The Bug is a Feature (Part II)

If you didn’t know by now that we are half human half bug, you have not been paying attention to the fast developing science of the microbiome. If you have been paying attention, you will know that our microbes are deeply interwoven into our chemistry, immunology, physiology and pathology; and now it appears that they are also an integral part of our ability to adapt to our ever-changing environment. In other words, they are an element in our portfolio of stress responses.

I first became interested in the adaptogenic role of the microbiome when I came across research showing that it adapts to enable us to utilize different food sources. 

Many of the enzymes produced by the bacteria living in Western guts play a role in the breakdown and utilization of plant-based non-digestible carbohydrates such as starches, pectins and hemi-celluloses (1). A decade ago, however, it was found that the Japanese microbiome contains bacteria that produce enzymes that can break down the rather different carbohydrates found in marine algae (aka seaweeds); such as the carrageenans, agars and porphyrans (2). 

These marine carbs are different from terrestrial carbs, because they are poly-sulphated. This means that they cannot be broken down by the standard enzymes made by bacteria in the gut of people who eat plant foods. If you regularly eat seaweed, however, at some point your bacteria develop a different set of enzymes that can utilize these poly-sulphated carbohydrates, derive energy from them, and (perhaps) contribute to your overall health and wellbeing. 

This may occur when you consume a dish of seaweed that contains some of its own microbiome, which then horizontally transfer the necessary gene or gene set to your microbiome. It may also happen spontaneously, if one of your own bacteria mutates. But it will happen.

The microbiome is a hotly contested ecosystem, and if one bacterium develops a mutation that allows it to exploit a hitherto unused food source it will take advantage of that to grow, multiply and seize its own ecological niche. 

That may well affect the host – and it can certainly present commercial opportunities.

I attended a sports science conference in San Diego and took the opportunity to talk with Jonathan Scheiman, CEO of FitBiomics. FitBiomics is a sports biotechnology company spun out of the Wyss Institute for Biologically Inspired Engineering at Harvard University. They sell athletes’ poop, made into drinks.

I don’t understand why anyone buys Jordan sneakers or Ronaldo shirts. Wearing Jordan shoes will not make you a better dribbler, and owning a Ronaldo shirt is unlikely to help you score, on or off the pitch. According to FitBiomics, however, regular consumption of a famous athlete’s poop may help you to be more athletic. Which begs the question, is this shit fo shizzle?

The microbiome of elite athletes contains bacteria that have adapted to utilise lactic acid as a fuel source (3). This is hardly surprising, as regular floods of lactic acid in the body and therefore the gut will encourage the growth of bacteria able to use this substrate. The growth of these microbes increases the body’s overall ability to break down lactic acid; and as lactic acid build-up is a major factor in muscle fatigue, this bacterial response forms part of a series of adaptations in the body to exercise, that lead to increased fitness and performance. 

But wait! There is more …  (I’m being commercial now).  As the bacteria consume lactic acid they excrete short chain fatty acids including butyric acid, which has significant anti-inflammatory properties. Here is another potential bonus for athletes, whose stamina and strength is degraded by excess inflammation. And finally, there is evidence that the bacteria may enhance mitochondrial function (4), which would also improve physical performance.

The FitBiome team showed that when large numbers of these bacteria were fed to mice, the rodents performed better on endurance tests. This work has not yet been published, as far as I know, although other researchers in Taiwan have published similar data (5). 

But let us stay skeptical. Even if we assume that the pre-clinical science is good, will it transfer to humans? 

Eating probiotics has very temporary effects. They don’t settle in the gut.

Once you stop eating them they disappear within 24 hours, so you have to take them every day. This is a good commercial model, of course, but can you eat enough of these bacteria to make a difference?  

Yakult, a typical probiotic drink, contains 6.5 billion bacteria (colony-forming units) per bottle. This seems like a large number – but to put it in perspective, once you drink a bottle of Yakult, the probiotic bacteria will be outnumbered 15 million to one by the bacteria already present in your gut. Can that really impact on the microbiome, let alone your performance? There is some rather sparse recent evidence that this may improve performance in human volunteers (ie 6), but this remains to be substantiated. 

In the meantime, however, you can train your own microbiome simply by taking more exercise. If you frequently produce large amounts of lactic acid, the bacteria inside you will adapt to utilize that lactic acid, while the rest of your body is also adapting.

And you will poop like an athlete.

References:

1.Martens EC, Lowe EC, Chiang H, Pudlo NA, Wu M, McNulty NP, Abbott DW, Henrissat B, Gilbert HJ, Bolam DN, Gordon JI. Recognition and degradation of plant cell wall polysaccharides by two human gut symbionts. PLoS Biol. 2011 Dec; 9(12):e1001221.

2. Hehemann JH, Correc G, Barbeyron T, Helbert W, Czjzek M, Michel G Nature. Transfer of carbohydrate-active enzymes from marine bacteria to Japanese gut microbiota.2010 Apr 8; 464(7290):908-12.

3. Mach N, Fuster-Botella D. Endurance exercise and gut microbiota: A review. J Sport Health Sci. 2017 Jun;6(2):179-197. 

4. Clark A, Mach N. The Crosstalk between the Gut Microbiota and Mitochondria during Exercise. Front Physiol. 2017 May 19;8:319.

5. Chen YM, Wei L, Chiu YS, Hsu YJ, Tsai TY, Wang MF, Huang CC. Lactobacillus plantarum TWK10 Supplementation Improves Exercise Performance and Increases Muscle Mass in Mice. Nutrients. 2016 Apr 7; 8(4):205. 

6. Huang WC, Hsu YJ, Li H, Kan NW, Chen YM, Lin JS, Hsu TK, Tsai TY, Chiu YS, Huang CC. Effect of Lactobacillus Plantarum TWK10 on Improving Endurance Performance in Humans. Chin J Physiol. 2018 Jun;61(3):163-170.