November 15, 2013
Probiotics May Be New Cure For Depression
Alan McStravick for redOrbit.com - Your Universe Online
Chances are, if you’re like the rest of us, you didn’t start hearing about probiotics until between six and seven years ago when they came into vogue in widely distributed commercial products. Probiotics, known as the “good” bacteria, are found in foods like yogurt. According to the Katherine Zeratsky, RD, LD, a nutritionist for the Mayo Clinic, there is evidence these good bacteria can improve your health in several ways.
Although further research is still required, Zeratsky says probiotics are useful in treating diarrhea, vaginal yeast infections and urinary tract infections. Some surprising applications for probiotics are include their ability to reduce bladder cancer recurrence, prevent and treat eczema in children, and even reduce the severity of colds and flu.
While some of the above claims have yet to be fully verified in clinical studies, it is certain that these microorganisms exert positive effects in the intestinal tract, especially when employed to counteract the effects of antibiotics, which make no differentiation between bad and good bacteria in the body.
Though relatively new to the lexicon of American medicine, the first known allusion to probiotics and their health benefits was detailed by Russian scientist Élie Metchnikoff in 1908. Metchnikoff noted rural Europeans who consumed fermented milk products regularly enjoyed longer life spans.
And now it seems the use of probiotics may have a new front where it can be of benefit. Studies have been exploring their possible impact on behavior. This new frontier has given rise to the new concept of psychobiotics.
The definition of a psychobiotic, according to research authors Timothy Dinan and his colleagues at the University College Cork in Ireland is “a live organism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness.” Their article was recently published in the journal Biological Psychiatry.
Their findings, they claim, show evidence that probiotics offer enormous potential in the treatment of depression and other stress-related disorders.
Contained in the gut microbiota of everyone is approximately 1 kilogram of bacteria. This level can be modulated by diet and other factors and is not static, as it can change from day-to-day. There is even evidence showing the form of delivery for a newborn infant (vaginal versus cesarean) can be responsible for altering an individual’s microbiota.
Dinan and colleagues explored an early life stress, maternal separation, which has been shown to induce long-term changes in the microbiome. One specific probiotic, B. infantis, was studied previously in rats that displayed depressive behavior as a result of early maternal separation. It was discovered that use of this bacterium was able to normalize not only their behavior but also their previously-abnormal immune responses. This, according to Dinan, strongly supports the hypothesis that probiotics could potentially be important in the altering of both behavioral and immunological health.
While rats have enjoyed the benefits of a psychobiotic regimen in studies, investigations on the human front are still largely lacking. The few that have been conducted, however, show promising results. One such study involved a cohort of healthy volunteers who received a probiotic combination of the bacteria L. helveticus R0052 and B. longum or a placebo for 30 days. Participants who received the combination of probiotics reported lower stress levels by the end of the study. Still another study showed participants consuming probiotic-containing yogurts also reported improved mood.
In addition to aiding in the treatment of psychological conditions, psychobiotics have also been shown to have anti-inflammatory effects. Both depression and stress have been linked to inflammation in the body. Also, infectious diseases, such as syphilis and lyme disease, will often leave their carriers feeling blue. The above noted immune activations could, they theorize, alleviate such depressive states.
The research team's article states, “The intestinal microbial balance may alter the regulation of inflammatory responses and in so doing, may be involved in the modulation of mood and behavior."
"What is clear at this point is that, of the large number of putative probiotics, only a small percentage have an impact on behaviour and may qualify as psychobiotics," said Dinan.
"This intriguing new area of research may open new possibilities for the treatment of depression," said Dr. John Krystal, Editor of Biological Psychiatry.
While this area of study is in its infancy, the addition of probiotics to your dietary regimen certainly seems like a worthy idea. The next step for scientists is to formulate and conduct large-scale, placebo-controlled trials to provide definitive evidence.