Do probiotics work? Research from 2018 suggests that some probiotic strains might struggle to find a home in our gut, being quickly forced out by the established microbes.
Do probiotics work?
Research into the human microbiome is demonstrating that gut health is both complex and nuanced. Complex because of the sheer quality and quantity of microbes that we humans host. For example according to the Human Genome Project each of us has around 22,500 human genes, however it’s estimated that we also carry 100 times that number in microbial genes! Understanding the colonies of microbes (predominantly bacteria) inside our gut is further complicated because no two people have exactly the same gut flora. So therefore each of us has a unique bacterial ecosystem.
A research paper published in the journal Cell in September 2018 and highlighted by the BBC website, has made the claim that “Humans feature a person-specific gut mucosal colonization resistance to probiotics”. The study found that an 11-strain probiotic mix, administered for a month had almost no impact on the long term gut health of 25 participants. Either passing straight through the digestive tract or lingering for a short time before being forced out by the well established resident bacteria. Although provisional, the results are highly suggestive that the gut has a defence mechanism designed to protect itself from rapid colonization by new visitors. This is kind of intuitive, if any new bacteria that we ingested could quickly establish a foothold in our body then we would be much more vulnerable to harmful microbes.
Although this initial study hasn’t been replicated and is based on a relatively small number of people it suggests that probiotics might work best if they are tailored to each of us individually. That probiotics might offer the greatest benefit if they are designed to coexist with our unique resident populations. From a consumer’s point of view I am left thinking how might I be able to tell if the probiotics I consume are having a lasting effect without going down the road of expensive lab based testing? Hopefully further studies offering greater insight will follow.
People suffering from migraines tend to have particular profile of bacteria linked to nitrate processing.
I am keen not to overstate the potential of any individual scientific study. However this story highlights exciting news about a potential relationship between bacteria and migraines. In 2016 The Guardian featured a study that appeared to demonstrate a link between the efficient break down of nitrates in humans and the occurrence of migraines. As I understand the research, migraineurs (people that suffer from migraine) tend to have more nitrate reductase genes in both the mouth and in stool samples, than the wider population.
Nitrate reductase genes are responsible for processing nitrates in food and drinks, point being the greater their abundance the more efficient the nitrate processing. So getting more nitrates from food (compared to non migraineurs) may be linked to triggers for migraines. Obviously further research will be needed but the link between nitrates and headaches is not new. What this study is demonstrating is that the key might rest with the microorganisms in the mouth and gut.
Many migraine sufferers are aware of a relationship between certain foods and increased risks of attacks, through chocolate and wine for example. It is also known that certain drugs high in nitrates can provoke severe headaches. When broken down, nitrates lead to increased blood circulation in the cardio vascular system, this increase may be a key factor in migraines. The complexity of the human microbiome, particularly the gut-brain axis, makes demonstrating causality between food and health challenging. However this seems like a promising area of research. Controlling the intake of foods high in nitrates might be a short term solution. But given that fruit and vegetables are rich sources of nitrates, cutting down on them could present a range of risks and benefits. For more information visit the Migraine Action or Migraine Trust websites.
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