Ingestion of High β-Glucan Barley Flour Enhances the Intestinal Immune System of Diet-Induced Obese Mice by Prebiotic Effects

Abstract

The prebiotic effect of high β-glucan barley (HGB) flour on the innate immune system of high-fat model mice was investigated. C57BL/6J male mice were fed a high-fat diet supplemented with HGB flour for 90 days. Secretory immunoglobulin A (sIgA) in the cecum and serum were analyzed by enzyme-linked immunosorbent assays (ELISA). Real-time PCR was used to determine mRNA expression levels of pro- and anti-inflammatory cytokines such as interleukin (IL)-10 and IL-6 in the ileum as well as the composition of the microbiota in the cecum. Concentrations of short-chain fatty acids (SCFAs) and organic acids were analyzed by GC/MS. Concentrations of sIgA in the cecum and serum were increased in the HGB group compared to the control. Gene expression levels of IL-10 and polymeric immunoglobulin receptor (pIgR) significantly increased in the HGB group. HGB intake increased the bacterial count of microbiota, such as Bifidobacterium and Lactobacillus. Concentrations of propionate and lactate in the cecum were increased in the HGB group, and a positive correlation was found between these organic acids and the IL-10 expression level. Our findings showed that HGB flour enhanced immune function such as IgA secretion and IL-10 expression, even when the immune system was deteriorated by a high-fat diet. Moreover, we found that HGB flour modulated the gut microbiota, which increased the concentration of SCFAs, thereby stimulating the immune system.

Diet-Related Changes of Short-Chain Fatty Acids in Blood and Feces in Obesity and Metabolic Syndrome

“…The study identification, selection, and inclusion process are summarized in Figure 2 . After eliminating duplicates, in total, 139 articles were included in this review, 112 from the first search term containing obesity [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , ...…”

“…There was a clear trend in dietary supplements, especially fibers, increasing fecal and blood SCFA levels that were decreased as a result of HFD [ 56 , 60 , 65 , 66 , 68 , 70 , 72 , 73 , 77 , 81 , 85 , 86 , 103 , 105 , 110 , 111 , 112 , 113 , 114 , 118 , 120 , 122 , 124 , 126 , 130 , 136 , 137 , 138 , 139 , 144 , 158 , 160 , 162 , 167 , 169 ].…”

“…Diet, unequivocally, has a significant influence on both fecal and blood levels of SCFAs, as well as the relative abundance of Ac, Prop, and Bu [ 36 , 37 , 39 , 41 , 42 , 43 , 44 , 45 , 47 , 52 , 54 , 56 , 57 , 60 , 63 , 65 , 66 , 68 , 70 , 72 , 73 , 76 , 77 , 80 , 81 , 83 , 85 , 86 , 89 , 93 , 95 , 98 , 99 , 100 , 103 , 105 , 110 , 111 , 112 , 113 , 114 , 118 , 120 , 122 , 124 , 125 , 126 , 129 , 130 , 131 , 134 , 136 , 137 ,…”

Barley Melanoidins: Key Dietary Compounds With Potential Health Benefits

“…In the context of barley melanoidins, it should be stated that barley dietary fiber and specifically beta-glucan, can be expected to exert beneficial prebiotic-like effects (79)(80)(81). Intriguingly, some of the initial studies on barley melanoidins have focused on their antimicrobial properties.…”

Beta-Glucan in Foods and Health Benefits

“…Many physiological functions, such as anti-obesity effects, reductions in postprandial glucose increases, and the normalization of serum cholesterol levels have been reported [ 6 , 7 ]. The recent interest in barley and oat β-glucans has been sparked by reports discussing their prebiotic action, which is dependent on molecular weight [ 8 , 9 ]. A marketing report discussing the health benefits of the β-glucans in oats and barley products has also been published [ 10 ].…”