24th August 2022 – By Aaruthy Suthahar

TwinsUK researchers have found that your B cell and T cell responses are linked to COVID-19 infection.  

The immune system is made up of lots of different cells and organs that help your body fight off infections. B cells create antibodies, which neutralise viruses, with the help of T cells. Doctors and scientists have been using antibody tests to find people with previous COVID-19 infections, particularly for research. The TwinsUK team wanted to see if T-Cell tests would be a helpful addition, or replacement, for antibody tests. This is particularly important now many people cannot access PCR (swab) tests from the NHS when they think they have COVID-19.  

The study looked at T-cell responses in participants who did or did not have a positive antibody response to the virus that causes COVID-19 (SARS-CoV-2) in participants who were symptomatic and asymptomatic during the COVID-19 pandemic. 

The team gathered data from the TwinsUK cohort who participated in the home visit study and the COVID Symptom Study cohort. They were put into groups based on if they presented symptoms associated with COVID or not, and if they had taken part in TwinsUK’s antibody testing during the first wave in the UK in Spring 2020.  

There were 32 participants who were part of the final analysis. None of the 17 participants without antibodies showed a T cell response, when their blood was tested against peptides specific to the virus. 14 out of the 15 participants who had antibodies against COVID-19 experienced a T cell response.  Therefore, the study found that there was a strong correlation between antibody responses, and T cell responses to the peptides specific to SARS-CoV-2. Also, individuals who were symptomatic, but didn’t have antibodies after the infection wave in Spring 2020, had no proof of T cell memory of COVID-19 infection either. 

The researchers also found no evidence of cellular immunity suggestive of COVID-19 infection in individuals with COVID-19-like symptoms but negative antibodies. 

First author Dr Marc Österdahl said: 

“Now that access to COVID-19 PCR testing is restricted, it is important for the public, doctors and researchers to know how we can pick-up previous COVID-19 infection. The standard is IgG Spike antibody testing, but not everyone who had symptoms that looked like COVID-19 showed antibodies. 

We wanted to know if T-Cell testing, which is more expensive and complicated, would be needed to pick up all cases. However, in people who had symptoms in recent months, antibody and T-Cell responses are strongly linked, and T-Cell testing didn’t add any benefit. This suggests that the established IgG Spike test is best, and that symptoms in antibody negative people might be from another similar illness.”  

19th July 2022 – King’s College London

Changes that occur in the body in response to an increase in belly fat have been put under the microscope as part of a study from TwinsUK, offering new insight into the cause of metabolic disease.

The study, led by King’s College London researchers Dr Jordana Bell and Colette Christiansen and published in the medical journal Genome Medicine, looked at how epigenetic marks (measures of how the human body reads DNA to affect the way genes work) in fat tissue change as belly fat accumulates.

Using samples from 538 TwinsUK participants and combining genetic, gene function, diet, and health data, the researchers examined epigenetic marks across the genome (the complete set of a person’s genetic material) and found nine genes that are highly relevant to metabolic disease risk.

Among these was a gene where the identified epigenetic changes were recognised as a potential mechanism through which diet can affect belly fat accumulation, as well as other epigenetic marks that translate genetic risk effects on metabolic health.

The findings also allowed the researchers to characterise the molecular changes that occur because of an increase in belly fat and the impact these changes have on gene function and insulin resistance.

Dr Jordana Bell, reader in Epigenomics in the School of Life Course & Population Sciences said:

“With rapidly rising rates of obesity worldwide, it is important that we understand how elevated body fat affects us at the molecular level and how this translates to metabolic disease risk,”

Metabolic diseases – the most common of which is diabetes – disrupt normal metabolism or the process of converting food to energy on a cellular level.

While previous studies in this field have explored the role of epigenetic marks in overall obesity using body mass index (BMI), the build-up of belly fat deep within the abdomen is known to be a greater risk factor for metabolic disease than BMI alone.

Dr Jordana Bell added:

“Our study brings us one step closer to this goal by identifying an epigenetic signature of excess belly fat, understanding its genetic and dietary triggers, and characterising its functional impacts and clinical consequences for insulin resistance,”

Based on the results of the study, the researchers also developed an epigenetic predictor of insulin resistance, relating their findings to the clinical consequences of elevated belly fat.

Colette Christiansen, PhD researcher in the School of Life Course & Population Sciences said:

“It is exciting to see that when we combine many different layers of biological information, we can start to unravel the mechanisms which drive the state of our biological health.”

6th April 2022 – By Aaruthy Suthahar

New research has found that black tea and semi-skimmed milk are the most consumed items by TwinsUK members. The study, which aimed to understand eating patterns, also identified the top paired food items that were most consumed by twins were tomatoes and lettuce.

Researchers found that eating breakfast was not linked to an individual having a lesser or greater BMI (Body Mass Index) status or weight, even though they had a higher calorie intake. However, the team also found that individuals with a longer eating window were strongly associated with an increased BMI and weight. Diet has lots of complexities and variability, with a major effect on human health. It is not only what someone eats that can have ramifications for their health but also how and when. TwinsUK researchers have therefore been investigating the relationship between diet and disease. One key element is to understand individuals typical eating patterns and intake of nutrients. 

An EFR (Estimated Food Record) is a type of food questionnaire that allows researchers to understand eating behaviours in individuals by collecting data about all foods consumed in participants over a period. The open-ended style of an EFR means that it can more effectively identify how complex and variable individual diets are compared to methods which are more structured, including further understanding into, for example, eating patterns and of co-occurring foods.  

The researchers included 2,184 participants from our TwinsUK cohort between 2012 and 2017 and collected 2343 EFR’s from them. Twins were asked to provide information on the size of their portions, time of their meals, details of food type they consumed, date and a yes/no answer to whether they considered it a standard day’s intake. 

The team also found that twins who skipped their breakfast were reported to have a longer eating window than individuals who had breakfast, which could partly explain the lack of consistency in weight and BMI status between the individuals who had breakfast and those who skipped it. Also, time-restricted consumption, like consuming food daily within an 8-to-10-hour window, has been shown to improve glucose tolerance, although further research needs to be carried out in humans.  

One limitation of the research is that the study looked at data mostly from women. This means it is difficult to make an accurate conclusion without further clinical studies which include participants more representative of the diversity of the population in the UK.  

100 most frequently consumed food items, and food co-occurrence network of food pairings consumed within a food record; A 100 most frequently appearing word within food item descriptions, with the font size and colour depicting the importance of the food item B 100 most frequently appearing food item description

16th February 2022 – By Guy’s and St Thomas’ NHS Foundation Trust

A new study has helped to shine light on the genetic pathways underlying obesity. The findings could help develop more personalised ways to help people maintain a healthy weight.

The work is the largest study of its kind looking at genomics and levels of metabolites – the molecules produced when the body breaks down food. It reports 74 previously unknown genomic regions that influence how people’s bodies break down food into energy.

The work was supported by the National Institute for Health Research (NIHR) Guy’s and St Thomas’ Biomedical Research Centre. The team behind the study were from the Department of Twin Research and Genetic Epidemiology, King’s College London and the NIHR BioResource.

The study involved 8,809 people who had joined the NIHR BioResource. The BioResource is a bank of individuals who consented to be contacted about research projects.

The team looked at blood samples to measure levels of 722 metabolites. These provide a snapshot of an individual’s wellbeing and the mechanisms that control key physiological processes. Metabolite levels can be affected by nutrition, drugs and the gut microbiome. However, the way the body breaks down food is known to be strongly driven by a person’s genetics.

From analysing these alongside whole genome sequencing, the team identified 202 unique genomic regions whose variations are associated with the levels of 478 different metabolites. These included 74 genomic regions not associated with any metabolites in previous works. They confirmed the findings in an independent cohort of 1,768 people.

Senior author Dr Cristina Menni from the Department of Twin Research and Genetic Epidemiology, King’s College London said:

“These results could have many practical implications. Human metabolism underlies a lot of different areas of human health and disease. Our findings could help understand certain diseases.”

“Some of the metabolites we looked at are linked to BMI and could give us an insight into obesity in some individuals. It is very early research, but in the future these findings could help to develop approaches to maintaining a healthy weight which take into account a person’s genetic profile.”

Dr Massimo Mangino, senior bio-informatician from the NHIR Guy’s and St Thomas’ Biomedical Research Centre and lead author of the study, said:

“Obesity is one of the most common conditions, and yet there’s still so much we need to understand about its biological mechanisms. Our latest findings may help to unravel some of them. Genetic studies hold real promise in helping us find new treatments for obesity. By teasing out the complex relationships between different genes, we have a huge opportunity to turn the tide against this condition.”

Dr Pirro Hysi from the Department of Twin Research and Genetic Epidemiology added:

“This study is the largest scale study of its kind of metabolite levels to date and its results enhance our knowledge of genetic mechanisms controlling human metabolism. The NIHR BioResource is a unique UK resource made possible by the amazing collaboration between doctors and researchers in the NHS. It’s because of collaborations like this that large scale studies like ours are possible.”

The World Health Organisation estimates that over four million people die each year as a result of being overweight or obese.