Complaints & connections · borters.ch
Microbiota intestinalis
Trillions of fellow inhabitants that help digest and protect — diversity on the plate strengthens them best.
Also known as: microbiome · gut flora · gut microbiota · gut bacteria
Open in the tool — with search and all the links →This compilation is for information and replaces neither medical diagnosis nor treatment. If you have symptoms, see a doctor.
Trillions of bacteria and other microbes colonise mainly the large intestine — together they form the microbiome. They help digest fibre, make vitamins and short-chain fatty acids and train the immune system. A diverse gut flora is regarded as favourable. Important to place in context: the field is young and full of marketing claims. Commercial home “microbiome tests” currently have little medical value, and probiotics are not a cure-all. What genuinely supports the gut flora is unspectacular: plenty of varied plant fibre, fermented foods and avoiding unnecessary antibiotics. On the often-heard question of “zonulin” and grains, see the Leaky Gut topic.
Vegetables, legumes, whole grains, nuts and fruit — variety feeds a varied flora.
Yoghurt, kefir, sauerkraut or kimchi bring live cultures and diversity.
Unnecessary antibiotics burden the flora — use them only when clearly indicated.
In certain situations (e.g. during/after antibiotics) they can help; as a permanent cure-all there are few studies.
Probiotics bring bacteria that as a rule do not settle permanently: after stopping, they are gone within one to three weeks. What they can do in that time is documented for a few clear cases — antibiotic diarrhoea, irritable bowel, acute infectious diarrhoea in children — and the effect hangs on the particular strain, not on “probiotics” in general. What changes the flora lastingly is fibre: measurable within days, stable for as long as it is eaten.
The gut holds roughly as many bacterial cells as the body has cells; the weight is about two hundred grams. After a course of antibiotics the composition largely recovers within one to three months, with individual species staying under-represented for up to two years. A change of diet alters the picture measurably within days and returns just as quickly if eating changes back. Around thirty grams of fibre a day is the amount most studies work with.
It’s not single “good” microbes that count, but a community as diverse as possible.
Gut bacteria live on plant fibres — the more variety, the better.
After antibiotics, the flora needs time to recover.
Home “microbiome tests” currently give no reliable, actionable guidance.
The value in the stool that actually decides something: inflammation yes or no. It says nothing about the composition of the gut flora.
Belongs before any longer change of diet, because the value is only meaningful while gluten is being eaten.
With years of bowel complaints a look at uptake is worthwhile. It answers a real question — unlike a list of bacterial genera.
Soluble fibres like psyllium and oats bind water and make the stool supple. Wheat bran and a lot of raw vegetables, by contrast, increase bloating and pain in a sensitive gut — this distinction explains most of the failures.
Fibre without water makes the stool harder instead of softer. The two belong together, and the effect only sets in after some days.
Draws water into the bowel and therefore works with a sluggish stool. The belly shows the upper limit: if the stool gets too loose, the dose at once was too high.
Yoghurt, kefir, sauerkraut and the like bring living cultures with them. Many tolerate them well; with a strongly bloated belly they can also do the opposite in the first weeks.
The effect hangs on the strain, not on the word “probiotic”. Particular strains are studied for particular situations — what works for antibiotic diarrhoea does not automatically work for irritable bowel. After stopping they mostly disappear again within weeks.
Food for one’s own bacteria rather than added bacteria. Studied at 5–10 g a day; start slowly, otherwise bloating follows. In irritable bowel and SIBO often poorly tolerated — there it is the opposite of helpful.
Effective when deficient; effects on sleep and stress plausible but moderate. Too much causes loose stool.
Gut bacteria make short-chain fatty acids from fibre, and these make the gut wall release GLP-1 — the same hormone the new weight-loss injections imitate. The body’s own route is weaker, but it is the same one.
About 90 per cent of the body’s serotonin arises in the gut wall, and particular bacteria stimulate that production. From there it does not reach the brain — it steers gut movement, not mood.
The connection runs both ways: chronic stress measurably changes the make-up of the gut flora, and the flora in turn influences how strongly the stress axis answers. In humans the second part is far less supported than in animals.
In studies the number of different plants per week counts for more than the amount of any single one. From about 30 different plant foods a week the clearest differences in gut diversity show up.
Gut bacteria live on what the small intestine does not absorb. The Swiss average is about 18–20 g. Increase by 5 g a week, otherwise bloating follows.
In a Stanford study six servings of fermented food a day over ten weeks lowered inflammatory markers. One serving is about 100 g yoghurt, 50 g sauerkraut or a glass of kefir. Starting from zero means starting with one serving.
Useful in certain situations, no cure-all. The effect usually ends with the taking.
Variety on the plate beats single preparations — thirty different plants a week is a workable measure.