[nectar_dropcap]L[/nectar_dropcap]ike during a corporation’s attempt to gather individuals of different ethnic backgrounds and BMI’s for a representative workforce photo of equality… diversity is crucial.

The gut is no different.

When it comes to overall health, diversity of gut microbes is key.

Now, I know what you’re thinking…

“Big whoop, but it’s not like a lack of a few specific strains of bacteria that are residing in my faeces could give me a debilitating cognitive dysfunction though”

Well you’ll be surprised.



Gut microbes talk to your brain

Your gut microbiota can influence your brain with the signals they secrete from the food you eat.

For instance, the gut-abundant Lactobacillus and Bifidobacterium species were found to produce a neurotransmitter called GABA (from the glutamate in the gut). Disruptions in GABA-signalling can cause anxiety, depression and Alzheimer’s Disease.

Further still, a clear link was established between the gut microbiota and Alzheimer’s Disease. The University of Lunds transferred intestinal bacteria from Alzheimer’s mice to germ-free mice, and discovered that the mice developed more beta-amyloid plaques (the cause of Alzheimer’s) in the brain compared to if they had received bacteria from healthy mice.

You see? So this suggests that microbes in your gut can actively communicate with your brain, and thus you, (we’ll explore how this happens later).

But don’t think that it’s just serious mental disorders that the gut microbes can impact.

Even minor emotions/conditions like general anxiety can originate from the gut..

Researchers found that a fecal microbiota transplant could also make calm mice anxious, (or as the nerds like to call it, ‘anxious-like behaviour’ because (like with some women) you can never really tell how a mouse is feeling). These calm mice were made anxious upon recieving the faeces from anxious mice.

Now I know what you’re thinking, “of course these mice became anxious, they’ve just been anally probed by white-cloak wearing nerds!”.

Well maybe you would be right, if it wasn’t for the fact that they did the reverse of this experiment, and guess what.. those anxious mice became more chill than Snoop Doggy Dogg when hotboxing a sauna amongst his side-chicks.

The brain in your gut

Now before you start holding your gut bacteria responsible for the anxious mental breakdown you had when the barista gave you a frappa lappa chino when you ordered a mocha locha choka, you must know that there’s another brain at play here.

It lives in your gut, has all the usual neurons that you have in your main brain, but is collectively the same size as a cat brain. It’s called the enteric system, but for your sake, we shall call it cat brain. Apologies to any (now confused) cats reading this.

It’s controlled by the same chemicals that influence your main brain and holds around 50% of your dopamine and 90% of your serotonin. It’s kind of a big deal, hence why research groups consider it the second brain.

Your cat brain’s original purpose is to control the movement and absorption of food along the intestinal tract. However, as with (what seems like) every computer in the NHS, the cat brain is regularly hacked. Signals secreted by the gut bacteria can intercept our own signals that bind to the cat brain, delivering our brain a specific message without us even realising.

What’s interesting is that when scientists bred mice without any gut bacteria, they found that the cat brain ceased to communicate with the main brain. This suggests that the communicative link between our cat brain and main brain has evolved purely to accommodate our gut microbes.

So should we consider our gut microbes to be part of who we are?

The line between us and not us becomes very blurred the more you study it. After all, the mitochondria (the powerhouse of the cell) is found in all our cells, but is strongly theorised to have originated as an individual bacterium, which became engulfed by another – larger – cell millions of years ago; this is the endosymbiotic theory.

But the mitochondria cannot survive without you, whereas the gut microbes can.

The gut microbes can survive without you and have the power to influence your mood and what you eat; they’re more like a parent than a part of you.

So perhaps you should be calling your gut daddy.

Perhaps you already do, in which case it’s none of my business and I suggest you don’t bring it up in front of friends.

Anyway…

Before you freak out and start sterilising yourself with antibiotics, it’s important to realise that this cat-main brain hijacking system has evolved between us and our little bacterial friends over millions of years. Of course, it is self-serving of our gut bacteria, however, for them to survive we need to survive to, so it can’t be that detrimental, can it?

It depends.

Here is a table of the type of microbes you would find in your gut, alongside the signals they produce and the effect they would have on you:

Microbe Product/Metabolite Potential Influence on You (Simplified) Escherichia & Lactobacillus Serotonin Irritable bowel syndrome, cardiovascular disease, and osteoporosis Bifidobacteria & Protovella Short-chain fatty acids Provide energy and reduce inflammation Bacillus Norepinephrine Reduces gut activity and stimulates fight or flight response Lactobacillus & Bacillus Acetylcholine Primarily muscle contraction, also memory, arousal, and attention

Lactobacillus & Lactococcus Histamine Primarily inflammation* Gram-Negative Bacteria (e.g. E.coli ) Endotoxin Obesity, diabetes and inflammation

*Inflammation doesn’t necessarily mean swelling, it’s purely defined as the recruitment of immune cells.

Most notably, Escherichia, Lactobacillus, and Lactococcus can produce dopamine which has a multitude of functions, depending on where it’s found. Exact levels are absolutely critical, however, and can cause Parkinson’s, Tourette’s, pleasure whilst also influencing memory.

Take this test: Do you ever find that you remember information when you’ve found it interesting? That’s because memories are much more easily created when dopamine is present in that part of the brain, and dopamine is only released when you are having pleasure.

So perhaps the next time you’re studying for an exam, try replacing the sugar in your tea with a little crack or LSD.

This is similar to what the eccentric mathematician Paul Erdős did. The man would turn up at a fellow mathematicians house all hyped up on amphetamines telling them his “mind is open”, followed by an intense 19-hour mathgasm.

As a result, huge advances were made in the field.

Then, one day during a sesh down the pub, a friend of Paul’s bet him £500 that he couldn’t go one month without the drug.

Paul Erdős won the bet but complained that during his abstinence, mathematics had been set back by a month.

So basically don’t do drugs unless you’re as hardcore as Paul Erdős.

Bacteria fighting bacteria

Perhaps the second biggest beneficial role of the gut microbiota is its ability to protect us from harmful microbes.

Flooding the competition

Our ‘good’ gut bacteria use their abundance to outcompete the pathogenic bacteria. This keeps the disease-causing microbes at low numbers, preventing them from releasing harmful toxins.

Training our immune system

Our immune system cunningly utilises our friendly gut microbes to train itself [Queue Rocky montage music], and therefore create a kind of ‘boot camp’. The more diverse our microbe army of ours is, the more intense the boot camp training for our immune system. For example, Bifidobacteria produce butyrate in the gut which enlists T-cells; these help control intestinal inflammation and induce antibod y production. Meanwhile, Bacteroides thetaiotaomicron cause our paneth cells to secrete a protein which activates defensin . Defensin is literally a protein that stabs pathogenic bacteria and viruses until they spill their essential nutrients .

The relationship that develops from this coalition teaches our immune system to recognise who the real pathogenic enemy is. Therefore allowing it to trigger an immune response much sooner.

So what happens to those with low gut microbe diversity?

When we lack gut microbe diversity (caused by e.g. poor diet or extreme cleanliness), the immune system goes into overdrive, and – like an ADHD kid cooped up in a council flat – the immune system begins to attack everything, including itself.

This leads to autoimmune disorders such as Crohn’s disease, IBS, and even rheumatoid arthritis.

They’re as scary as they sound, but they don’t have to happen to you.

What should you do?

Besides eating diverse foods, you may be thinking about probiotics to help your gut.

Well unfortunately, most probiotics are transient, meaning they do not become permanent residents of the gut and instead most likely pass through with the sugary yogurt that it comes in. Imagine a fast-flowing river that’s swamped with river weed. If you were to throw more weed in, it’s unlikely to become fixed to the river bed and grow, instead (like probiotics) it would simply just pass on by.

So what’s the solution?

Focus on prebiotics instead. These are foods that feed your current gut microbes. An easy way to do this is by consuming fibrous vegetable skins like that of the sweet potato. These indigestible fibres are gobbled up by beneficial gut bacteria like bifidobacteria, that in turn provide energy to us.

Microbes trapped in the dirt of organic vegetables can also add diversity to our gut. So simply hold back on the rigorous pressure washer-like cleaning of those organic veggies you should be buying/growing, leave some skin on and you’ll be beautifully diverse.

#leavetheskinon