Abstract

The relationship between the human oral microbiota and the aging process has emerged as a focal point in scientific investigation. Modern research shows the oral microbiome's critical role in nutrient metabolism, immune function, and disease resistance.  The human microbiota plays a critical role in regulating immune function overall. Healthy aging is influenced by multiple biological and environmental factors, such as the oral microbiota. The oral microbiome undergoes compositional changes with age which is linked to susceptibility to chronic diseases, inflammation, and diminished immune capabilities.

This pilot study explores the relationship between the microbiota composition and healthy aging in a cohort of Egyptian adults aged 50 years old and older. The research aims to identify age-related microbial shifts and examine how lifestyle factors can influence the microbial diversity and abundance. This study used saliva samples collected from 32 participants, 16S rDNA metagenomic sequencing was performed to analyze microbiota composition across different age groups. The AL-SEHA questionnaire was used to collect detailed healthy and lifestyle data from each participant. This study investigates the effects of lifestyle factors on the microbiota composition among Egyptian seniors, evaluating the potential of lifestyle modifications to foster healthy aging through microbiota modulation. It also investigates the composition of the microbiota across different age groups in the Egyptian population to explore its role in promoting healthy aging. By comparing the oral microbiota of healthy versus unhealthy seniors, based on lifestyle choices seen through a questionnaire, the research aims to identify specific microbiota patterns that correlate with aging and lifestyle. Enrolling a cohort of healthy Egyptian adults over the age of 50—excluding those under treatment for chronic conditions—the study will employ saliva samples for DNA extraction and subsequent microbiome analysis. This approach will show the relationship between microbiota diversity and aging, seeking to provide valuable insights into how microbiome-based interventions could promote healthy aging and mitigate age-related diseases within the Egyptian populace. This study used bioinformatics and statistical analyses to reveal a significant decline in microbial diversity with increasing age, and also notable shifts in specific bacterial families. The younger individuals exhibited higher levels of beneficial taxa, such as Christensenellaceae, while the older age groups showed an increased amount of Streptococcaceae and unclassified taxa, showing an indication of potential dysbiosis.

Sex-based differences and correlations with education, physical activity and self-reported health were also observed. These suggested that social and behavioral factors may contribute to microbiome variability. These findings highlight the potential for microbiota-targeted interventions to promote healthy aging and reduce age-related disease risks.

This study provides the foundational data on the oral microbiome aging patterns in the Egyptian population and underscores the importance of lifestyle-based strategies in maintaining microbial health. Future longitudinal studies can expand on the findings presented here to further explore the functional implications of the microbiome dynamics over the lifespan.

School

School of Sciences and Engineering

Department

Biotechnology Program

Degree Name

MS in Biotechnology

Graduation Date

Spring 6-10-2026

Submission Date

2-5-2026

First Advisor

Mohamed Salama

Second Advisor

Ahmed Moustafa

Committee Member 1

May Bakr

Committee Member 2

Sara Elfarrash

Committee Member 3

Fayrouz Ashour

Extent

113 p

Document Type

Master's Thesis

Institutional Review Board (IRB) Approval

Approval has been obtained for this item

Disclosure of AI Use

Thesis editing and/or reviewing

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Available for download on Saturday, February 12, 2028

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