• Home
  • Health & Wellness
  • Disclaimer
    • Terms of Use
    • Privacy Policy
    • DMCA Notice
  • Home
  • Health & Wellness
  • Disclaimer
    • Terms of Use
    • Privacy Policy
    • DMCA Notice
24/7 Health News
No Result
View All Result
Home Article

Gut bacteria and the immune system: How aging changes the microbiome and can lead to ‘inflammaging’

April 3, 2024
in Article
Gut bacteria and the immune system: How aging changes the microbiome and can lead to ‘inflammaging’
Changes to the composition and diversity of the microorganisms in the gut may explain differences in immune system aging. (Shutterstock)

The human immune system changes with age. Immune responses start to become less robust as people get older, which makes them more vulnerable to certain infections and diseases. However, immune system aging looks different from person to person. Research has shown that changes to the composition and diversity of the microorganisms in the gut may explain these differences in immune system aging.

The gut microbiome — the population of microorganisms that lives in the gastrointestinal tract — helps the body maintain a stable internal environment when it is faced with external changes. This is known as homeostasis. The gut microbiome supports homeostasis in different ways, such as through helping to keep the immune system alert, and digesting dietary fibre into short-chain fatty acids to strengthen the intestinal wall.

The gut microbiome also helps us to regulate our inflammatory reactions. Inflammation helps the body fight microorganisms that cause disease, and helps repair damaged tissues. However, as the composition of our gut microbiome changes with age, a low level of inflammation can become constant throughout the body. This is called inflammaging.

When inflammaging develops in the gut, it leads to a decrease in immune responses, which puts people at a higher risk for infection and disease.

Let’s take a closer look at the gut microbiome and how it changes with age.

Table of Contents

  • Gut microbiome imbalances in older adults
  • How inflammaging works
  • Maintaining a healthy balance of gut microbiota

Gut microbiome imbalances in older adults

Our gastrointestinal tract can be compared to a densely populated city inhabited by a variety of different bacteria, fungi, archaea and viruses collectively called the gut microbiota. In fact, compared to other parts of the body, the gut microbiome has the largest number of bacteria. In a healthy gut microbiome, there are four dominant families (or phyla) of microorganisms, including Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria.

Firmicutes and Bacteroidetes make up around 80 to 90 per cent of the gut microbiota in the digestive tract. Firmicutes help with the production of short-chain fatty acids to support intestinal health and the secretion of mucus to improve intestinal wall defence. Bacteroidetes metabolize complex carbohydrates into vitamins and nutrients, and help promote glycogen storage to improve glucose metabolism.

The gut microbiome and immune system work closely together. The microorganisms in the gut send out signals that are detected by immune sensors. This allows the immune system to regulate the beneficial bacteria in the gut, helping maintain immune homeostasis. Through this interaction, the adaptive immune system also receives stimuli from harmful substances called antigens, which trigger an immune reaction.

However, as people age, the composition and balance of microorganisms in the gut changes. This gives rise to microbial dysbiosis, which means there is a reduction in the number of beneficial bacteria in the gut, alongside a higher number and pro-inflammatory organisms and bacteria that can cause disease. In addition to this, research has also shown that the general diversity of bacteria in our gut also decreases with age.

Over time, the shortage of beneficial bacteria such as Firmicutes in older adults starts to compromise the integrity of their intestinal barrier, causing it to become leaky. This is because the Firmicutes family plays a very important role in keeping the intestinal wall healthy and strong by producing a short-chain fatty acid called butyrate. Short-chain fatty acids such as butyrate help provide nutrients to strengthen the intestinal wall, inform immune responses and lower inflammation.

When intact, the intestinal barrier works to prevent harmful bacteria from passing through the intestinal wall, entering the circulatory system and reaching important organs. However, when there are not enough gut bacteria to produce the short-chain fatty acids that are needed for the intestinal wall to function, bacteria are able to enter the bloodstream. This contributes to the formation of intestinal inflammaging, which refers to a low level of inflammation that becomes steady throughout the body with age.

How inflammaging works

Inflammaging creates an environment that is prone to inflammation, which is caused and maintained by several factors. These can include microorganism imbalances in the intestines (microbial dysbiosis), psychological stress, physical inactivity, poor nutrition and chronic infections.

When the body is exposed to these factors on a regular basis, cellular senescence occurs. Cellular senescence is a state in which cell growth is permanently arrested, which means that cells are no longer able to self-renew. Eventually, this leads to a decrease in immune responses, which are important to prevent foreign substances and pathogens from entering the body.

Maintaining a healthy balance of gut microbiota

There is a common saying that claims “you are what you eat.” Indeed, nutrition and diet play an important role in regulating the number of different microorganisms that live in the gut. This means that diet may also play a key role in the immune function of older adults.

The Mediterranean diet, known for its lower intake of refined carbohydrates, saturated fats, dairy products and red meat, has been shown to have a positive effect on the balance of microorganisms in the gut and the strength of the intestinal barrier. The Mediterranean diet has also been linked to a lower risk of Type 2 diabetes in older adults, allowing these individuals to live a longer and healthier life.

The use of probiotics and prebiotics can also help fight age-related inflammation. Probiotics, such as Lactobacilli and Bifidobacteria, are live microorganisms that can be consumed to support overall health. More specifically, probiotics help improve the function of the intestinal barrier and regulate immune responses by modifying the composition of the gut microbiome. However, there is still some debate around whether the acidic conditions in the stomach allow probiotics to survive long enough to be able to move into the intestine.

It is clear that the immune system has an intricate relationship with the gut microbiome. A healthy and well-balanced gut microbiome will strengthen the intestinal barrier, which helps to reduce inflammation throughout the body and support the immune system.

To achieve this, it is important to maintain a healthy and well-balanced lifestyle as we grow older. This can include lower intake of dairy products and red meats, and harnessing the benefits of probiotics and prebiotics.

This article was co-authored by Flore Van Leemput. She is a Bachelor of Science student in health sciences, with a pre-clinical specialization and a minor in gerontology, at the University of Waterloo.

The Conversation

Narveen Jandu does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ShareTweetSharePin
Next Post
Could sharing a bedroom with your pets be keeping you from getting a good night’s sleep?

Could sharing a bedroom with your pets be keeping you from getting a good night’s sleep?

Most Read

What causes stuttering? A speech pathology researcher explains the science and the misconceptions around this speech disorder

What causes stuttering? A speech pathology researcher explains the science and the misconceptions around this speech disorder

December 15, 2022
morning back pain

Morning Again Ache Trigger Is Not the Mattress

October 11, 2021

4 steps to building a healthier relationship with your phone

January 28, 2025

Why Circadian Rhythms Matter for Your Health

July 30, 2024
lower back pain relief exercises

5 decrease again ache aid workouts

October 11, 2021
Nasal vaccines promise to stop the COVID-19 virus before it gets to the lungs – an immunologist explains how they work

Nasal vaccines promise to stop the COVID-19 virus before it gets to the lungs – an immunologist explains how they work

December 14, 2022
bleeding in gum

When The Bleeding in gum Is Severe ?

October 11, 2021
Good Night Sleep

6 Causes of Good Evening Sleep

October 11, 2021
3 years after legalization, we have shockingly little information about how it changed cannabis use and health harms

3 years after legalization, we have shockingly little information about how it changed cannabis use and health harms

October 15, 2021
Kick up your heels – ballroom dancing offers benefits to the aging brain and could help stave off dementia

Kick up your heels – ballroom dancing offers benefits to the aging brain and could help stave off dementia

January 3, 2023
Biden is getting prostate cancer treatment, but that’s not the best choice for all men − a cancer researcher describes how she helped her father decide

Biden is getting prostate cancer treatment, but that’s not the best choice for all men − a cancer researcher describes how she helped her father decide

May 20, 2025
Ten small changes you can make today to prevent weight gain

Ten small changes you can make today to prevent weight gain

October 12, 2021

COVID vaccines: how one can pace up rollout in poorer international locations

October 5, 2021

Maximize Your Performance – Sync with Your Circadian Rhythms

August 9, 2024
Five ways to avoid pain and injury when starting a new exercise regime

Five ways to avoid pain and injury when starting a new exercise regime

December 30, 2022

This Simple Hygiene Habit Could Cut Your Risk of Stroke, New Research Reveals

February 1, 2025

Multiple sclerosis: the link with earlier infection just got stronger – new study

October 12, 2021
Support and collaboration with health-care providers can help people make health decisions

Support and collaboration with health-care providers can help people make health decisions

December 16, 2021
Greece to make COVID vaccines mandatory for over-60s, but do vaccine mandates work?

Greece to make COVID vaccines mandatory for over-60s, but do vaccine mandates work?

December 1, 2021
woman covered with white blanket

Exploring the Impact of Sleep Patterns on Mental Health

August 4, 2024
Nurses’ attitudes toward COVID-19 vaccination for their children are highly influenced by partisanship, a new study finds

Nurses’ attitudes toward COVID-19 vaccination for their children are highly influenced by partisanship, a new study finds

December 2, 2022
News of war can impact your mental health — here’s how to cope

Binge-eating disorder is more common than many realise, yet it’s rarely discussed – here’s what you need to know

December 2, 2022
FDA limits access to COVID-19 vaccine to older adults and other high-risk groups – a public health expert explains the new rules

FDA limits access to COVID-19 vaccine to older adults and other high-risk groups – a public health expert explains the new rules

May 21, 2025
As viral infections skyrocket, masks are still a tried-and-true way to help keep yourself and others safe

As viral infections skyrocket, masks are still a tried-and-true way to help keep yourself and others safe

December 14, 2022
GPs don’t give useful weight-loss advice – new study

GPs don’t give useful weight-loss advice – new study

December 16, 2022
Four ways to avoid gaining weight over the festive period – but also why you shouldn’t fret about it too much

Four ways to avoid gaining weight over the festive period – but also why you shouldn’t fret about it too much

December 22, 2022
Nutrition advice is rife with misinformation − a medical education specialist explains how to tell valid health information from pseudoscience

Nutrition advice is rife with misinformation − a medical education specialist explains how to tell valid health information from pseudoscience

January 28, 2025
How hot is too hot for the human body? Our lab found heat + humidity gets dangerous faster than many people realize

How hot is too hot for the human body? Our lab found heat + humidity gets dangerous faster than many people realize

July 6, 2022
How regulatory agencies, not the courts, are imposing COVID-19 vaccine mandates

How regulatory agencies, not the courts, are imposing COVID-19 vaccine mandates

October 24, 2021
The promise of repairing bones and tendons with human-made materials

The promise of repairing bones and tendons with human-made materials

January 4, 2022
  • Home
  • Health & Wellness
  • Disclaimer

© 2020 DAILY HEALTH NEWS

  • Home
  • Health & Wellness
  • Disclaimer
    • Terms of Use
    • Privacy Policy
    • DMCA Notice

© 2020 DAILY HEALTH NEWS