Centenarian-Sourced Lactobacillus casei Combined with Dietary Fiber Complex Ameliorates Brain and Gut Function in Aged Mice.

Minhong Ren,Zhen Fu,He Li,Quanyang Li

doi:10.3390/nu14020324

Abstract

Dietary intervention could modulate age-related neurological disorders via the gut–brain axis. The potential roles of a probiotic and the dietary fiber complex (DFC) on brain and gut function in aged mice were investigated in this study. Lactobacillus casei LTL1361 and DFC were orally administrated for 12 weeks, and the learning and memory ability, as well as the oxidative parameters, inflammatory markers, gut barrier function and microbial metabolite short-chain fatty acids (SCFAs), were investigated. LTL1361 and DFC supplementation ameliorated cognitive ability, attenuated oxidative stress in brain and inflammation in serum and colon, ameliorated gut barrier function, and increased the SCFA concentrations and gene expression of SCFA receptors. The protective effect was more significantly enhanced in aged mice treated with the combination of LTL1361 and DFC than treated with LTL1361 or DFC alone. These results could be associated with the protected morphology of pyramidal nerve cells in hippocampus of mice brain and the downregulation of apoptosis marker caspase-3 in brain and upregulation of tight junction proteins in small intestine and colon. The results indicated that Lactobacillus casei LTL1361 and DFC alleviated age-related cognitive impairment, as well as protected brain and gut function. Lactobacillus casei LTL1361 and DFC might be used as novel and promising antiaging agents in human.

Highlights

Rodriguez-NogalesThe proportion of the population aged over 60 years was predicted to exceed 30%in China by 2050, as China is facing the severe challenge of population aging [1]
Lactobacillus casei LTL1361 combined with dietary fiber complex (DFC) significantly prolonged the swim time and distance in the platform quadrant in the spatial probe test (Figure 1C,D)
There was no significant difference in the mRNA expression of GPR41 and GPR43 in colon between the control group and treatment groups. These findings suggest that Lactobacillus casei LTL1361 and the DFC might have a synergistic effect on upregulating the expression of short-chain fatty acids (SCFAs) receptors in the small intestine

Summary

Introduction

The proportion of the population aged over 60 years was predicted to exceed 30%. In China by 2050, as China is facing the severe challenge of population aging [1]. Aging has been a known major risk factor in many chronic human diseases, such as Alzheimer’s, diabetes, cardiovascular disease, and cancer [2–4]. Previous studies have reported that the accumulation of free radicals and reactive oxygen species in organism cells cause oxidative stress, resulting in the destruction of tissue and cell structure, dysfunction of the organism, and acceleration of aging [5–8]. There is a bidirectional connection between aging and inflammation [9,10]. Harmful microorganisms and toxins generated by metabolism in the intestinal tract reach the circulatory system of the host, causing chronic inflammation and accelerating aging [12]

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Conclusion