These 5 January “Healthy” Habits Could Actually Be Triggering Your Gut Symptoms

January always brings a burst of motivation for new routines, and social media trends often add fuel to the myth-spreading fire. But while many habits sound gut-nourishing on the surface, some can actually leave your digestive system more unsettled than supported. As a registered dietitian and gut health scientist, these are the five patterns I see every January that actually might be upsetting your gut more than helping it.

1. Adding Lots Of New Plant Foods All At Once

Dietary fibre is one of the most powerful ways to support your gut microbes. It’s linked with benefits that extend well beyond digestion, including mental wellbeing, hormone regulation and metabolic health. While over 95% of people fall short of the recommended daily 30g fibre target, come January, there’s a temptation to dramatically increase your intake in a short period. However, this can overwhelm the digestive system, causing your gut bacteria to ferment it more rapidly, producing gas and drawing water into the bowel. This can result in more uncomfortable symptoms like bloating, abdominal discomfort and changes in bowel habits. 

But this isn’t a sign you need to skip fibre altogether; it’s just that your gut hasn’t adapted to this increased volume yet. The most effective approach is to increase fibre gradually — start by increasing your intake by just one portion a day, then after a week add another portion and continue this pattern until you’ve hit your target. This helps your gut to become what I call ‘fibre fit’ over time (think of it like training your gut, as you would any other muscle at the gym), meaning you can comfortably digest fibre, reaping the benefits without unwanted side effects.

2. Intermittent Fasting

Intermittent fasting is often promoted for a gut-healthy January reset, particularly after the indulgence of the festive period. However, it’s not something I tend to recommend as restrictive eating windows can place unexpected strain on the gut. Compressing food intake into a shorter timeframe — especially when following a plant-rich diet — can mean consuming large amounts of fibre in just one or two meals rather than spreading intake across the day. This can lead to what I call fibre dumping, where a sudden fibre load overwhelms the gut, triggering bloating and discomfort. 

In clinic what we tend to see is that fasting routines often reduce overall fibre intake, limiting the consistent nourishment gut microbes rely on and taking us further away from hitting the recommended daily intake. From a gut health perspective, regular and predictable eating patterns are often better tolerated than prolonged fasting windows. That said, if weight management is your goal, pushing your breakfast back by an hour and bringing your last meal of the day forward by an hour, can be helpful for some.

3. Daily Probiotics

We’ve learnt more about the gut in the last few years than ever before. But with this has come an influx of supplements promising to support gut health. While it’s great to see how people have embraced the power of the gut, when it comes to probiotic supplements, the science is often miscommunicated. They are widely marketed as a simple solution, but the evidence does not support a one-size-fits-all approach for ‘general’ gut health and digestion. That’s why research* shows that 77% of people who take probiotics in this way actually report no noticeable benefit.

This isn’t because probiotics aren’t effective.  But just like you wouldn’t take a vitamin D supplement for an iron deficiency, you need to get specific when it comes to probiotics. You need the right strain (specific bacteria), at the right time (for a defined need e.g. preventing thrush reoccurrence or cold and flu risk), in the right format (capsule, liquid, powder, depending on your goal). For example, the World Gastroenterology Organisation (WGO) recommends taking the LGG strain of bacteria at 10 billion twice per day alongside any antibiotic treatment to help protect against unwanted side effects. That’s the exact strain you’ll find in SMART STRAINS for when you’re on antibiotics. Other conditions that have significant clinical evidence to support probiotic use include: supporting your immune health through cold and flu season, imbalances in the vaginal microbiome such as thrush and bacterial vaginosis, travellers’ diarrhoea, and also digestive upset and colic in babies.

My advice? Don’t waste your money on generalised probiotics for “good” gut health, no matter how convincing the marketing or how innovative the capsule technology claims to be. If you want to better support gut health and digestion, eating a more diverse range of plants is the best place to start. Plus, always check that the probiotic formulation has a clinical trial supporting its use for your specific condition, and avoid mixes of multiple strains that haven’t been tested all together, as they can compete with each other.

4. Over-Exercising

We all know that regular exercise is great for our overall wellbeing, but did you know your microbes reap the benefits of movement, too? Research shows that regular exercise (at least three times a week) can significantly improve gut bacteria diversity. However, you can have too much of a good thing. Excessive or high-intensity exercise without adequate recovery can have the opposite effect. This places added stress on the body, which can reduce blood flow to the gut and increase gut permeability (sometimes referred to as leaky gut) in the short term. For some individuals, it can also trigger digestive symptoms such as cramps, urgency to ‘go’ or bloating. A balanced approach to movement, combining activity with sufficient rest and nutrition, is more supportive of long-term gut health.

5. Cutting Out Gluten Unnecessarily

Gluten is often removed in January as part of a perceived “clean” eating reset. But unless you have coeliac disease or a diagnosed intolerance, removing gluten has been shown in published studies to actually reduce gut bacteria diversity. Plus, a study of nearly 200,000 people by Harvard University in the US, found that those who consumed the most gluten had a 20% lower risk of type 2 diabetes compared with those who had the lowest gluten intake. This is not because gluten is particularly essential, but it meant people were restricting some high fibre grains like barley and rye that are naturally rich in gut-nourishing fibre. If you are struggling with a reaction to gluten, speak to your healthcare professional who can test for Coeliac disease as a first step (just be sure you’re including gluten in your diet ahead of the test to avoid a false negative result).

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*Research by Opinium on behalf of SMART STRAINS® 2,000 Nationally Representative UK Respondents, aged 18+.