How Dietary Fibre Can Improve Sleep Quality

Why fibre matters more than you think for better rest

When people struggle with sleep, they often focus on bedtime habits. But a powerful new lever might be hiding in your meals. Research now suggests that fibre — a nutrient often overlooked for sleep — can have a measurable impact on how deeply and how long you rest at night.

In this article, we explore how fibre interacts with your gut microbiome, what the latest human research shows, and how to apply this in simple steps that support better recovery.

The overlooked link between fibre and your sleep cycle

While fibre is typically recommended for digestion and heart health, it is now being investigated as a sleep-enhancing nutrient. A high-fibre diet supports a healthier gut microbiome, and the gut is deeply connected to the brain through what researchers call the gut-brain axis. This pathway includes signalling that affects sleep-related hormones like melatonin and cortisol.

A new study tested how fibre intake shapes sleep outcomes. The researchers found that when people increased their fibre intake from real foods, sleep efficiency and subjective sleep quality both improved. These findings add to a growing consensus that your dietary patterns throughout the day can shape how well you sleep at night.

What this new fibre–sleep study found

In a large 2025 clinical trial, 147 healthy adults took part in an eight-week dietary intervention. One group focused on increasing their fibre intake using whole foods, while the control group made no major dietary changes.

The fibre group showed:

• Better sleep efficiency

• Improved subjective sleep quality

• Shorter bowel transit time

• Enhanced microbial diversity

• Stronger anti-inflammatory immune markers

The key insight was not just that fibre improved gut health. It was that these gut improvements appeared to carry through to the nervous system and influence sleep.

According to the researchers, this likely happens through increased production of short-chain fatty acids like butyrate, which are known to affect the central nervous system and help regulate melatonin rhythms.

How fibre works with your body to improve sleep

Dietary fibre cannot be digested by your own enzymes. Instead, it is fermented by specific types of gut bacteria. This fermentation process produces metabolites that are essential to regulating inflammation, energy metabolism, and even neurotransmitter activity.

A healthy, fibre-rich diet encourages a diverse gut environment. This diversity is linked to more stable circadian rhythms and less disruption in melatonin release — the hormone that tells your brain when to fall asleep.

Fibre also supports regular digestion, which can reduce nighttime discomfort and bloating. When digestion and inflammation are under control, your body can shift into rest and recovery mode more easily.

How to add more fibre to your day without overthinking it

You do not need to make extreme changes to see the benefits. Start with these low-effort, high-reward fibre strategies.

Easy fibre habits that support sleep:

Eat plant foods at every meal
Build meals around vegetables, legumes, nuts, seeds, and fruits. These foods contain both soluble and insoluble fibres.

Switch to whole food carbs
Choose oats, sweet potato, barley, quinoa, and wholegrain bread instead of processed carbs like white rice or pasta.

Add ground seeds daily
A tablespoon of flax or chia provides 5–6 grams of fibre and can be stirred into breakfast or added to yoghurt.

Track your fibre once a week
Use a free app or food log to see if you are consistently reaching the recommended 25–30 grams of daily fibre. Most people are not.

Why this approach matters for real recovery

Good sleep is not just about closing your eyes. It is about giving your brain and body the time and conditions they need to recover, reset, and repair.

By improving your gut environment with fibre, you make it easier for your sleep hormones to do their job. You reduce internal inflammation that might be disrupting your rest. And you take a consistent, food-first approach to performance and recovery that does not rely on supplements or guesswork.

References

Wastyk, H.C., Dahan, D., et al. (2025). Distinct modulatory effects of high-fibre and fermented-food diets on gut microbiota, immune function, transit time, and sleep quality. medRxiv.
Read the full study title here