Can gut bacteria be linked to greenspace composition in the UK?

22nd March 2022 – By Aaruthy Suthahar

Hills and trees

The bacteria in your gut is linked to the environment around you, according to latest research from TwinsUK.  

Exposure to natural environments, also known as greenspace, has been shown to have a positive influence on our health, but the mechanisms as to why are still not clear. We know from previous research that gut bacteria is linked with inflammatory illnesses; inflammatory illnesses are also more prevalent in urban areas and in individuals who have lower levels of exposure to greenspace. Therefore, gut bacteria could act as one of the links between greenspace and health.  

The team studied 2,443 participants from the TwinsUK cohort to see if there was a difference in gut bacteria in individuals living in rural and urban environments. The researchers looked at the amount of greenspace at three different distances from a participant’s home: 800 m, 3000 m, and 5000 m. The aim was to understand if there was any evidence of bacteria differing with the amount of greenspace. 

The team found there were differences in bacteria between different greenspace areas and when comparing rural versus –urban microbes. One hypothesised reason could be that people are exposed to a range of microorganisms and therefore have a stronger immune system as they are exposed to a wider range of bacteria. Levels of bacteria associated with disease were higher in individuals living in more urban environments compared to rural environments. 

A limitation of the study was the broad interpretation of “greenspace” as being any area in a non-urban environment. This meant that factors like the accessibility of land or the type and quality of habitats that were present could not be considered. Further work could design experiments to understand this further by comparing urban areas with high, accessible greenspace with urban areas of low, accessible greenspace. 

The different microrganisms residing along the human digestive tract, along with the things these microbes produce is collectively called the human gut microbiome. It has a crucial role as it interacts with the immune system, is vital for processing nutrients and protects individuals against pathogens.  

First author Ruth Bowyer said: 

“The results show that there are geographical patterns in the composition of the microbiota which does not appear to be explained by diet, BMI (Body Mass Index), and health deficit. Therefore, the results bring to light the potential importance of considering non-lifestyle factors that could affect microbiota composition.” 

What’s the link between gut bacteria and blood pressure in women?

13th October 2021- By Aaruthy Suthahar

person holding blood pressure monitor

Women with high blood pressure have lower diversity in their gut bacteria, according to our latest TwinsUK research. This means that addressing the microbiome could be one way to help treat or prevent high blood pressure.

The researchers also identified two types of key gut microbes associated with high blood pressure. The team found that bacteria from the Erysipelotrichaceae family were more abundant in people with high blood pressure, and bacteria from the Ruminiclostridium family were less abundant.

High blood pressure is a serious medical condition that significantly increases the risk for heart disease cases and deaths, and affects over 1.3 billion people around the world.

There are multiple factors that affect blood pressure, like genetic and environmental factors, including inadequate diet, obesity, lack of exercise and smoking. The gut microbiome is an important factor associated with inflammation, obesity, type-2 diabetes and stiffness of the arterial walls, all of which are linked to an increased risk of high blood pressure.

The researchers investigated the relationship between blood pressure and gut microbiome composition in 871 TwinsUK members using data collected at clinic visits and from donated stool samples. The team checked their findings by carrying out the same analysis in a further 448 women from the PREDICT study, and confirmed their results.

In their paper, the researchers highlighted that there was a lack of data gathered on the Ruminiclostridium microbe. Therefore, more research is needed to understand how the mechanisms of Ruminiclostridium can have an influence on high blood pressure. The study did however include data from a large number of people and the analysis of many microbes.

On the findings, first author Panayiotis Louca said: 

“Further research is needed to look into validating the association between the gut microbiome and blood pressure and to understand how exactly the gut microbiome affects high blood pressure.”

Louca et al. (2021) Gut microbiome diversity and composition is associated with hypertension in women. Journal of Hypertension.

Appetite linked to healthier gut bacteria and better muscle function in over-60s

15th February 2021 – by Paz García

Pizza cut into slices

Over-60s with a good appetite have more diverse and different communities of microbes in their gut than those with a poor appetite, according to a new study from King’s College London and the University of Southampton.

The study, published in the Journal of Cachexia, Sarcopenia and Muscle, is the first to identify differences in gut bacteria based on appetite between otherwise healthy older adults.

In addition, the researchers found that lower appetite was associated with reduced muscle strength and function, with gut bacteria as a potential link between the two.

Co-first author Dr Ruth Bowyer, Research Associate at TwinsUK, King’s College London, said:

“Loss of appetite is very common in older people, and this can have serious consequences including loss of muscle mass and function. Our research is the first to explore the links between appetite and gut bacteria, and how this may be related to muscle strength.”

The team used appetite questionnaire answers to identify 102 twins who had small appetites and 102 twins who had greater appetites, and compared their gut bacteria. The two groups of twins were otherwise as similar as possible in terms of age, body mass index, calorie consumption, antibiotic use and other factors that could impact gut bacteria.

The researchers found that twins with a poor appetite had less variety in their gut bacteria than twins with a good appetite. They also found that twins with healthy appetites were more likely to have microbes associated with diets high in vegetables and fibre.

The team then looked at participants’ muscle strength, based on previous muscle strength assessments completed during clinic visits, and found that twins with a lower appetite had reduced muscle strength compared to twins with a good appetite.

Co-first author Dr Natalie Cox, Clinical Research Fellow at the University of Southampton, explained:

“A lower appetite can lead to undernutrition, which in turn can lead to loss of muscle mass and so reduced muscle strength. We know from previous research however that a poor appetite is also linked to loss of muscle strength independent of overall weight loss.

“We now need studies to understand how exactly appetite, gut bacteria and muscle function affect each other and in what order. This could inform the development of treatments in the future to preserve muscle mass and function, to improve health in older age.”

Professor Tim Spector wins award for gut bacteria research

13th December 2019 – by Paz Garcia

Professor Tim Spector has been awarded the 2019 DuPont Nutrition & Biosciences Microbiome Science Award, in recognition for his leadership and pioneering work in the microbiome field.

Professor Spector is Director of TwinsUK, which he founded in 1992. Over 14,000 twins take part in TwinsUK, which is the richest collection of health research information on a cohort worldwide.

Professor Spector’s research in recent years has focused on the microbiome – the millions of bacteria that live in our gut – and its relationship with health. This has led to the world’s largest personalised nutrition study of its kind, called PREDICT.

Speaking ahead of the award ceremony in Denmark, Professor Spector paid tribute to all the twins who take part in TwinsUK:

 “We now have a better understanding of how the microbiome is intimately linked with our health. I am excited to continue working in this field as we unravel the relationships between our genetics, the food that we eat, the bacteria in our guts and our health.

“I would like to take this opportunity to say thank you to everyone involved in TwinsUK, and in particular the twins. After all, our twins were giving up stool samples for microbiome science long before it became mainstream.”

Gut bacteria need each other – and that affects our metabolism

3rd October 2019 – by Paz Garcia

Pile of lego bricks
Gut bacteria work together like Lego

Teamwork is key for the trillions of bacteria that live in our gut and this has a big impact on our metabolism, according to new research led by King’s College London, published today in Nature Communications.

The human gut is home to bacteria that help us digest our food, produce vitamins and perform many other tasks that influence our health.

Gut bacteria work together in groups to carry out different functions. The researchers, led by the Department of Twin Research & Genetic Epidemiology, found that this teamwork is much more important and more closely linked with our metabolism than individual species of bacteria.

The researchers studied the gut bacteria, blood and stool of over a thousand twins who take part in TwinsUK. This allowed the team to run the first large study on the link between gut bacterial species, their functions and the metabolism in the gut and blood of the participants.

The team found that while unrelated people share only 43% of gut bacteria species, they still share 82% of functions carried out by groups of gut bacteria. This is because different bacterial species can contribute to the same function and so different groups can work together to can carry out similar activities.

This research therefore suggests that health treatments designed to target gut bacteria – and our metabolism – should focus on groups of gut bacteria that carry out a particular function, rather than individual bacterial species.

Senior author Dr Mario Falchi explained:

“We can think of our gut bacteria like Lego bricks – the colour of the bricks doesn’t matter as much compared with how they fit together to make something. With gut bacteria, the individual species don’t matter as much as the group working together to carry out a function.”

“This is the first large study to explore the metabolic potential of the entire gut bacteria ecosystem. Our findings underline the importance of studying groups of bacteria and their functions overall, rather than focusing on specific species. These results add to the growing body of evidence that gut bacteria are intrinsically linked with human health.”

*

Visconti A, Le Roy CI, Rosa F, Rossi N, Martin TC, Mohney RP, Li W, de Rinaldis E, Bell JT, Venter JC, Nelson KE, Spector TD and Falchi M. Interplay between the human gut microbiome and host metabolism. Nature Communications (2019).

Could a glass of red wine improve your gut health?

28th August 2019 – by Paz Garcia

Drinking red wine is linked with an increase in gut bacteria diversity, according to the latest research from TwinsUK.

White wine had a similar although much smaller effect, while researchers found no association between other types of alcohol and gut bacteria variety.

In addition, twins who drank more red wine than their co-twin had more diverse gut bacteria.

Previous research suggests that a more varied community of bacteria in your gut leads to a healthier gut.

First author Dr Caroline Le Roy, from the Department of Twin Research, King’s College London, explained:

“We’ve known for some time that red wine has some health benefits, which likely come from certain molecules called polyphenols.

“Our research shows how red wine is associated with an increase in gut bacteria diversity.

“At this time however we cannot say that drinking red wine directly causes an increase in gut bacteria diversity – we need more research first.”

What did the researchers do?

The team analysed food and drink questionnaire responses and gut bacteria diversity in 916 female TwinsUK participants. The researchers also looked at a number of other factors such as weight and blood cholesterol levels.

The researchers then checked their results by carrying out a similar analysis on participants in two other studies from The Netherlands and the USA.

What did they find?

Participants who reported drinking red wine had greater levels of gut bacteria diversity than non-red wine drinkers.

The team also found that red wine consumption was linked with lower levels of obesity and “bad” cholesterol, which was in part due to associated changes in gut bacteria communities.

What does this mean?

The researchers believe the main reason for the association is due to the many polyphenols in red wine. Polyphenols are defence chemicals naturally present in many fruits and vegetables. They have beneficial properties and mainly act as a fuel for our microbes.

Professor Tim Spector, senior author on the study, explained:

“Although our results are very consistent, they are only associations and do not imply causation.

“We would need to carry out studies where humans or animals were given red wine in order to test whether red wine – or rather the polyphenols it contains – is causing an increase in gut bacteria diversity and limiting weight gain in turn.”

The researchers stressed that it is still advised to drink alcohol in moderation, although they have a recommendation for your tipple of choice:

“If you have to choose one alcoholic drink, then red wine is definitely the one to pick as it may have a positive effect on your gut bacteria and wider health.”

Can bacteria beat the belly fat?

5th July 2019 – by Paz Garcia

Man measuring his waist with a tape measure

Gut bacteria play an important role in the accumulation of fat around the midriff, a new TwinsUK study has found.

This makes gut bacteria a prime target for developing effective weight-management strategies.

Currently, over 12% of the global population is considered obese, up from 5% in 1975. In the UK, nearly 25% of the population is obese. Existing weight loss strategies however that focus on diet or exercise have not been very effective.

TwinsUK researcher Dr Caroline Le Roy explained:

“We know that fat that sits around the organs in the abdomen is harmful and can lead to heart disease, cancer and type 2 diabetes. Our research shows that gut bacteria play a key role in fat accumulation. We hope our findings will lead to more effective weight-loss strategies.”

The work was published today in Scientific Reports .

What did they do?

The gut is home to trillions of bacteria which help us to digest our food.

The team wanted to find out the role of gut bacteria in the accumulation of visceral fat – which surrounds the organs in the abdomen – and how it relates to diet.

The researchers analysed stool samples and diet questionnaires from over 1,700 TwinsUK participants.

What did they find?

They found that certain diet nutrients and gut bacteria affect the accumulation of visceral fat in different ways.

The team identified 93 groups of bacteria linked to visceral fat levels. Of these, 85 groups were linked with lower fat levels and 8 with higher fat levels.

Nutrients such as protein and cholesterol were associated with greater visceral fat. Other nutrients, including fibre, magnesium and vitamin E however were linked with lower visceral fat.

Further analysis found that the effect of fibre, magnesium and vitamin E on fat might be partly mediated by gut bacteria.

Intriguingly, the role of certain nutrients on visceral fat depended on the presence of gut bacteria, but in contrast, specific gut microbes appeared to affect fat accumulation regardless of dietary intake.

What does this mean?

Overall, differences in gut bacteria explain differences in visceral fat levels to a greater extent than nutrients alone.

The researchers stress in their paper that their findings do not prove causal relationships. Further research will need to check whether and how certain nutrients and gut bacteria actively cause accumulation of visceral fat, accounting for differences in lifestyle.

This work however brings us one step closer to understanding the importance of good diets and a healthy gut for overall health.

TwinsUK researcher Dr Jordana Bell said:

“I’d like to thank our twins who so generously give up their time and samples to make this research possible. It’s because of them that we’re beginning to unravel the relationships between food, gut bacteria and abdominal fat.”

 

How is bacteria linked to the development of rheumatoid arthritis?

6th March 2019 – by Paz Garcia

Old hands with rheumatoid arthritis clasped together

The way the immune system interacts with oral and gut bacteria may lead to the development of rheumatoid arthritis, according to researchers from King’s College London.

These findings may one day help us predict who is likely to develop rheumatoid arthritis, and prevent and treat the condition in new ways.

Rheumatoid arthritis is an autoimmune condition in which the body’s immune system mistakenly attacks the lining of the joints. The condition affects 400,000 people in the UK, and leads to painful, swollen joints and reduced mobility.

This is the first time researchers have investigated how genes and bacteria may work together to lead to rheumatoid arthritis.

The review was published today in the Journal of Autoimmunity.

Why did they do this research?

We know that rheumatoid arthritis is largely inherited through certain genes, but only about a third of identical twins – who have identical genes – have matching cases of the condition. This suggests that in many cases, genes alone are not enough to lead to rheumatoid arthritis.

Researchers have also previously found differences in the oral, lung and gut bacteria of people diagnosed with rheumatoid arthritis and those without.

In this work, the team decided to review the available evidence to see how certain genetic factors and bacteria in the body – the microbiome – may lead to rheumatoid arthritis.

The work was led by Philippa Wells, a PhD student at the Department of Twin Research and Genetic Epidemiology at King’s College London.

What did they find?

The team analysed many previous studies that looked at how genes and the microbiome were linked with rheumatoid arthritis.

Based on their analysis, the researchers suggested that certain genes to do with the immune system are the key link between genes, the microbiome and rheumatoid arthritis.

Genes largely determine how the immune system behaves. The researchers proposed that the immune system then responds inappropriately to certain bacteria in the body, which ultimately leads to the immune system mistakenly attacking the joints.

What does this mean?

This is the first time researchers have investigated how interactions between genes and bacteria may lead to rheumatoid arthritis.

In the future, we may be able to use the microbiome to predict whether and when someone might develop rheumatoid arthritis. Researchers could also develop treatment strategies for the condition that work through targeting bacteria in the body.

Researcher Philippa Wells explained:

“These methods let us investigate what is happening with the microbiome before onset of rheumatoid arthritis, as well as unpicking what influences the microbiome differences we see in people with rheumatoid arthritis.

“From that, we can gain insight in to the direction of influence, i.e whether changes in the microbiome cause rheumatoid arthritis or vice versa, and get a clearer idea of the underlying biology.

“This will be important groundwork for future clinically focused studies.”

What’s the next step?

In their paper, the researchers stress that it will be important to understand the effect of current rheumatoid arthritis medication on the microbiome.

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