Microbiome musings

Good day, all! It’s been an interesting few weeks for microbiome science. Here’s a round-up of some articles that have caught my eye.

Galloping to Gut Health?

Over in Italy, researchers explored the impact of a 15-day biodiversity intervention with horses on the gut microbiome of 10 urban-living Italian children. The children’s gut microbiome was assessed before and after 10 daily interactions with horses on an educational farm. The horses’ skin, oral, and faecal microbiomes were similarly assessed using DNA sequencing technology (metagenomics). They found that the interaction with horses potentially led to children acquiring health-promoting features in their gut microbiomes, such as higher species diversity, enhanced production of butyrate (a fatty acid that’s important in regulating inflammation) and an increase of health-promoting species, generally considered as ‘next-generation probiotics’. They also found no evidence of an increase in pathogens in the children's gut microbiomes after their interaction with horses. This supports the calls for more interactions with biodiversity from a young age to promote gut and immune health.

Butyrate producers

I mentioned butyrate above. It’s an important chemical because it plays a vital role in maintaining gut health. It’s produced by certain gut bacteria during the fermentation of dietary fibre and helps maintain the integrity of the intestinal barrier­, and as mentioned, has anti-inflammatory properties. Yet, we know little about the ecology and distribution of butyrate-producing bacteria. Cue my colleague, Dr Joel Brame. During his PhD, Joel charted the distribution of these important bacteria globally. By collaborating with others (myself included) Joel recently published the world’s first global map of butyrate-producing bacteria. He also separated samples into habitats and, using metagenomics, developed a cool index that assesses the potential of bacteria to produce butyrate. Check it out here!

Mud cakes and soil kebabs

On a similar topic, Dr Marja Roslund and team over in Finland published a review on whether “soil microorganisms are missing from the Planetary Health Plate?”. For millennia, many cultures have been eating soil to acquire nutrients. It’s known as ‘geophagy’ – ‘geo’ for ‘earth’ and ‘phagy’ meaning ‘to eat’ or ‘consume’. In some African communities, soil kebabs known as ‘pemba’ are eaten by pregnant women, and I’ve spoken about the potential benefits of this before in talks (and in my book Invisible Friends). However, I also try to emphasise that we’ve polluted soil so much now with metals and nanoparticles that consuming it (as children do regularly) probably comes with a variety of novel risks.

The authors of the review state that Western lifestyles have “reduced our contact with soil, which can induce extinctions in the gut microbiota and decrease immunological resilience”. They investigated whether the scientific literature supported the notion that consuming soil provides immunological resilience via its microbiome. They found a few human intervention trials that suggest soil microbiota may provide immunological resilience. But they also identified studies on soil-eating risks, such as heavy metals, microplastics and drug residues. So, when we say, “Go and play in the mud”, we must now consider the emerging invisible risks along with the benefits. It’s another reason why remediation and restoration of soils are vital endeavours. The team also published a paper today on how indoor gardening could influence the microbiome and enhance immunity!

Recently, many other interesting microbiome papers have enriched the scientific literature, but I’ll save them for another blog.

You might also be interested in the new Netflix documentary Hack your Health: The Secrets of your Gut, featuring John Cryan, Giulia Enders and others. I haven’t watched it yet so I can’t provide a review.

Enjoy!

Jake

For more News from the Invisible World, check out the podcast Interconnected, which I co-host with Robin Taylor: https://podcasts.apple.com/us/podcast/interconnected/id1727055271

We have a slot at the end dedicated to all things microbial!

Also, check out my book Invisible Friends: How Microbes Shape Our Lives and the World Around Us.