Day: February 21, 2023

Categories : Diet and NutritionTags :

Changing the Structure of Fibre to be Even Better for the Gut

On By ModernMedia
Gut microbiome. Credit: Darryl Leja, NIH

Changing the structure of a dietary fibre commonly found in a range of food products has been found to promote healthy gut bacteria and reduce gas formation, a finding that could help people with intolerances to fibre and irritable bowel conditions. The findings have been published in Food Hydrocolloids.

A team of scientists from the University of Nottingham, Quadram Institute Biosciences and the University of East Anglia examined psyllium, a type of natural dietary fibre that is used in a range of products including cereals and yoghurts. They showed that the physical state of the fibre has a major impact on gas production which often is linked to bowel discomfort.

The team performed in vitro fermentation experiments seeded with human stool. They conducted analysis of fermentation products and evaluated the impact of different structures on the broad categories of microorganisms.

Dr Gleb Yakubov, Associate Professor in Food Physics at the University of Nottingham was one of the lead researchers on the study, he explains: “Although fibre is an important part of any diet, for many people it can cause bowel discomfort and for people with IBS or IBD fibre can be a trigger. This is because some foods cause bacterial interactions in the gut that create gas that can lead to pain or discomfort. Our study shows that the physical state of the fibre has a major impact on gas production by creating beneficial compounds that promote the creation of the good bacteria in the gut.”

Psyllium fibre comes from the seeds of Plantago ovata plants, known by many common names such as blond plantain. These seeds produce a jelly-like material called mucilage, which comes in a variety of shapes and forms and these feature long-chain sugars, called polysaccharides. It is these polysaccharides that lead to the production of beneficial short-chain fatty acids that contribute positively to gut health and systemic metabolism. This study shows that different physical states of fibre impact the way dietary fibre breaks down and that microbes ‘colonise fibre’ during fermentation.

Professor Yakubov continues: “These findings show that there are new opportunities for designing targeted structures using psyllium, either through seed processing or selective breeding, to achieve new fibre materials with clear clinical benefit above that of unrefined psyllium powders aiding in the treatment of gastrointestinal discomfort.”

Research is already underway to create and test psyllium-mimicking materials as medical nutrition which could provide a source of fibre for people with some bowel conditions.

Source: University of Nottingham

Categories : Cardiovascular Disease GenderTags :

Female and Male Hearts may Respond Differently to Noradrenaline

On By ModernMedia
Source: Wikimedia CC0

A new study published in Science Advances shows that female and male hearts respond differently to the stress hormone noradrenaline. The study in mice may have implications for human heart disorders like arrhythmias and heart failure and how different sexes respond to various drugs.

Using fluorescence imaging, the researchers were able to see in real time and in vivo how a mouse heart responds to hormones and neurotransmitters, including noradrenaline.

The results reveal that male and female mouse hearts respond uniformly at first after exposure to noradrenaline. However, some areas of the female heart return to normal more quickly than the male heart, producing differences in the heart’s electrical activity.

“The differences in electrical activity that we observed are called repolarisation in the female hearts. Repolarisation refers to how the heart resets between each heartbeat and is closely linked to some types of arrhythmias,” said Jessica L. Caldwell, first author of the study.

“We know that there are sex differences in the risk for certain types of arrhythmias. The study reveals a new factor that may contribute to different arrhythmia susceptibility between men and women,” Caldwell said.

Methods

The novel imaging system uses a genetically modified ‘CAMPER’ mouse to emit light during a very specific chemical reaction in the heart: cAMP binding.

The cAMP molecule (an abbreviation of cyclic adenosine 3′,5;-monophosphate) is an intermediate messenger that turns signals from hormones and neurotransmitters, including noradrenaline, into action from heart cells.

The light signals from the CAMPER mouse are transmitted by a biosensor that uses a fluorescence signal that can be picked up at high speed and high resolution by a new imaging system specially designed for hearts. This allows the researchers to record the heart’s reaction to noradrenaline in real time, along with changes in electrical activity.

This new imaging approach revealed the differences in the breakdown of cAMP in female and male mice and the associated differences in electrical activity.

Including female mice leads to discoveries

The researchers had not planned to study sex-based responses, according to Crystal M. Ripplinger, senior author of the study. But the researchers started seeing a pattern of different reactions, which led them to realise the differences were sex-based.

When Ripplinger started her lab at the UC Davis School of Medicine over a decade ago, she exclusively used male animals. That was the norm for most research at the time. But several years ago, she began including male and female animals in her studies.

“Sometimes the data between the two sexes is the same. But if the data start to show variation, the first thing we do is look at sex differences. Using both male and female mice has revealed clues into differences we would never have suspected. Researchers are realising you can’t extrapolate to both sexes from only studying one,” Ripplinger said.

She notes that with the current study, it’s not clear what the differences in cAMP and electrical activity may mean.

“The response in the female mice may be protective – or it may not. But simply documenting that there is a measurable difference in the response to a stress hormone is significant. We are hoping to learn more in future studies,” Ripplinger said.

Source: University of California – Davis Health