Estrogen deficiency increases the risk of osteoporosis and fracture. The aim of this study was to investigate whether a hop extract standardized in 8-prenylnaringenin (8-PN), a potent phytoestrogen, could improve bone status of osteopenic women and to explore the gut microbiome roles in this effect. In this double-blind, placebo-controlled, randomized trial, 100 postmenopausal, osteopenic women were supplemented with calcium and vitamin D3 (CaD) tablets and either a hop extract (HE) standardized in 8-PN (n = 50) or a placebo (n = 50) for 48 weeks. Bone mineral density (BMD) and bone metabolism were assessed by DXA measurements and plasma bone biomarkers, respectively. Participant’s quality of life (SF-36), gut microbiome composition, and short-chain fatty acid (SCFA) levels were also investigated. In addition to the CaD supplements, 48 weeks of HE supplementation increased total body BMD (1.8 ± 0.4% vs. baseline, p < 0.0001; 1.0 ± 0.6% vs. placebo, p = 0.08), with a higher proportion of women experiencing an increase ≥1% compared to placebo (odds ratio: 2.41 ± 1.07, p < 0.05). An increase in the SF-36 physical functioning score was observed with HE versus placebo (p = 0.05). Gut microbiome α-diversity and SCFA levels did not differ between groups. However, a higher abundance of genera Turicibacter and Shigella was observed in the HE group; both genera have been previously identified as associated with total body BMD. These results suggest that an 8-PN standardized hop extract could beneficially impact bone health of postmenopausal women with osteopenia.

Traditional functional ingredients, such as conventional emulsifiers (surfactants, animal-derived proteins), and synthetic antioxidants may become obsolete in the development of clean-label, plant-based, sustainable food emulsions. Previously, we showed that tailor-made antioxidant-loaded particles can yield both physically and oxidatively stable emulsions, and we expected that natural particles with related properties could also show these beneficial effects. Here, we investigated Pickering emulsions prepared with natural plant particulate materials. Particles that showed weak aggregation in acidic aqueous media, indicating a relatively hydrophobic surface, were able to physically stabilize oil-in-water emulsions, through either Pickering stabilization (powders of matcha tea, spinach leaves, and spirulina cake), or an increase in viscosity (pineapple fibers). Matcha tea and spinach leaf particle-stabilized emulsions were highly stable to lipid oxidation, as compared to emulsions stabilized by conventional emulsifiers. Taking this dual particle functionality as a starting point for emulsion design is, in our view, essential to achieve clean-label food emulsions.