One of the biggest problems in researching the benefits of meditation is understanding the potential confounds. In essence, what factors other than the meditation method itself exert an influence on subsequent behavior. Lifestyle questionnaires normally reveal significant differences between long standing meditators and the wider population. Given the range and diversity of meditation methods available, generalisations are quite difficult . However I’d expect experienced meditators from the Buddhist schools to eat less meat and take fewer intoxicants than the wider population. There are also more subtle variations. For example, in some approaches, meditators may drink alcohol yet abstain from scallions (the food group that includes garlic and onions). Another group might have a tendency to eat meat but not consume any food after their lunchtime meal. So does this matter and if so why?
The emerging research of the human microbiota (microorganisms living in or on humans, primarily in the gut) is demonstrating an increasingly close connection between gut bacteria, health and wellbeing. This is a dynamic area of enquiry but studies have implicated gut bacteria in conditions as diverse as obesity, migraine and depression. Typically science demonstrates a correlation between gut bacteria and a particular condition. For example people that suffer from migraines tend to have different bacteria when compared to people not suffering from migraines.
The key message is that meditators should think about what they eat if they want to maximize the benefits of their meditation practice.
The early signs are that the human biome may be more influential than causal in health. Meaning that your gut flora makes it more or less likely that you will or won’t suffer from a particular condition. Our gut flora is established at birth but it is subject to changes throughout our lives. We introduce bacteria from a range of sources, primarily from what we eat and drink. So if, for example, it was discovered that bacteria associated with eating chicken was linked to depression (which it isn’t as far as I know). It would have implications for meditators working with depression.
All this won’t come as any great surprise to long standing practitioners, many of the people in my own meditation circle already think about what they eat quite carefully. The influence of the biome on human health shouldn’t really make any difference to meditators. Reliable meditation is likely to have an effect in every instance, although your practice might be strongly influenced by what you eat.
via 
