Ethnicity and The Microbiome: is there a link?

As soon as you are introduced to solid foods, your gut microbiome begins to develop. Research suggests that race and ethnicity associated changes can been seen in the gut microbiome as early as three months. And by the age of three, your gut microbiome is fairly stable, meaning the overall divseristy and composition of bugs in your gut won’t change much into adulthood.

You are where you eat.

One study looked at the difference in microbiomes of children in Europe versus Africa. Compared to European children, children living in a rural village in  Western Africa (Burkina Faso) had a greater variety of bacteria with more producing short-chain fatty acids (SCFAs).  

SCFAs including acetate, propionate and butyrate, are important for health, but they also provide calories. In fact, around 10% of our daily calories come from SCFAs. They are created when certain bacteria break down fibre in our gut. The diet of these children from Sub-Saharan Africa contained twice as much fibre as the European children, whose diet was very much “Westernised” consisting mostly of animal protein, fat, sugar, and starch. 

The scientists found that certain bacteria unique to the African children, including Xylanibacter, Prevotella, Butyrivibrio, and Treponema, may help to extract more calories from hard to digest fibre. Food can be much sparser in this hot and dry region, so to have bacteria living in your gut that help you get more nutrients from food may be advantageous.

Methane – not just a greenhouse gas!

Some African populations also have microbes in their gut that can produce a certain type of gas – methane. These microbes are not bacteria, but archaea which means “ancient organism”. One study found that native African populations had greater diversity of these methane-producing microbes than African Americans and European Americans. In fact, colon cancer rates are some of the highest in African Americans, yet colon cancer is almost obsolete in rural Africa. Scientists suspect that methanogens may play a protective role against cancer, but that diet is likely a significant factor. African American diets are higher in animal protein and saturated fat compared to Native Africans. Interestingly, consumption of fibre is similar between Native African and African American populations, but cornmeal is a regular part of the Native African diet, which is high in resistant starch – a type of indigestible carbohydrate linked to reduced colon cancer risk. 

Methanogens have been linked to slower movement of food through the digestive system, allowing for increased energy and nutrient absorption. So, when these people move to the west, it could lead to weight gain. One study found that people with methane who undergo weight loss surgery found it more difficult to lose weight than those who did not produce methane. Higher levels of methane are linked with bloating and constipation. It seems that in low numbers, methanogens may be helpful for the human gut, but they can cause issues if overgrown. Luckily, this can be identified with a simple methane breath test. 

Should I relocate to change my microbiome?

Of course, where you live can influence your microbiome, but ethnicity remains a stronger determiner of gut microbiome composition. For example, 25,000 people all living in Amsterdam showed differences in their microbiome which depended on their ethnic background.  

Four other studies also showed it isn’t just down to where you live. These studies all looked at people from different ethnic backgrounds living in the same area. All four studies found microbiome differences associated with different ethnic groups. So, it does look like ethnicity could play a part in these variations.    

Hunter-gatherer populations also tend to have more Prevotella, Proteobacteria, Spirochaetes, Clostridiales and Ruminobacter. While, more Westernised, urban populations have more Bacteroides, Bifidobacteria and Firmicutes.  

Table 1. Summary of the predominant bacteria found in the gastrointestinal tract of different populations across the world. 

Table 2. Summary of the different dietary patterns/foods linked to specific bacteria 

What are signs of a healthy gut microbiome?

1. Diversity – the greater the variety of bacteria, the better. This can bring protection against inflammation and cardiometabolic diseases like heart attacks, strokes and diabetes 
2. Butyrate producers – e.g. Faecalbacterium prausnitzii, Roseburia intestinalis 
3. Akkermansia – these bacteria are associated with better metabolism and are linked to cultural practices of fasting  
4. Bifidobacteria – resembles up to 10% of the Western gut microbiome but is almost obsolete in populations like Hadza tribes 

Can I change my microbiome?

In short, yes. But the question should be, do you want to? 

Changing your diet and lifestyle can alter your microbiome. But when it comes to ethnicity, your microbiome is adapted to the way you eat and live. If you do not have any gut health issues, then it could be that your microbiome works for you.  

The best thing we can all do, irrespective of ethnicity, is to eat lots of different plant foods. 

Fruits, vegetables, wholegrains, nuts, seeds, herbs, spices, teas, coffee, you name it – each different one counts. And yes, if it’s a different colour, it counts as another plant food (e.g. red, yellow, orange and green bell peppers = all different). 

Emerging research is also showing promising gut health benefits from fermented food. For example, “sauerkraut” in Eastern Europe and “kimchi” in East Asia are two types of traditionally fermented cabbage which have been shown to improve gut microbiota diversity in research. Fermented vegetables are a large part of some people’s diets in Asia and one study found that people who consumed more of these had better gut health and overall health markers. 

Having said that, not everyone thrives off the same foods. Eating the foods you grew up on are often the ones that will cater to your microbiome the most. It’s common for people to experience digestive issues when they sway too far from their usual diet. Have you ever experienced toilet troubles when eating the local food on holiday? This is because your gut microbes are simply not used to it! 

Check out some gut health products proven to help traveller’s tummy here. 

Could my ethnicity be causing any of my other gut issues?

Lactose intolerance can be influenced by ethnicity, although that’s not down to your microbiome. Lactose intolerance occurs due to a lack of enzymes that break down lactose (the natural sugar found in milk and dairy) that can cause these unpleasant symptoms…  

If you have an African or Asian background, your chance of being lactose intolerant is pretty high. But if you’ve got a North American, Australian or Northern European background, then you can probably enjoy your ice creams and milkshakes worry-free. But of course that isn’t always the case, and everyone is different.  

Check out this blog post if you want to find out more about lactose intolerance and how you can test for it.