Wednesday, 25 March 2015

How Modern Living Has Affected Our Gut Microbiome

You're out shopping for handwash. You scour the shelves. What do you choose? Almost certainly, you'll see antibacterial hand wash on display somewhere. But it's not just handwash that we use to kill bacteria living on our skin - there's travel-sized antibacterial spray, antibacterial cleaning products, facial cleansers and wipes and now antibacterial washing powder.

If you judged from our shopping habits, you might think we're a population scared of bacteria. But not all bacteria is bad, is it?

The short answer is no. No it isn't.

We actually rely on trillions of microbes every single day just to complete basic bodily needs: digesting our food, keeping infections out of our bodies and maintaining healthy skin. Bacterial cells actually outnumber our own human cells 10 to 1. You are 10% human and 90% microbes. That's a LOT of microscopic bugs that we're carrying around with us. The human microbiome is a whole new (and exciting) area of research and scientists think that an imbalance in these good bacteria could be responsible for the onset of autoimmune diseases, obesity, personality and even mental disorders. In short, we need to look after these bugs, not kill them off.


We need to look after the good bacteria in the gut
Image courtesy of Ohmega1982 at FreeDigitalPhotos.net

So how is modern life treating them? Well, while antibacterial sprays and handwash are important (when there's an infection in the house, or in hospitals where there's a risk of cross-contamination of serious disease) I'm not so sure they should be an every day thing at home. Here's why...  

Antibiotics
When I was a child, doctors prescribed antibiotics at the merest hint of an infection. I remember during my first pregnancy nearly ten years ago, the doctor printed off a prescription for some 'just in case'. That wouldn't happen now. Medical professionals have acknowledged that antibiotic medicines, while very important to help us see off serious infections, also see off many of the good bacteria that are only doing good things. Now, doctors are likely to assess whether your body can fight off the infection by itself first, before prescribing you with antibiotics. Studies have shown that when exposed to antibiotic treatment, the gut microbiome suffers a big hit in microbial diversity- but does recover after a period of time. However a 2012 Spanish study noted that: "The results demonstrate that ABs (antibiotics) targeting specific pathogenic infections and diseases may alter gut microbial ecology and interactions with host metabolism at a much higher level than previously assumed." Being prescribed some antibiotic treatment? Eat lots of vegetables and probiotics like raw sauerkraut to help them replenish.

Antibacterial Products
Look in your cleaning cupboard and where you keep your toilertries. See lots of 'kills 99% of bacteria'? Then you may be killing good bacteria off as well as bad. Problem is, that could also be creating an environment where every time bacteria are wiped from a surface (your skin, for example) only the strongest microbes remain, meaning we could end up making certain bugs stronger and developing a resistance to them. ABC reported that experts were concerned over people using too much antibacterial soap, quoting them as saying that "antibacterials may also kill bacteria that actually are helpful to the body because they keep other troublesome bugs in check." 

Diet
I've heard it said quite a lot lately: 'You are what you eat.' Basically, this is true. The New York Times reported on an Israeli study carried out in September 2014 that found using artificial sweeteners altered the gut microbiome and gave mice an intolerance to glucose. Not good. And if you're eating pre-packed, processed foods - whether sweet or savoury - you're probably eating artificial sweeteners without knowing it (read the labels). I did a course recently on the gut microbiome and it was said that a diet particularly rich in vegetables is good for keeping your gut microbiome balanced and healthy. And our sugar-rich, Western diets? A study by Payne, Chassard and Kacroix in 2012 noted that "these sugar compounds, particularly fructose, condition the microbiota, resulting in acquisition of a westernized microbiome with altered metabolic capacity." In short? Sugar has been found to alter the natural balance of our gut bacteria. And it doesn't sound good.

Lifestyle
When I was a kid, my sister and I spent the weekends out making mud pies, digging up artefacts (we lived in a 1940s semi and there seemed to be a lot of buried, cracked pieces of china in the back garden), and climbing trees. Often, in the middle of play, we'd just rub our hands on our jeans before eating a quick sandwich in the garden. My parents' attitude was that a little bit of dirt was good for you. Quite different, I suspect from the mostly sanitary lifestyle of many young kids nowadays - in from school and then playing on their X-Boxes or watching films on the iPad while their mum makes them a sandwich on a board regularly doused with antibacterial spray. A study carried out in 2012 found that mice who had been exposed to everyday microbes actually had better health than germ-free mice. The germ-free mice ended up with more inflammation in the lungs and colon, leaving us humans to scratch our heads and suggest that maybe exposure to a little dirt while you're growing up might actually be good for you

What do you think? Anyone want to come out Saturday and make mud pies?