Our gut flora plays an imperative role when it comes to keeping us healthy, balancing bacteria levels to aid digestion, metabolism, immunity and cardiovascular health – to name but a few.
So, how do we keep our microbes functioning at their highest level? Well, new research shows that eating a seasonal diet – similar to that of the few remaining hunter-gatherer groups – might be the answer.
A team at the Human Food Project, a non-profit organisation, spent more than a year collecting stool samples from 350 Hadza People, who live in Tanzania and still practice a traditional tribal lifestyle – eschewing agriculture in favour of hunting and foraging.
It was found that Hadza gut bacteria is roughly 30% more diverse than that of people from Western nations – making it some of the most varied (and therefore healthy) gut flora in the world. Although this isn’t too surprising considering the Hadza people have never been exposed to antibiotics or processed food, lead researcher Jeff Leach hypothesises that it is the seasonal nature of the groups’ diet that gives them an edge.
It seems that diversity peaks in the dry season, when the Hadza eat a lot of meat, followed by the wet season, during which they mostly forage for berries and honey. On top of this, the Hadza eat starchy tubers and baobob fruits all year round. The report reads:
“Between seasons, striking differences were observed in [the Hadza’s] gut microbial communities, with some taxa (microbes) apparently disappearing, only to reappear when the seasons turned. Further comparison of the Hadza microbiota with that of diverse urbanized peoples revealed distinctly different patterns of microbial community composition.”
Commenting on this, Dr Lawrence David PhD – who studies the microbiome at Duke University – said:
“I think [these findings are] really exciting… It suggests the shifts in the microbiome seen in industrialized nations might not be permanent — that they might be reversible by changes in people’s diets… [It] supports the idea that the microbiome is plastic, depending on diet.”
It is thought that certain health problems – such as colon cancer, colitis, or Crohn’s disease (which, incidentally, the Hadza people don’t suffer from) – may arise because our microbiomes are simply not functioning to a level that Western diets and lifestyles demand.
Although way more research needs to be done into this particular area of science, it will do no harm to make the most of seasonal, fresh produce.
For example, in the UK that might mean basing meals around leafy or root vegetables in the winter, and incorporating more fruit and summer vegetables from June-August.