Intense physiological stress can change the composition of our gut microbiota
Imbalances in the gut are linked to diabetes, obesity and some cancers
Findings raise concerns for endurance athletes and military personnel
The study is the first to investigate gut bateria during military training
Long periods of intense exercise can change the composition of your gut bacteria, a new study has found.
The research looked at soldiers taking part in an intensive training programme and found that pro-longed exercise caused the protective barrier in their guts to become permeable.
In other words, the prolonged exertion triggered ‘leaky guy syndrome’ – a condition that could let harmful substances leak into the bloodstream.
With our gut health and overall health believed to be strongly linked, intense physiological stress could therefore raise the risks of many types of illnesses.
The new research is the first to investigate the response of gut microbiome – the term for the population of microbes in the intestine – during military training.
It provides a stark warning for endurance athletes and military personnel.
The study suggests physical stress can increase intestinal permeability, which can raise the risk of inflammation and illness
Most of us are aware that the bacteria in our gut play an important role in digestion. Furthermore, they are known to aid the production of certain vitamins – such as vitamins B and K – and play a key role in immune function.
But increasingly, research is emerging showing how poor gut health is linked to conditions ranging from irritable bowel syndrome, diabetes, high blood pressure, depression, obesity, childhood asthma, to colitis and colon cancer.
The study is the first to investigate the response of gut microbiome – the term for the population of microbes in the intestine – during military training.
It looked at a group of 73 Norwegian Army soldiers taking part in a military-style cross country skiing training programme.
Recent research suggests our gut bacteria holds the key to improving our health – and may be the key to tackling obesity
The group skied 31 miles (51 km) while carrying 99-pound (45 kg) packs, across four days.
Before and after the training exercise, researchers collected blood and stool samples from the soldiers.
It was found that the microbiome and metabolites – the substance formed in or necessary for metabolism – in the soldiers’ blood and stool altered ‘significantly’ by the end of the aggressive training period.
Furthermore, sucralose excretion in their urine samples rose considerably, indicating an increase in intestinal permeability (IP).
Scientists know that healthy intestines have a semi-permeable barrier, which acts as a defense to keep bacteria and other harmful substances out, while allowing healthy nutrients into the bloodstream.
It is thought that physical stress can increase IP, increasing the risk of inflammation, illness and symptoms such as diarrhoea.
The findings may spell bad news for endurance athletes and military personnel
The researchers wrote: ‘Intestinal microbiota appear to be one influencing factor in the gut’s response to physical stress.
‘Our findings suggest that the intestinal microbiota may be one mediator of IP responses to severe physiologic stress, and that targeting the microbiota before stress exposure may be one strategy for maintaining IP.’
The study was published ahead of print in the American Journal of Physiology – Gastrointestinal and Liver Physiology.
MICROBIOME: DOES IT CONTROL EVERYTHING?
Researchers now estimate that a typical human body is made up of about 30 trillion human cells and 39 trillion bacteria.
These are key in harvesting energy from our food, regulating our immune function, and keeping the lining of our gut healthy.
Interest in, and knowledge about, the microbiota has recently exploded as we now recognise just how essential they are to our health.
A healthy, balanced microbiome helps us break down foods, protects us from infection, trains our immune system and manufactures vitamins, such as K and B12.
It also sends signals to our brain that can affect mood, anxiety and appetite.
Imbalances in the gut are increasingly being linked to a range of conditions. Last year, scientists at California Institute of Technology found the first ever link between the gut and Parkinson’s symptoms.
The composition of our gut microbiota is partly determined by our genes but can also be influenced by lifestyle factors such as our diet, alcohol intake and exercise, as well as medications.
Source: Daily Mail