Being happy can rescue you from gastrointestinal issues

Researchers have found that Serotonin, a chemical known for encouraging happiness and well-being, can reduce the ability of some intestinal pathogens to cause deadly infections.

The findings, publishing in the journal Cell Host & Microbe, could offer a new way to fight infections for which few truly effective treatments currently exist.

“Although the vast majority of research on serotonin has centred on its effects in the brain, about 90 per cent of this neurotransmitter - a chemical that nerve cells use to communicate with each other - is produced in the gastrointestinal tract, study lead author Vanessa Sperandio from UT Southwestern Medical Centre in the US, explained.

In humans, trillions of bacteria live within this space. Most of these gut bacteria are beneficial, but pathogenic bacteria can also colonise the gastrointestinal tract, causing serious and potentially fatal infections.

Because gut bacteria are significantly affected by their environment, the research team wondered whether the serotonin produced in the gut can affect the virulence of pathogenic bacteria that infect the gastrointestinal tract.

They worked with Escherichia coli O157, a species of bacteria that causes periodic outbreaks of often deadly foodborne infection.

The team grew these pathogenic bacteria in Petri dishes in the lab, then exposed them to serotonin.

Gene expression tests showed that serotonin significantly reduced the expression of a group of genes that these bacteria use to cause infections.

Additional experiments using human cells showed that the bacteria could no longer cause infection-associated lesions on the cells if these bacteria were exposed to serotonin.

Next, the researchers examined how serotonin affected virulence in living hosts.

Using mice, the researchers studied how serotonin might change the ability for Citrobacter rodentium - a mouse gut bacterium often used as an analog for E. coli in humans - to infect and sicken their hosts.

These mice were genetically modified to either over- or underproduce serotonin in their gastrointestinal tracts.

Those that overproduced this neurotransmitter were less likely to become colonised by C. rodentium after being exposed to this bacterium or had relatively minor courses of illness, according to the study Treating mice with fluoxetine (sold under the brand name Prozac) to increase serotonin levels prevented them from getting sick from C. rodentium exposure.

However, the mice that underproduced serotonin became much sicker after bacterial exposure, often dying from their illness.

In the future, the research team plan to study the feasibility of manipulating serotonin levels as a way of fighting bacterial infections in the gastrointestinal tract.

On the other hand, people who use a coin toss to decide on an important change in life are more likely to follow through with that decision, are more satisfied with that decision, and report higher overall happiness after a six-month period, a fascinating study has revealed.

Society teaches us that “quitters never win and winners never quit”.

“But in reality, the data from my experiment suggests we would all be better off if we did more quitting,” said study author Steven Levitt from the University of Chicago in the US.

“A good rule of thumb in decision making is, whenever you cannot decide what you should do, choose the action that represents a change, rather than continuing the status quo,” Levitt added.

For the findings, published in the journal The Review of Economic Studies, the researchers asked people to make significant decisions, such as whether or not to move house, quitting your job or propose, and assign either an affirmative or a negative choice to heads or tails.

Levitt created a website (Freakonomics Experiments) where participants answered a series of questions.

Some examples were: Should I quit my job? Should I move? Should I propose? Should I adopt? Users were also invited to create their own questions, including Should I get a tattoo? Should I try online dating? Should I rent or buy? One choice, either the affirmative or the negative, was then assigned to heads and the other assigned to tails. Prior to the coin flip, the participants were encouraged to identify the third party to verify their outcomes.

Both the initial coin-flipper and the third parties received a follow-up survey after two-months and six-months.

The two-month survey found that participants favoured the status quo, making a change less frequently than they predicted they would before the coin toss. At the six-month survey, this bias toward the status quo was gone.

Furthermore, those who were instructed by the coin toss to switch their current position were more likely to actually make the change, reported that they were substantially happier, and said that they were more likely to make the same decision if they were to choose again.

This was true for virtually every question at both the two- and six-month surveys.

Indo-Asian News Service