Age-related Muscle Mass Decline And Intestinal Microbiota Dysbiosis

Aim:to explore the intestinal microbiota composition in elderly with low muscle mass and the correlation of low muscle mass and intestinal microbiota dysbiosisMethod:This study collected data from medical record of Chinese elderly above 60 year who were admitted within 1st June 2013 to 31st December 2015, had both DEXA measurement and fecal microbiota examination in our department. This study divided into 2 groups low skeletal muscle mass index and no low muscle mass group. We excluded patient who had acute diseases or coma or in terminal state regardless to any causes of the diseases; one month prior to the fecal sample collection had administered antibiotic, chemotherapy, radiotherapy, immunosuppressant, probiotics, prebiotics or others treatments that impact intestinal microbiota composition. Sarcopenia or low SMI level measured by DEXA and based on AWGS recommendation:SMI< 7 kg/m2 for male and < 5.4 kg/m2 for female. DEXA measurement and fecal sample collection duration should be performed within three months. Intestinal microbiota composition was analyzed by qPCR. Haemoglobin and albumin level represented nutrition parameters, and CRP level as inflammation marker.Results:Fifty-nine elderly were enrolled in the study that forty-eight elderly had low muscle mass. Both groups were equivalent in the distribution of age (median age 84.2 years), BMI (mean BMI score=23.9), haemoglobin level (mean 123 g/L), albumin level (mean 39.6mg/L) and CRP level (mean 2.3 mg/L). Between two groups, Enterobacteriaceae was marked difference with seven-times higher in muscle mass decline elderly (p=0.03) and was negatively correlated with SMI level (r=-0.31). In addition to muscle mass decline group, haemoglobin level has negative correlation to pathogenic bacteria. Conversely, in non-muscle mass decline elderly, pathogenic bacteria Enterobacteriaceae showed negative correlation with anti-inflammatory bacteria F.prausnitzii (r=-0.7) and haemoglobin had positive correlation with anti-inflammatory bacteria F.praustnizii and Lactobacillus.Conclusion:Age-related muscle mass decline in this study showed similar intestinal microbiota dysbiosis with previous studies, specifically with increased pathogenic bacteria Enterobacteriaceae and has negative correlation with SMI score. New evidence of present study proposed a correlation among muscle mass decline, haemoglobin level and intestinal microbiota dysbiosis. Larger samples and future longitudinal studies are encouraged to determine the causal relationship between sarcopenia and microbiota dysbiosis.