Modulation of Postprandial Plasma Concentrations of Digestive Hormones and Gut Microbiota by Foods Containing Oat ß-Glucans in Healthy Volunteers

Abstract

Cereal β-glucans are beneficial health ingredients that reduce cholesterolemia and postprandial glycaemia. However, their impact on digestive hormones and gut microbiota is not yet fully established. Two randomized, double-blind, controlled studies were conducted. In the first study, 14 subjects ingested a breakfast with or without β-glucan from oats (5.2 g). Compared to the control, β-glucan increased orocecal transit time (p = 0.028) and decreased mean appetite score (p = 0.014) and postprandial plasma ghrelin (p = 0.030), C-peptide (p = 0.001), insulin (p = 0.06), and glucose (p = 0.0006). β-glucan increased plasma GIP (p = 0.035) and PP (p = 0.018) without affecting leptin, GLP-1, PYY, glucagon, amylin, or 7α-hydroxy-4-cholesten-3-one, a biomarker of bile acid synthesis. In the second study, 32 subjects were distributed into 2 groups to ingest daily foods with (3 g/day) or without β-glucan for 3 weeks; stools were collected before/after treatment. No changes in fecal microbiota composition/diversity (deep sequencing) were detected with β-glucans. These results indicate that acute intake of 5 g β-glucan slows transit time and decreases hunger sensation and postprandial glycaemia without affecting bile-acid synthesis, these changes being associated with decreased plasma insulin, C-peptide, and ghrelin, and increased plasma GIP and PP. However, regular daily intake of 3 g β-glucan is not sufficient to have an effect on fecal microbiota composition.

A comprehensive review on oat milk: from oat nutrients and phytochemicals to its processing technologies, product features, and potential applications

“…44 In addition to reducing the risk of heart disease, β-glucans of oat also have other health beneficial effects including blood-cholesterol and blood-glucose-lowering ability, antitumor activity, gut microflora normalization, and protection against DNA damage, as well as increasing feelings of fullness and satiety. 45 In terms of micronutrients, oats are particularly rich in phosphorus and potassium. 35,36 The vitamins in oats are dominated by vitamin E (16 mg kg −1 -94 mg kg −1 ) with α-tocotrienol and α-tocopherol being the major ones (up to 90%), and also consist of low levels of thiamine, biotin, choline, riboflavin, pantothenic acid, vitamin B 6 , folic acid, and niacin.…”

“…44 In addition to reducing the risk of heart disease, β-glucans of oat also have other health beneficial effects including blood-cholesterol and blood-glucose-lowering ability, antitumor activity, gut microflora normalization, and protection against DNA damage, as well as increasing feelings of fullness and satiety. 45…”

Review: Pengolahan dan Pengembangan Oat (Avena sativa L.) menjadi Susu Nabati Rendah Lemak bagi Penderita Hiperkolesterolemia

“…Dibandingkan dengan sereal lainnya, seperti gandum (10,69%-13,68%), beras merah (7,50%), barley (9,91%), sorgum (10,62%), millet (11,02%) dan rye (10,34%), kandungan protein oat biasanya lebih tinggi berkisar antara 11% hingga 20%. Selain itu, protein oat memberikan keseimbangan asam amino esensial yang lebih baik bagi manusia dan hewan monogastrik lainnya dibandingkan kebanyakan sereal lainnya, terutama termasuk lisin, treonin, metionin, dan sistin [12], [20], [21]. Faktanya, oat adalah sumber beta-glucan yang sangat baik (3,90%-7,50%) dan efek menguntungkannya bagi kesehatan sangat bergantung pada kandungan beta-glucan [12], [20].…”

“…Baik Badan Pengawas Obat dan Makanan Amerika Serikat (FDA) dan Health Canada telah mengklaim bahwa 3 gram sehari dosis beta-glucan dari oat akan mengurangi risiko penyakit jantung. Selain mengurangi risiko penyakit jantung, beta-glucan oat juga memiliki efek menguntungkan kesehatan lainnya termasuk kemampuan menurunkan kolesterol darah dan glukosa darah, aktivitas antitumor, normalisasi mikroflora usus, dan perlindungan terhadap kerusakan DNA, serta memberikan rasa kenyang [21]. Diketahui bahwa beta-glucan yang sangat larut dalam air dengan berat molekul rata-rata sedang hingga tinggi lebih efektif dalam menurunkan kolesterol serum dibandingkan beta-glucan yang larut dalam air dengan berat molekul rendah [11].…”