Eating yogurt helps ease depression

Eating yogurt rich in lactobacillus -- a probiotic bacteria -- may help alleviate symptoms of depression and anxiety, a finding that could lead to new strategies for treating psychiatric conditions, researchers have found.

Depression is a huge problem and the treatments are not very good, because they come with huge side effects.

"The study will help us not to bother with complex drugs and side effects when we can just play with the microbiome. It would be magical just to change your diet, to change the bacteria you take, and fix your health -- and your mood," said lead researcher Alban Gaultier from the University of Virginia in the US.

In the study, conducted on mice, the researchers have discovered a specific mechanism for how the lactobacillus bacteria affect mood, providing a direct link between the health of the gut microbiome and mental health.

For the study, published in the journal Scientific Reports, the team induced depression symptoms in mice to analyse their composition of the gut microbiome and found that the major change was the loss of lactobacillus.

With the loss of lactobacillus came the onset of depression symptoms. Conversely, feeding the mice lactobacillus with their food returned them to almost normal, the researchers said.

"A single strain of lactobacillus, is able to influence mood," Gaultier observed.

In addition, the study found that the amount of lactobacillus in the gut affects the level of a metabolite in the blood -- called kynurenine -- which has been shown to drive depression.

When lactobacillus was diminished in the gut, the levels of kynurenine went up -- and depression symptoms set in.

While there is no harm in people with depression eating yogurt, people receiving treatment for depression should not stop taking their medications without consulting their physicians, the researchers suggested.

Based on the findings, the researchers plan to begin studying the effect in humans as soon as possible.

Sweet cravings in obese people

Obese people may find it difficult to stay away from sweet foods than individuals who are lean, because of a dysfunction in their brains, finds a new study.

Extra body fat can exert effects on how our brains perceive rewards when we eat sweets, the study said.

The findings showed that the reward system in obese people brains’ operates in a different manner than in those who are lean.

As people move from adolescence to adulthood, they tend to be less fond of sweets as a result of a decrease in dopamine levels-the main chemical in the brain that makes us feel good.

The fall in dopamine levels makes the older adults less attracted to sweets.

Both younger age and fewer dopamine receptors were found to be associated with a higher preference for sweets in those of normal weight.

“We found disparities in preference for sweets between individuals and also found individual variations in dopamine receptors,” said Tamara Hershey, Professor at Washington University.

“Some people have high levels and some low. In people with normal weight having fewer dopamine receptors was associated with a higher preference for sweets,” Hershey noted.

However, in people with obesity, that is not the case, the researchers said.

Dysfunctioning in the brain’s reward system of obese individuals makes them more vulnerable to sweet cravings.

The relationship between their age, sweetness preferences and dopamine receptors also did not follow the pattern seen in people who weighed less.

Insulin resistance or some other metabolic change linked to obesity could contribute to the absence of these associations in the obese group, the researchers explained.

“We believe we may have identified a new abnormality in the relationship between reward response to food and dopamine in the brains of individuals with obesity,” lead author M Yanina Pepino, Assistant Professor at Washington University, added.

For the study, published online in the journal Diabetes, the team analysed 20 healthy volunteers who were aged between 20-40 years and compared them with 24 people considered obese, each of whom had a body mass index of 30 or higher.

The participants received drinks containing varying levels of sugar to determine the degrees of sweetness each individual preferred.

Positron emission tomography (PET) scans was conducted to identify dopamine receptors linked to rewards in each person’s brain.