Could balance microbiota be the secret to healthy ageing?

What changes are observed as the intestinal microbiota ages?

The intestine is one of the organs most seriously affected by ageing.

Various aspects of ageing affect the intestinal microbiome:

  • Decreased appetite;
  • Decreased production of gastric acid;
  • Reduced production of digestive enzymes;
  • Reduced intestinal barrier function;
  • Increased intake of medication, particularly antibiotics.

These phenomena influence the state of the microbiota and are associated with increased fragility, increased inflammation and a higher potential for intestinal disorders (constipation, bloating, etc.).

Protective bacteria such as Bifidobacteria generally decline in the intestine with age. Bifidobacteria account for just 5% of the microbiota of the elderly (compared with 90% in newborn babies).

Yet these lactic acid bacteria are beneficial for the balance of the intestinal microbiota.

As a result, potentially harmful microorganisms such as Escherichia, Legionella and Salmonella can proliferate. They can cause gastrointestinal problems (diarrhoea, nausea, vomiting, etc.), often accompanied by fever.

In addition, the quantity of the commensal intestinal bacterium Akkermansia muciniphila decreases as we approach 80 years of age. Yet it is essential for maintaining good health. It supports immunity, the integrity of the intestinal barrier and produces short-chain fatty acids (SCFAs).

 

What are the consequences of these changes?

Broadly speaking, the main features of ageing are immunosenescence, defined as the decline in the innate and adaptive immune system, and an imbalance in the pro/anti-inflammatory balance, leading to chronic low-grade inflammation known as inflammaging.

Immunosenescence, inflammaging and changes in the intestinal microbiota promote the body’s fragility and are associated with certain pathological conditions:

  • Cognitive decline,
  • Neurodegenerative diseases (Alzheimer’s, Parkinson’s),
  • Type 2 diabetes,
  • Metabolic disorders,
  • Cardiovascular diseases,
  • cancer, etc.

 

Are other microbiota also affected by ageing?

Vaginal microbiota

At the menopause, with the drop in female hormones, the composition of the vaginal microbiota, mainly dominated by Lactobacilli (around 90%), undergoes major changes. A decrease in Lactobacilli is observed (10 to 100 times less), leading to a change in vaginal pH. The vaginal microbiota changes from a protective acidity to a basicity that encourages colonisation by pathogens and increases susceptibility to infections (such as bacterial vaginosis, vulvovaginal candidiasis, etc.).

 

Urinary microbiota

In adult women, the urinary commensal flora is also predominantly composed of Lactobacilli (50%). To a lesser extent, it is also home to Bifidobacteria (12%) and Escherichia coli (2%). Escherichia coli can become pathogenic if it proliferates to the detriment of beneficial bacteria. Scientists have observed a decrease in Lactobacilli with age and, as a result, a greater frequency of urinary tract problems such as:

  • Incontinence;
  • An overactive bladder;
  • Urinary tract infections (such as cystitis).

Men may also experience changes to their urinary microbiota during their lives.

Dysbiosis of the microbiota in urine and prostate secretions could lead to benign prostatic hyperplasia (BPH). This is an increase in the size of the gland caused by a proliferation of prostate cells. This condition is non-cancerous. However, this dysbiosis could also promote its development or even its progression to cancer.

 

Respiratory microbiota

Similarly, the respiratory microbiota changes with age, again in the direction of reduced diversity, making the elderly more prone to respiratory infections such as influenza or the common cold. One of the main reasons for this is immunosenescence. This leads to long-term fragility of the respiratory and immune systems.

 

Skin microbiota

Finally, as we age, the diversity of the skin’s microbiota decreases as the pH of the skin increases. This change in the skin leads to:

  • Healing problems;
  • Skin fragility;
  • Skin dryness.

 

What can be done to combat ageing of the microbiota and its consequences?

Studies have shown that following a traditional Mediterranean diet over the long term causes a healthy and stable change in the intestinal microbiota, increasing the number of beneficial microorganisms in older people.

Consumption of probiotics and prebiotics can also have a positive effect on intestinal ecology, which :

  • Helps maintain a healthy intestinal barrier,
  • Improves immune responses,
  • Increases muciniphila levels,
  • Reduces chronic inflammation (inflammaging), which is common in the elderly.

Supplementation with Lactobacilli and Bifidobacteria may be recommended to rebalance and maintain microbial ecosystems.

Taking care of all your microbiota can be essential for healthy ageing. Prebiotic, probiotic and postbiotic solutions exist to support you and improve your well-being.

 

References

Image : Freepik