Bacteria don’t get the credit they deserve. There is reasonable certainty that they have been around on this planet since the PreCambrian era, which means they have been here for about 3.5 billion years. Yet what are the adjectives that we, who have been here a mere 4 million years, come up with to describe bacteria? Generally we rise to terminology like “ickyâ€, “damn†or “ewwww†when we describe bacteria, but why aren’t we using terms like “persistentâ€, “intrepid†or “ingeniousâ€? You don’t hang around any biosphere for more than three billion years without those admirable qualities, yet we view bacteria as things to be avoided and derided even though we know that our own bodies are full of these noble entities. In fact, research is showing that the bacteria in your digestive tract can even affect your thinking.
It has been calculated that a human adult houses about 1012 bacteria on the skin, 1010 in the mouth and 1014 in the gastrointestinal tract. That means there are around 10 times more bacteria than cells in the average human body. Probiotic bacteria from the digestive tract are increasingly used in food and pharmaceutical applications to balance disturbed intestinal microflora and related dysfunction of the human gastrointestinal tract. Research over recent decades has revealed that the intestinal microflora is important for maintenance of overall health, energy, optimal nutrition, manufacturing vitamins like K and biotin, production of short chain fatty acids to feed the cells of the colon, and protection against invading organisms. Increasingly we are understanding that the bacteria in your digestive tract also affect how your brain operates.
In a new report researchers analysed existing data to see whether probiotic supplements can affect brain function. In one study rats showing depressive behaviour due to separation from their mother were given the probiotic strain Bifidobacterium infantis. The probiotics not only normalised the rats’ behaviour but improved their immune function as well.
In another study volunteers who received either probiotics or a placebo for 30 days were measured for stress levels. It emerged that those given probiotics showed significantly reduced levels of stress. Yet another study showed that subjects taking probiotic yoghurt experienced improvements in mood.
According to the researchers both depression and stress are associated with inflammation in the body. They theorise that it is the immune modulating effects of probiotics that reduce inflammation and therefore support mood. At this stage it is a relationship that remains to be definitely clinically proven but sometimes you have to go on gut feeling.
