Prebiotics
Reviewed by Dr. Nikita Dinger, Founder & CEO, BioMeBar. Last reviewed 7 October 2026.
Click to WhatsAppTake the Gut Quiz
Prebiotics are substrates that gut bacteria use selectively and that give a health benefit to the person. In everyday words, they are the fibres that feed the bacteria you want to encourage. At BioMeBar, India’s first personalised synbiotic company, prebiotics are one of the three parts of what we call synbiotic: advanced probiotics, prebiotics and postbiotics together.
Why fibre is only half the story
Not all fibre behaves the same way. Some fibres pass through mostly unchanged and add bulk. Others are fermented by gut bacteria, and among those, only the ones that selectively nourish helpful groups such as bifidobacteria and lactobacilli count as prebiotic. The type, the dose and the person all matter. Someone with a sensitive gut may feel unwell on a fibre that another person digests happily.
The prebiotic fibres we work with
Each fibre in our toolkit has its own character, and the strain library describes them alongside the strains.
- PHGG (partially hydrolysed guar gum) is a soluble fibre that is generally well tolerated and low in FODMAPs. It has been studied for IBS symptoms and quality of life, for regularity, and for encouraging bacteria that make butyrate.
- Inulin (chicory root fibre) is the classic prebiotic. It has been studied for raising bifidobacteria, supporting regularity and helping calcium absorption.
- GOS (galacto-oligosaccharides) feed bifidobacteria even at low doses, and a GOS mixture has been studied for bloating and abdominal discomfort.
- Acacia fibre (gum arabic) is gentle and has been studied for supporting bifidobacteria and lactobacilli at doses that people usually tolerate comfortably.
- FOS (fructo-oligosaccharides) are short-chain fibres also found in onion, garlic and banana.
- Psyllium husk (isabgol) is a gel-forming soluble fibre traditionally used for regularity. It is best taken with plenty of water.
How prebiotics work in the gut
These fibres travel undigested to the large intestine, where bacteria ferment them. In the process, the bacteria multiply and produce short-chain fatty acids such as acetate, propionate and butyrate. Butyrate is the preferred fuel for the cells lining the colon, and short-chain fatty acids are studied for their roles in the gut barrier and in signalling to the immune system. Fibres such as psyllium also hold water, which is why they have a long traditional use for stool consistency. You can read more in our guide on fibre types and gut bacteria.
Why prebiotics are paired with probiotics
A live strain arrives in an environment where food is already spoken for. A prebiotic chosen to suit that strain may help it settle in and stay active while you take it, and the same fibre also feeds helpful bacteria that already live in you. That is the “syn” in synbiotic. When we design a combination, we pick the fibre to suit the strains and your tolerance, which is why two people might receive quite different prebiotic parts. See the advanced probiotics page for the other side of that pairing.
Who prebiotics may suit
People who eat little fibre, who are often constipated, or who want to support the bacteria they have after antibiotics may find prebiotics a natural fit. If your main concerns are constipation or bloating, or you live with IBS or a sensitive gut, the choice of fibre matters even more, and the dose usually starts low. Fibres that feed butyrate-producing bacteria are also of interest for immunity. Our article on FODMAPs explains why some fibres are friendlier than others for sensitive guts.
Click to WhatsAppTake the Gut Quiz
Prebiotic foods in Indian kitchens
You do not need to wait for a sachet to start. Many everyday ingredients are rich in prebiotic fibre:
- Onion and garlic, in tadka, curries and chutneys
- Slightly under-ripe banana
- Oats, barley, jowar, bajra and ragi
- Dal, rajma, chana and other whole pulses
- Cooked and cooled rice or potato, which develop resistant starch
- Isabgol stirred into water or buttermilk
- Seasonal vegetables such as raw or cooked leafy greens
Variety is the point. Aim for several plant foods a day instead of leaning on one. If you have IBS, some of these, especially onion, garlic and certain legumes, may be better introduced slowly or in smaller portions.
How we personalise the prebiotic part
We ask about your stool pattern, what makes you bloated, how much fibre you eat now and how you responded to fibre in the past. That decides which fibre goes in the sachet and how much. To start, message BioMeBar on WhatsApp or take the gut assessment. Our approach page explains the method.
How to take it
One sachet a day, stirred into half a glass of a drink of your choice, with plenty of water through the day. Build the habit and keep it going. Fibre does its best work when it arrives regularly.
What to expect
When you introduce fibre, your gut bacteria busy themselves fermenting it, and a bit more gas or a change in stool texture can show up in the first days. It usually passes. Regularity, if it improves, tends to show over a couple of weeks. Let us know how you feel and we can fine-tune.
Frequently asked questions
Is prebiotic the same as fibre?
Not exactly. All prebiotics are fibre-like substrates, but not all fibre is prebiotic. A prebiotic is one that selectively feeds helpful bacteria.
Can I get enough prebiotics from food?
Food is the foundation, and many Indian diets are good at it. A sachet adds specific, measured fibres chosen for you, on top of food and not in place of it.
Do prebiotics make you gassy?
Fermentation makes gas, so a little at first is normal. Starting small and choosing gentle fibres such as PHGG or acacia helps.
Which prebiotic is best for constipation?
PHGG, inulin and psyllium have each been studied for regularity. The best match depends on your pattern, which is where personalisation helps.
Should I drink more water?
Yes. Fibre works best with good hydration, especially psyllium.
Are prebiotics safe with IBS?
Many people with IBS tolerate gentle, low-FODMAP fibres. Tell us about your symptoms and we will select with that in mind.
How do prebiotics differ from postbiotics?
Prebiotics feed bacteria. Postbiotics are what bacteria produce. See the explainer for the full comparison.
A note on safety
Prebiotics are dietary supplements and not for medicinal use. Please talk to your doctor if you are pregnant, immunosuppressed, on blood thinners, or have a central line.
Keep reading
See the synbiotics overview, the strain library, and the page on postbiotics.
BioMeBar provides nutrition and gut health guidance and does not replace medical care. See a doctor for severe, persistent or worrying symptoms.