipase (47.82%) and α-glucosidase (52.14%); L. acidophilus most strongly inhibited α-amylase (43.67%); and L. paracasei exhibited the strongest urease inhibition (20.66%). All strains displayed enhanced antioxidant activity, with ABTS scavenging reaching 87.02%. The supplemented beverages improved antioxidant activity by ~20%. The fermentation of these oligosaccharides thus yields a microbially matured phytomedicine with multi-target activity, supporting postbiotics as active mediators of plant-based therapeutics.