Association of Lifelong Intake of Barley Diet with Healthy Aging: Changes in Physical and Cognitive Functions and Intestinal Microbiome in Senescence-Accelerated Mouse-Prone 8 (SAMP8).

Chikako Shimizu,Naoyuki Kobayashi,Toshitaka Nabeshima,Youichi Tsuchiya,Makoto Kihara,Yoshihisa Wakita

doi:10.3390/nu11081770

Chikako Shimizu, Naoyuki Kobayashi + Show 4 more

Open Access

https://doi.org/10.3390/nu11081770

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Abstract

Barley intake reportedly reduces the risk of cardiovascular disease, but effects on the systemic phenotypes during healthy aging have not yet been examined. Therefore, we examined the effects of barley on the lifespan; behavioral phenotypes, such as locomotor activity, and cognitive functions, and intestinal microbiome in the senescence-accelerated mouse-prone 8 (SAMP8) mouse. We prepared two mild high-fat diets by adding lard, in which the starch components of AIN-93G were replaced by rice or barley “Motchiriboshi.” SAMP8 (four weeks old, male) mice were fed AIN-93G until eight weeks old, and then rice (rice group) or barley diet (rice: barley = 1:4, barley group) until death. Changes in aging-related phenotypes, object and spatial recognition, locomotor and balancing activities, and the intestinal microbiome were recorded. Moreover, plasma cholesterol levels were analyzed at 16 weeks old. Barley intake prolonged the lifespan by approximately four weeks, delayed locomotor atrophy, and reduced balancing ability and spatial recognition. Barley intake significantly increased the medium and small particle sizes of high-density lipoprotein (HDL) cholesterol, which is associated with a reduced risk of total stroke. The Bacteroidetes to Firmicutes ratio in the barley group was significantly higher than that in the rice group during aging. Thus, lifelong barley intake may have positive effects on healthy aging.

Highlights

Barley (Hordeum vulgare) is widely consumed as whole grain or pearled barley in a variety of healthy foods, such as bread, cereal, rice, and pasta
For our aging evaluation, we have reported the healthy aging effects of moderate drinking [15] and lemon polyphenols [16] on the lifespan and age-related changes in phenotypes during the lifespan in senescence-accelerated mouse prone 8 or 1 strains established by Takeda et al [17]
Three mice in the rice group and one mouse in the barley group suffered severe diabetes indicated by excessive urination and a strong positive reaction in urine glucose test, which could lead to greater food intake

Summary

Introduction

Barley (Hordeum vulgare) is widely consumed as whole grain or pearled barley in a variety of healthy foods, such as bread, cereal, rice, and pasta. It is rich in dietary fiber, and the main component is the mixed linkage of (1, 3) (1, 4)-β-D-glucan similar to oats. The soluble beta-glucan content of barley ranges from 2% to 10% per grain weight depending on the variety, with a generally higher content in waxy barley than in normal varieties [1]. Pearled barley contains much more water-soluble β-glucan than its whole grain, as the β-glucan content in the barley endosperm is higher than that in the bran [2].

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