By Tim Sandle May 30, 2013
Scientists now argue that beneficial bacteria ingested in food (‘probiotics’) can affect brain function in humans. This is based on a study of women who consumed probiotic yoghurts.
The research found that women who regularly consumed probiotics (a term applied to beneficial bacteria) added to yogurt showed altered brain function in terms of less stress and anxiety when exposed to images designed to trigger such reactions. Probiotics are commonly consumed as part of fermented foods with specially added active live cultures, such as in yogurt, soy yogurt, or as dietary supplements.
For the study, thirty-six women between the ages of 18 and 55 were divided into three groups: one group ate a specific yogurt containing a mix of several probiotics twice a day for four weeks; another group consumed a dairy product that looked and tasted like the yogurt but contained no probiotics; and a third group ate no product at all.
The change to brain function was seen in the majority of the women both while they were resting and when exposed to various images designed to elicit an emotional response. The researchers found that, compared with the women who did not consume the probiotic yogurt those who did consume probiotic activity showed a decrease in brain activity associated with ‘stress’ and ‘anxiety’. This was shown through magnetic resonance imaging.
This leads into other research where scientists have known that the brain sends signals to the gut in a way that explains is why stress and other emotions can contribute to gastrointestinal symptoms like irritable bowel syndrome.
The finding, which seems to suggest that changing the bacterial environment in the gut can affect the brain carries implications for future research into dietary or drug interventions aimed at improving or altering brain function (to treat digestive, mental and neurological disorders). It may also be that a diet high in fat and carbohydrates has the reverse effect. However, given that the study was quite small, further research will be required.
The study was carried out by scientists based at UCLA’s Gail and Gerald Oppenheimer Family Center for Neurobiology of Stress and the Ahmanson-Lovelace Brain Mapping Center at UCLA. The findings have been published in the journal Gastroenterology. The paper is titled “Consumption of Fermented Milk Product with Probiotic Modulates Brain Activity”.