We often talk about "trusting our gut" when making big decisions. But physically, your gut is carrying a massive crowd of tiny passengers that influence your hunger, mood and health far more than you might realise.
Inside your digestive system lives a community of trillions of microbes, mostly bacteria, along with fungi, viruses and other tiny residents. The old textbook line was that bacteria outnumber our own cells ten to one. Better arithmetic has since replaced it: the current best estimate is about 38 trillion bacterial cells alongside roughly 30 trillion human cells, close to a 1:1 balance.1 Still, those microbes carry far more genetic variety than we do. The first large gene catalogue of the human gut counted 3.3 million microbial genes, about 150 times the number in the human genome, running biological chores our bodies cannot handle alone.2
What Are You Actually Carrying?
We start life with a nearly clean slate in the womb, pick up our first batch of microbes during birth, and let toddlerhood fill in the rest. By adulthood the overwhelming majority of these microbes, well over 90%, live in the large intestine,1 acting like a hidden control centre:
- The friendly helpers. Good bacteria eat the fibre your own enzymes can't digest. When they ferment it, they produce short-chain fatty acids, butyrate above all, that fuel the cells lining your colon, strengthen the gut barrier and dial down inflammation throughout the body.3
- The brain messengers. Your gut and brain constantly chat through what scientists call the gut-brain axis, a two-way line built from the vagus nerve, immune signals and microbial by-products.4 Roughly 90% of your body's serotonin is made in the gut, and your microbes help set how much gets made. One honest footnote: gut serotonin mainly runs digestion, not mood, it can't cross into the brain, so the gut influences your head through nerves and metabolites rather than a direct "happiness pipeline". 4 Scientists have also proposed that microbes can nudge your cravings toward the foods that feed them; it's a hypothesis under active study, not a settled fact. What is well established: fibre-fed microbes produce compounds that trigger your fullness hormones, helping keep appetite steady.3
- The unwanted freeloaders. Harmful bugs, Salmonella from undercooked food or unwashed hands, for instance, try to sneak in. A healthy, well-fed microbial community keeps them locked out by hogging the space, the food and the attachment sites they would need. Scientists call this colonisation resistance.5
The gut-brain axis: less a hotline, more a very long piece of string.
Feed the right bugs the food they actually need.
Dropping The Baggage With SILT Nutrition
Keeping your gut happy doesn't mean buying into confusing health fads, drinking sour tonics packed with hidden sugars, or scrubbing your house completely sterile. It comes down to feeding the right bugs the food they actually need, and what they need, overwhelmingly, is fibre.5
At SILT Nutrition, we skip the hype to focus on daily nutrition that actually works:
- Pure, high-fibre nourishment. Giving your good bacteria the fuel they need to thrive, produce their protective short-chain fatty acids3 and naturally crowd out bad bugs.5 Most adults get nowhere near the recommended fibre intake.
- No sugar traps. Curbing the quick-fix refined sugars that favour the wrong microbes5 and set up the crash-and-crave cycle that has you hungry again two hours later.
- Simple daily balance. Helping you build a steady, healthy gut routine that supports overall health and sustained energy, because a microbiome is shaped by what you do most days, not what you do once.5
Dinner for the good bugs. Sugar cube not on the guest list.
When you feed your body well, you lighten the load on your digestive system. Nourish the good bugs, drop the gut baggage, and trusting your gut becomes easy.
References
- Sender R, Fuchs S, Milo R. Revised estimates for the number of human and bacteria cells in the body. PLoS Biology. 2016;14(8):e1002533. doi:10.1371/journal.pbio.1002533
- Qin J, Li R, Raes J, et al. A human gut microbial gene catalogue established by metagenomic sequencing. Nature. 2010;464(7285):59–65. doi:10.1038/nature08821
- Koh A, De Vadder F, Kovatcheva-Datchary P, Bäckhed F. From dietary fiber to host physiology: short-chain fatty acids as key bacterial metabolites. Cell. 2016;165(6):1332–doi:10.1016/j.cell.2016.05.041
- Cryan JF, O'Riordan KJ, Cowan CSM, et al. The microbiota-gut-brain axis. Physiological Reviews. 2019;99(4):1877–2013. doi:10.1152/physrev.00018.2018
- Makki K, Deehan EC, Walter J, Bäckhed F. The impact of dietary fiber on gut microbiota in host health and disease. Cell Host & Microbe. 2018;23(6):705–715. doi:10.1016/j.chom.2018.05.012