• Food and fibre variety help your gut bacteria recover more than any single supplement.
• Two probiotic strains, Saccharomyces boulardii and Lactobacillus rhamnosus GG, have good evidence for easing diarrhoea linked to antibiotics.
• Taking probiotics for too long afterwards may slow your own bacteria coming back. Timing matters.
• Zinc carnosine and bovine colostrum have decent human trial evidence. L-glutamine and modified citrus pectin have weaker evidence than their popularity suggests.
• Sleep, stress, and hormonal changes shape your gut recovery as much as diet does, and they’re easy to ove

Restoring gut health after antibiotics is rarely quick. Maybe you have just finished a course. The infection has gone, but your gut feels different. Loose stools, new bloating, a stomach that reacts more than it used to.

That’s a normal response. Antibiotics clear bacteria without much selection. So your gut’s good bacteria take a hit alongside the harmful ones.

Many people assume things settle within a week or two. But research tells a different story. Recovery often takes longer, and some bacteria may never fully return. I’ve covered that timeline in more depth in another post.

This post focuses on what actually helps. Which foods, which probiotics, and which supplements are worth your money, and which aren’t.

Your gut holds trillions of bacteria, fungi, and other microbes. Together, they’re called your gut microbiome. I’ve written more on what a microbiome actually is if you want the fuller picture.

These microbes help break down food and pull out nutrients your body can’t access alone. They also produce short-chain fatty acids, compounds made when bacteria break down fibre. The main one, butyrate, feeds the cells lining your gut wall and helps keep that lining strong.

Your gut bacteria do more than digestion, too. They help train your immune system. They’re also linked to mood, through the gut-brain connection and the body’s production of serotonin. So when antibiotics disrupt this community, the effects reach further than your stomach.

Antibiotics work by killing bacteria. That’s exactly what they’re meant to do, but they can’t always tell good bacteria from harmful ones.

So during and after a course, your gut’s bacterial diversity often drops. Research shows recovery is slower than most people assume. One well-known study found that, six months later, nine common species were still missing in most people.

Other research has gone further. One large study followed almost 15,000 people for up to eight years. It found that certain antibiotics left a detectable drop in gut bacteria diversity for years afterwards. This included antibiotics commonly prescribed for skin and urinary infections, such as flucloxacillin and fluoroquinolones.

I’ve gone through this timeline in detail in another post, including which antibiotics tend to cause the most disruption. If you want the full picture, that’s the place to look. For now, the main point is this: your gut doesn’t necessarily bounce back on its own.

I’ve written separately about which foods support your gut microbiome after antibiotics

Gut lining changes

Antibiotics can also affect the tight junctions in your gut wall. These are the protein structures that control what passes from your gut into your bloodstream.

When these loosen, it’s sometimes called increased intestinal permeability, or leaky gut in plain terms. This doesn’t happen to everyone, and it isn’t usually permanent. But it’s one reason gut-soothing nutrients, covered later in this post, are sometimes worth considering alongside food changes.

Vitamin production

Your gut bacteria also make vitamins. They produce most of your vitamin K2 and several B vitamins, including folate, riboflavin, and biotin. This doesn’t replace what you get from food, but it adds to it.
When antibiotics disrupt your gut bacteria, that production drops.

Research has linked this to general B vitamin and vitamin K2 shortfalls. These shortfalls can affect everything from energy to normal blood clotting. Eating vitamin-rich foods during and after a course of antibiotics is a sensible, simple step.

Bile acid processing

Some of your gut bacteria also help process bile acids, the compounds your liver makes to help digest fat. When these bacteria are disrupted, bile acid processing becomes less efficient.

This matters for a specific reason. An altered bile acid balance is a known risk factor for Clostridioides difficile, a harmful bacterium that can take hold after antibiotics. It’s part of why finishing your course as prescribed, and supporting your gut afterwards, both matter.

This isn’t just about digestion. When your gut bacteria are out of balance, the effects can reach further than your gut.

You might notice ongoing bloating, irregular bowel habits, or new food reactions you didn’t have before. Some people also notice low energy, disrupted sleep, or a flatter mood. Others notice changes in appetite or blood sugar, since gut bacteria help regulate both. That’s because your gut bacteria are linked to your immune system and to serotonin, a chemical involved in mood and sleep.

None of this means something is seriously wrong. But it does explain why “just give it time” doesn’t always feel like enough advice. Understanding what’s happening helps you choose where to focus your energy.

Recovery isn’t the same for everyone. A few things make it slower or less complete.

If your diet was already low in fibre and plant variety before you took antibiotics, your starting point is lower. That tends to mean a slower recovery too.

Repeated courses of antibiotics also add up. If your gut hasn’t fully recovered from one course before the next begins, the disruption tends to compound over time.

Age plays a role as well. Older adults tend to have less diverse gut bacteria to begin with, which can make full recovery less likely without targeted support.

Hormonal changes can play a part too. Gut bacteria diversity often changes around perimenopause and menopause, partly independent of antibiotics. I’ve written more on how menopause affects the gut if that’s relevant to you. If you’re already going through that transition, a course of antibiotics on top can feel like more of a setback.

If any of this sounds like your situation, it’s worth being more deliberate about the steps in this post. Don’t just assume things will settle on their own.

The strongest evidence for gut recovery isn’t a supplement. It’s food, and specifically, how varied your diet is.

Different gut bacteria feed on different types of fibre. So the wider the range of plant foods you eat, the more of your bacterial community you’re feeding. The American Gut Project studied this directly. People who ate more than 30 different plant foods a week had noticeably more diverse gut bacteria. Those eating fewer than ten had less diversity.

That means vegetables, fruit, beans, wholegrains, nuts, and seeds, not just salad. I’ve written more about why eating a wide range of plants matters so much for your microbiome, and how to build that variety without overhauling your whole diet.

Fermented foods are also worth including. Kefir, natural yoghurt, kimchi, and sauerkraut all carry live bacterial cultures. They won’t rebuild what’s been lost on their own. But they help keep your gut environment stable while your own bacteria find their feet again.

If you’d like specific food ideas, I’ve written a separate post on the best foods to restore gut health.

Prebiotic fibre: feeding what’s left

Prebiotics are a specific type of fibre that your gut bacteria can ferment and use as fuel. They’re different from probiotics, which are live bacteria themselves. I’ve explained that difference between probiotics and prebiotics in more depth elsewhere.

Foods like onions, garlic, leeks, oats, and slightly underripe bananas are natural sources. Cooked and cooled potatoes, rice, and pulses also contain resistant starch, a type of fibre your gut bacteria particularly favour. I’ve covered resistant starch and how to use it in a separate post.

Adding these little and often, rather than all at once, tends to be better while your gut is still settling.

Probiotics are usually the first thing people reach for after antibiotics. There’s a reasonable case for that, but it’s worth knowing the detail.

Two strains have solid evidence behind them: Saccharomyces boulardii, a yeast-based probiotic, and Lactobacillus rhamnosus GG. Both are recommended in international gut health guidelines specifically for easing diarrhoea linked to antibiotics. For that purpose, the evidence is good.

However, probiotics aren’t a simple win in every case. A well-known 2018 study looked at this. It found that taking probiotics straight after antibiotics slowed some people’s bacteria coming back. That’s compared with doing nothing at all. The probiotic strains settled in and got in the way of the native community re-establishing itself.

This doesn’t mean probiotics are pointless. It means timing and purpose matter. If you’re trying to ease diarrhoea during or shortly after antibiotics, using them makes sense. If you’re further along and want your own microbiome to fully recover, that’s different. Food and fibre are likely doing more of the real work.

It’s also worth knowing that multi-strain probiotic blends aren’t automatically better than single-strain products. A large review of 65 trials found single strains worked just as well as mixtures in most cases. The right strain for your specific need matters more than how many strains are on the label.

Not all probiotics are the same, and the strain matters more than the price tag. I’ve written a guide on choosing the right probiotic for your gut if you want help picking one. I’ve also written separately about spore-based probiotics, which work differently to the strains mentioned here.

Plenty of supplements are marketed for gut repair after antibiotics. Some have real evidence. Others rely more on branding than research. I’ve written a wider overview of gut-repair nutrients separately. Here’s an honest look at five of the most common options for antibiotic recovery specifically.

Zinc carnosine

Zinc carnosine has some of the better human trial evidence here. It helps maintain tight junctions, the protein structures that hold your gut lining cells together and control what’s allowed to pass through. One trial found it reduced gut permeability caused by a strong anti-inflammatory drug, when the two were taken together. It’s a reasonable option if your gut lining feels especially sensitive after antibiotics. I’ve written more on zinc and gut health generally, including other forms of zinc worth knowing about.

Bovine colostrum

A meta-analysis of ten randomised trials found that colostrum measurably reduced gut permeability. This included studies in athletes and in people taking medicines known to irritate the gut lining. Of the options here, it’s one of the more consistently evidenced ways to support your gut barrier directly.

L-glutamine

L-glutamine is one of the most recommended gut-repair supplements, but the evidence is more mixed than its popularity suggests. A 2024 review found no overall improvement in gut permeability from glutamine supplements. Higher doses, above 30 grams a day for under four weeks, showed some benefit. At typical supplement doses, the evidence for a real effect is weak. If you want to understand gut lining repair more broadly, I’ve covered that in a separate post on healing your gut lining.

DGL liquorice

DGL liquorice (deglycyrrhizinated liquorice) has older evidence, mostly for soothing the stomach lining and supporting ulcer healing rather than antibiotic recovery specifically. It can help a sensitive or irritated stomach. One safety note: standard liquorice root can raise blood pressure. Check with a medical herbalist if you take blood pressure medication or you’re pregnant. DGL itself has the problem compound removed, but it’s still worth checking the product you choose.

Modified citrus pectin

Modified citrus pectin has the thinnest human evidence here. Most of what’s known comes from lab and animal studies, showing it can support beneficial bacteria and gut lining proteins. There’s very little human trial data specific to gut recovery. 

Food and supplements aren’t the whole picture. Sleep and stress shape your gut recovery too, and they’re easy to overlook.

Poor sleep changes the balance of your gut bacteria within days, not months. I’ve written about the link between sleep and gut health if you’d like to understand that connection better.

Stress works in a similar way. It can change your gut bacteria within hours. I’ve covered that research in a separate post on stress and gut bacteria. After antibiotics, your gut community is already thin. Added stress makes it harder for the right bacteria to re-establish themselves.

None of this means you need to overhaul your life. But protecting sleep and managing stress, even in small ways, supports everything else you’re doing for your gut.

This doesn’t mean you should question every prescription. Antibiotics are chosen for good clinical reasons, and treating the infection properly comes first. But if you have a choice point, or you’re prone to digestive problems, it’s worth asking your GP a simple question. Would a narrower-spectrum option work just as well for this infection?

This is a conversation worth having, not a reason to delay or avoid antibiotics you need.

If your digestion still isn’t right weeks or months after finishing antibiotics, working through supplements alone often isn’t the most useful next step.

Ongoing bloating, irregular bowel habits, fatigue, or new food reactions can have several different causes. Sometimes it’s straightforward dysbiosis that settles with diet and time. Sometimes there’s something else going on. That might be SIBO, or a food intolerance the antibiotics have brought to the surface rather than caused.

A personalised consultation can help you understand what’s happening and provide support that fits your situation. That’s usually more useful than trying supplement after supplement and hoping something works.

Can I take probiotics while I’m still on antibiotics?

Yes, and for easing diarrhoea, this is when the evidence is strongest. Just take them a couple of hours apart from your antibiotic dose. That way, the antibiotic doesn’t kill the probiotic before it can do its job.

How long should I keep taking a probiotic afterwards?

There’s no fixed answer, but most evidence supports a few weeks rather than months. After that, food and fibre are likely doing more of the work than a continued probiotic.

Is it normal to still feel off two or three months later?

It happens more often than people expect, especially after broad-spectrum antibiotics. It’s not necessarily a sign that something is seriously wrong. But it is a sign that your gut needs more support than time alone is giving it. If things haven’t settled by then, it’s worth getting a clearer picture rather than waiting it out further.

Do I need a stool test to know what’s going on?

Not always. For most people, a sensible food-first approach and time are enough. Testing can help when recovery has stalled, or when there’s a pattern that needs untangling, such as suspected SIBO. A medical herbalist or functional medicine practitioner can help you work out whether testing would actually change your approach.

If you want a simple way to sequence this, start with food. Add more plant variety and a fermented food or two most days.

If diarrhoea is the main problem, a course of Saccharomyces boulardii or Lactobacillus rhamnosus GG alongside your antibiotics is reasonable. Take probiotics a couple of hours away from your antibiotic dose. Taking them together can reduce how well either one works. Stop the probiotic once things have settled, rather than continuing indefinitely.

Sleep and stress matter too. Poor sleep and high stress can both slow gut recovery. Protecting both matters alongside diet changes.

None of this needs to be perfect all the time. Steady, ordinary habits do more than any single supplement.

Antibiotics are sometimes necessary, and the gut disruption that follows is real. But what you do afterwards makes a difference to how completely your gut recovers.

Food and fibre variety matter more than any single supplement. The right probiotic strain, used at the right time, helps with specific problems like diarrhoea. Sleep, stress, and hormonal changes matter more than most people realise, too. And among the supplements marketed for gut repair, some have genuine evidence behind them. Others don’t, whatever the packaging says.

If you’ve taken antibiotics recently, or you’re still feeling the effects of a course from a while back, the same applies. It’s worth getting clear on what your gut actually needs.