In July 2019 researchers from Spain published the results of their study to assess age-associated changes in gut microbiota. The researchers stated that the faecal microbiota plays an important role in human health and it appears that alterations in the microbiota-host interaction are involved in the aging process. However, the specific changes in the microbiota which take place during the transition from adulthood to old age and how they are associated with the age-related decline in the immune system are not yet understood. A total of 153 adults from four age groups (under 50, 50-65, 66-80, and over 80 years) were involved in the study. Faecal samples were taken from each individual and the levels of different bacterial groups and the amount of short chain fatty acids were assessed. Dietary information was collected via a food frequency questionnaire. Results showed that the levels of Bifidobacterium, Faecalibacterium, Bacteroides group and Clostridium cluster XIVa were seen to gradually decrease in the groups up to and including the 66-80 years group. However, it was noted that the levels of some of these microorganisms recovered in those in the over 80 years group. It was also noted that the individuals in the over 80 years group had significantly higher counts of Akkermansia and Lactobacillus group than those in the first three age groups. In addition, aging appeared to be associated with a progressively and statistically significant reduction in the faecal concentrations of short chain fatty acids. Dietary intakes also showed some significant differences among the groups for some macro- and micronutrients. Moreover, some of the microorganisms appeared to be associated with age and macronutrients.
Salazar N et al. Age-Associated Changes in Gut Microbiota and Dietary Components Related with the Immune System in Adulthood and Old Age: A Cross-Sectional Study. Nutrients. 2019 Jul 31;11(8). pii: E1765.