Reboot the Gut

Reboot the Gut

Restore balance, calm inflammation, and support your microbiome with simple, science-informed changes.

The gut is far more than a digestive tube. It is an ecosystem, an immune organ, and a metabolic control centre. When it's out of balance, it can affect mood, weight, hormones, energy, skin and even sleep. This page explores practical, evidence-informed ways to "reboot" your gut and support long-term health.

The gut is an ecosystem, an immune organ, and a metabolic control centre. When it is out of balance, there is something we can all do to get it back on track.

Explore methods below:

Low FODMAP for IBS:

A Forgotten Tool

From years in clinical practice, as well as my own family's health journeys, I've rarely seen patients with Irritable Bowel Syndrome (IBS) offered the Low FODMAP diet as an option – yet it can be life-changing for some. I wanted to minimise the prescription medications we were all taking for IBS and take back some control which I did not know was possible, even as a General Practitioner!

The Low FODMAP protocol involves temporarily removing certain fermentable carbohydrates that can trigger bloating, pain, diarrhoea or constipation, and then reintroducing them in a structured way. Explore the low FODMAP diet pages.

Following a Low FODMAP diet for 6–8 weeks can give the gut a chance to settle. During the reintroduction phase, you learn which FODMAP groups trigger symptoms. Interestingly, once the gut calms, some previously problematic foods can become tolerable again. From personal experience, it was one of the best things I did. Not only I was able to realised what triggered me, I started planning my meals where I was not combining too many FODMAPs and also I started re tolerating some FODMAPs. Although I follow a diverse diet to build my microbiome, majority of the times, I apply the concepts of a low FODMAP diet in my meals too, especially if I have IBS flare up. Now I see my meal as FODMAPs, food for the microbiome and how it will spike my glucose (more on this on my other pages)! Explore further on my page about "A day on the low FODMAP diet".

From personal experience, the low FODMAP diet was one of the best things I did for my IBS - I started eating foods which I was not tolerating before.

Important: Always speak to your GP or a dietitian before starting the Low FODMAP diet, especially if you have other medical conditions or are underweight.

Gut Reset for Everyone:

Rebooting the Gut Even Without IBS

Many people experience low-grade gut dysfunction without a formal diagnosis: bloating, irregular bowel habits, sugar cravings, fatigue or "brain fog". Often, this reflects an unhappy microbiome rather than a dramatic disease. 

In my opinion, most us are probably walking around with some form of dysbiosis due to the ultra-processed foods we consume in our diet. From the highly processed oils we use, to the low fat yogurts, the labelled 'health' foods. Majority of our food shopping is ultra-processed and has multiple ingredients that looks nothing like the original food. And for those of us who think we are buying fruits and vegetables, even these are not what they were in ancestral times! They are covered with waxes, pesticides, packed in plastics. Not to mention the soil these days. The lack of nutrients in our soil today means we are not even getting fresh fruit and vegetables we once had. We drink water from plastic bottles and overall the plastics in our diet is shockingly high. And then there are all these additives and emulsifiers in our diet. All these are destroying our gut microbiome and causing a level of dysbiosis. 

Most us are probably walking around with some form of dysbiosis due to the ultra-processed foods we consume in our diet today.

Is there anything we can do? One of the most effective ways to reboot the gut is simply to clean up the diet:

Simple Gut-Friendly Changes

• Remove or drastically reduce ultra-processed foods

• Eat more whole foods (fruits, vegetables & grains) or minimally processed foods

• Cut back on refined sugars and white flours (which are highly processed and bleached!)

• Minimise seed oils (e.g. sunflower, palm oil, rapeseed blends in UPFs). The opinion on this is mixed. I am support the opinion that seed oils are not good for us (the reasoning is in the omega 6: omega 3 ratio - more on this in upcoming blog).

• Increase leafy greens, fibre and polyphenol-rich plants

• Eat a diverse diet with more that 30 plants per week 

• Increase fibre atleast 30 grams per week 

• Try and get a variety of protein even from plants. If protein is not vegan, then grass-fed or minimally processed meat where possible (normal meat is grain fed & has antibiotics and hormones injected in them). 

• Healthier fats in the diet - You could use extra virgin olive oil as your main fat. Some prefer coconut oil. I use grass fed butter too but in lower quantities. I support the opinion that grass fed butter (which our ancestors also ate) is better for us than seed oils. Major nutrition programs do not agree with that idea but there are a group of scientists and doctors who are moving away from seed oils. 

• Add fermented foods such as kefir, sauerkraut, kimchi, kombucha and live yogurt

• Reduce snacking between meals. This allows insulin levels to normalise. 

• Try Intermittent Fasting. The biggest studies support the 16 hours fasting and 8 hours eating window. The fasting window allows our microbiome to recover and start fresh the next day. The microbiome needs minimal 12 hours fast to recover. 

This is not a fad; it's closer to how our ancestors ate – whole foods, natural fats, and plenty of fibre and fermentation.

The principles of eating a clean diet is closer to how our ancestors ate – whole foods, natural fats, and plenty of fibre and fermentation.

Ultra-Processed Diets vs the Ancestral Microbiome

Historically, human diets were rich in fibre, resistant starch, polyphenols and naturally fermented foods. Our ancestors ate whole foods. They had to go out everyday and hunt for food rather than opening a fridge in their cave! Sometimes they came back with food and they would have a feast. On other days, they did not have any food to bring back. This means they went through cycles of feast and fasting. They ate whole foods, greens and natural fats.

Today, many diets are dominated by ultra-processed foods containing additives, emulsifiers, refined sugars and altered fats. We have food available to us all the time in our kitchen cupboards, fridge and freezers. The pre packed foods were probably packed months to years ago. The so called fresh bread is made of ten plus ingredients and packed in plastic bags. The fruit and vegetables have been selectively bred to taste more sweet and is covered in pesticides and wrapped in plastic bags. The "healthy vegetable oils" have gone through extensive industrial processing to become oils. Children are growing up thinking of sweets and chocolates as treats. Low sugar drinks have become a normality even though evidence shows that sweeteners damage the gut and have long term health side effects. It is actually hard to source good food now. 

There is clear evidence now that these additives and emulsifiers are causing a direct damage to the microbiome, weakening the gut lining, creating gaps where pathogens and other unwanted bacterial elements can leak in to the blood stream. This initiates a cascade of immune response by the body and chronic inflammation. 

There is clear evidence now that these additives and emulsifiers are causing a direct damage to the microbiome & weakening the gut lining.

This shift can directly impact the micriobime in the following way:

• reduce microbial diversity, allowing good bacteria to reduce and the bad bacteria to overgrow. 

• lower beneficial short-chain fatty acids (SCFAs) which has various functions in the protective barrier of the gut and in the body.

• slow gut motility due to lack of mucus and impaired peristalsis signals (via the gut brain axis).

• weaken the mucosal barrier and creating a leaky gut syndrome. 

• promote low-grade inflammation which overtime is associated with various chronic inflammantory diseases. 

Not surprisingly, conditions like obesity, type 2 diabetes, fatty liver and autoimmune diseases have risen alongside these changes in how and what we eat. These conditions are thought to be like an epidemic of today due to the ultra-processed diets we eat! I think we need to tackle the root of the problem alongside medical treatment. We also need to seriously address cleaning up the diet.

This is where I feel that education is important. The message of eating clean needs to start from early age where we introduce good habits. Education needs to continue in schools. Medical students needs to be trained more on nutrition. As doctors, we also need to talk about this more in our consultation rooms. At home, as families we need to implement healthy eating together. 

To change the trajectory of chronic disease, we must go back to the root: early education. Clean eating and nutrition literacy should be taught at home, in schools, and in medical training — not introduced after illness begin.

Fasting as a tool for Gut Repair

Intermittent fasting is not a new trend—our ancestors practiced it out of necessity, long before it had a name. Humans evolved to go for extended periods without food, relying on metabolic flexibility to switch between glucose and fat as fuel. It wasn't until the 20th century that constant snacking, ultra-processed foods and irregular eating patterns disrupted these natural rhythms. 

Modern clinicians reintroduced this ancient concept under the term "time-restricted eating," highlighting how strategic fasting can support metabolic health, improve insulin sensitivity and reduce inflammation. In recent years, fasting has also been discussed in the context of "gut rest," allowing the digestive tract to repair and reset between meals. I have gained a lot of interest in this concept which lead me in to reading countless books and research in this subject. 

One of the longest and most influential studies on time-restricted eating called the "Big IF" (Intermittent Fasting) study, conducted by ZOE and researchers in the UK, is recognized as the largest, involving over 100,000 participants. The study was successful in demonstrating benefits on weight control, metabolic markers and even microbiome diversity.

Other researchers and clinicians now advocate structured fasts—such as 24-hour "gut reset" fasts or fasting synced with circadian rhythm—to support digestive health, reduce bloating and encourage healthier microbial communities. When paired with dietary cleanup (reducing ultra-processed foods, lowering sugar intake and unhealthy oils while increasing whole foods and fibre), intermittent fasting becomes a powerful tool for restoring metabolic flexibility and improving the resilience of the gut microbiome. 

Fasting gives the gut a chance to rest and reset. A minimal of 12 hours fast is needed to reset the microbiome. It can support:

• autophagy (cellular clean-up processes) - this happens more effectively when we fast

• improved microbial diversity - allowing the good bacteria to re grow in the fasting window

• reduced inflammation - the gut lining is able to recover which allows the body to address any inflammation

• better insulin sensitivity - repeat snacking causing insulin levels to rise which can causes less insulin sensitivity and more insulin resistance. The fasting window allows insulin levels to normalise. 

• less bloating and dysmotility 

• more stable energy and appetite - fasting improves hunger signals and more focus while teaching the body to switch between glucose metabolism to using fast stores for energy. Utilising fat stores increases ketone production which leads to more stable energy, less brain fog and less hunger. 

Types of Fasts That May Help

• Intermittent fasting (14–16 hours):
  A daily eating window of up to 8-12 hours and an overnight fast to give the gut a break. This method is supported by the bigger study IF. 

• 24-hour fasts (e.g. dinner-to-dinner):
  Once a week or fortnightly; a gentle metabolic and gut reset.

• 36-hour fasts
  Some scientists suggest 36 hour fast once in a while. This is a gut reset and also can help individuals with insulin resistance and if they are stuck in a plateau phase of weight loss. This length fast takes a lot of training and I would recommend anyone considering this to seek medical advice before considering this. I have tried this a few times but I prefer to adhere to the more evidence based fasts suggested by the IF study. 

• Longer fasts have been done but I will not be discussing those!

Women, especially in perimenopause and menopause, may benefit from fasting protocols tailored to female physiology and hormonal rhythms. I discuss this in more detail in my hormone and menopause sections. Always seek advice from your own medical professional before implementing fasting, especially longer fasts. 

When paired with dietary cleanup (reducing ultra-processed foods and increasing whole foods and fibre), intermittent fasting becomes a powerful tool for restoring metabolic flexibility and improving the resilience of the gut microbiome.

Fermented Foods vs Probiotics

Fermented foods are one of the most powerful – and underused – tools for gut repair. They often provide a wider range and higher volume of beneficial bacteria than many commercial probiotic capsules.

Fermentation is an ancient practice found in nearly every civilisation, long before microbes were discovered or named. Our ancestors relied on fermentation as a natural method of food preservation, especially in times when refrigeration did not exist. What seemed like simple survival techniques actually introduced beneficial bacteria into the diet for thousands of years. Growing up, my mother would make homemade pickles and I never gave them much thought beyond their flavour; little did I know I would one day be writing about them in the context of gut health. Even our mothers and grandmothers would leave dough to ferment for days, and rather than worry about it, they baked the most aromatic and delicious breads from it. 

Today, fermented foods have re-emerged as a "health food" because we now understand what our ancestors already practiced intuitively: fermentation seeds the gut with beneficial bacteria, supports microbial diversity, and contributes to the production of vitamins and metabolites such as short-chain fatty acids. Research also suggests that regular intake of fermented foods can reduce post-prandial glucose spikes, improve digestion, and modulate the gut-brain axis. Foods like kimchi, sauerkraut, kefir, kombucha, miso and cultured yoghurts are now recognised for their role in modulating the microbiome, reducing inflammation and improving digestive resilience. 

I often smile and wonder how did our mothers know that the ferments were so good for us! I look back at our traditional remedies and foods habits and realise how they made so much sense even scientifically. What was once a cultural tradition has become a scientifically validated tool for supporting metabolic and gastrointestinal health. 

Examples  of fermented foods include:

• kefir

• sauerkraut

• kimchi

• kombucha

• miso

• live natural yogurt

Fermented foods offer a naturally diverse ecosystem of live microbes delivered within a matrix of fibre, organic acids, enzymes and bioactive compounds that support microbial survival and function. This combination helps beneficial bacteria travel through the digestive tract, interact with the resident microbiome, and contribute to the production of metabolites such as short-chain fatty acids. 

In contrast, probiotic supplements tend to provide a smaller number of isolated strains, often from just a handful of species, and their effects can vary depending on the dose, formulation and the host microbiome. While supplements can be helpful in targeted situations (for example after antibiotics, during acute gut symptoms, or as part of a specific clinical strategy), they do not always replicate the microbial richness found in traditional fermented foods.

If tolerated, fermented foods can be used as an excellent daily foundation for supporting microbial diversity and gut resilience, while probiotics can be viewed as an adjunct or therapeutic tool. Ultimately, the most beneficial approach depends on the individual — their microbiome, symptoms, tolerance and nutritional status — but incorporating fermented foods as part of a real-food dietary pattern provides a more holistic strategy for strengthening gut health. 

Culture and cuisine have always understood something that science is only now catching up to: fermented foods are not just a flavour enhancer or preservation technique; they are alive, functional, and deeply connected to both our health and our heritage.

After Antibiotics:

Rebuilding the Gut After Antibiotics

Antibiotics have revolutionised modern medicine, dramatically reducing deaths from bacterial infections. Yet while they eliminate harmful pathogens, they also disrupt the beneficial bacteria that line our gut and contribute to our immune, metabolic and digestive functions. 

Antibiotics can alter the gut microbiome by reducing beneficial bacterial species, lowering microbial diversity and allowing more pathogenic bacteria or fungi to overgrow. This shift can increase gut permeability, impair SCFA production, and weaken immune signalling. 

Recovery depends on the individual microbiome and can take weeks to months. This disruption can lead to a temporary imbalance known as dysbiosis, weakening the microbiome's ability to defend against inflammation or opportunistic microbes.

While antibiotics are often necessary, their impact on the gut is a strong reason to focus on dietary repair and microbiome restoration afterwards. Supporting microbial diversity through fibre, polyphenols, fermented foods and time-restricted eating can help rebuild balance and strengthen gut resilience during recovery.

 After a course of antibiotics, it's worth focusing intentionally on gut repair:

• emphasise fermented foods

• aim for fibre and plant diversity (lots of different plants)

• consider prebiotics (e.g. inulin, GOS, beta-glucan) if tolerated

• prioritise omega-3 fats

• include polyphenol-rich foods (berries, olives, herbs, green tea, cacao)

• avoid ultra-processed foods during the recovery phase

Some people develop IBS-like symptoms after antibiotics; a structured approach to diet and microbiome support can be very helpful.

While antibiotics are the most well-known disruptors, non-antibiotic medications can have similar downstream effects. Proton pump inhibitors (PPIs) lower stomach acid, reducing an important antimicrobial barrier and increasing SIBO risk. Non-steroidal anti-inflammatory drugs (NSAIDs) can increase intestinal permeability and contribute to low-grade gut inflammation. Oral contraceptives, metformin and certain psychotropic medications have also been associated with microbiome changes in emerging research, though clinical implications vary.

While antibiotics are often necessary, their impact on the gut is a strong reason to focus on dietary repair and microbiome restoration afterwards. Supporting microbial diversity through fibre, polyphenols, fermented foods and time-restricted eating can help rebuild balance and strengthen gut resilience during recovery.

Exercise & Gut Motility:

Movement, Motility and the Microbiome

Movement is a simple but often overlooked gut therapy. Physical activity:

• improves gut motility and helps prevent constipation

• reduces transit time

• positively influences microbial diversity

Even a daily walk can make a noticeable difference. Resistance training adds extra benefit by improving metabolic health, which in turn supports a healthier microbiome.

Regular physical activity has been shown to positively influence the gut microbiome. Studies demonstrate that moderate aerobic exercise can increase microbial diversity and enrich beneficial bacterial species, particularly those involved in producing short-chain fatty acids (SCFAs) such as butyrate. Higher butyrate levels are associated with improved gut barrier integrity, reduced inflammation, and better insulin sensitivity. These effects have been observed even without major dietary changes, indicating that exercise itself can modulate microbial composition and function. Observational data comparing athletes with sedentary individuals also show greater microbial diversity and enhanced metabolic pathways in the more active populations, reinforcing the microbiome–metabolic connection.

From a gastrointestinal perspective, exercise improves gut motility, supporting more regular bowel habits and reducing symptoms such as bloating and constipation. This is particularly relevant in functional gut disorders such as IBS and in conditions like SIBO, where delayed motility contributes to symptom persistence. Even light post-meal movement (such as a 10–15 minute walk) has been shown to reduce post-prandial glucose spikes, ease digestive workload and improve glycaemic regulation—mechanisms that indirectly support gut health. Emerging research also suggests that exercise can influence the gut-brain axis through enhancements in vagal tone, reductions in stress hormones, and improvements in mood, sleep, and perceived stress, all of which have secondary effects on motility and microbial resilience.

Practical Approaches for a "Gut Reboot"

A balanced approach combining aerobic movement, walking and resistance training appears most beneficial. Practical examples include:

• Daily walking: 20–30 minutes minimum, ideally with a 10–15 minute walk after meals to support glucose regulation and motility.

• Aerobic exercise: 3–5 times per week (e.g., brisk walking, cycling, swimming, dancing) at moderate intensity.

• Resistance training: 2–3 times per week to improve muscle mass and insulin sensitivity, which indirectly supports metabolic and microbial health.

• Mind–body exercises: Yoga, Pilates and tai chi may support the gut via improvements in stress physiology, vagal tone and gut-brain axis signalling.

• Low symptom days vs high symptom days: During symptom flares (IBS, SIBO, dyspepsia), lower-impact activities or gentle walking may be better tolerated.

Movement does not need to be excessive to support gut health - rather, the consistency and rhythm are important. Exercise functions as a microbiome modulator, an insulin sensitiser, and a natural motility enhancer, making it a valuable component of a "gut reboot" strategy alongside dietary modification, fasting windows, and fermented foods.

Exercise functions as a microbiome modulator, an insulin sensitiser, and a natural motility enhancer, making it a valuable component of a "gut reboot" strategy alongside dietary modification, fasting windows, and fermented foods.

The Gut–Brain Axis: Mood, Sleep and Stress

The gut is not just a digestive organ—it talks directly to the brain through what is known as the gut–brain axis. This is a bidirectional connection of the gastrointestinal system with the central nervous system through multiple pathways, including the vagus nerve, immune mediators, neurotransmitters, hormones, and microbial metabolites. 

The cells lining the gut and the microbes living there produce many of the same signalling molecules found in the brain, such as serotonin, GABA and dopamine precursors. Serotonin is often associated with mood and wellbeing and is predominantly produced in the gut.

When the gut microbiome is balanced (symbiosis), the gut brain axis supports healthy motility, digestion, mood regulation, sleep patterns and appetite. 

When dysbiosis occurs, inflammatory metabolites, endotoxins such as LPS, and changes in neurotransmitter production can disturb this communication. 

Clinically, this may appear as symptoms such as bloating, altered bowel habits, sleep disturbances, anxiety, low mood, food sensitivities, pain amplification or worsening stress tolerance. 

Many patients with IBS report increased symptom flares during stressful periods, illustrating how psychological stress can influence gut function through autonomic pathways. Similarly, dysbiosis and gut inflammation can influence how the brain processes stress.

How the Gut–Brain Axis Supports a "Gut Reboot":

Reducing ultra-processed foods, increasing dietary fibre and polyphenols, using fermented foods, intermittent fasting, and restoring circadian eating patterns can reduce inflammatory signalling and improve microbial balance. This, in turn, strengthens the intestinal barrier and reduces metabolic stress on the brain.

Exercise, sleep and stress-management techniques can help strengthen the gut–brain axis. These lifestyle components can help re establishing gut–brain communication and helping the microbiome recover:

• Physical activity enhances vagal tone and increases butyrate-producing bacteria
• Sleep regulates cortisol and circadian rhythms that govern digestive motility. 
• Stress reduction can reduce sympathetic overdrive, which otherwise slows digestion and increases visceral pain sensitivity. These lifestyle components are therefore not add-ons—they are integral to re-establishing gut–brain communication and helping the microbiome recover.

A gut reboot works best when approached holistically: supporting the microbes, the gut lining, immune system and nervous system together. When these systems synchronise, the gut becomes more resilient, symptoms improve and the microbiome can return to a more balanced state.

Gut Health in Perimenopause and Menopause

Menopause brings a major hormonal shift that affects far more than reproductive tissues. Declining oestrogen and progesterone influence the composition and diversity of the gut microbiome, particularly through an interconnected system called the estrobolome, which regulates oestrogen metabolism. 

During perimenopause and menopause, hormonal shifts start multiple microbial ecosystems:

• the gut microbiome (including the estrobolome)

• the vaginal microbiome (often less Lactobacillus)

• the urogenital microbiome (influencing UTIs and urgency)

After menopause, reductions in short-chain fatty acid–producing bacteria, altered bile acid metabolism, increased inflammation and changes in gut permeability contribute to symptoms such as bloating, constipation, mood changes, weight gain, inflammation, pelvic and bladder symptoms and reduced insulin sensitivity. These microbial changes help explain the rise in metabolic syndrome, non-alcoholic fatty liver disease, visceral fat accumulation and cardiovascular risk seen in midlife women.

Understanding menopause related micriobiome imbalance brings hope for anyone suffering during menopause. Supporting microbial diversity through dietary fibre, polyphenols, fermented foods, healthy fats, stress reduction, restorative sleep, and time-restricted eating can help regulate glucose metabolism, improve gut barrier function, modulate inflammation and support hormonal balance indirectly. In this way, a "gut reboot" is not just a digestive intervention, it becomes part of a broader strategy to navigate menopause with better metabolic health, better mood, and greater resilience.

A "gut reboot" is not just a digestive intervention, it becomes part of a broader strategy to navigate menopause with better metabolic health, better mood, and greater resilience.

Metabolism, Immunity & the Gut

The gut is a major site of immune and metabolic regulation. Approximately 70% of the immune system sits in and around the gastrointestinal tract, where immune cells continuously interact with dietary antigens, microbes and microbial metabolites. 

Beneficial bacteria produce short-chain fatty acids (SCFAs) such as butyrate, propionate and acetate, which help maintain the gut barrier, reduce inflammation and regulate metabolic pathways including glucose metabolism, lipid metabolism and insulin sensitivity. 

When the gut microbiome becomes imbalanced (dysbiosis), low grade inflammation can develop. This inflammation can drive or worsen insulin resistance, visceral fat deposition, non-alcoholic fatty liver disease (NAFLD), PCOS, metabolic syndrome and type 2 diabetes. 

Dysbiosis can also trigger immune dysregulation through mechanisms involving increased intestinal permeability (often referred to as "leaky gut"), translocation of bacterial products such as lipopolysaccharide (LPS) into the bloodstream, and altered cytokine signalling. These pathways link the microbiome to systemic autoimmune tendencies, chronic fatigue, joint pain and skin conditions. This metabolic–immune connection explains why so many modern inflammatory diseases are multi-system.

Understanding this relationship is intriguing! A "gut reboot" supports the microbiome in producing SCFAs, strengthening the gut barrier and reducing inflammatory tone, which in turn improves insulin sensitivity, metabolic flexibility and immune balance. Dietary diversity, polyphenols, fermented foods, intermittent fasting, exercise and improved sleep all contribute to restoring microbial balance. In this way, repairing or supporting the microbiome becomes a powerful tool for improving both metabolic and immune health - not simply for managing digestive symptoms.

Repairing or supporting the microbiome becomes a powerful tool for improving both metabolic and immune health - not simply for managing digestive symptoms.

Key Nutrients for Gut Reboot:

Nutrients That Support a Gut Reboot

Some of the key nutritional factors that support gut repair and microbial balance include:

• Plant & fibre diversity – fuels beneficial bacteria & SCFA production
• Polyphenols – from colourful fruits, herbs, spices, teas & EVOO to enhance microbial diversity
• Fermented foods – introduce live microbes & improve resilience (if tolerated)
• Omega-3 fats – support metabolic + inflammatory balance
• Magnesium & potassium – optimise motility, electrolytes & cellular function
• Vitamin D – modulates immune responses & gut barrier integrity

Supporting a healthy microbiome requires feeding the bacteria that support us. The nutrients most consistently shown to improve gut health are dietary fibres (especially prebiotic fibres), polyphenols, fermented foods, and omega-3 fats. Prebiotic fibres act as fuel for beneficial bacteria such as Bifidobacteria, which in turn produce Short-Chain Fatty Acids (SCFAs) like butyrate. SCFAs help repair the gut lining, regulate glucose metabolism, reduce inflammation, and contribute to immune balance. Polyphenols from extra virgin olive oil, berries, nuts, tea and coffee are partially digested by microbes and converted into anti-inflammatory metabolites that increase microbial diversity.

Fermented foods such as kefir, yogurt, kimchi, sauerkraut, and tempeh introduce live bacteria directly into the gut, which appears to enhance microbial diversity and resilience. Omega-3 fatty acids further support microbial diversity and reduce inflammatory pathways linked to metabolic and cardiovascular disease. Alongside these foods, collagen-rich broths, spices like turmeric and ginger, and plant-based enzymes help maintain the gut barrier ("tight junctions") and support epithelial repair. Together, these dietary elements form the foundation of what many people call a "gut reboot"—a period focused on restoring microbial balance, repairing the gut lining, improving metabolic signaling, and reducing immune overactivation.

This approach matters because dysbiosis—when the microbiome loses diversity or balance—has been linked to conditions such as obesity, insulin resistance, non-alcoholic fatty liver disease (NAFLD), metabolic syndrome, inflammatory bowel disorders, and autoimmune tendencies. Increasing plant diversity (aiming for 30 plus plants per week), reducing ultra-processed foods, avoiding excessive refined sugar and seed oils, and strategically using fermented foods or fasting windows can support microbiome recovery. Nutrition becomes less about restriction and more about feeding the ecosystem that lives inside us - and that ecosystem determines much of our inflammation, metabolism, and long-term health.

Nutrition becomes less about restriction and more about feeding the ecosystem that lives inside us - and that ecosystem determines much of our inflammation, metabolism, and long-term health.

Where to Start

Rebooting the gut doesn't have to be complicated. You don't need to do everything at once. Start with one or two changes and then keep building up on it. Personally I believe that understanding the principles is important for building the foundation. Then you can build that foundation by following some rules. In the same way understand the principles of microbiome and how to support it. Then understand the principles of how to clean up the diet. Ask yourself why you want to do this. Let that be the initiative and motivation to implement changes to your diet. Then follow some rules and stick to them. Follow one rule at a time. Eventually you will succeed. Here is my summary of where to start in 5 steps: 

1. Clean up the diet (see my full list of how to do this)
2. Eat more fermented foods 
3. Try time restricted eating (12 hours is enough for microbiome to reboot)
4. Exercise daily if it is gentle exercise daily
5. Address stress & sleep

Over time, these small steps can transform your microbiome, your gut, your health & how your digestive system and the rest of your body feels.

This page suggests starting point and the principles of how to reboot the gut, it is not a replacement for medical advice. 

Always speak to your GP or a qualified professional before making major dietary or fasting changes, especially if you have underlying health conditions.

Citations: 

Microbiome, SCFA & Barrier Function

1. Koh A, et al. Short-chain fatty acids and host metabolism. Nat Rev Microbiol. 2016.

2. Chambers ES, et al. SCFA supplementation improves metabolic and inflammatory markers.
3. Rivera-Chávez F, et al. Dysbiosis & barrier function.
4. Sonnenburg ED & Sonnenburg JL. Diet–microbiome interactions.

5. De Filippis F, et al. Mediterranean diet & microbial diversity. Gut. 2020 & 2024 update.

Dysbiosis, Metabolism & Chronic Disease
6. Bäckhed F. Mechanisms linking microbiota and metabolic disease. Cell Metab. 2022.
7. Tilg H & Moschen AR. Microbiota and metabolic syndrome. Nat Rev Endocrinol. 2020.
8. Spector T, et al. The PREDICT studies (dietary responses & metabolic individuality). Nat Med & Cell Metab. 2020–2024.
9. Cani PD, et al. Metabolic endotoxemia and insulin resistance. Diabetes. 2007 & updates through 2022.

Polyphenols, Fibre, Plant Diversity
10. Tomas-Barberan F, et al. Microbial metabolism of polyphenols. Adv Nutr. 2022.
11. Mas-Capdevila A, et al. Polyphenols & vascular/metabolic outcomes. Nutrients. 2021.
12. Sonnenburg JL. Diversity hypothesis & 30-plant rule. ISAPP / Proceedings 2020–2024.

Fermented Foods vs Probiotics
13. Wastyk HC, et al. Fermented foods increase microbial diversity & reduce cytokines. Cell. 2021.
14. Marco ML, et al. Fermented foods and microbiome: mechanisms. Nat Rev Gastro Hepatol. 2021.
15. Taylor BC, et al. Fermented foods shape microbiome composition. Nat Commun. 2020.

Omega-3 and Lipid-Microbiome Interaction
16. Watson H, et al. Omega-3 modulates microbiome diversity. Gut. 2018.
17. Costantini et al. Omega-3 and immune signaling. Front Immunol. 2022.

Vitamin D, Immunity & Epithelial Barrier
18. Cantorna MT. Vitamin D and immune signaling. Nutrients. 2019.
19. Gubatan J, et al. Vitamin D and IBD epithelial outcomes. Aliment Pharmacol Ther. 2020.

Magnesium, Motility & Stress Axis
20. Tarleton EK, et al. Magnesium, sleep, stress regulation. Nutrients. 2020.
21. Schuchardt JP, Hahn A. Magnesium and motility. Nutrients. 2017.

Potassium & Metabolic Regulation
22. Zhang M, et al. Potassium intake reduces metabolic syndrome risk. Nutrients. 2022.

Exercise & Microbiome
23. Barton W, et al. Exercise increases microbiome diversity. Gut. 2018.
24. Clark A & Mach N. Exercise, athlete microbiomes & SCFAs. Front Microbiol. 2017.
25. Estaki M, et al. Cardiorespiratory fitness and microbiome diversity. Microbiome. 2016.

Gut-Brain Axis & Mood
26. Cryan JF, et al. Microbiota–gut–brain axis. Physiol Rev. 2019.
27. Foster JA. Gut microbes & mental health. Nat Rev Gastroenterol Hepatol. 2021.

Menopause, Estrogen & Microbiome
28. Flores R, et al. Estrobolome, estrogen metabolism & microbiota. J Clin Endocrinol Metab. 2012 + follow-up reviews (2020–2024).
29. Santos-Marcos JA, et al. Sex hormones, menopause & microbiome. Clin Endocrinol. 2021.
30. Davani-Davari D, et al. Menopause & dysbiosis–metabolism link. J Menopause. 2023.

Immune System & Microbiome (70% GALT)
31. Belkaid Y & Hand T. Immune-microbiota crosstalk. Science. 2014 & updated 2020 review.
32. Murphy K, et al. GALT & adaptive immunity. Nat Rev Immunol. 2021.

Antibiotics, PPIs, NSAIDs & Microbiome Injury
33. Dethlefsen L & Relman DA. Recovery post-antibiotic. PLoS Biol. 2011 + updated reviews 2020.
34. Maier L, et al. Antibiotics + pathobionts. Nature. 2018.
35. Freedberg DE, et al. PPIs & dysbiosis + infections. Nat Commun. 2019.
36. Rogers MAM, et al. NSAIDs & gut permeability. Gastroenterology. 2020.
37. Chassaing B, et al. Emulsifiers & leaky gut. Nature. 2022.

UPFs (Ultra-Processed Foods)
38. Hall KD, et al. UPF vs unprocessed: metabolic differences. Cell Metab. 2019.
39. Zinocker & Lindseth. UPFs, additives & dysbiosis. Microbiome. 2018.

Fasting & Gut Reset
40. Jordan S, et al. Fasting remodels microbial communities. Nat Metab. 2021.
41. Thaiss CA, et al. Circadian rhythms, feeding & microbiome. Cell. 2016.