{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T09:07:48Z","timestamp":1789031268429,"version":"build-2803163510"},"reference-count":38,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background\/Objectives: Dietary fiber supplementation has been associated with blood pressure (BP) reduction, but evidence comparing soluble (SDF) and insoluble (IDF) fiber types in high-risk populations is limited. This study aimed to compare the effects of SDF and IDF supplementation on BP and to explore correlations between changes in BP and alterations in gut microbiota composition and serum biomarkers in adults with type 2 diabetes (T2D) and hypertension. Methods: This secondary analysis was based on a 12-week, randomized, double-blind, parallel-group clinical trial. Thirty-five adults with T2D and hypertension were assigned to receive either 5 g\/day of oat \u03b2-glucan (SDF, n = 19) or microcrystalline cellulose (IDF, n = 16). BP, gut microbiota composition (quantitative polymerase chain reaction; qPCR), and inflammatory biomarkers were assessed at baseline and after the intervention. Results: The mean age of the participants was 50.7 \u00b1 5.7 years, and 77% were female. Both groups exhibited comparable reductions in systolic blood pressure (SBP) (SDF: \u221211.2 \u00b1 20.9 mmHg; IDF: \u221211.6 \u00b1 17.0 mmHg; p = 0.965 between groups). In the SDF group, significant positive correlations were observed between increases in Firmicutes abundance and changes in diastolic blood pressure (DBP) (r = 0.90, p &lt; 0.01), as well as between increases in Bifidobacterium spp. abundance and changes in DBP (r = 0.90, p &lt; 0.05). Conclusions: Supplementation with either soluble or IDF was associated with reductions in SBP in this sample of adults with T2D and hypertension. The observed associations between changes in gut microbiota composition and BP should be considered exploratory and interpreted with caution. Placebo-controlled studies are required to confirm these findings and elucidate the underlying biological mechanisms.<\/jats:p>","DOI":"10.3390\/nu18182945","type":"journal-article","created":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T08:10:22Z","timestamp":1788855022000},"page":"2945","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Dietary Fiber Supplementation Reduces Systolic Blood Pressure in High-Risk Patients with Type 2 Diabetes and Hypertension: A Secondary Analysis of a Randomized Trial"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1047-1426","authenticated-orcid":false,"given":"Jos\u00e9 Luis","family":"Pino-Villal\u00f3n","sequence":"first","affiliation":[{"name":"Escuela de Nutrici\u00f3n y Diet\u00e9tica, Facultad de Salud, Universidad Santo Tom\u00e1s, Talca 3460000, Chile"},{"name":"Food Observatory (ODA360), Health Prevention and Care Research Center (+SALUD), Faculty of Health Sciences, Universidad Santo Tom\u00e1s, Santiago 8370003, Chile"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0342-5237","authenticated-orcid":false,"given":"Bastian","family":"Parada-Flores","sequence":"additional","affiliation":[{"name":"Escuela de Nutrici\u00f3n y Diet\u00e9tica, Facultad de Salud, Universidad Santo Tom\u00e1s, Talca 3460000, Chile"},{"name":"Department of Physical Activity Sciences, Faculty of Education Sciences, Universidad Cat\u00f3lica del Maule, Talca 3480112, Chile"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6277-4090","authenticated-orcid":false,"given":"Miguel","family":"Arredondo","sequence":"additional","affiliation":[{"name":"Micronutrient Laboratory, Institute of Nutrition and Food Technology (INTA), Universidad de Chile, Santiago 7830490, Chile"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4017-502X","authenticated-orcid":false,"given":"Roberto","family":"Fuentealba","sequence":"additional","affiliation":[{"name":"Escuela de Enfermer\u00eda, Facultad de Salud, Universidad Santo Tom\u00e1s, Talca 3460000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3463-9991","authenticated-orcid":false,"given":"Jessica","family":"Noack","sequence":"additional","affiliation":[{"name":"Escuela de Enfermer\u00eda, Facultad de Salud, Universidad Santo Tom\u00e1s, Talca 3460000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"resources","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6190-938X","authenticated-orcid":false,"given":"Exal","family":"Garcia-Carrillo","sequence":"additional","affiliation":[{"name":"Department of Physical Activity Sciences, Universidad de Los Lagos, Osorno 5290000, Chile"},{"name":"Department of Physical Activity Sciences, Faculty of Education Sciences, Universidad Cat\u00f3lica del Maule, Talca 3480112, 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Metab."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1017\/S0029665119000673","article-title":"Dietary fibre and cardiovascular health: A review of current evidence and policy","volume":"79","author":"Evans","year":"2020","journal-title":"Proc. Nutr. Soc."},{"key":"ref_4","first-page":"564","article-title":"Dietary fiber deficiency in individuals with metabolic syndrome: A review","volume":"26","author":"Veluvali","year":"2023","journal-title":"Curr. Opin. Clin. Nutr. Metab. Care"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.numecd.2017.09.007","article-title":"The effect of viscous soluble fiber on blood pressure: A systematic review and meta-analysis of randomized controlled trials","volume":"28","author":"Khan","year":"2018","journal-title":"Nutr. Metab. Cardiovasc. Dis."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1186\/s12937-023-00879-0","article-title":"Effect of soluble fiber on blood pressure in adults: A systematic review and dose-response meta-analysis of randomized controlled trials","volume":"22","author":"Ghavami","year":"2023","journal-title":"Nutr. J."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1480","DOI":"10.1017\/S0007114515003098","article-title":"Total, insoluble and soluble dietary fibre intake in relation to blood pressure: The INTERMAP Study","volume":"114","author":"Aljuraiban","year":"2015","journal-title":"Br. J. Nutr."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Ye, Z., Wu, Q., Yang, S., Zhang, Y., Zhou, C., Liu, M., Zhang, Z., He, P., Zhang, Y., and Li, R. (2023). Variety and quantity of dietary insoluble fiber intake from different sources and risk of new-onset hypertension. BMC Med., 21.","DOI":"10.1186\/s12916-023-02752-7"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1139\/apnm-2024-0317","article-title":"Effect of oat \u03b2-glucan in managing blood pressure: A randomized cross-over pilot trial","volume":"50","author":"Iman","year":"2025","journal-title":"Appl. Physiol. Nutr. Metab."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Yu, J., Xia, J., Yang, C., Pan, D., Xu, D., Sun, G., and Xia, H. (2022). Effects of Oat Beta-Glucan Intake on Lipid Profiles in Hypercholesterolemic Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients, 14.","DOI":"10.3390\/nu14102043"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"9210","DOI":"10.1038\/s41598-018-27446-6","article-title":"Acceptability of placebo multiparticulate formulations in children and adults","volume":"8","author":"Lopez","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1080\/19490976.2015.1134082","article-title":"Formation of short chain fatty acids by the gut microbiota and their impact on human metabolism","volume":"7","author":"Morrison","year":"2016","journal-title":"Gut Microbes"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"4410","DOI":"10.1073\/pnas.1215927110","article-title":"Olfactory receptor responding to gut microbiota-derived signals plays a role in renin secretion and blood pressure regulation","volume":"110","author":"Pluznick","year":"2013","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"826","DOI":"10.1152\/physiolgenomics.00089.2016","article-title":"Microbial short chain fatty acid metabolites lower blood pressure via endothelial G protein-coupled receptor 41","volume":"48","author":"Natarajan","year":"2016","journal-title":"Physiol. Genom."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Mottawea, W., Sultan, S., Landau, K., Bordenave, N., and Hammami, R. (2020). Evaluation of the Prebiotic Potential of a Commercial Synbiotic Food Ingredient on Gut Microbiota in an Ex Vivo Model of the Human Colon. Nutrients, 12.","DOI":"10.3390\/nu12092669"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"104311","DOI":"10.1016\/j.jff.2020.104311","article-title":"Effect of dietary supplementation with oat \u03b2-glucan for 3 months in subjects with type 2 diabetes: A randomized, double-blind, controlled clinical trial","volume":"77","author":"Pino","year":"2021","journal-title":"J. Funct. Foods"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Usuda, H., Okamoto, T., and Wada, K. (2021). Leaky Gut: Effect of Dietary Fiber and Fats on Microbiome and Intestinal Barrier. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms22147613"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Rudzka , A., Zieli\u0144ska, D., Neffe-Skoci\u0144ska, K., Sionek, B., Szyd\u0142owska, A., G\u00f3rnik-Horn, K., and Ko\u0142o\u017cyn-Krajewska , D. (2025). The Role of Intestinal Microbiota and Dietary Fibre in the Regulation of Blood Pressure Through the Interaction with Sodium: A Narrative Review. Microorganisms, 13.","DOI":"10.3390\/microorganisms13061269"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1183","DOI":"10.1161\/CIRCRESAHA.117.309715","article-title":"Gut Microbiota in Cardiovascular Health and Disease","volume":"120","author":"Tang","year":"2017","journal-title":"Circ. Res."},{"key":"ref_20","first-page":"e29927","article-title":"Association of Gut Microbial Dysbiosis and Hypertension: A Systematic Review","volume":"14","author":"Naik","year":"2022","journal-title":"Cureus"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"623","DOI":"10.1161\/HYPERTENSIONAHA.109.148213","article-title":"Positive Relationship Between Plasma Leptin Level and Hypertension","volume":"56","author":"Shankar","year":"2010","journal-title":"Hypertension"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Verhaar, B.J.H., Prodan, A., Nieuwdorp, M., and Muller, M. (2020). Gut Microbiota in Hypertension and Atherosclerosis: A Review. Nutrients, 12.","DOI":"10.3390\/nu12102982"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1097\/HJH.0000000000003903","article-title":"Effects of glucagon-like peptide-1 receptor agonists on blood pressure in overweight or obese patients: A meta-analysis of randomized controlled trials","volume":"43","author":"Wong","year":"2025","journal-title":"J. Hypertens."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Chen, H.Q., Gong, J.Y., Xing, K., Liu, M.Z., Ren, H., and Luo, J.Q. (2022). Pharmacomicrobiomics: Exploiting the Drug-Microbiota Interactions in Antihypertensive Treatment. Front. Med., 8.","DOI":"10.3389\/fmed.2021.742394"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1039\/D5FO03598H","article-title":"Cereal beta-glucan and cardiovascular disease risk reduction in overweight and obese populations: A systematic review and meta-analysis of lipid, blood pressure, and anthropometric parameters","volume":"17","author":"Zheng","year":"2026","journal-title":"Food Funct."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1097\/HJH.0000000000000515","article-title":"Effects of dietary fibre type on blood pressure: A systematic review and meta-analysis of randomized controlled trials of healthy individuals","volume":"33","author":"Evans","year":"2015","journal-title":"J. Hypertens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"786","DOI":"10.1038\/sj.ejcn.1602562","article-title":"Effects of consuming foods containing oat \u03b2-glucan on blood pressure, carbohydrate metabolism and biomarkers of oxidative stress in men and women with elevated blood pressure","volume":"61","author":"Maki","year":"2007","journal-title":"Eur. J. Clin. Nutr."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Haswell, C., Ali, A., Page, R., Hurst, R., and Rutherfurd-Markwick, K. (2021). Potential of Beetroot and Blackcurrant Compounds to Improve Metabolic Syndrome Risk Factors. Metabolites, 11.","DOI":"10.3390\/metabo11060338"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"640","DOI":"10.1080\/10641963.2020.1764015","article-title":"Effects of blackcurrant extract on arterial functions in older adults: A randomized, double-blind, placebo-controlled, crossover trial","volume":"42","author":"Okamoto","year":"2020","journal-title":"Clin. Exp. Hypertens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1016\/j.carbpol.2017.04.021","article-title":"Functionality and nutritional aspects of microcrystalline cellulose in food","volume":"172","author":"Chen","year":"2017","journal-title":"Carbohydr. Polym."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1038\/nrcardio.2017.120","article-title":"Beyond gut feelings: How the gut microbiota regulates blood pressure","volume":"15","author":"Marques","year":"2018","journal-title":"Nat. Rev. Cardiol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1441","DOI":"10.1007\/s00424-019-02322-y","article-title":"Butyric acid, a gut bacteria metabolite, lowers arterial blood pressure via colon-vagus nerve signaling and GPR41\/43 receptors","volume":"471","author":"Onyszkiewicz","year":"2019","journal-title":"Pflug. Arch."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.clnesp.2022.03.008","article-title":"The effects of butyrate supplementation on glycemic control, lipid profile, blood pressure, nitric oxide level and glutathione peroxidase activity in type 2 diabetic patients: A randomized triple -blind, placebo-controlled trial","volume":"49","author":"Khosravi","year":"2022","journal-title":"Clin. Nutr. ESPEN"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1674","DOI":"10.1161\/HYPERTENSIONAHA.120.14473","article-title":"Microbial Peer Pressure: The Role of the Gut Microbiota in Hypertension and Its Complications","volume":"76","author":"Muralitharan","year":"2020","journal-title":"Hypertension"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2923941","DOI":"10.1155\/2022\/2923941","article-title":"Human Gut Microbes Associated with Systolic Blood Pressure","volume":"2022","author":"Joishy","year":"2022","journal-title":"Int. J. Hypertens."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Zhou, Z., Sun, B., Yu, D., and Zhu, C. (2022). Gut Microbiota: An Important Player in Type 2 Diabetes Mellitus. Front. Cell Infect. Microbiol., 12.","DOI":"10.3389\/fcimb.2022.834485"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Amiri, P., Hosseini, S.A., Ghaffari, S., Tutunchi, H., Ghaffari, S., Mosharkesh, E., Asghari, S., and Roshanravan, N. (2022). Role of Butyrate, a Gut Microbiota Derived Metabolite, in Cardiovascular Diseases: A comprehensive narrative review. Front. Pharmacol., 12.","DOI":"10.3389\/fphar.2021.837509"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Cookson, T.A. (2021). Bacterial-Induced Blood Pressure Reduction: Mechanisms for the Treatment of Hypertension via the Gut. Front. Cardiovasc. Med., 8.","DOI":"10.3389\/fcvm.2021.721393"}],"container-title":["Nutrients"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6643\/18\/18\/2945\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T08:17:11Z","timestamp":1789028231000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6643\/18\/18\/2945"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,8]]},"references-count":38,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["nu18182945"],"URL":"https:\/\/doi.org\/10.3390\/nu18182945","relation":{},"ISSN":["2072-6643"],"issn-type":[{"value":"2072-6643","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,8]]}}}