Gut health is talked about a lot. Sometimes it feels like every health problem gets blamed on "the gut" at some point, which makes it hard to know when something is genuinely worth paying attention to.
The truth is that the gut microbiome, the trillions of bacteria, fungi, and other microorganisms living in your digestive tract, does play a significant role in a surprisingly wide range of bodily systems. When it's disrupted, you often know about it, though not always in the ways you'd expect.
Here are five signs worth taking seriously, and what the research says about each.
1. You're Bloated More Often Than Not
Some bloating after a big meal is completely normal. Persistent, uncomfortable bloating that happens regularly is a different story.
Bloating is one of the most common symptoms of gut dysbiosis, the scientific term for an imbalance in the gut microbiome. When the balance between beneficial and harmful bacteria is disrupted, fermentation patterns in the gut change, often producing more gas than usual and causing the kind of discomfort that sits with you most of the day.1
A 2025 study in Microbiology Spectrum found that specific gut microbiome profiles were reliably associated with digestive discomfort, including bloating, and that increasing microbial diversity was one of the most significant factors in improving gut health scores.2
If you're bloating consistently, it's worth looking at both what you're eating and the diversity of your diet. A narrow diet tends to produce a less diverse microbiome.
2. Your Energy Is Unpredictable
Energy levels are influenced by a lot of things: sleep, stress, iron levels, thyroid function. But the gut microbiome is increasingly understood to be one of the contributing factors.
A systematic review published in PMC (2022) found consistent evidence linking gut dysbiosis with fatigue-like symptoms. The proposed mechanism involves the gut microbiome's influence on the production of short-chain fatty acids (SCFAs), which play a role in cellular energy metabolism, as well as its effects on the immune system and systemic inflammation.3
Disrupted gut bacteria can also affect the absorption of nutrients including iron, magnesium, and B vitamins, all of which are relevant to energy. So if your tiredness doesn't have an obvious explanation and your bloods are coming back fine, your gut is worth considering.
3. Your Skin Is Playing Up
The gut-skin axis is a well-established area of research. The gut and the skin are both major interface organs, they both interact heavily with the immune system, and they influence each other more than most people realise.
A 2024 review published in PMC found causal evidence linking gut microbiota composition with immune-mediated skin conditions including eczema and psoriasis.4 The mechanism runs through the immune system: gut dysbiosis can trigger systemic inflammation that manifests in the skin.
An earlier review in PMC titled "From Leaky Gut to Leaky Skin" examined how gut permeability contributes to skin barrier disruption.5 The underlying concept of increased intestinal permeability is a real and researched phenomenon.
If you're dealing with skin issues that don't respond well to topical treatments, looking at the gut can be a useful next step.
4. Your Mood or Anxiety Feels Off
This one surprises people. Around 90 to 95% of the body's serotonin is produced in the gut, and the gut and brain communicate directly via the vagus nerve.
Research published in PMC (2024) found that people with depression and anxiety consistently show different gut microbiome profiles compared to healthy individuals, including lower microbial diversity and reduced populations of beneficial bacterial species.6 Whether the gut changes cause the mood changes, or the other way around, is still being worked out. The relationship appears to run both ways.
This doesn't mean gut health is the only factor in mood disorders, or even the main one. But it does mean it's worth including in the picture, particularly if you're already trying to support your mental health through lifestyle.
You can read more about the gut-brain connection in our dedicated post on the topic.
5. You're Getting Ill More Often Than Usual
Roughly 70 to 80% of the body's immune cells are located in the gut. The gut microbiome plays a direct role in training and regulating immune responses: beneficial bacteria help calibrate the immune system so it responds appropriately to threats without overreacting.1
When the microbiome is disrupted, immune function can be compromised. Gut dysbiosis has been linked to increased susceptibility to infections and to heightened systemic inflammation, both of which make you more vulnerable.
Antibiotic use is one of the most common causes of sudden gut dysbiosis, since antibiotics can't distinguish between harmful and beneficial bacteria. If you've had a course recently and noticed increased susceptibility to illness since, rebuilding the microbiome with fermented foods and a high-fibre diet is worth prioritising.
What You Can Actually Do About It
The research on supporting the gut microbiome points consistently towards a few practical interventions:
Eat more variety. Microbial diversity in the gut mirrors dietary diversity. Eating 30 or more different plant-based foods per week has been shown to correlate with significantly better gut microbiome outcomes in research. This includes herbs, spices, and different whole grains as well as vegetables and fruit.1
Add fermented foods. Yoghurt, kefir, kimchi, sauerkraut, and naturally fermented kombucha all introduce live cultures into the gut. A 2021 study in Cell found that a high-fermented-food diet significantly increased microbiome diversity and reduced inflammatory markers compared to a high-fibre diet alone.7
Reduce ultra-processed food. Emulsifiers and additives in ultra-processed foods have been shown to disrupt the gut microbiome even in fairly small quantities.
Be consistent. The gut microbiome changes slowly. Dietary changes that improve it need to be sustained over weeks and months to have meaningful impact.
Our small-batch kombucha is one of the easier fermented foods to incorporate into daily life. It's a proper grown-up soft drink that happens to contain live cultures. Try our Lemon, Ginger and Black Pepper, our Blackberry, Apple and Mint, or grab a mixed case to try both. Learn more about us and why we started Future Ferments here.
References
- Valdes AM, et al. Role of the gut microbiota in nutrition and health. BMJ, 2018. BMJ
- Gut health predictive indices linking gut microbiota dysbiosis with healthy state, mild gut discomfort, and inflammatory bowel disease phenotypes. Microbiology Spectrum, 2025. ASM
- Gut dysbiosis in severe mental illness and chronic fatigue: a systematic review and meta-analysis. PMC, 2022. PMC8960409
- Feng F, et al. Cited in: From Leaky Gut to Leaky Skin: A Clinical Review of Lifestyle Influences on the Microbiome. PMC, 2024. PMC11556587
- Gut-Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions. PMC, 2021. PMC7916842
- The Bidirectional Relationship Between the Gut Microbiome and Mental Health: A Comprehensive Review. PMC, 2024. PMC12007925
- Wastyk HC, et al. Gut-microbiota-targeted diets modulate human immune status. Cell, 2021. PubMed