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Effect of a Hop Extract Standardized in 8-Prenylnaringenin on Bone Health and Gut Microbiome in Postmenopausal Women with Osteopenia: A One-Year Randomized, Double-Blind, Placebo-Controlled Trial.
Lecomte, M, Tomassi, D, Rizzoli, R, Tenon, M, Berton, T, Harney, S, Fança-Berthon, P
Nutrients. 2023;15(12)
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Osteoporosis is a bone condition characterized by weakened and brittle bones, leading to an increased risk of fractures. Oestrogens play a vital role in maintaining bone health, whereby oestrogen deficiency elevates the risk of osteoporosis and fractures, particularly in menopausal women due to the decline in oestrogen levels. Phytoestrogens, plant-derived compounds capable of interacting with human oestrogen receptors, have presented an intriguing non-pharmaceutical avenue for preventing bone loss. Other phytoestrogens have received some attention in the field, however, limited human research exists on prenylflavonoids, a phytoestrogens found in hops (Humulus lupulus). This randomized, double-blinded, placebo-controlled trial aimed to investigate the effects of a year-long supplementation of standardised hop extract (8-PN) Lifenol® on bone mineral density in postmenopausal women. Additionally, the study explored potential mechanisms, particularly focusing on changes in gut bacteria. Notably, gut bacteria play a role in bone metabolism and the pathogenesis of osteoporosis. They are also, along with the liver, responsible for converting hops phenols into active phytoestrogenic compounds. The trial was completed by 95 postmenopausal, women with Osteopenia aged 50 to 85. They all received calcium and vitamin D3 tablets in addition either a hop extract (100mcg) or a placebo for 48 weeks. Changes were monitored using DXA scans for bone mineral density (BMD) and bone metabolism, blood samples for markers for bone health, a quality of life questionnaire, gut microbiome testing, and tests for short-chain fatty acid (SCFA) levels. In conclusion, the intake of hop extract confirmed a previously observed trend of a slight increase in total bone mineral density (BMD), in addition to the benefits linked to calcium and vitamin D supplementation. Although there were no significant changes in the composition of gut bacteria and SCFA levels, the hop extract candidates had a higher abundance of specific genera associated with total body BMD, suggesting a potential positive impact. Larger studies are required to validate these findings.
Abstract
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.
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Gut microbiota alterations associated with reduced bone mineral density in older adults.
Das, M, Cronin, O, Keohane, DM, Cormac, EM, Nugent, H, Nugent, M, Molloy, C, O'Toole, PW, Shanahan, F, Molloy, MG, et al
Rheumatology (Oxford, England). 2019;58(12):2295-2304
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Osteoporosis, characterised by reduced bone density or ‘brittle bones’ affects a significant number of individuals over the age of 50 worldwide. Contributing factors include calcium and vitamin D deficiency and the presence of other inflammatory conditions. The composition of gut bacteria, the gut microbiome, plays an important role in immune activity and changes in composition have been associated with other inflammatory conditions. This cohort study of 181 individuals at high risk of reduced bone density and fractures, aimed to determine whether different gut microbiota composition is associated with bone density. Dexa scans and faecal samples were used as part of the assessment and confounding factors of diet, BMI, supplementation and medication were included in the analysis. The authors of the study found 6 species of gut bacteria that were significantly altered in numbers in the groups with osteoporosis and osteopenia, after controlling for confounding factors, and suggest that they could be used as markers of disease risk or progression and as a therapeutic target. Nutrition Practitioners working with bone density can focus on supporting the gut microbiome as part of their nutrition protocols.
Abstract
OBJECTIVE To investigate compositional differences in the gut microbiota associated with bone homeostasis and fractures in a cohort of older adults. METHODS Faecal microbiota profiles were determined from 181 individuals with osteopenia (n = 61) or osteoporosis (n = 60), and an age- and gender-matched group with normal BMD (n = 60). Analysis of the 16S (V3-V4 region) amplicon dataset classified to the genus level was used to identify significantly differentially abundant taxa. Adjustments were made for potential confounding variables identified from the literature using several statistical models. RESULTS We identified six genera that were significantly altered in abundance in the osteoporosis or osteopenic groups compared with age- and gender-matched controls. A detailed study of microbiota associations with meta-data variables that included BMI, health status, diet and medication revealed that these meta-data explained 15-17% of the variance within the microbiota dataset. BMD measurements were significantly associated with alterations in the microbiota. After controlling for known biological confounders, five of the six taxa remained significant. Overall microbiota alpha diversity did not correlate to BMD in this study. CONCLUSION Reduced BMD in osteopenia and osteoporosis is associated with an altered microbiota. These alterations may be useful as biomarkers or therapeutic targets in individuals at high risk of reductions in BMD. These observations will lead to a better understanding of the relationship between the microbiota and bone homeostasis.