Which foods can improve your gut bacteria?

In this series the team of BBC journalists and doctors investigate the truth behind a variety of different health topics that have recently been highlighted in the media. For example they regularly test which diets intended to lose weight actually work the best by carrying out simple experiments with volunteers. The experiments are generally well designed though often involve too few people to be 'proper' science - and the presenters point this out. Their aim is to inform us better on how we can improve our health without any commercial biase.

Originally written for BBC Website for their series on health entitled Trust Me, I'm A Doctor this episode looked at how eating certain food influenced our gut microbes. Our gut contains billions of microbes that we are rapidly discovering have a huge influence on our health. We have found that some species of microbe (including fungi) are good for us while others are not - they can even influence our emotional state! In this program the doctors tested the contents of the gut of several volunteers before and after they ate specific foods for a period of time. The results were interesting in that eating fibre (mostly found in plant foods) promoted good microbial growth which is in agreement with similar experiments already carried out, but the biggest difference in gut microbes was found in the group that drank a fermented drink called kefir which contained large number of 'good' microbes that were able to boost health.

The team then took the observation that fermented foods had a large impact on our gut contents another step. They compared a variety of foods and drinks prepared in traditional ways at home with similar foods prepared commercially and (not unexpectedly) found that the commercial foods (which are pasteurised) had far fewer microbes living within them. Traditional foods should therefore have a much bigger positive impact on our gut health compared with sterile commercial foods - another example of how commercially prepared foods remove components of food that we would have been eating up to 50 years ago, and not for the better. 

Give traditional fermented foods a try and you might be surprised with the results - let us know what happens in the comments below!