Microbiota, ageing and basic changes

When you age, your microbiota ages with you. Most significant changes in adult microbiota are caused by diet and medicine. After age of 65 hormone regulation changes, impacting energy levels, changing the physical activity, the smell, taste, feeling of fullness and satiety. Sometimes this can lead to a nutritionally imbalanced diet. Elderly people microbiota contains Proteobacteria (a group of bacteria with many potential pathogens) and because of this group, they are at higher risk of infections. Intestinal microbiota of older people is less diverse and has a compromised stability, making them vulnerable to infections and chronic diseases. Taking medicines can disturb the microbiota, but eating healthy and doing exercise helps to age graciously. Microbiota seems to play a role in healthy ageing, keeping immune system in check and protecting against pathogens.

At the moment 13 % of the world population is over 60 years old and this will only increase in the future. There are age-related diseases (cancer, diabetes type 2, atherosclerosis, insulin resistance etc.) and surprisingly many of them are associated with an alteration to the microbiota.

Is the microbiota composition changing with age? Let's first define ageing as a continuous and progressive decrease of physiologic function across all organ systems. All these changes sometimes lead to different diseases. One of the most important effect in our case is the reduction of the gut motility as you get older. The changes in the microbiota follow the changes in the diet, physical activity patterns and other gut related physiological changes. As you get old, there is a decrease in the core gut microbiota (and we already know that the gut microbiota is a very important modulator of the immune system, being involved in ageing related low-grade inflammatory responses). Being an adult, the core microbiota is dominated by Ruminococcaceae, Lachnospiraceae and Bacteriodaceae. The older we get, the smaller the core microbiota becomes. For example semi-super centenarians (105-109 years old) microbiota will have a reduction of the core and an increase of the subdominant fraction (the sub-dominant fraction has many health-associated groups like Bifidobacteria, Akkermansia and Cristensenellaceae).

But overall there are not many researches related to the gut relation with healthy ageing, and the existent ones will consider the elderly age 60, 65 or even 70, so they are not using the same subcategories of people age segments.

Next post will be about centenarians and microbiota.
See you soon!
G.