The 38 Trillion Beings Who Call You Home

As Above, So Below

The old alchemists carved that phrase over their doorways, and the yogis said the same thing in their own idiom:

yathā piṇḍe tathā brahmāṇḍe
As in the body, so in the cosmos.

Our Earth is a living planet teeming with life. It is home to 8.7 million species across its varied environments or biomes.

Your body is itself a little Earth that is home to so many inhabitants that they slightly outnumber the cells in your body. Some 38 trillion bacteria live in and on your body, and the vast majority of them reside in the large intestine we call the gut microbiome: the most densely populated microbial habitat on Earth.

To your bacteria, you are not a person. You are the planet. You are the climate and the seasons and the whole habitable world — their Mother Earth. They are born in you, live out their entire generations in you, and are carried in your wake wherever you go.

The Invisible Hand

Your body’s inhabitants might be too small to see, yet the smallest tenants are running the biggest systems in your body:

1. They shape what you crave.
   Gut microbes want foods that help them flourish, which are not always the foods that help you. And they have tools to lobby for their preferences. Researchers reviewing the mechanisms describe how microbes may generate cravings for the foods they specialise in — or make us feel bad until we eat them — by acting on reward and satiety pathways and even hijacking the vagus nerve, the neural cable running from gut to brain.

   Your food cravings feel like yours. Some of them are theirs.

2. They influence your mood.
   90% of the body's serotonin — the neurotransmitter that keeps you feeling happy, focused and calm — is made by your gut cells, and gut microbes signal the cells to produce serotonin via metabolites like short-chain fatty acids. Particular strains of Lactobacillus and Bifidobacterium produce GABA, the body's primary calming neurotransmitter, which quiets feelings of fear, anxiety and stress.

   The mood you carry onto the mat is, in part, a conversation happening in your belly.

3. They heal your gut wall.
   When your microbes ferment the fibre you eat, they exhale a family of compounds called short-chain fatty acids, chief among them butyrate. Butyrate is the primary energy source for the cells lining your colon, fuelling their growth and maintaining the integrity of the gut barrier, preventing harmful substances from leaking out of the gut into the bloodstream — the breach that underlies so much low-grade, body-wide inflammation.

   This means that your gut wall is quite literally fed and repaired by the waste products of the beings living on it.

4. They unlock food you couldn't otherwise reach.
   Much of what's nourishing in plants is chemically locked away — bound in fibres and compounds our own enzymes simply can't open. The microbes can, effectively pre-digesting the world on our behalf and handing us the good parts. Without them, a salad is far less nourishing than it looks.

Mitāhāra: Tending the Garden

The Haṭha texts name a discipline called mitāhāra — literally "measured eating." is one of the foundational observances of a serious yogi: wholesome, moderate food, taken with awareness, leaving part of the stomach empty. For centuries this was framed as a matter of discipline and purity. We can now read it a second way: as remarkably good husbandry for the 38 trillion beings in your care.

Three practices, old and new at once:

1. Eat with the sun.
   The yogis ate their main meal at midday, when the digestive fire is highest, and kept a natural fast through the dark hours. Modern research on time-restricted eating is catching up: your gut microbiome, it turns out, runs on its own daily rhythm, with different bacterial populations rising and falling across the cycle of feeding and fasting.

   Concentrating your eating into the daytime and giving the gut a long nightly rest amplifies these healthy daily fluctuations in the microbiome, and eating earlier in the day rather than late appears to increase microbial diversity in step with the body's circadian clock.

2. Eat the rainbow.
   The American Gut Project, which analysed the microbiomes of over 10,000 people, found that those who ate thirty or more different types of plant per week had a significantly more diverse gut microbiome than those eating ten or fewer. Every different plant carries a different fibre, and each species of bacteria thrives on its own kind of food, so a wide variety of plants feeds a wide variety of microbes.

   Herbs, spices, nuts, seeds, whole grains, legumes, even coffee and dark chocolate all count. A sattvic, whole-food, plant-forward plate isn't just traditionally pure. It is, in the most literal sense, the most generous thing you can set before your inner ecosystem.

3. Feed them, and send in reinforcements.
   Prebiotics are the fibres that feed the microbes you already have — the raw material they ferment into that gut-healing butyrate. Probiotics are living beneficial microbes you bring in from outside, classically through fermented foods. Fermented plant foods like sauerkraut, kimchi and pickles deliver plant fibre and live probiotic bacteria at the same time, and fermented foods more broadly are a rich source of probiotics that, eaten regularly, increase the beneficial bacteria in the gut.

   This is exactly where a cold-pressed juice and a jar of live-culture yoghurt earn their place: the juice a concentrated hit of plant nutrients and enzymes, the yoghurt a living reinforcement of good bacteria. Prebiotic and probiotic, the field and the seeds.

To practise mitāhāra, then, is stewardship. Every mindful, moderate, plant-rich meal is a small act of care for a teeming inner world — one that will, in return, steady your moods, quiet your cravings, mend your gut, and let you meet your mat with more energy and less noise. Deepen the practice from the inside out.

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Want to Learn More?

We're bringing this inner ecosystem to life in a hands-on afternoon at the school.

Cold-Pressed Juice & Yoghurt-Making Workshop
🗓 Monday, 10 August 2026 (National Day observed) · 1–3pm

Learn how your gut shapes your energy on the mat, make your own probiotic yoghurt to take home, and taste your way through the cold-pressed range — the prebiotics and probiotics of this whole story, in a glass and a jar. Led by the Nuejuice & Nutriment Wellness team. The Nuejuice booth runs all day, so come by even if you can't join the session.

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References

1. Alcock, J., Maley, C. D., & Aktipis, C. A. (2014). Is eating behavior manipulated by the gastrointestinal microbiota? Evolutionary pressures and potential mechanisms. BioEssays, 36(10), 940–949.

2. Koh, A., De Vadder, F., Kovatcheva-Datchary, P., & Bäckhed, F. (2016). From dietary fiber to host physiology: Short-chain fatty acids as key bacterial metabolites. Cell, 165(6), 1332–1345.

3. McDonald, D., Hyde, E., Debelius, J. W., et al. (2018). American Gut: An open platform for citizen science microbiome research. mSystems, 3(3), e00031-18.

4. Zarrinpar, A., Chaix, A., Yooseph, S., & Panda, S. (2014). Diet and feeding pattern affect the diurnal dynamics of the gut microbiome. Cell Metabolism, 20(6), 1006–1017.