In vitro–in vivo Validation of Stimulatory Effect of Oat Ingredients on Lactobacilli

Abstract

The prebiotic activity of a commercially available oat product and a novel oat ingredient, at similar β-glucan loads, was tested using a validated in vitro gut model (M-SHIME®). The novel oat ingredient was tested further at lower β-glucan loads in vitro, while the commercially available oat product was assessed in a randomised, single-blind, placebo-controlled, and cross-over human study. Both approaches focused on healthy individuals with mild hypercholesterolemia. In vitro analysis revealed that both oat products strongly stimulated Lactobacillaceae and Bifidobacteriaceae in the intestinal lumen and the simulated mucus layer, and corresponded with enhanced levels of acetate and lactate with cross-feeding interactions leading to an associated increase in propionate and butyrate production. The in vitro prebiotic activity of the novel oat ingredient remained at lower β-glucan levels, indicating the prebiotic potential of the novel oat product. Finally, the stimulation of Lactobacillus spp. was confirmed during the in vivo trial, where lactobacilli abundance significantly increased in the overall population at the end of the intervention period with the commercially available oat product relative to the control product, indicating the power of in vitro gut models in predicting in vivo response of the microbial community to dietary modulation.

Effects of Dietary Fibers on Short-Chain Fatty Acids and Gut Microbiota Composition in Healthy Adults: A Systematic Review

“…Two studies [41,42] assessed the impact of eating bread with in situ produced arabinoxylan oligosaccharides (AXOS) obtained by xylanase treatment. The remaining trials tested the effects of a diet [43][44][45][46] or a specific food [12,[47][48][49][50] providing a defined quantity of DFs.…”

“…A total of 1377 subjects were involved in the 44 trials. The study population was mainly represented by healthy adults except for 156 subjects (in three studies) with mild hypercholesterolemia, moderate hypercholesterolemia, and overweight [40,46,48,49].…”

“…The target population had a normal BMI: the mean BMI ranged from a minimum of 20.9 kg/m 2 [22,41] to a maximum of 27.9 kg/m 2 [43]. Three studies reported different ranges in the inclusion criteria without specifying the average [16,44,49] while two studies did not report any data [12,28]. In one case, only the exclusion criteria about the BMI of population were reported [14], while in another the BMI median value was reported [41].…”

“…The mean age of the subjects ranged from a minimum of 20 years [22] to a maximum of 55 years [45]. Three studies reported the age ranges of the subjects recruited, but not the group mean [14,23,49], while two studies reported the different age ranges in the inclusion criteria without specifying the mean [30,44]. One study reported the median age only [41].…”

From Cancer Therapy to Winemaking: The Molecular Structure and Applications of β-Glucans and β-1, 3-Glucanases

“…β-glucans are biologically active biopolymers that can interact with several protein receptors, present both in micro- and macro-organisms, eliciting a wide spectrum of biological responses. These responses often result in important bioactivities including immunomodulating, anticancer, antioxidant, cholesterol-lowering and prebiotic effects [ 5 , 7 , 8 , 9 , 132 ]. Naturally, it is not surprising that numerous studies have tried to harness the potential therapeutic properties of β-glucans, which can be generally divided into immunomodulatory or metabolic properties [ 10 , 11 , 12 , 13 , 14 , 15 , 133 , 134 ].…”